U.S. PATENT AND TRADEMARK OFFICE
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U.S. Patent Classification System - Classification Definitions
as of June 30, 2000
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Class 376
INDUCED NUCLEAR REACTIONS: PROCESSES, SYSTEMS, AND ELEMENTS
Class Definition:
This class provides for patents directed to processes
involving induced nuclear reactions and structures which
implement such processes.
(1) Note. For purposes of classification in this class, an
induced nuclear reaction is defined as a change in the
nucleus of an atom brought about by subjecting it (the
nucleus) to (a) an impact with other nuclei of the same or
different type, or (b) an impact with, or bombardment by,
subatomic particles or high energy electromagnetic
radiations.
(2) Note. Reactions of type (a) in (1) Note, above, include
those which cause or result in the combining or uniting of at
least two nuclei to form a different nucleus which reactions
are generally referred to as fusion reactions. Reactions of
type (b) in (1) Note, above, include (1) those which cause a
splitting or subdivision of the nucleus (usually a heavy
nucleus) into a plurality of different nuclei and are
generally referred to as fission reactions, and (2) those
which result in a single but different nucleus of the same or
a different element and are generally referred to as
transmutations.
(3) Note. A basis for placing a patent into this class is
that a nuclear reactor be claimed or that it be utilized to
obtain a nuclear reaction even though the sole or primary aim
of the patent in regard to the reactor is to obtain useful
nuclear energy or to utilize such nuclear energy yielding
system for conversion into other forms of useful energy or
power. This is true even though from a chemical view there
may be nothing novel, or from an economical view, nothing of
value, with respect to the products or materials resulting
from the nuclear reaction.
(4) Note. Patents to processes are not segregated from
patents to the structure, but are classified together
depending upon the type of structure claimed or used in the
claimed process.
Included within the scope of the class are patents directed
to (a) the nuclear reactor as a system of elements or parts
so interrelated as to produce induced nuclear reactions and
to (b) such elements or parts, per se, as are essential and
peculiar components of nuclear reactors. Included among (a),
for example, are neutron detectors wherein the detection
takes place by means of an induced nuclear reaction. Included
among (b), for example, are fuel element structures
(including fuel "targets" or "pellets"), control component
structures, moderator component structures, fuel element
storage structures, and refueling machines.
LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
Also included in this class are the following (see Subclass
References to the Current Class, below, for subclass
references):
(1) Note. Patents to processes or apparatus including a
step or means for (a) converting the nucleus of a substance
other than the reactor fuel to a nucleus of another
substance, (b) treating or irradiating of material, or (c)
making a material radioactive, all within such reactor,
including for such purposes as the production of nuclear fuel
or experimentation, study or research, etc.
(2) Note. Patents to processes or apparatus including a
step or means for converting the nucleus of a substance or
for making a substance radioactive by bombardment with
accelerated particles from a source other than a nuclear
reactor.
(3) Note. Patents directed to combination of a process or
apparatus under the class definition with a step or means,
e.g., (a) of cooling or heat exchange even though the purpose
is to generate steam for extraneous uses, or (b) with a step
or means for carrying out of a chemical reaction, etc.
(4) Note. Patents to processes or apparatus including an
arrangement of steps or means for amplifying neutrons of a
subcritical mass to controllable fission reaction levels,
i.e., subcritical reactors.
(5) Note. Patents to all devices, structures, and processes
for irradiating a nucleus with its antinucleus (e.g.,
protonantproton) so as to produce annihilation radiation,
i.e., induced matter-antimatter reaction.
(6) Note. Patents to processes or devices that utilize a
gaseous or light element fuel material, the particles of
which are electrically charged or excited to the point where
they become highly ionized and the forces of repulsion of
like nuclei is overcome, or substantially so, wherein it is
the intent of the patent that this be the result of such
ionization, to the end that nuclear fusion of such like
nuclei is obtained or sought to be obtained.
Reactor structure in combination with any other art device is
classified in this class.
(1) Note. The line between the subject matter of this class
and those classes utilizing nuclear energy reactors or
reactions in an ancillary fashion for such purposes as the
production of power either electrical or mechanical and for
similar purposes is as follows: this class provides for
claimed apparatus and processes wherein the reactor or
reaction is recited either specifically or broadly and
wherein structure utilizing the reactor or reaction, e.g.,
motor, generator, ship, aircraft, etc., is recited either
specifically or broadly.
(2) Note. Patents to processes utilizing nuclear energy to
bring about chemical reactions between either inorganic or
organic compounds in order to provide a different compound or
product, provided neither reactor structure nor a nuclear
reaction is claimed are classified elsewhere (see References
to Other classes, below). Class 376, however, takes such
patents if some reactor structure is claimed or if the
resulting compound or product is either claimed, or is
disclosed as being radioactive.
(3) Note. This class also provides for patents to all
processes and to certain devices or structures for
irradiating a substance of a subject specimen or sample for
research and related purposes or for making such substance
radioactive. This holds true however only if the irradiation
produces a transformation or similar modification of the
nucleus of the substance, or if the treatment makes the
substance radioactive. For other types of irradiation, see
References to Other classes, below.
(4) Note. Elements and subcombinations of nuclear reactors
which may, if recited in general terms, be provided for
elsewhere, are classified in this class if recited in terms
of the subject matter of this class.
(5) Note. A process of utilizing nuclear energy to bring
about chemical reactions that treat or prepare a synthetic
resin or rubber, provided neither nuclear reactor structure
nor a nuclear reaction is claimed, is elsewhere (see
References to Other Classes, below). Class 376, however,
takes such patents if some reactor structure is claimed or if
the resulting product is either claimed or disclosed as being
radioactive.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 100+ for patents to processes or devices that
utilize a gaseous or light element fuel material, the
particles of which are electrically charged or excited to the
point where they become highly ionized and the forces of
repulsion of like nuclei is overcome, or substantially so,
wherein it is the intent of the patent that this be the
result of such ionization, to the end that nuclear fusion of
such like nuclei is obtained or sought to be obtained.
subclasses 156+ for patents to processes or apparatus
including a step or means for (a) converting the nucleus of a
substance other than the reactor fuel to a nucleus of another
substance, (b) treating or irradiating of material, or (c)
making a material radioactive, all within such reactor,
including for such purposes as the production of nuclear fuel
or experimentation, study or research, etc.
subclasses 156+ patents to all devices, structures, and
processes for irradiating a nucleus with its antinucleus
(e.g., protonantproton) so as to produce annihilation
radiation, i.e., induced matter-antimatter reaction.
subclasses 190+ for patents to processes or apparatus
including a step or means for converting the nucleus of a
substance or for making a substance radioactive by
bombardment with accelerated particles from a source other
than a nuclear reactor. See subclasses.
subclasses 317+ for patents directed to combination of a
process or apparatus under the class definition with a step
or means, e.g., (a) of cooling or heat exchange even though
the purpose is to generate steam for extraneous uses, or (b)
with a step or means for carrying out of a chemical reaction,
etc.
347 for patents to processes or apparatus including an
arrangement of steps or means for amplifying neutrons of a
subcritical mass to controllable fission reaction levels,
i.e., subcritical reactors.
REFERENCES TO OTHER CLASSES
SEE OR SEARCH CLASS:
47, Plant Husbandry, appropriate subclasses for processes of
subjecting living plant or plant matter to nuclear radiation
devices other than within a nuclear reactor.
60, Power Plants, subclass 644.1 for a power plant energized
by externally applied heat in which heat directly from
radioactive decay or indirectly from a nominally recited
nuclear reactor is used.
74, Machine Element or Mechanism, appropriate subclasses for
control elements, per se, (including its moving parts) except
where (a) the element is structurally associated with the
reactor and some reactor structure is also recited (other
than in a mere broad reference to the reactor), or where (b)
the control element or portion thereof is defined as being
absorbing material or neutron absorbing material - patents to
such elements are classified in this class (376).
114, Ships, appropriate subclasses for patents to ship
structures utilizing nuclear reactors for power-generating
purposes in which no structural elements of the nuclear
reactor are claimed.
166, Wells, subclass 247 for well processes involving
nuclear energy in general.
204, Chemistry: Electrical and Wave Energy, subclass 157.2
and 193 for processes and structure for bringing about
chemical reactions by subjecting material to nuclear
radiation; subclasses 157.15+ for patents to processes
utilizing nuclear energy to bring about chemical reactions
between either inorganic or organic compounds in order to
provide a different compound or product, provided neither
reactor structure nor a nuclear reaction is claimed. (See
Lines With other Classes, "Reactor structure in combination
with any other art device.").
244, Aeronautics, appropriate subclasses, particularly
subclasses 53+, for patents to aircraft using a nuclear
reactor as a power-generating source in which no structural
elements of the nuclear reactor is claimed.
250, Radiant Energy, subclass 251 for molecular or atomic
beam devices for producing and propagating a unidirectional
stream of neutral molecules or atoms through a vacuum,
usually at thermal velocities; subclasses 253+ for geological
signal processing steps or apparatus involving only a
nominally recited nuclear reaction; subclasses 324+ for
methods and apparatus to irradiate materials by corona
radiation; subclasses 390.01+ for neutron responsive means
involving no induced nuclear reactions; subclasses 423+ for
methods and apparatus to generate ions not involving induced
nuclear reactions; subclasses 453.11+ for methods and
apparatus including supports for objects to be irradiated
with or without an irradiating source; subclasses 458.1+ for
methods and apparatus to irradiate luminophors; subclasses
492.1+ for methods and apparatus to irradiate objects or
materials generally; subclasses 493.1+ for invisible
radiation generation and sources not involving induced
nuclear reactions; and subclasses 505.1+ for generic storage
devices for radioactive material.
290, Prime-Mover Dynamo Plants, appropriate subclasses for
prime-mover plant using nuclear reactor as power-generating
source in which no structural elements of the nuclear reactor
is claimed.
322, Electricity: Single Generator Systems, appropriate
subclasses for patents to generator systems utilizing nuclear
reactors for power source in which no structural element of
the nuclear reactor is claimed.
378, X-Ray or Gamma Ray Systems or Devices, appropriate
subclasses, particularly subclass 120 for gamma ray
sources.
424, Drug, Bio-Affecting and Body Treating Compositions,
particularly subclass 1.11 for radionuclide containing
subject matter, for: compositions (A) for preventing,
alleviating, treating, or curing abnormal and pathological
conditions of the living body, for maintaining, increasing,
decreasing, limiting, or destroying a physiologic body
function, for diagnosing a physiological condition or state
by an in vivo test, for controlling or protecting an
environment or living body by attracting, disabling,
inhibiting, killing, modifying, repelling, or retarding an
animal or micro-organism, (B) for deodorizing, protecting,
adorning, or grooming a body, (C) for fermentates and
extracts for use in A or B and not elsewhere provided for,
and (D) for such compositions defined in terms of specific
structure; methods of making the above compositions; methods
of using the class defined compositions for purposes in A and
B; and methods of using compounds, per se, for purposes in A
and B.
426, Food or Edible Material: Processes, Compositions, and
Products, subclass 240 for process of subjecting food to
nuclear radiation devices other than within a nuclear
reactor.
522, Synthetic Resins or Natural Rubbers, for a process of
utilizing nuclear energy to bring about chemical reactions
that treat or prepare a synthetic resin or rubber, provided
neither nuclear reactor structure nor a nuclear reaction is
claimed.
600, Surgery, subclasses 1+ for treatment of the body with
radioactive substances.
976, Nuclear Technology, for an alternative search, based on
a modification of the European Patent Office Classification.
GLOSSARY:
Certain terms employed in this class have been assigned
definitions tailored to meet the needs of this class and
therefore may be more or less restricted or even altogether
different from those in common usage. These terms are listed
below and are flagged with an asterisk where they occur in
the subclass definition that follow. The meaning to be
given to the various "art" terms appearing in this class, but
which have not been included in the Glossary below, is the
same as that generally accepted or is in common usage.
ABSORBING MATERIAL
See Neutron Absorbing Material.
ACTIVE VOLUME
See Reactor Core.
AMPLIFICATION, NEUTRON
See Subcritical Reactor.
BLANKET MATERIAL
A layer of fertile material placed external to core of the
fission reactor. See Fertile Material.
BREEDER MATERIAL
See (a) Blanket Material and (b) Fertile Material.
BURNABLE POISON
A substance with high neutron capture cross section which has
a capture reaction product of low capture cross section and
which is purposely put in a fission reactor to influence the
long term reactivity variations.
BY-PRODUCT MATERIALS
Are nuclear reaction products (except special nuclear fuel
material (see Nuclear Fuel) including gases yielded in or
made radioactive by exposure to the radiation incident to the
process of producing or utilizing special nuclear fuel in the
nuclear reaction.
COMPONENT, REACTOR
For the purpose of this class, relates to any of the
functional segments or parts comprising, when properly
associated together, a nuclear reactor, e.g., fuel,
moderator, coolant (fluid or solid), control rod, reflector,
shield, etc.
CONFINEMENT PLASMA
For the purpose of this class, is either the containment or
restraint force or the means (structure) for producing such
force placed upon the charged particles or plasma, e.g., by
electric or magnetic fields, so as to restrict said particles
or plasma within a given volume.
CONTROL ELEMENT
For the purpose of this class, is rods, tubes, plates, etc.,
of a reactivity affecting material used to hold a fission
reactor at a given power level or to vary the rate of
reaction. Control elements can be given three names
corresponding to three different functions, namely: (a) power
control, regulating or fine control (affecting only a small
change in reactivity); (b) safety or scram (capable or
reducing the reactivity below critical and used general when
some emergency condition exists, such as power level to
high); and (c) shim (affecting a relatively large change in
reactivity of a reactor, i.e., it is used for coarse control
or reactivity).
CONTROL ROD
See Control Element.
CONVERSION
For the purpose of this class, is the process of artificially
bringing about a change or transformation in the nucleus of
an atom. Nuclear conversion is generally caused by subjecting
a material to particle bombardment, usually by neutron
irradiation as happens in a fission reactor. See also
Transmutation.
COOLANT
A fluid (liquid, gaseous, or particulate) whose function is
to absorb heat from the reactor core and to deliver this
absorbed heat to a heat exchanger or other utilization means
exterior to the reactor core.
CORE, REACTOR
See Reactor Core.
CRITICAL
For the purpose of this class, is the term used to describe
the condition in which a chain reaction is being maintained
at a constant level, i.e., it is just self-sustaining. In
order for this state to exist a sufficient quantity of
fissile material (critical mass) must be assembled in the
proper shape and concentration.
FAST NEUTRONS
See Thermal Neutrons.
FAST (FISSION) REACTOR
A nuclear reactor in which most of the fissions are caused by
neutrons moving with substantially the high speeds they
possess at the time of their birth in fission. Such reactors
contain little or no moderator.
FERTILE MATERIAL
An element (isotope) capable of being readily transformed or
converted into a fissionable substance by capture of a
neutron, examples include, U[supscrpt]238[end supscrpt] and
Th[supscrpt]232[end supscrpt].
FISSILE MATERIAL
See Fissionable Material.
FISSION
The splitting of a heavy nucleus into two (or, very rarely,
more) fragments (fission products) of more or less equal mass
accompanied by the emission of neutrons and the release of
energy. It can be spontaneous or it can be caused by the
impact or a neutron, a fast charged particle or a photon. See
Fissionable Material. Cf. Spallation.
FISSIONABLE MATERIAL
Any element or isotope the nucleus of which can be caused by
nuclear bombardment to undergo nuclear fission and to produce
a fission chain reaction U[supscrpt]233[end supscrpt],
U[supscrpt]235[end supscrpt], and Pu[supscrpt]239[end
supscrpt], are examples. Unless a patent refers to a
distinction, "fissionable" and "fissile" are considered
synonymous for the purpose of this class.
FLUIDIZED BED (FISSION) REACTOR
A reactor in which the fuel in the form of particles is
maintained in a fluidized state by a fluid medium. (The fuel
and the fluid are general moving in opposite directions). See
subclass 355. (Includes also support of fuel in pellet form
in a liquid bath by an upwardly flowing liquid).
FUEL, FUEL ELEMENT, or FUEL COMPONENT
See Nuclear Fuel.
FULLY IONIZED
For the purpose of this class, is state in which atoms are
entirely stripped of their orbital electrons for atoms of low
mass number, this occurs at kinetic temperatures in the
region of 1 Kev or more. In other words, matter is in a state
of complete ionization; it consists of a gas composed of
positively charged nuclei and an equivalent number of
negative electrons with no neutral particles. See also
Plasma.
FUSION
For the purpose of this class, is a nuclear reaction in which
light nuclei combine to form a nucleus of a heavier mass
number. See also Thermonuclear Fusion Reaction.
HOMOGENEOUS FUEL
See Homogeneous Fission Reactor.
HOMOGENEOUS (FISSION) REACTOR
A reactor in which the fuel and moderator are intimately
mixed or dispersed (e.g., the fuel may be a uranium salt
dissolved in heavy water) as a solution or slurry.
INDUCED NUCLEAR REACTION
See section I, (1) Note.
INTERMEDIATE NEUTRONS
See Thermal Neutrons.
IONIZED
See (a) Fully Ionized and (b) Plasma.
MAGNETIC MIRRORS
See Mirror Field.
MIRROR FIELD
For confinement of plasma, a system has been devised whereby
a longitudinal magnetic field is applied to the plasma, but
instead of being uniform, the field strength is increased at
spaced points. The region of enhanced magnetic field is
referred to as a mirror field or magnetic mirror.
Substantially all of the charged particles moving from the
region of lower to that of the higher field strength, will be
reflected back into the former region. This field thus acts
as a sort of potential well which inhibits escape of many of
the charged particles (and consequent loss of energy).
MODERATOR
For the purpose of this class, is a substance used within a
fission reactor core in special relationship with the fuel to
reduce the energy, and hence speed, of fast neutrons (so far
as possible) emanating from the fuel by means of collisions
without capturing them. Graphite and heavy water are
examples.
MODERATED NEUTRONS
See Thermal Neutrons.
NEUTRON ABSORBING MATERIAL
As it relates to nuclear reactors, a substance that poses a
high neutron absorption ability.
NEUTRON APLIFICATION
See Subcritical Reactor.
NUCLEAR FUEL
(a) Light elements such as hydrogen, deuterium tritium,
lithium, boron beryllium, etc., which are capable of fusing
or combining to form a nucleus of higher mass number, (b)
fissionable fissile, or special nuclear material such as
U[supscrpt]233[end supscrpt], U[supscrpt]235[end supscrpt],
or uranium enriched with either of these Pu[supscrpt]239[end
supscrpt], etc., capable of sustaining a chain reaction.
NUCLEAR REACTION
For the purpose of this class, a change in the composition or
physical characteristics of an atomic nucleus produced (a)
directly or indirectly, by its irradiation or bombardment by
high energy alpha particles, protons, deuterons, slow or fast
neutrons or high energy radiations (gamma rays) or (b) by
fusing or combining nuclei of low atomic number to produce a
nucleus of higher mass number. See also class definition,
section I, and (1) Note.
NUCLEAR REACTOR
For the purpose of this class, a structure inside which an
induced nuclear reaction is confined, manipulated, or
controlled. A nuclear fission reactor is a structure in which
a fission chain reaction is a fissionable material can be
maintained and controlled. Besides the fuel, it generally
contains control apparatus, moderator, coolant, etc., and is
often surrounded by a biological shield. A nuclear fusion
reactor is a structure in which a fusion reaction in a
nuclear fuel capable of fusing is controlled or manipulated.
Although it is implied that the rate of such reactions
increases as the relative velocities of such particles at the
time of collision, nothing is implied about the means by
which such precollision velocities are attained. The same
reaction may and usually does produce one or more other
particles such as neutrons or protons, in accordance with
well-known reactions.
PINCH EFFECT
The self-constriction that occurs in a plasma as a result of
the passage of a unindirectional current, which current
produces an azimuthal self-magnetic field that tends to
constrict (or pinch) the plasma; or the equivalent effect
which is produced when a plasma is contained between parallel
circuits carrying current in the same direction attracting
each other.
PLASMA
For the purpose of this class is a very hot, at least
partially, ionized gaseous system consisting of equivalent
(substantially so) numbers of positive ions and electrons,
irrespective of whether neutral particles are present or not.
It is nearly neutral electrically and highly conducting. See
also Fully Ionized and subclasses 100+.
REACTION BY-PRODUCTS
See By-Product Materials.
REACTIVITY
A measure of the amount of the possible departure of a
reactor from the critical condition where the reaction is
just self- supporting. At any steady state of operation the
reactivity is zero. Addition of positive reactivity causes
divergence; addition of negative reactivity causes the
reaction to die down.
REACTIVITY AFFECTING MATERIAL
As it relates to fission nuclear reactors, this is a material
which affects the criticality of the reactor and can be (a) a
neutron absorbing material (which for the purpose of this
class is a material which can absorb neutrons without
reproducing them, e.g., boron, or a fertile material such a
uranium (U[supscrpt]238[end supscrpt] or thorium) thus
providing a decrease in reactivity, (b) a fissionable
material such as U[supscrpt]235[end supscrpt],
Pu[supscrpt]239[end supscrpt], U[supscrpt]233[end supscrpt]
(thus providing an increase in reactivity), and (c) a
reflector (moderator) material such as graphite or water
(thus providing an increase in reactivity).
REACTOR CORE (FISSION REACTOR)
The central or heart of a nuclear reactor containing as its
main constituent the nuclear fuel (e.g., enriched uranium,
Pu[supscrpt]239[end supscrpt], etc.), and the moderator, if
any. Also known as the active volume of the reactor.
REACTOR GEOMETRY (FISSION REACTOR)
See subclasses 347+.
REFLECTOR
A volume of material placed around the active volume (core)
or other neutron yielding source serving to scatter back into
the active volume some of the neutrons which would otherwise
be lost to the chain reaction thus permitting a reduction in
the critical size of the active volume.
SAFETY ELEMENT or ROD
See Control Element.
SCRAM ROD
See Control Element.
SHIELD
For the purpose of this class, generally a mass or armor of
concrete, lead or other heavy material or other neutron
absorbing material erected around a reactor or other
radioactive source to shield operating staff by absorbing and
reducing dangerous radiations (especially neutrons and gamma
rays) to permissible levels. See also Neutron Absorbing
Material.
SHIM
See Control Element.
SLURRY
See Homogeneous Reactor.
SPALLATION
A nuclear reaction induced by high energy bombardment and
involving the ejection of two or more small particles or
fragments leaving only one large residual nucleus.
SPECIAL NUCLEAR MATERIAL
See Nuclear Fuel (b).
SPLITTING
See Fission.
STRIPPED of ORBITAL ELECTRONS
See Fully Ionized.
SUBATOMIC PARTICLES
All particles of less than atomic mass, i.e., the elementary
particles (proton, neutron, electron, positron, neutrino,
meson, etc.) as well as the alpha particles and deutrons, the
charge and mass of which indicates them to be composite
particles.
SUBCRITICAL (FISSION) REACTOR
For the purpose of this class, is a reactor which has (a) an
active volume (core) containing less than the necessary
amount of fissionable material (fuel) to become critical, and
(b) an auxiliary neutron source combined therewith in such a
way as to trigger fissioning with the active volume and with
proper amplification of neutrons whereby a steady state chain
reaction results, i.e., it becomes critical.
TARGET
The substance which is subjected bombardment by particles of
photons of high energy in order to produce nuclear reactions
therein.
THERMAL NEUTRONS
As the energy of any substance has a temperature factor, that
of the prevailing temperature is termed thermal energy, and
when neutrons reach equilibrium with the moderator they are
called thermal neutrons. Their most probable energy is about
0.025 ev; or the speed of a gas molecule at room temperature.
It is this type of neutron that can best enter the nucleus of
a fissionable atom and remain there long enough to excite the
atom to the breaking point, attaining fission. Two other
categories of neutrons are intermediate and fast. Fast
neutrons are those resulting from fission that have lost
relatively little of their energy by collision, etc.; having
energies exceeding 0.1 Mev. Intermediate neutrons have
energies lying between thermal and fast neutrons.
THERMONUCLEAR FUEL
See Nuclear Fuel.
THERMONUCLEAR (FUSION) REACTORS
Apparatus in which fusion reactions occur primarily as the
result of random collisions within the apparatus between gas
particles having a Maxwellian distribution of velocities
about some average temperature. It is implied that such
reactions are not the result of accelerating one particle
into another. While it is also implied that a high average
gas temperature is sought for to attain a high thermonuclear
reaction rate, nothing is implied as to the attainment of any
minimum temperature.
TRANSMUTATION
The bombardment of a nucleus by particle or photon so as to
bring about a change in the nucleus resulting in a different
isotope of the original nucleus or resulting in different
element(s).
SUBCLASSES
Subclass:
100
NUCLEAR FUSION:
This subclass is indented under the class definition. Subject
matter comprising structures and processes in which two
reacting nuclei are combined to yield at least one nucleus
having a greater mass than either of the reacting nuclei.
(1) Note. Subject matter of this subclass and of the
subclasses indented hereunder may include, for example,
reactions and methods including neutron generators wherein
the neutron is a product of a fusion reaction, e.g., A D-T
reaction.
(2) Note. Patents are included in this and indented
subclasses even if there is failure of the system to actually
obtain fusion if it is clear that the intent or aim of the
patent is to obtain it.
(3) Note. Neutrons from an ionized or plasma system or
reaction may be appropriately utilized or moderated to bring
about or cause a fission-type nuclear reaction.
(4) Note. Energy or heat of a nuclear fission reaction
system may be appropriately utilized to bring about
ionization to plasma or fusion reaction levels.
SEE OR SEARCH CLASS:
219, Electric Heating, subclass 121.36 for plasma heating.
Subclass:
101
Pellet guidance system (e.g., pellet injection means):
This subclass is indented under subclass 100. Subject matter
wherein a fusion fuel body is caused to be directed to a
predetermined position.
SEE OR SEARCH CLASS:
250, Radiant Energy, subclasses 396+ for deflection or
focusing of charged particles.
315, Electric Lamp and Discharge Devices: Systems, subclass
507 for injection or extraction of charged particles.
Subclass:
102
Inertial confinement (e.g., nuclear explosive):
This subclass is indented under subclass 100. Subject matter
wherein the reacting nuclei are contained in a fuel body and
the disassembly of the body is prevented or retarded for a
predetermined time by mass forces within the body, said
nuclei being caused to react by the application of external
or internal sources of energy.
(1) Note. The above mass forces includes but is not
restricted to the mass of outer layer.
(2) Note. Nuclear explosives are included in this and
indented subclasses. The nuclear explosive may include a
chemical explosive to aid in causing the nuclei to react.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 151+ for fuel bodies of this subclass type, per
se.
Subclass:
103
Photon beam (e.g., laser) irradiation:
This subclass is indented under subclass 102. Subject matter
wherein the source of energy is a source of coherent
electromagnetic radiation.
SEE OR SEARCH CLASS:
219, Electric Heating, subclass 121.6 for laser heating of a
material in general.
372, Coherent Light Generators, appropriate subclasses for
laser structure.
Subclass:
104
Optics:
This subclass is indented under subclass 103. Subject matter
wherein a laser beam is directed to the fuel body by way of
reflectors and/or refractors.
Subclass:
105
Particle beam irradiation (excluding photons):
This subclass is indented under subclass 102. Subject matter
wherein the source of energy is either a charged particle
beam or a neutral particle beam.
SEE OR SEARCH CLASS:
219, Electric Heating, subclass 121.12 for electron beam
heating of a material in general.
250, Radiant Energy, subclass 492.3 for electron beam
irradiation of a material in general.
Subclass:
106
Ion beam irradiation:
This subclass is indented under subclass 105. Subject matter
wherein the charged particles are ions.
SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 492.3 for ion irradiation of a
material in general.
Subclass:
107
Fusion reaction by plural colliding plasmas or particle
beams:
This subclass is indented under subclass 100. Subject matter
wherein the nuclei which are to undergo reaction are in the
form of plasma or beams which are directed towards and caused
to impact one another so as to cause the fusion reaction.
Subclass:
108
Including accelerating particles into a stationary or static
target (e.g., cockcroft-walton generator type):
This subclass is indented under subclass 100. Subject matter
wherein at least one of the reacting nuclei is directed into
a fixed fuel body containing the other of the reacting nuclei
in nongaseous form with sufficient energy to produce fusion.
SEE OR SEARCH THIS CLASS, SUBCLASS:
107 for patents which may also illustrate structure for
accelerating charged particles.
subclasses 151+ for fuel bodies of this subclass type, per
se.
Subclass:
109
With target replenishing:
This subclass is indented under subclass 108. Subject matter
having structure or steps for renewing or replacing the
nuclei in the fixed fuel body.
Subclass:
110
With means for modifying the resultant neutron output, e.g.,
moderator means:
This subclass is indented under subclass 108. Subject matter
wherein the reacting nuclei produce a neutron of a given
energy and wherein this given energy is altered or
attenuated.
Subclass:
111
With means to pulsate ion beam:
This subclass is indented under subclass 108. Subject matter
wherein a plurality of ionized nuclei are directed towards a
target along a given path and the average number of nuclei in
the path per unit volume varies with time.
Subclass:
112
Cyclotron type acceleration of nuclei:
This subclass is indented under subclass 108. Subject matter
wherein the directed nuclei reach the sufficient energy
through traversal of an orbital path.
Subclass:
113
With electrostatic voltage generating means:
This subclass is indented under subclass 108. Subject matter
wherein the directed nuclei reaches the sufficient energy by
means which creates a static electric accelerating
potential.
(1) Note. The accelerating potential can be provided by a
Van de Grof belt-driven generator.
Subclass:
114
Self-contained neutron sources (e.g., neutron or accelerator
tube):
This subclass is indented under subclass 108. Subject matter
wherein all reacting nuclei are contained within the same
enclosure and the product of the reacting nuclei includes a
neutron.
Subclass:
115
With cooled electrodes or target:
This subclass is indented under subclass 114. Subject matter
wherein either (a) the fixed fuel body, or (b) a conductor of
electrical energy for accelerating or directing the nuclei
has a provision for removal of heat therefrom.
SEE OR SEARCH THIS CLASS, SUBCLASS:
151 for structured targets, per se, which may have provision
for cooling incorporated therein.
Subclass:
116
With ion beam collimator or filtering structure (e.g.,
extractor electrode):
This subclass is indented under subclass 114. Subject matter
wherein (a) the cross-sectional area, or (b) the density of
the directed nuclei in space, traversed by the directed
nuclei is altered prior to reaction with the fixed nuclei.
(1) Note. The subject matter of this subclass provides for
an extractor electrode or other means to modify the diameter
of the ion beam.
Subclass:
117
With ion beam collimator or filtering structure:
This subclass is indented under subclass 108. Subject matter
wherein (a) the cross-sectional area occupied by the directed
nuclei, or (b) the density of the directed nuclei in space is
altered prior to reaction with the fixed nuclei.
(1) Note. The subject matter of this subclass provides for
an extractor electrode or other means to modify the diameter
of the ion beam.
Subclass:
118
Subterranean source:
This subclass is indented under subclass 108. Subject matter
wherein the reaction between the reacting nuclei takes place
beneath the surface of the earth.
Subclass:
119
With control circuitry:
This subclass is indented under subclass 108. Subject matter
having electronic means to vary or regulate a parameter of
the fusion apparatus.
Subclass:
120
Including bunched particle beam:
This subclass is indented under subclass 100. Subject matter
wherein traveling in an ordered path organized in clusters at
least some of the nuclei involved in the reaction traverse
fixed paths in groups.
Subclass:
121
Magnetic confinement of plasma:
This subclass is indented under subclass 100. Subject matter
wherein (a) the nuclei are in a plasma* state in a given
volume, and (b) the plasma is restrained to the given volume
through magnetic forces.
(1) Note. Patents wherein magnetic forces solely generated
by (a) electric discharge, or (b) self-generation in a plasma
are not proper for this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
107 for patents which may also illustrate structure for
magnetically accelerating ions or plasmas.
SEE OR SEARCH CLASS:
313, Electric Lamp and Discharge Devices, subclass 231.01
for plasma-type discharge systems.
315, Electric Lamp and Discharge Devices: Systems, subclass
111.01 for plasma-type discharge systems.
Subclass:
122
Plasma formed in situ by laser:
This subclass is indented under subclass 121. Subject matter
wherein the nuclei after introduction into the given volume
in a nonplasma state are changed to the plasma state with the
aid of coherent light.
(1) Note. The nuclei can be introduced into the given volume
in the form of a liquid, solid, or gas.
Subclass:
123
Principal heating by wave energy:
This subclass is indented under subclass 121. Subject matter
wherein most of the energy imparted to the nuclei for
bringing the nuclei to a condition sufficient for reaction to
take place is imparted through electromagnetic energy.
Subclass:
124
Heating by time varying magnetic field (e.g., by
compression):
This subclass is indented under subclass 123. Subject matter
wherein the electromagnetic energy is in the form of magnetic
flux lines whose density changes with time so as to compress
the confined plasma.
SEE OR SEARCH THIS CLASS, SUBCLASS:
132 for subject matter of this subclass type wherein the
heating represents auxiliary heating.
Subclass:
125
Imploding liners:
This subclass is indented under subclass 121. Subject matter
wherein the restraining of the nuclei is assisted by the
sudden inward movement of a body which at least partially
encloses the plasma.
(1) Note. Liners of this subclass type may be either liquid
or solid.
Subclass:
126
With enveloping charged particle confinement (e.g., with e or
p layer):
This subclass is indented under subclass 121. Subject matter
wherein the magnetic force cooperates with a charged particle
layer (e.g., a layer of electrons or protons) separate from
an external to the plasma to form a further restraining means
for maintaining the plasma within the given volume.
(1) Note. The enveloping charged particle layer can be
formed from a beam of high energy particles injected within a
cylindrical zone or chamber, which beam is parallel to and
enveloping a long axis and is subjected to the effects of a
magnetic field in a way so as to contain a plasma between it
and the long axis of the chamber.
(2) Note. The rotary motion of an E layer would generally be
in a direction opposite to that of the contained plasma.
Subclass:
127
With injection of electrically charged or accelerated
particles:
This subclass is indented under subclass 121. Subject matter
wherein electrically charged or accelerated particulate
bodies are injected into the given volume.
SEE OR SEARCH THIS CLASS, SUBCLASS:
107 for patents which may also illustrate structure for
accelerating charged particles.
SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 251 for acceleration of
particles.
313, Electric Lamp and Discharge Devices, subclass 359.1 for
acceleration of particles.
Subclass:
128
Plasma injection:
This subclass is indented under subclass 127. Subject matter
wherein the particulate bodies comprise substantially equal
numbers of positively and negatively charged ions.
(1) Note. The bodies may be in the form of protons and
electrons.
Subclass:
129
Negatively charged particle injection:
This subclass is indented under subclass 127. Subject matter
wherein the charged particulate bodies are comprised of
electrons or ions of negative charge.
(1) Note. The particulate bodies of this subclass may be
macroparticles, i.e., comprised of atoms and/or molecules,
having an overall negative charge.
Subclass:
130
Neutral particle injection:
This subclass is indented under subclass 127. Subject matter
wherein the particulate bodies have no net charge.
SEE OR SEARCH THIS CLASS, SUBCLASS:
128 for subject matter wherein the particulate bodies
comprise substantially equal numbers of positively and
negatively charged ions.
Subclass:
131
Auxiliary heating:
This subclass is indented under subclass 121. Subject matter
wherein supplemental energy is introduced into the given
volume.
Subclass:
132
Electromagnetic wave energy:
This subclass is indented under subclass 131. Subject matter
wherein the energy is selected from a predetermined portion
of the electromagnetic spectrum.
Subclass:
133
Toroidal confinement of plasma:
This subclass is indented under subclass 121. Subject matter
wherein the given volume is generated by a rotation of a
plane closed curve about an axis lying in its plane.
(1) Note. The given volume may be in the shape of a torus,
or doughnut or race track.
Subclass:
134
Divertors:
This subclass is indented under subclass 133. Subject matter
for removing particles at the extremities of the given volume
which would otherwise (a) impact on means (i.e., chamber)
physically containing the volume, or (b) enter the given
volume and mix with the plasma.
(1) Note. The difference between the divertors of this
subclass type and the limiters and liners of subclass 136 is
that the divertors remove the particles, as by means of
gaseous flow or magnetic fields, whereas limiters and liners
are structural elements which trap or absorb the particles.
Subclass:
135
Effuser:
This subclass is indented under subclass 134. Subject matter
wherein the removal is accomplished by means of a gaseous
stream.
(1) Note. The gas stream is usually flowing tangentially to
the enclosure.
Subclass:
136
Limiters or liners:
This subclass is indented under subclass 133. Subject matter
for protecting at least a portion of physical means (i.e.,
chamber) containing the given volume.
Subclass:
137
With solid internal conductor:
This subclass is indented under subclass 133. Subject matter
wherein at least a portion of the magnetic restraining force
is created by electrical current-carrying structure located
within means (i.e., chamber) physically containing the
volume.
Subclass:
138
Bumpy torus:
This subclass is indented under subclass 133. Subject matter
having means (i.e., chamber) physically containing the given
volume and wherein the physical surface of the means has
regularly spaced depressions.
Subclass:
139
Linear confinement:
This subclass is indented under subclass 121. Subject matter
wherein the given volume forms a linear containment zone or
chamber for the plasma, the lines of magnetic force generally
being concentric to the axis of the zone or chamber.
Subclass:
140
Mirror devices:
This subclass is indented under subclass 139. Subject matter
having substantially constant magnetic force along a portion
of the axis of the zone or chamber with at least one other
portion of the axis having a magnetic force whose intensity
is substantially greater than the intensity of the constant
magnetic force.
Subclass:
141
Plasma formed or contained between spaced electrodes:
This subclass is indented under subclass 140. Subject matter
wherein the plasma is bounded on two sides by electric
charge-carrying conductors.
Subclass:
142
Magnetic structure:
This subclass is indented under subclass 121. Subject matter
comprising means for producing magnetic confinement forces
and support structure therefore.
(1) Note. This may include the coil design by itself or
other additional features of the electromagnet system such as
a coil support structure, a coil cooling system.
Subclass:
143
With circuitry:
This subclass is indented under subclass 121. Subject matter
wherein electrical signal processing means is employed to
vary, determine, or otherwise affect the physical
characteristics of the reacting nuclei in a fusion device
directly or indirectly.
Subclass:
144
Plasma formed between spaced electrodes:
This subclass is indented under subclass 100. Subject matter
wherein the plasma is produced by an electrical discharge
between two current carrying conductors.
Subclass:
145
Plasma focus:
This subclass is indented under subclass 144. Subject matter
wherein compression of the plasma is induced bymagnetic
forces generated by the electrical discharge and/or by
magnetic forces self-generated in the plasma.
Subclass:
146
Including removal or use of impurities or reaction products
(e.g., energy):
This subclass is indented under subclass 100. Subject matter
for removing (a) reaction products which may be in the form
of particles (charged or neutral) or electromagnetic
radiation, or (b) undesired particles which have been
introduced into the given volume, or (c) a portion of the
energy of the particles.
SEE OR SEARCH CLASS:
60, Power Plants, subclass 203.1 for propulsion systems
involving radiant energy.
Subclass:
147
Direct conversion of energy:
This subclass is indented under subclass 146. Subject matter
wherein a portion of the energy of the particles is
transformed into electrical output with the use of a one-step
process or apparatus for accomplishing said one-step
process.
(1) Note. Subject matter of this subclass type includes, for
example, MHD conversion.
Subclass:
148
Including use of heat or radiation to effect a chemical
reaction:
This subclass is indented under subclass 146. Subject matter
wherein the electromagnetic or thermal energy resulting
directly or indirectly from the reaction of the nuclei causes
or aids a chemical reaction between materials other than said
nuclei.
Subclass:
149
Shock wave heating of plasma or gas (e.g., mhd heating):
This subclass is indented under subclass 100. Subject matter
wherein the nuclei which are to undergo reaction are in a
plasma or gaseous state and wherein the plasma or gas is
subjected to compressional force acting at a rate greater
than the velocity of a compressional wave through the plasma
or gas.
(1) Note. The action of force on the plasma or gas may be
direct or indirect.
(2) Note. The shock wave may be produced by an electrical
discharge.
Subclass:
150
Chamber structure or material:
This subclass is indented under subclass 100. Subject matter
including details of the geometry or composition means (i.e.,
chamber) for physically containing a given volume in which
the nuclear fusion reaction occurs.
(1) Note. Subject matter under subclass type must consist of
more than a nominal recitation of a toroidal chambers. A
geometrical description of the type in subclass 133 of a
normal toroid is considered a nominal recitation of a
toroidal chamber for purposes of this subclass.
Subclass:
151
Fusion targets or pellets:
This subclass is indented under subclass 100. Subject matter
wherein either (a) the two nuclei are caused to react with
the aid of an irradiating energy beam, or (b) one of the two
nuclei is part of an energy beam which is to irradiate the
other nuclei to cause the two nuclei to combine, and (c)
wherein at least one of the irradiated nuclei comprises in
part a fusion fuel body having physical characteristics
determined by the nature of the irradiating energy beam.
SEE OR SEARCH THIS CLASS, SUBCLASS:
109 for combination of target, accelerator, and provision
for replenishing the target.
115 for combination of target, accelerator, and provision
for cooling the target.
SEE OR SEARCH CLASS:
427, Coating Processes, appropriate subclasses for methods of
making the targets.
445, Electric Lamp or Space Discharge Component or Device
Manufacturing, subclasses 1+ for methods of making
targets.
Subclass:
152
For inertial confinement:
This subclass is indented under subclass 151. Subject matter
wherein the physical characteristics of the fuel body are
such that the disassembly of the body is prevented or
retarded for a predetermined time by mass forces within the
body when the body is irradiated by an energy beam of
coherent light.
SEE OR SEARCH THIS CLASS, SUBCLASS:
103 for laser irradiation of targets or pellets of this
subclass (152) type.
Subclass:
153
DETECTION OF RADIATION BY INDUCED NUCLEAR REACTION:
This subclass is indented under the class definition. Subject
matter wherein the induced nuclear reaction takes place in
response to the incidence of electromagnetic or particulate
energy upon the material and a product of the nuclear
reaction within a structure, which structure is used to
indicate incidence of such radiation.
(1) Note. Class 376, this subclass takes all detection whose
claims include an induced nuclear reaction.
(2) Note. The reactions may include B[supscrpt]10[end
supscrpt] + N Li[supscrpt]7[end supscrpt] +
He[supscrpt]4[end supscrpt], He[supscrpt]3[end supscrpt] + N
H[supscrpt]3[end supscrpt] + p (proton recoil),
B[supscrpt]11[end supscrpt] + N (B[supscrpt]12[end
supscrpt]) C[supscrpt]12[end supscrpt] + e, or
N[supscrpt]1[end supscrpt] + Li[supscrpt]6[end supscrpt]
H[supscrpt]3[end supscrpt]+ He[supscrpt]4[end supscrpt].
SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 390.01 for neutron responsive
means which claim no induced nuclear reaction.
Subclass:
154
By fission:
This subclass is indented under subclass 153. Subject matter
wherein the reaction is fission, i.e., the splitting of a
nucleus.
Subclass:
155
With boron:
This subclass is indented under subclass 153. Subject matter
wherein the nucleus undergoing nuclear reaction is boron.
Subclass:
156
NUCLEAR TRANSMUTATION (E.G., BY MEANS OF PARTICLE OR WAVE
ENERGY):
This subclass is indented under the class definition. Subject
matter comprising the bombardment of a material to produce an
induced nuclear reaction other than that resulting in the
splitting of a nucleus.
(1) Note. The subject matter of this class includes
reactions wherein a nucleus of the material is converted or
transformed into a different nucleus; inclusive of (a) making
the material radioactive, (b) producing isotopes of the same
or a different element, e.g., Co[supscrpt]59[end supscrpt]
Co[supscrpt]60[end supscrpt], Th[supscrpt]232[end supscrpt]
U[supscrpt]233[end supscrpt], and (b) producing annihilation
radiation, e.g., a matter antimatter reaction.
(2) Note. Where a substance such as U[supscrpt]238[end
supscrpt] (or other material) is merely used as a fuel
carrier with no stated intention of converting it to fuel,
the substance U[supscrpt]238[end supscrpt] is not regarded as
fertile material for this and indented subclasses.
SEE OR SEARCH THIS CLASS, SUBCLASS:
340 for reactors, per se, specifically designed to provide
for the irradiation of material to produce a nonfission
reaction.
SEE OR SEARCH CLASS:
117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth
Processes; Non-Coating Apparatus Therefor, for processes and
non-coating apparatus for growing therein-defined
single-crystal of all types of materials, and such processes
combined with perfecting operations. A subsequent step of
irradiation to produce a nuclear transformation is provided
for in Class 376.
424, Drug, Bio-Affecting and Body Treating Compositions,
subclass 1.11 for class defined compositions and methods
comprising a radionuclide or intended radionuclide.
Subclass:
157
Gamma or charged particle activation analysis:
This subclass is indented under subclass 156. Subject matter
wherein gamma or charged particle bombardment of the material
results in the production of a transmuted nuclei of the
material, which product is to be analyzed to yield data
concerning the nucleus of the material and/or its
environment.
Subclass:
158
By neutron bombardment:
This subclass is indented under subclass 156. Subject matter
wherein the material is bombarded with neutrons.
SEE OR SEARCH CLASS:
250, Radiant Energy, subclass 390.01 for neutron responsive
means involving no induced nuclear reaction.
423, Chemistry of Inorganic Compounds, subclasses 2+ and
249+ for radioactive materials and treatment thereof which
does not involve irradiation to produce the radioactive
material.
Subclass:
159
Neutron activation analysis:
This subclass is indented under subclass 158. Subject matter
wherein the neutron bombardment of the material results in
the production of a product which is to be analyzed to yield
data concerning the nucleus of the material and/or its
environment.
Subclass:
160
Subterranean:
This subclass is indented under subclass 159. Subject matter
wherein the bombardment takes place beneath the surface of
the earth.
(1) Note. As between Class 376 and Class 250, subclasses
253-269.8 (well-logging), Class 376 takes all well-logging
apparatus and processes involving induced nuclear reactions
even if only nominally recited except when the nuclear
reaction is nominally recited and the signal processing steps
or apparatus are recited in detail (e.g., developing of a
ratio of two signals, classification is in Class 250,
subclasses 253-269.8.
Subclass:
161
Specific nuclides:
This subclass is indented under subclass 160. Subject matter
wherein a specified activated nucleus is recited.
Subclass:
162
Metals:
This subclass is indented under subclass 161. Subject matter
wherein the recited nucleus is a nucleus of a metal atom.
Subclass:
163
Aluminum, silicon:
This subclass is indented under subclass 162. Subject matter
wherein the metal nucleus is either aluminum or silicon.
Subclass:
164
Uranium:
This subclass is indented under subclass 162. Subject matter
wherein the metal nucleus is uranium.
Subclass:
165
Hydrogen, chlorine:
This subclass is indented under subclass 161. Subject matter
wherein the recited nucleus is either hydrogen or chlorine.
Subclass:
166
Oxygen, carbon:
This subclass is indented under subclass 161. Subject matter
wherein the recited nucleus is either oxygen or carbon.
Subclass:
167
With tracer injection:
This subclass is indented under subclass 160. Subject matter
wherein the material is injected into the earth and then
activated or transmuted.
(1) Note. The material is usually in fluid form.
Subclass:
168
Halogens:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded by neutrons is a halogen.
Subclass:
169
Iodine:
This subclass is indented under subclass 168. Subject matter
wherein the halogen is iodine.
Subclass:
170
Actinides:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded by neutrons is an element of
atomic number 89 or greater.
Subclass:
171
Breeder or converter reactor structures:
This subclass is indented under subclass 170. Subject matter
wherein the material bombarded with neutrons is a fertile
material and this fertile material is a component of and
positioned in, a nuclear fission reactor* comprised of two or
more of the following structural elements: moderator
structure, fuel structure, coolant structure (including
primary coolant, per se), or fuel support structure.
(1) Note. The nuclear reactor will generally comprise a
core of fissile fuel assemblies with or without moderator,
and a coolant. The fertile material may be (1) positioned in
the fissile fuel assembly either (a) mixed with the fissile
fuel material itself, or (b) as a separate distinct component
of the fissile fuel assembly; or (2) positioned in a
nonfissile fuel assembly, i.e., a fertile fuel assembly.
(2) Note. Methods of operation directed refueling schemes
are provided for in subclass 267.
Subclass:
172
Fertile fuel assembly structure or arrangement:
This subclass is indented under subclass 171. Subject matter
wherein the structure or arrangement of the fertile material
component is more than nominally recited.
Subclass:
173
Having internal fertile regions:
This subclass is indented under subclass 172. Subject matter
wherein components containing fertile material are positioned
inside the reactor core proper.
(1) Note. Since it is normal for most fissile fuel
components to include fertile materials along with the
fissile materials and still be classified as fissile fuel
components, for a patent to be placed in this subclass as an
original, there must be such a preponderance of fertile
material present that the component itself is classified as a
fertile fuel component.
Subclass:
174
Having particular coolant fluid flow path or pattern within
reactor core:
This subclass is indented under subclass 171. Subject matter
wherein the coolant* is made to traverse a specifically
defined route or channel within the reactor core or the route
taken is such as to place the coolant into a pattern or
network.
(1) Note. The recitation of a coolant flowing or
circulating through the reactor core is not by itself proper
subject matter for this subclass.
Subclass:
175
Orifice or fluid control at inlet or outlet of coolant
channels:
This subclass is indented under subclass 174. Subject matter
wherein means are provided which will alter the amount of
coolant which is (a) flowing into the coolant channel, or (b)
flowing out of the coolant channel.
SEE OR SEARCH THIS CLASS, SUBCLASS:
352 for similar subject matter.
Subclass:
176
Hydraulic holddown:
This subclass is indented under subclass 175. Subject matter
wherein a fuel assembly is positioned in the coolant channel
and the pressure of the coolant is utilized to help maintain
the fuel assembly in its desired position in the coolant
channel.
Subclass:
177
Plural coolant loops or passes through reactor core:
This subclass is indented under subclass 174. Subject matter
wherein (a) coolant is caused to traverse the reactor core
through separate and independent routes, or (b) coolant is
caused to traverse the reactor core a plurality of times
prior to its being sent to a heat exchanger or other
utilization means which would remove the heat from the
coolant.
Subclass:
178
Fuel assembly holddown or support:
This subclass is indented under subclass 171. Subject matter
wherein means are provided for maintaining the fuel assembly
in its desired position within the nuclear reactor.
Subclass:
179
Coolant manipulated and used exterior of reactor core:
This subclass is indented under subclass 171. Subject matter
wherein the coolant circulating within the reactor core area
has energy (e.g., thermal or kinetic) added to or removed
therefrom (e.g., by a heat exchanger, pump, or turbine)
exterior of the reactor core.
(1) Note. The "energy" may be transferred by heat exchange
to a secondary fluid, etc., which is then utilized in a
turbine.
Subclass:
180
Formation of uranium isotopes:
This subclass is indented under subclass 170. Subject matter
wherein the neutron bombardment of the actinide material
results in the production of uranium isotopes.
Subclass:
181
Uranium 233:
This subclass is indented under subclass 180. Subject matter
wherein the isotope produced is U-233.
Subclass:
182
Formation of plutonium isotopes:
This subclass is indented under subclass 170. Subject matter
wherein the neutron bombardment of the actinide material
results in the production of plutonium isotopes.
Subclass:
183
Doping of semiconductors:
This subclass is indented under subclass 158. Subject matter
wherein the material is a semiconductor which contains an
element which is converted to a desired dopant by the neutron
bombardment.
SEE OR SEARCH CLASS:
117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth
Processes; Non-Coating Apparatus Therefor, for processes and
non-coating apparatus for growing therein-defined
single-crystal of all types of materials, and such processes
combined with perfecting operations. A process comprising
the step of irradiation to produce a nuclear transformation
is provided for in Class 376.
438, Semiconductor Device Manufacturing: Process, subclass
512 for methods of introducing an electrically active dopant
into a semiconductor region having a combination of diverse
steps in which one step involves the conversion of an element
into a dopant by nuclear transmutation.
Subclass:
184
Rare earths:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded is at least one of La, Ce, Pr,
Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.
Subclass:
185
Alkali and alkaline elements:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded is selected from Group I or
Group II of the periodic table.
Subclass:
186
Molybdenum, technetium:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded is molybdenum or technetium.
Subclass:
187
Lead, polonium, bismuth:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded is lead, polonium, or
bismuth.
Subclass:
188
Sulfur, phosphorus:
This subclass is indented under subclass 158. Subject matter
wherein the material bombarded is sulfur or phosphorus.
Subclass:
189
With reaction product treatment (e.g., recovery,
separation):
This subclass is indented under subclass 158. Subject matter
wherein the neutron bombarded material or its by-products are
treated or acted on.
Subclass:
190
By charged particle bombardment:
This subclass is indented under subclass 156. Subject matter
wherein the bombardment of the material is effected with
electrically charged particles.
Subclass:
191
Alpha-neutron sources:
This subclass is indented under subclass 190. Subject matter
wherein the charged particles is an alpha particle and a
by-product of the reaction is a neutron.
Subclass:
192
To produce spallation reaction:
This subclass is indented under subclass 190. Subject matter
wherein the charged particle bombardment causes the ejection
of two or more particles from a nucleus in the material.
(1) Note. The ejected particles can by neutrons, protons,
deuterons, alpha particles, etc.
Subclass:
193
To produce fissile isotopes:
This subclass is indented under subclass 192. Subject matter
wherein the ejected particles produce fissile isotopes in a
second material.
Subclass:
194
Proton bombardment:
This subclass is indented under subclass 190. Subject matter
wherein the charged particle is a proton.
Subclass:
195
With reaction product treatment (e.g., recovery,
separation):
This subclass is indented under subclass 194. Subject matter
wherein the proton bombarded material or its by-products are
treated or acted on.
Subclass:
196
Alpha (helium nucleus) bombardment:
This subclass is indented under subclass 190. Subject matter
wherein the charge particle is an alpha particle.
SEE OR SEARCH THIS CLASS, SUBCLASS:
191 for alpha-neutron sources.
Subclass:
197
Wherein the reaction product is an actinide or transuranium
element:
This subclass is indented under subclass 196. Subject matter
wherein the alpha bombardment of the material produces an
element of atomic number 89 or greater.
SEE OR SEARCH THIS CLASS, SUBCLASS:
192 wherein alpha particles cause spaliation.
Subclass:
198
With reaction product treatment (e.g., recovery,
separation):
This subclass is indented under subclass 196. Subject matter
wherein the alpha bombarded material or its by-products are
treated or acted on.
Subclass:
199
Deuteron bombardment:
This subclass is indented under subclass 190. Subject matter
wherein the charged particle is a deuteron.
Subclass:
200
Wherein the reaction product is an actinide or transuranium
element:
This subclass is indented under subclass 199. Subject matter
wherein the deuteron bombardment of the material produces an
element of atomic number 89 or greater.
Subclass:
201
With reaction product treatment (e.g., recovery,
separation):
This subclass is indented under subclass 199. Subject matter
wherein the deuteron bombarded material or its by-products
are treated or acted on.
Subclass:
202
Irradiation capsule, holder, or support:
This subclass is indented under subclass 156. Subject matter
wherein the material to be bombarded is in a carrier or other
support structure and this carrier or other support structure
is subsequently used to convey, position, or insert the
material into or remove it from the vicinity of the radiation
means.
(1) Note. Subject matter of this subclass type includes,
for example, insertable carriers of the rabbit tube type.
Subclass:
203
SEAL ARRANGEMENT:
This subclass is indented under the class definition. Subject
matter for substantially preventing the escape of fluid from
a joint between two elements of a nuclear reactor fluid
confining means.
SEE OR SEARCH CLASS:
277, Seal for a Joint or Juncture, for a generic sealing
means or process, subclasses 628+ for a static contact seal
for other than an internal combustion engine, or a pipe,
conduit, or cable.
Subclass:
204
For nozzle:
This subclass is indented under subclass 203. Subject matter
wherein one of the two elements is a fluid conduit which
projects from a surface of a pressure vessel.
Subclass:
205
Between pressure vessel cover and vessel or portion thereof:
This subclass is indented under subclass 203. Subject matter
wherein one of the elements is a container, the interior
pressure of which is different from the ambient pressure and
the other element is a closure element for such a container.
Subclass:
206
Rotating plug-type cover:
This subclass is indented under subclass 205. Subject matter
wherein the closure means is capable of rotary movement.
Subclass:
207
WITH CONTROL OF REACTOR (E.G., CONTROL OF COOLANT FLOW):
This subclass is indented under the class definition. Subject
matter for changing (including "shut down") or maintaining
constant the fission reaction rate or power output of a
nuclear fission reactor.
(1) Note. Detection of a reactor state is proper subject
matter for this subclass provided it is in combination with a
control means for the fission reactor.
(2) Note. For the structure of the subcombination control
component which is an absorber, see this class (376),
subclass 327.
Subclass:
208
Pulsed reactors:
This subclass is indented under subclass 207. Subject matter
involving a nuclear reactor which is designed to be operated
in a pulsed mode or which is designed for the sudden
injection of a large amount of reactivity.
Subclass:
209
Spectral shift:
This subclass is indented under subclass 207. Subject matter
wherein control is realized through an adjustment made to the
energies of the total neutron population.
(1) Note. For purposes of this subclass, the word "total"
in regard to neutron population means the overall or
core-wide neutron population.
Subclass:
210
By coolant flow:
This subclass is indented under subclass 207. Subject matter
wherein the control involves changing the rate at which a
given mass of coolant enters or exits a fixed volume of
reactor structure.
Subclass:
211
Exterior of core (e.g., secondary loop control):
This subclass is indented under subclass 210. Subject matter
wherein the fixed volume is located outside of the primary
coolant loop of the reactor.
Subclass:
212
By altering quantity or characteristic of fuel within
critical area:
This subclass is indented under subclass 207. Subject matter
wherein control of the fission reaction is realized (a) by
reducing the effective quantity of fission fuel in the
critical area, or (b) by effecting an in situ change in the
physical state of the fuel.
(1) Note. The change of the physical state is brought about
by the lowering of density, such as by melting.
Subclass:
213
Wherein control element includes a fissile material:
This subclass is indented under subclass 212. Subject matter
wherein a control element includes a material which increases
the neutron population present.
Subclass:
214
Reactor start-up:
This subclass is indented under subclass 207. Subject matter
wherein the fission rate is manipulated to achieve a critical
condition having at least as many neutrons produced by
fission as their are fissions, i.e., self-sustaining fission
reaction.
Subclass:
215
By electronic signal processing circuitry (e.g., plural
redundant circuits):
This subclass is indented under subclass 207. Subject matter
comprising electronic circuit means which derives a control
signal for raising or lowering reactor power from an
electrical signal representative of a measured reactor
variable.
SEE OR SEARCH CLASS:
340, Communications: Electrical, subclasses 500+ for
condition responsive electrical systems in general.
Subclass:
216
Plural sensed different conditions or measured variables
correlated:
This subclass is indented under subclass 215. Subject matter
wherein representation of at least two different measured
variables are utilized in the formulation of the control
signal.
(1) Note. The body of art in this subclass is that which
utilizes, for example, electronic computers to analyze
practically instantaneously, a number of reactor variables or
conditions and to automatically warn of change of a critical
reactor condition or actually apply the safety control or
other element; to energize a system which automatically makes
the appropriate adjustment.
SEE OR SEARCH CLASS:
235, Registers, appropriate subclasses for electronic
computers or calculators, per se.
236, Automatic Temperature and Humidity Regulation,
appropriate subclasses for the automatic temperatures and
humidity regulation.
Subclass:
217
Control programs:
This subclass is indented under subclass 216. Subject matter
wherein at least one of the measured variables is caused to
be altered by a computerized program or its analog equivalent
so as to produce a predetermined desired result.
Subclass:
218
Xenon control:
This subclass is indented under subclass 217. Subject matter
wherein an operating program is developed to minimize the
xenon concentration in the nuclear fuel.
Subclass:
219
By movement of control element or by release of neutron
absorbing material:
This subclass is indented under subclass 207. Subject matter
wherein control is realized by the insertion or withdrawal of
a reactivity affecting material from the area occupied by
fissioning reactor fuel.
(1) Note. For the Structure of the subcombination of the
control component, per se, see this class (376), subclass
327.
Subclass:
220
Wherein the control element is a reflector or moderator
material:
This subclass is indented under subclass 219. Subject matter
wherein the control element is fabricated from a material
which either attenuates incident neutron energy or alters the
vector velocity of the neutron.
Subclass:
221
Variable fluent reflector/moderator level or density:
This subclass is indented under subclass 220. Subject matter
wherein a quantity of liquid, gaseous, or particulate
material having the capacity to alter neutron energy or
velocity relative to the quantity of fission fuel can be
changed.
Subclass:
222
Moderator dump:
This subclass is indented under subclass 221. Subject matter
wherein the fluent material is rapidly or completely
withdrawn.
Subclass:
223
Rotatable control elements:
This subclass is indented under subclass 219. Subject matter
wherein the surface of the control element adjacent the
surface of a fuel element revolves about an axis parallel to
each of said surfaces.
Subclass:
224
Finger-type control elements (insertable into fuel element
positions):
This subclass is indented under subclass 219. Subject matter
wherein plural control elements joined at their points most
remote from the fission fuel are moved into a repetitive
assemblage of fission fuel elements to vacant positions which
would otherwise be occupied by fission fuel elements.
Subclass:
225
Including shock absorber:
This subclass is indented under subclass 224. Subject matter
wherein the control elements are provided with some means to
retard motion.
Subclass:
226
Wherein control element is driven directly into bed of fuel
elements:
This subclass is indented under subclass 219. Subject matter
wherein the control element is moved into an assemblage of
fuel elements having no fixed position.
(1) Note. These fuel elements are usually piles of
spherically shaped bodies.
Subclass:
227
Control element movable by means of cable and winch, chains
or reels:
This subclass is indented under subclass 219. Subject matter
wherein the motion is induced by means of a flexible linear
member.
Subclass:
228
Wherein driver or motivating is electric:
This subclass is indented under subclass 219. Subject matter
wherein the means to move the control element is electrically
actuated.
Subclass:
229
Electrofluidic:
This subclass is indented under subclass 228. Subject matter
having motion induced by an electrical means which drives a
fluid pressure means which in turn moves the control
element.
Subclass:
230
Wherein driver or motivating is fluidic:
This subclass is indented under subclass 219. Subject matter
having motion directly produced by means of fluid pressure.
Subclass:
231
Pneumatic:
This subclass is indented under subclass 230. Subject matter
wherein the fluid is a gas.
Subclass:
232
By motion transforming means, e.g., rack and pinion:
This subclass is indented under subclass 219. Subject matter
wherein the movement of the control element is effectuated by
at least a pair of interconnected and relatively movable
motion transmitting members.
Subclass:
233
Releasable coupling:
This subclass is indented under subclass 219. Subject matter
wherein a disconnectable joint is provided between the
control element and the means producing motion so that the
motion means may be separated from the control element.
Subclass:
234
Including shock absorber:
This subclass is indented under subclass 219. Subject matter
wherein the control element is provided with a means to
retard motion.
(1) Note. The subject matter of this subclass type usually
involves motion into the fuel elements.
Subclass:
235
Means for locking control element in desired position:
This subclass is indented under subclass 219. Subject matter
including means to prevent motion of the control element from
a desired fixed position.
Subclass:
236
Including control rod insertion and removal schemes:
This subclass is indented under subclass 219. Subject matter
having specific patterns for the movement of control
elements.
(1) Note. This is usually done to improve the fuel
consumption in region near the control elements.
Subclass:
237
Group movement of control elements:
This subclass is indented under subclass 236. Subject matter
wherein simultaneous movement is induced in a plurality of
control elements.
Subclass:
238
Setback:
This subclass is indented under subclass 236. Subject matter
wherein the neutron control element is inserted into a fuel
region to less than its full extent and maintained at that
level for a predetermined time period.
Subclass:
239
Rod or support carrying plural elements or diverse
materials:
This subclass is indented under subclass 219. Subject matter
wherein at least two neutron absorber elements, other nonfuel
reactivity affecting mechanisms, or one of the above in
combination with another reactor component are secured to
each other and moved as a single unit.
Subclass:
240
Sensing or detecting device attached to, embedded in, or
integral with control element:
This subclass is indented under subclass 207. Subject matter
wherein the structure of the control element includes a means
for measuring the state of a reactor.
(1) Note. The state is usually the temperature or neutron
density.
Subclass:
241
Power output control (e.g., load follows with steam dump):
This subclass is indented under subclass 207. Subject matter
wherein control is realized through means external to the
region of fission reaction which raises or lowers the
deliverable energy of the system.
(1) Note. For similar subject matter involving a boiling
water reactor, see this class (376), subclass 379.
Subclass:
242
Means to inhibit control rod movement:
This subclass is indented under subclass 207. Subject matter
wherein a reactivity affecting material is locked in a fixed
position relative to the reactor fuel for a predetermined
time period.
(1) Note. During this period normal control signals
inducing movement are usually overridden.
Subclass:
243
With cooling of control element:
This subclass is indented under subclass 207. Subject matter
wherein provision is made to remove heat from the control
element.
Subclass:
244
Temperature reactivity control:
This subclass is indented under subclass 207. Subject matter
wherein the fission rate of the fuel is changed by altering
the temperature of the fuel.
Subclass:
245
TESTING, SENSING, MEASURING, OR DETECTING A FISSION REACTOR
CONDITION:
This subclass is indented under the class definition. Subject
matter for determining the state of the reactor system or a
component thereof.
(1) Note. When the determination involves a nuclear
reaction as a portion of the detection chain, see this class
(376), subclass 153.
(2) Note. Merely providing a window or a trap for visually
detecting or sampling or inspecting or mentally judging is
not considered as proper subject matter for this and indented
subclasses.
(3) Note. "Operation" or "reaction" is inclusive of the
period from startup through shutdown.
(4) Note. The "conditions" generally "measured" or
"detected", etc., included such as for example, reactor power
level, or reactor period, neutron density, neutron flux,
neutron flux distribution, radioactivity or other radiations,
temperature, etc.
SEE OR SEARCH THIS CLASS, SUBCLASS:
409 for fuel element having enclosed within it, or
integrally associated with it, some means, device, or
material which may be used to warn of a condition or in
measuring, sensing, monitoring, etc., of a condition during
normal use of the fuel.
450 for fuel element and its closure structure which
includes a feature, means, or material useful or assisting in
detecting or warning in regard to leaks or of an otherwise
improperly constructed or functioning fuel element.
SEE OR SEARCH CLASS:
73, Measuring and Testing, appropriate subclasses for testing
or measuring of physical properties.
250, Radiant Energy, appropriate subclasses for miscellaneous
measuring or detecting, etc., devices for use in conjunction
with neutrons or other invisible radiations.
324, Electricity: Measuring and Testing, appropriate
subclasses for testing or measuring of electrical
properties.
340, Communications: Electrical, subclasses 500+ for
condition responsive signalling.
374, Thermal Measuring and Testing, appropriate subclasses
for measuring or testing of thermal properties.
Subclass:
246
Flowmeters:
This subclass is indented under subclass 245. Subject matter
wherein the state determined is the passage of a given fluid
volume passing a fixed point per unit time.
Subclass:
247
Temperature or pressure measurement:
This subclass is indented under subclass 245. Subject matter
wherein the state being determined is a temperature or
pressure of the reactor system or component thereof.
SEE OR SEARCH CLASS:
374, Thermal Measuring and Testing, subclasses 100+ for
temperature measurement, in general.
Subclass:
248
Optics:
This subclass is indented under subclass 245. Subject matter
wherein the state determined is the visual condition of a
component.
Subclass:
249
Vessel monitoring or inspection:
This subclass is indented under subclass 245. Subject matter
wherein the state being determined is the integrity of a
reactor vessel.
SEE OR SEARCH CLASS:
901, Robots, subcollection 44 for robot devices which perform
an inspecting operation.
Subclass:
250
Leak detection:
This subclass is indented under subclass 245. Subject matter
wherein the state being determined is the undesirable release
of material from within a reactor system or component
thereof.
Subclass:
251
Fuel element leak detection:
This subclass is indented under subclass 250. Subject matter
wherein the component is the fission fuel element.
Subclass:
252
By acoustic or ultrasonic wave energy:
This subclass is indented under subclass 251. Subject matter
wherein the determination is made by the analysis of
compressional wave energy reflected or emitted from the fuel
element.
Subclass:
253
By the detection of fission product external to the fuel
element:
This subclass is indented under subclass 251. Subject matter
wherein the determination is made by sensing the presence of
nuclear fission reaction product outside the fuel element.
Subclass:
254
Flux monitoring:
This subclass is indented under subclass 245. Subject matter
wherein the state being determined is the quantity of
neutrons existing in a given area per unit time.
Subclass:
255
Directly generating electrical signal (e.g., ion detection):
This subclass is indented under subclass 254. Subject matter
wherein the determination is performed by electrical means
directly responsive to neutrons which means produce an
electrical signal proportional to neutron incidence.
Subclass:
256
Gas sensors (e.g., hydrogen detectors):
This subclass is indented under subclass 245. Subject matter
wherein the state determined is the presence of a particular
gas in the reactor system or component, such as hydrogen.
Subclass:
257
Fuel assay (e.g., burnup):
This subclass is indented under subclass 245. Subject matter
wherein the state determined is the quantity of fissionable
material, i.e., material whose nuclei have the capacity to
split under irradiation, in a reactor fission fuel element.
Subclass:
258
Position detection:
This subclass is indented under subclass 245. Subject matter
wherein the state determined is the extent to which an
element is inserted or withdrawn relative to the position of
another element.
Subclass:
259
By particular instrumentation circuitry:
This subclass is indented under subclass 245. Subject matter
comprising electrical circuitry designed to process signals
representing measured quantities from which the state can be
determined.
Subclass:
260
HANDLING OF FISSION REACTOR COMPONENT STRUCTURE WITHIN
REACTOR SYSTEM:
This subclass is indented under the class definition. Subject
matter for physically moving structure within the nuclear
fission reactor system.
(1) Note. "Handling" as used in this and indented
subclasses includes moving, or any motion, of a component or
segment thereof from one position or location to another
within or to the outside of; or altogether externally of the
reactor; and is inclusive also of a rotating or a
reciprocating motion, but not of a stationary vibrating
motion.
(2) Note. The mere circulation of a fluid component is not
considered as "handling" for this and indented subclasses;
however, a peculiar or particular nature of circulation may
be so considered.
SEE OR SEARCH THIS CLASS, SUBCLASS:
156 for particular "handling" of materials or components
wherein nuclear conversion is also involved.
308 for "handling" of reactor materials not provided for
elsewhere in this class. For example, the handling of
fluid-type reaction products.
SEE OR SEARCH CLASS:
414, Material or Article Handling, appropriate subclasses for
handling devices and equipment, per se.
Subclass:
261
Fuel component:
This subclass is indented under subclass 260. Subject matter
wherein the object moved is the fission reactor fuel.
(1) Note. The fuel material, component, or segment as used
in this and indented subclasses may be a single fuel element
or a cluster, etc., of fuel elements.
SEE OR SEARCH THIS CLASS, SUBCLASS:
308 for treatment of fission reactor material.
356 for fuel dispersed in liquid moderator, etc.
359 for fuel in molten state or in molten vehicle.
Subclass:
262
Including handling of a second different, diverse reactor
component, (e.g., control element, moderator element, vessel
cover removal):
This subclass is indented under subclass 261. Subject matter
wherein the fission reactor fuel is moved together with
another fission reactor system component.
(1) Note. The fission reactor fuel may be moved relative to
the other reactor component at the same time they are moved
together relative to fixed element of the reactor system.
Subclass:
263
With pressure vessel cover removal:
This subclass is indented under subclass 262. Subject matter
wherein the movement of fuel requires the prior movement of
the closure of the fuel containing receptacle.
Subclass:
264
Charging or discharging of fuel:
This subclass is indented under subclass 261. Subject matter
wherein the fuel is moved into or out of the nuclear fission
reactor system.
(1) Note. This normally referred to as refueling of the
fission reactor.
SEE OR SEARCH CLASS:
74, Machine Element or Mechanism, appropriate subclasses for
machine elements or mechanisms, per se, which can be used for
mechanically manipulating the fuel or other reactor
component.
294, Handling: Hand and Hoist-Line Implements, subclasses 6+
for grapples for handling core components.
414, Material or Article Handling, appropriate subclasses for
material handling equipment, per se.
Subclass:
265
Refueling ball-type reactors:
This subclass is indented under subclass 264. Subject matter
wherein the movement of fuel occurs within a nuclear fission
reactor of the type wherein the fuel elements of which have a
generally spherical shape.
(1) Note. Such fission reactors are commonly referred to as
pebble-bed reactors.
Subclass:
266
Means for separating low exposure from high exposure
elements:
This subclass is indented under subclass 265. Subject matter
wherein the movement of the fuel elements include means for
directing fuel elements which have been in the reactor system
for a short period of time to one location and means for
directing fuel element which have been in the reactor system
for a longer period of time to another location.
(1) Note. Fuel elements which have no fuel left, i.e., are
burned up, are usually removed from the reactor system.
Subclass:
267
Refueling schemes, patterns, or fuel cycles (e.g., in/out
systems):
This subclass is indented under subclass 264. Subject matter
wherein the movement involves at least a partial
rearrangement of the fuel elements in the reactor system to
new positions previously occupied by other fuel elements or
by movement of the fuel from or to different portions of the
reactor system.
(1) Note. The purpose of the above is typically to improve
fission fuel consumption.
(2) Note. For the purpose of this subclass, the
rearrangement of fuel elements may include the movement of
other core elements such as control elements or reflector
elements.
Subclass:
268
Refueling machines:
This subclass is indented under subclass 260. Subject matter
wherein the object is an apparatus for moving fission fuel
elements.
Subclass:
269
With magazine:
This subclass is indented under subclass 268. Subject matter
wherein the transfer of fuel involves the use of a temporary
fuel storage means.
(1) Note. Subject matter of this subclass type includes for
example, (a) fuel transferring machines which have the
capacity to store a fuel element, and (b) transfer paths
which have storage areas therein.
Subclass:
270
With nonaxial transfer capability:
This subclass is indented under subclass 268. Subject matter
wherein the fuel element is rotated from a position in axial
alignment with respect to its position in the core to another
position about an axis which intersects the axis of its
original alignment.
Subclass:
271
Upper axial transfer:
This subclass is indented under subclass 268. Subject matter
wherein the fuel element is moved between its position in the
core and a position above and in axial alignment with its
core position by means located above the core.
Subclass:
272
Storage container systems for new and/or irradiated core
elements:
This subclass is indented under subclass 260. Subject matter
wherein reactor core elements are in a physical enclosure
within the reactor system, which enclosure is distinct
therefrom.
(1) Note. Subject matter of this subclass type consists of
more than a mere container for a single core element and
therefore referred to as container systems. Structures
consisting of more than one container, or storage for plural
core assemblies, or one container with means to support or
affix the container in a storage pool are typical of the
systems of this subclass type, such systems are distinguished
by their operative or structural association with nuclear
reactors.
(2) Note. Search Class 250, subclasses 506.1+, and 515.1+
for generic storage devices (particularly shipping casks for
radioactive material.
(3) Note. The storage systems herein may include a specific
means for preventing (and therefor controlling) nuclear
fission reactions, e.g., by the use of neutron absorber
materials or by limiting the number of fuel elements in a
given storage system.
(4) Note. Included in this subclass are storage systems
which include means for cooling the core elements.
(5) Note. The storage systems herein are for core elements
(new, used, or irradiated, or damaged) that still retain
their structural form which identifies them as core elements,
for example, before they have been physically or chemically
altered for processing of the irradiated or radioactive
material therein.
SEE OR SEARCH THIS CLASS, SUBCLASS:
347 for similar subject matter. The structure and also the
cooling systems for the subject matter of this subclass (272)
may be similar to the structure and cooling systems for the
core elements in the nuclear reactor itself.
Subclass:
273
SUBTERRANEAN REACTOR STRUCTURES (E.G., UNDERGROUND
CONTAINMENT, UNDERGROUND EXPLOSIVE):
This subclass is indented under the class definition. Subject
matter wherein the reactor structure is recited as being
located beneath the surface of the earth.
(1) Note. Underground nuclear explosives are proper subject
matter for this and indented subclass.
(2) Note. The nuclear reaction energy may be obtained from
nuclear explosives (either fission or fusion) or from a
nuclear reactor.
SEE OR SEARCH THIS CLASS, SUBCLASS:
118 for subterranean systems utilizing Crockcroft-Walton
Neutron generators.
160 for subterranean neutron activation analysis.
Subclass:
274
For minimizing radioactive contamination within an
underground chamber or of the material removed therefrom:
This subclass is indented under subclass 273. Subject matter
wherein the reactor structure is in an underground cavity or
is caused to form the cavity and radioactive contamination
resulting from operation of the reactor structure is removed
or reduced.
Subclass:
275
For extracting materials, or energy from the earth:
This subclass is indented under subclass 273. Subject matter
wherein the energy of the nuclear reaction is transferred to
the earth or to the reactor structure surroundings so as to
recover material or transferred energy therefrom.
SEE OR SEARCH CLASS:
166, Wells, subclass 247 for similar processes which do not
involve a nuclear reactor or which do not involve details of
the nuclear explosive.
Subclass:
276
In the form of heated water or steam:
This subclass is indented under subclass 275. Subject matter
wherein the extracted energy or material is H[subscrpt]2[end
subscrpt]O in a heated or vaporized state.
Subclass:
277
REACTOR PROTECTION OR DAMAGE PREVENTION:
This subclass is indented under the class definition. Subject
matter for reducing undesired effects resulting from the
operation, malfunction, or failure of a nuclear fission
reactor component.
1) Note. The utilization of shielding or insulation to
reduce or prevent irradiation damage is proper subject matter
for this subclass.
SEE OR SEARCH THIS CLASS, SUBCLASS:
274 for means or steps for minimizing radioactive
contamination within an underground chamber or of the
material removed therefrom.
Subclass:
278
By minimizing positive coolant void coefficient:
This subclass is indented under subclass 277. Subject matter
wherein means is provided which minimizes or reduces the
amount of reactivity increase due to a loss of coolant.
Subclass:
279
Fire extinguishing or prevention:
This subclass is indented under subclass 277. Subject matter
wherein the burning of reactor components is the undesired
effect.
Subclass:
280
Core catchers:
This subclass is indented under subclass 277. Subject matter
wherein component failure within the fissile and/or fertile
region of a reactor is mitigated through the use of a barrier
that slows or stops the egress of said components(s) from the
region.
(1) Note. The barrier will also serve to prevent the egress
of any other component transported with the failed
component.
Subclass:
281
Fluid flow reversal protection:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is a change in the direction of
flow of a fluid within a reactor component.
Subclass:
282
Emergency core coolant systems (e.g., injecting coolant into
reactor or pipe systems):
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is fuel melting which undesired
effect is minimized by providing an alternate supply of
coolant to the fuel in the event of stoppage or partial
diminution of the normally present supply of coolant.
(1) Note. The alternate coolant is usually supplied at a
rate significantly lower than normal coolant.
Subclass:
283
Pressure suppression and relief:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is component damage (e.g.,
rupture) due to overpressure which undesired effect is
minimized by providing an energy removal means to dissipate
said overpressure.
Subclass:
284
By fusible means (e.g., ice):
This subclass is indented under subclass 283. Subject matter
wherein the energy removal means includes a material which
absorbs energy through a physical change of state.
Subclass:
285
Expansion means (e.g., shock absorbers roller bearings):
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is the deformation of reactor
components due to thermal stress which undesired effect is
minimized by providing a structure to accommodate such
deformation.
Subclass:
286
Pipe expansion joints:
This subclass is indented under subclass 285. Subject matter
wherein the structure is included in reactor piping system.
Subclass:
287
Shield or barrier between radiation or heat source and object
to be protected (e.g., insulation, thermal shield):
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect (a) is the presence of radiation
in a given area which undesired effect is minimized by
providing means to attenuate the radiation prior to its entry
into said area, or (b) to attenuate the egress of material
into the area to be protected.
(1) Note. Means to attenuate includes means to prevent or
retard the egress of steam or effluent from a malfunctioning
reactor component. Said steam or effluent will contain at
least nominal radioactivity.
Subclass:
288
Particular materials:
This subclass is indented under subclass 287. Subject matter
wherein the means to attenuate includes a specific
composition of matter.
Subclass:
289
Thermal insulation:
This subclass is indented under subclass 287. Subject matter
wherein the radiation attenuated is thermal radiation.
Subclass:
290
For liquid metal cooled fast reactors (e.g., insulation for
vault roof, or for the vessel walls as by a layer of stagnant
or quasi-stagnant coolant):
This subclass is indented under subclass 289. Subject matter
having the attenuation in a system which includes an
unmoderated fission fuel system cooled by molten metal.
Subclass:
291
Concentric tubes or conduits with insulation:
This subclass is indented under subclass 289. Subject matter
wherein the means to attenuate thermal radiation is or
supported by set(s) of nested cylinders.
Subclass:
292
Concentric tubes or conduits:
This subclass is indented under subclass 287. Subject matter
wherein the means to attenuate radiation and/or egress of
material includes set of nested cylinders.
(1) Note. The outer cylinder may provide an additional
means to retard the egress of material within the inner
cylinder.
Subclass:
293
Containment structures:
This subclass is indented under subclass 287. Subject matter
wherein the means to attenuate either (a) completely
surrounds the fission fuel region, or (b) provides the last
level of attenuation of radiation prior to its entry into the
environment.
Subclass:
294
Pressure vessels:
This subclass is indented under subclass 293. Subject matter
wherein the means to attenuate completely surrounds the
fission fuel region, and has the capacity to contain a
pressurized fluid.
Subclass:
295
Concrete:
This subclass is indented under subclass 294. Subject matter
wherein the means to attenuate is constructed from a mixture
of cement and aggregate.
Subclass:
296
Prestressed:
This subclass is indented under subclass 295. Subject matter
wherein the means to attenuate includes structure having
built-in compressive or tensile forces.
Subclass:
297
With turbine protection means (e.g., turbine trip or
overspeed protection means):
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is turbine damage which
undesired effect is minimized by reducing or eliminating the
energy transfer from the fissioning fuel.
Subclass:
298
Auxiliary heat removal structure:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is component overheating which
undesired effect is minimized by providing additional thermal
energy transfer from said component.
SEE OR SEARCH CLASS:
165, Heat Exchange, appropriate subclasses for cooling
towers.
261, Gas and Liquid Contact Apparatus, appropriate subclasses
for cooling towers.
Subclass:
299
Decay heat removal:
This subclass is indented under subclass 298. Subject matter
wherein the components are the fission fuel bodies and the
energy removed is generated when the reactor is shutdown.
Subclass:
300
Recombiners:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is the decomposition of water
into hydrogen and oxygen which undesired effect is minimized
by providing structures or processes to join the hydrogen and
oxygen to form water.
Subclass:
301
Catalytic:
This subclass is indented under subclass 300. Subject matter
having a catalyst present to assist in the formation of
water.
Subclass:
302
Core restraint means:
This subclass is indented under subclass 277. Subject matter
wherein the effect is the undesired movement of components in
the region of the fission fuel bodies which effect is
minimized by providing structures or processes to retard such
movement.
Subclass:
303
In-core restraint means:
This subclass is indented under subclass 302. Subject matter
wherein the structures or processes to retard such movement
are positioned among or within the fuel bodies.
Subclass:
304
For moderator structures:
This subclass is indented under subclass 302. Subject matter
wherein the components whose movement is retarded are those
components which attenuate neutron energy.
Subclass:
305
Corrosion or damage prevention:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is the chemical decomposition of
a reactor component which undesired effect is minimized (a)
by providing the component with a barrier to retard the
dissolution, or (b) by providing a reactant which will react
with the corrosion causing agent to remove it from or reduce
presence in the reactor system.
Subclass:
306
By addition of material to coolant:
This subclass is indented under subclass 305. Subject matter
wherein the barrier is established by the introduction of a
material into the coolant which forms a barrier layer on the
component or which will react with the corrosion causing
agent.
Subclass:
307
With pressurizer means:
This subclass is indented under subclass 277. Subject matter
wherein the undesired effect is the uncontrolled or pressure
variations which undesired effect is minimized by means for
maintaining a desired coolant pressure.
Subclass:
308
FISSION REACTOR MATERIAL (INCLUDING REACTION PRODUCTS)
TREATMENT:
This subclass is indented under the class definition. Subject
matter for adding or removing a material from the system or
component thereof.
Subclass:
309
Post accident impurity or contaminant removal:
This subclass is indented under subclass 308. Subject matter
including the removal of material dislocated by accident or
by the failure of a reactor component.
Subclass:
310
Impurity removal:
This subclass is indented under subclass 308. Subject matter
wherein undesired material is withdrawn from the system.
Subclass:
311
Reprocessing of fuel during reactor operation:
This subclass is indented under subclass 310. Subject matter
wherein impurities are removed from the fuel while the
reactor is operating.
SEE OR SEARCH THIS CLASS, SUBCLASS:
358 for similar subject matter but wherein there is no
treatment of the fuel itself.
SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use
Therein, Consolidated Metal Powder Compositions, and Loose
Metal Particulate Mixtures, subclasses 393+ for processes
of producing or treating Radioactive metal.
423, Chemistry of Inorganic Compounds, subclasses 3+ for
processing or reprocessing, in general, of nuclear reactor
fuel.
Subclass:
312
By cold traps or hot traps:
This subclass is indented under subclass 310. Subject matter
wherein the impurities are removed from a fluid stream by
lowering the temperature thereof to a point which induces
precipitation of the impurities.
Subclass:
313
By filters, ion exchangers, or absorbers:
This subclass is indented under subclass 310. Subject matter
wherein the impurity is removed from a fluid through the use
of (a) a porous mass through which the fluid is passed to
separate from it the material held in suspension, or (b) a
composition of matter which has the property of replacing the
charged specie of the material in solution with ions of the
composition.
(1) Note. This and indented subclasses include filters at
the coolant inlet and of, and integral with, the fuel
assembly.
SEE OR SEARCH THIS CLASS, SUBCLASS:
253 for the collection of fission products used in the
detection of fuel element flaws.
Subclass:
314
Gas filters (e.g., adsorbers):
This subclass is indented under subclass 313. Subject matter
wherein the material to be removed is in the gaseous or vapor
state.
SEE OR SEARCH CLASS:
55, Gas Separation, digest 9 for radioactive filters.
Subclass:
315
Electrostatic or magnetic filters:
This subclass is indented under subclass 313. Subject matter
wherein the removal is accomplished by an electrostatic or
magnetic field.
Subclass:
316
By pressurized fluid (i.e., blowdown):
This subclass is indented under subclass 310. Subject matter
wherein the impurities are flushed from the surface of a
reactor component by a fluid driven by a fluid pressure
differential.
(1) Note. Subject matter of this subclass type includes,
for example, the removal of corrosion products from a heat
exchanger by a pressurized fluid.
SEE OR SEARCH CLASS:
122, Liquid Heaters and Vaporizers, subclass 381 for
blowdown systems in general.
Subclass:
317
COMBINED:
This subclass is indented under the class definition. Subject
matter in combination with structures or processes not
provided for in this class, per se.
(1) Note. The combination of a reactor with a heat
exchanger, pump, or turbine is provided for elsewhere in this
class, see subclasses 179, 211, 378, 391, and 402.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 340+ for reactor structures with testing or
irradiation facilities.
subclasses 347+ for typical nuclear reactor power plant
structure which may include a turbine.
Subclass:
318
With propulsion means:
This subclass is indented under subclass 317. Subject matter
including a nuclear fission reactor combined with a device to
move the combined structure.
SEE OR SEARCH CLASS:
60, Power Plants, subclass 203.1 for propulsion systems
involving radiant energy.
Subclass:
319
Gaseous core:
This subclass is indented under subclass 318. Subject matter
wherein the nuclear reactor has its fissionable portion in
the gas or vapor state or dispersed in a gas or vapor.
Subclass:
320
With direct conversion means:
This subclass is indented under subclass 317. Subject matter
wherein the nuclear reaction produces energy, a portion of
which energy is transformed into electrical output by a
one-step process or apparatus for accomplishing such one-step
process.
SEE OR SEARCH CLASS:
136, Batteries: Thermoelectric and Photoelectric, subclasses
200+ for thermoelectric systems, per se; and subclass 202
for the combination with radioactive decay heat source.
Subclass:
321
Thermionic:
This subclass is indented under subclass 320. Subject matter
wherein the one-step includes the heating of a material by
the products of the nuclear reaction which material emits
electrons or ions due to the high temperature induced
therein.
Subclass:
322
For storing excess energy:
This subclass is indented under subclass 317. Subject matter
wherein the energy produced by the nuclear reaction is
converted to a storable form for later utilization.
Subclass:
323
With chemical reaction:
This subclass is indented under subclass 317. Subject matter
wherein the energy of a nuclear reaction is employed to aid a
chemical reaction.
Subclass:
324
To produce a combustible fuel:
This subclass is indented under subclass 323. Subject matter
wherein a product of the chemical reaction can be burned to
produce energy.
SEE OR SEARCH THIS CLASS, SUBCLASS:
275 for similar subject matter wherein underground
hydrocarbons are converted in situ to a combustible fuel.
Subclass:
325
Cracking of hydrocarbons:
This subclass is indented under subclass 324. Subject matter
wherein the chemical reaction includes the breaking of
hydrogen carbon molecular linkages.
Subclass:
326
With laser:
This subclass is indented under subclass 317. Subject matter
wherein the structure or process to be combined with is a
source of coherent electromagnetic radiation.
SEE OR SEARCH CLASS:
372, Coherent Light Generators, appropriate subclasses for
lasers, per se.
Subclass:
327
CONTROL COMPONENT FOR A FISSION REACTOR:
This subclass is indented under the class definition. Subject
matter comprising a reactor control element.
SEE OR SEARCH THIS CLASS, SUBCLASS:
207 for a control component in combination with means to
move the component to control the reactor.
subclasses 458+ for moderator structure which is not usable
to control the reactor.
SEE OR SEARCH CLASS:
501, Compositions: Ceramic, appropriate subclasses for
ceramic compositions useful as a nuclear reactor component or
fuel element material.
Subclass:
328
Liquid control component:
This subclass is indented under subclass 327. Subject matter
wherein the reactivity affecting material is in a liquid
state.
Subclass:
329
With vaporization:
This subclass is indented under subclass 328. Subject matter
wherein the liquid is vaporized to adjust the amount of
reactivity affecting material that is within the reactor core
region.
(1) Note. Subject matter of this subclass includes, for
example, the use of a heat pipe for varying the amount of
reactivity affecting material in the reactor.
Subclass:
330
Liquid metal control component:
This subclass is indented under subclass 328. Subject matter
wherein the liquid is a fused or molten metal.
Subclass:
331
Gaseous control component:
This subclass is indented under subclass 327. Subject matter
wherein the reactivity affecting material is in a gaseous
state.
Subclass:
332
Telescopic control devices:
This subclass is indented under subclass 327. Subject matter
wherein the reactivity affecting material is in the form of a
plurality of elements adapted to slide or move one within the
other as in the manner of a telescope.
Subclass:
333
Wherein concentration of the reactivity affecting material
varies radially or axially of the control element:
This subclass is indented under subclass 327. Subject matter
wherein the control element is comprised of reactivity
affecting material and some other material and the relative
amounts of each material varies radially and/or axially along
the length of the control element.
Subclass:
334
By utilizing a follower:
This subclass is indented under subclass 333. Subject matter
wherein the axial variation in the amount of reactivity
affecting material is effected by axially joining an
auxiliary control element (follower) having one reactivity
effect to a primary control element having a different
reactivity effect.
Subclass:
335
Flexible control element:
This subclass is indented under subclass 327. Subject matter
wherein the control component is in the form of a nonrigid or
nonself-supporting element (e.g., a cable or a plurality of
short elements joined one to the other with flexible or
pivotal couplings).
Subclass:
336
Fuse actuated devices:
This subclass is indented under subclass 327. Subject matter
wherein the control component is moveable with respect to the
reactor core and the means for affecting movement of the
control component is actuated by or is responsive to, an
abnormal reactor operating condition (e.g., abnormal increase
in temperature or abnormal increase in neutron flux).
(1) Note. The abnormal increase in temperature or neutron
flux may cause the melting of a solder plug which will then
allow the control component to move relative to the reactor
core into a position which will cause a decrease in the
reactivity of the reactor core.
Subclass:
337
Particulate type:
This subclass is indented under subclass 336. Subject matter
wherein the control component is comprised of a mass of
separate individual elements which are released for movement
with respect to the reactor core when the fuse is actuated.
Subclass:
338
Particulate type (e.g., balls):
This subclass is indented under subclass 327. Subject matter
wherein the control component comprises a mass of separate
individual elements of reactivity affecting material.
Subclass:
339
Nonconventual control material:
This subclass is indented under subclass 327. Subject matter
wherein the reactivity affecting material is defined in terms
of its composition or elemental constituents and in other
than one of the conventional control material, i.e., boron or
cadmium.
Subclass:
340
REACTOR STRUCTURES WITH TESTING OR IRRADIATION FACILITIES:
This subclass is indented under the class definition. Subject
matter comprising the combination of two or more of the
following: moderator structure, fuel structure, coolant
structure, fuel support structure along with structure
designed to facilitate or enhance the capability of the
reactor structure for the testing or irradiation of
materials.
Subclass:
341
With material holder or support positioned outside the
radiation source:
This subclass is indented under subclass 340. Subject matter
wherein the target holder or support is positioned or caused
to be positioned outside or adjacent to the radiation
source.
Subclass:
342
With provision for insertion of material to be irradiated
into the radiation means:
This subclass is indented under subclass 340. Subject matter
wherein the reactor structure is designed to allow insertion
of the material to be irradiated.
Subclass:
343
Flux trap reactor structures:
This subclass is indented under subclass 342. Subject matter
wherein a nuclear fission reactor* specially constructed so
as to provide an internal fuel* free region in which the
target can be inserted, the fuel free region having a high
thermal neutron flux*.
(1) Note. The fuel free region will constitute a region or
island of internal reflector/moderator.
(2) Note. Flux trap reactors utilized for testing of
reactor components is proper subject matter for this
subclass.
Subclass:
344
By fluid pressure:
This subclass is indented under subclass 342. Subject matter
wherein the material holder is conveyed into and through the
radiation means by a fluid.
Subclass:
345
Wherein the fluid is a liquid:
This subclass is indented under subclass 344. Subject matter
wherein the transporting fluid is a liquid.
Subclass:
346
EPI-THERMAL REACTOR STRUCTURES (E.G., INTERMEDIATE NEUTRON
SPECTRUM):
This subclass is indented under the class definition. Subject
matter comprising a nuclear fission reactor having some
moderating material and wherein the neutrons which induce the
splitting of nuclei, i.e., fission, have velocities in excess
of thermal velocities, 2200 meters per second.
Subclass:
347
REACTOR STRUCTURES:
This subclass is indented under the class definition. Subject
matter comprising the combination of two or more of the
following structural elements: moderator structure, fuel
structure, coolant structure (including primary coolant, per
se), or fuel support structure.
(1) Note. Subject matter of this subclass type includes,
for example, thermal reactors, i.e., reactors which contain
moderating material which, though not necessarily disclosed,
reduces the energy of the neutrons to thermal energy, e.g.,
2200 meters per second or 0.03 ev.
(2) Note. If a reactor is generically recited but is
disclosed in the preferred embodiment as a type of reactor
specifically provided for in the preceding subclasses, the
original copy is placed in the appropriate subclass and a
cross-reference copy may be placed in this subclass or in a
subclass indented hereunder.
(3) Note. The coolant structure must be other than such
structure built into the fuel structure. For such
structures, see subclasses 424 and 439.
(4) Note. The fuel support structure of this subclass type
is other than the support structure for fuel components, per
se, as provided for, for example, in subclass 437.
(5) Note. Subject matter of this subclass type may include
subcritical or neutrons amplifying reactor structures.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 171+ for breeder reactors.
340 for reactor structures with testing or irradiation
facilities.
346 for epi-thermal reactors.
423 for the moderator enclosed together with the fuel.
subclasses 458+ for moderator structure, per se.
subclasses 904+ for specified materials used as moderator
and coolant.
SEE OR SEARCH CLASS:
165, Heat Exchange, subclasses 81+ for heat exchangers
including expansion and contraction relieving or absorbing
means.
Subclass:
348
Fast thermal composite core:
This subclass is indented under subclass 347. Subject matter
wherein the reactor core is comprised of at least two
regions, one region operating with fast neutrons and the
other region operating with neutrons at thermal energies,
i.e., about 0.025 ev.
Subclass:
349
Flux flattening:
This subclass is indented under subclass 347. Subject matter
for providing a flatter flux profile across the reactor
core.
Subclass:
350
Moderator component varies in its effective density or
materials:
This subclass is indented under subclass 347. Subject matter
wherein (a) the number of atoms of moderator component per
unit volume varies in space, or (b) the nature of the
composition of the moderator varies in space so as to display
a different moderating effect in one zone of the reactor core
area relative to that displayed in another zone.
(1) Note. The normal change in coolant density as is found
along the length of a fuel assembly in a boiling water
reactor is not proper for placement in this subclass.
Boiling water reactors are in subclasses 370+.
Subclass:
351
Spaced internal reflectors or moderators:
This subclass is indented under subclass 350. Subject matter
wherein reflector* or moderator* material is placed inside
the reactor core at spaced intervals occupied normally by
fuel assemblies or other internal reactor core structure.
Subclass:
352
Orifice or fluid control at inlet or outlet or coolant
channels:
This subclass is indented under subclass 347. Subject matter
wherein means are provided which alter the amount of coolant*
which is (a) flowing into the coolant channel, or (b) flowing
out of the coolant channel.
SEE OR SEARCH THIS CLASS, SUBCLASS:
175 for similar subject matter involving a breeder or
converter reactor structure.
243 where the orifice is at the inlet or outlet of a control
element.
246 wherein the orifice functions as a flow meter.
Subclass:
353
With particular control rod guide structure:
This subclass is indented under subclass 347. Subject matter
wherein the reactor is controlled by use of a control rod*
and structure is provided for guiding the control rod during
movement thereof, said structure being other than the normal
in-core control rod guide tube structure.
Subclass:
354
Fuel material in contact with and supported by fluid:
This subclass is indented under subclass 347. Subject matter
wherein the fuel material is in contact with a fluid and at
some point in the reactor, or at some time during the
reaction, the fuel is also supported by the fluid.
Subclass:
355
Fluidized beds:
This subclass is indented under subclass 354. Subject matter
wherein the fuel material is in the form of particulate
bodies, a plurality of which are grouped together to form a
bed and wherein a fluid flows through the bed of fuel bodies
with sufficient force to expand the bed of bodies against any
force, e.g., gravity.
Subclass:
356
Fuel dispersed in liquid moderator, solution, etc.:
This subclass is indented under subclass 354. Subject matter
wherein the moderator is in liquid form and the fuel is
dissolved in, or a particulate form of the fuel is
homogeneously distributed throughout the liquid moderator to
form a solution, colloid, or slurry.
Subclass:
357
Vapor forming, separating, or manipulating:
This subclass is indented under subclass 356. Subject matter
wherein steam or vapor is (a) formed from the liquid
moderator at least in part during the course of the reaction,
(b) separated as steam or vapor from the liquid moderator, or
(c) wherein such steam or vapor is handled in some way
internally or externally of the reactor.
(1) Note. For other boiling liquid reactors, see subclasses
370+.
Subclass:
358
With particular in situ reconstitution or modification of
fuel moderator material:
This subclass is indented under subclass 356. Subject matter
wherein the fuel moderator component is reconstituted or
modified during the operation of the reactor by the addition
or removal of material other than a gas or vapor.
SEE OR SEARCH THIS CLASS, SUBCLASS:
311 for similar subject matter but wherein the material is
treated.
Subclass:
359
Fuel in molten state or in molten vehicle:
This subclass is indented under subclass 354. Subject matter
wherein either the fuel or its carrier is in a fused or
melted state.
(1) Note. The fuel may be a liquefied metal, alloy, or
compound or one of these dispersed (in particulate form) in a
liquefied carrier metal alloy, salt, or other compound.
Subclass:
360
Fuel in form of fused salt:
This subclass is indented under subclass 359. Subject matter
wherein the molten fuel or molten carrier is a salt.
Subclass:
361
Circulating fluid within reactor:
This subclass is indented under subclass 347. Subject matter
wherein one of the reactor components is a fluid and is under
sufficient pressure as to flow into or within the reactor
during its operation.
(1) Note. A patent is placed in this and indented
subclasses even if it is not explicit in the claim that a
fluid is circulating or flowing if by disclosure the fluid
must be or is intended to flow or to circulate.
(2) Note. In the subject matter of this subclass type the
flow or circulation may be intermittent or pulsed.
(3) Note. A patent is not placed in this and indented
subclasses where there is no flow or circulation but there is
a static pressure acting on a fluid.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 354+ for circulating fluids containing the
fuel.
Subclass:
362
Fuel assembly supports:
This subclass is indented under subclass 361. Subject matter
wherein structure is provided for supporting or maintaining
the fuel assemblies in their desired positions within the
nuclear reactor.
Subclass:
363
Suspended fuel assembly:
This subclass is indented under subclass 362. Subject matter
comprising means for supporting fuel assemblies by their
upper ends from the top of the reactor, e.g., or by being
attached to the closure plug.
Subclass:
364
Fuel assembly holddown or locking means:
This subclass is indented under subclass 362. Subject matter
wherein means are provided for maintaining the fuel assembly
in its desired position within the reactor against the force
of the coolant.
Subclass:
365
Hydraulic or pneumatic:
This subclass is indented under subclass 364. Subject matter
wherein a fuel assembly is positioned in the coolant channel
and the pressure of the coolant itself is utilized to help
maintain the fuel assembly in its desired position in the
coolant channel.
Subclass:
366
Plural fluids or a fluid in plural phases circulating within
reactor (e.g., pressure tube reactor):
This subclass is indented under subclass 361. Subject matter
involving the circulation within a reactor (e.g., pressure
tube reactor) of at least two fluid streams which may differ
from each other in chemical composition or physical state,
e.g., water and steam, water and molten metal, or
hydrocarbon.
(1) Note. For a pressure tube reactor to issue in this or
indented subclasses, a first fluid must be circulating
through the pressure tubes with a second fluid being present
or circulating outside of the tube through which the first
fluid circulates.
(2) Note. For single fluid pressure tube reactors, search
this class (376), subclass 401.
Subclass:
367
In heat pipe means:
This subclass is indented under subclass 366. Subject matter
wherein the fluid in plural phases flows in a conduit
comprised of two zones, one for transport of the fluid in the
liquid state and the other for transport of the fluid in the
gaseous state.
Subclass:
368
Including chemically distinct gas:
This subclass is indented under subclass 366. Subject matter
wherein one fluid is a gas which is chemically different from
other fluids present, e.g., water and helium.
(1) Note. The term "gas" includes a liquid or solid in the
vapor state.
Subclass:
369
With formation, separation, or manipulation of a second gas:
This subclass is indented under subclass 368. Subject matter
wherein a second gaseous component is present in the reactor
as either steam or vapor and is (a) formed during the course
of the reaction, (b) separated from another fluid present, or
(c) handled in some way internally or externally of the
reactor.
Subclass:
370
With formation, separation, or manipulation of a vapor (e.g.,
boiling water reactor (bwr) type):
This subclass is indented under subclass 366. Subject matter
wherein one of the fluids is steam or vapor which is (a)
formed at least in part during course of reaction, (b)
separated as steam or vapor from another fluid, or (c)
handled as such in some way internally or externally of the
reactor.
Subclass:
371
With vapor-liquid separating means:
This subclass is indented under subclass 370. Subject matter
having structure for separating or removing the vapor from
the liquid.
Subclass:
372
With jet pump:
This subclass is indented under subclass 370. Subject matter
wherein at least one of the fluids is caused to circulate
with the aid of a jet pump.
SEE OR SEARCH THIS CLASS, SUBCLASS:
392 and 407, for other combinations having jet pumps.
SEE OR SEARCH CLASS:
417, Pumps, subclasses 151+ for jet pumps, per se.
Subclass:
373
Having specified fluid flow path or pattern within reactor
core:
This subclass is indented under subclass 370. Subject matter
wherein the coolant is made to traverse a specified or
predetermined route or channel within the reactor core or the
route taken is such as to place the coolant into a pattern or
network which serves to exert a particular effect upon the
reactor or reaction.
(1) Note. The recitation of a coolant flowing or
circulating through the reactor core is not by itself enough
to place a patent in this or indented subclasses.
Subclass:
374
Plural separate coolant loops through reactor core:
This subclass is indented under subclass 373. Subject matter
wherein coolant is caused to traverse the reactor core
through separate and independent routes.
Subclass:
375
With plural, coolant passes through reactor core:
This subclass is indented under subclass 373. Subject matter
wherein the coolant is caused to traverse the reactor core a
plurality of times prior to its being sent to a heat
exchanger or other utilization means.
Subclass:
376
Re-entrant type:
This subclass is indented under subclass 375. Subject matter
wherein the plural coolant passes, the coolant flows first
along one flow path in a fuel element structure in one
direction and then flow through a different flow path in the
same fuel element structure in the reverse direction.
(1) Note. The flow, for example, may first be along the
inner surface of the outer wall of the fuel assembly and then
reverse its direction and flow back through a center portion
of the fuel assembly.
Subclass:
377
With particular flow directing or diverting means (e.g., flow
baffle):
This subclass is indented under subclass 373. Subject matter
wherein structure is provided solely for the specific
purposes of altering the direction of coolant flow.
Subclass:
378
Vapor manipulated or used exterior of reactor core:
This subclass is indented under subclass 370. Subject matter
wherein the steam or vapor has energy (e.g., thermal or
kinetic) added to or removed therefrom (e.g., by a heat
exchanger, pump, or turbine) exterior of the reactor core.
Subclass:
379
With flow control of fluid within reactor:
This subclass is indented under subclass 378. Subject matter
wherein the manipulation or utilization of the vapor
exteriorly of the reactor effects some control of (a) the
flow of the fluids within the reactor core, or (b) the flow
of the fluids to an external component.
Subclass:
380
Nonaqueous vapor:
This subclass is indented under subclass 370. Subject matter
wherein one of the fluids is nonaqueous.
Subclass:
381
Pebble bed reactor:
This subclass is indented under subclass 361. Subject matter
wherein the fuel material is in the form of generally
spherical elements, a plurality of which are held together in
a container.
Subclass:
382
Having core of separate pebble containers:
This subclass is indented under subclass 381. Subject matter
wherein the fuel elements are in a plurality of separate
containers which are arranged together to form the active
region of the core.
Subclass:
383
Fluid is a gas:
This subclass is indented under subclass 361. Subject matter
wherein the only fluid being circulated or otherwise flowing
within the reactor is in a gaseous state.
(1) Note. Patents are placed into this and indented
subclasses even though the gas is capable of existing
normally in a nongaseous phase provided it is maintained in
the reactor without permitting any substantial quantity of it
to revert to the nongaseous phase.
(2) Note. This subclass is inclusive of gas having
entrained solids.
Subclass:
384
Wherein the gas is steam:
This subclass is indented under subclass 383. Subject matter
wherein the fluid is the vapor phase of water.
Subclass:
385
Having specified flow path or pattern within reactor core:
This subclass is indented under subclass 383. Subject matter
wherein the coolant is made to traverse a specified or
predetermined route or channel within the reactor core or the
route taken is such as to place the coolant into a pattern or
network which serves to exert a particular effect upon the
reactor or reaction.
(1) Note. The recitation of a coolant flowing or
circulating through the reactor core is not by itself enough
to place a patent in this or indented subclasses.
Subclass:
386
Plural separate loops:
This subclass is indented under subclass 385. Subject matter
wherein coolant is caused to traverse the reactor core
through separate and independent routes.
Subclass:
387
Plural passes through core:
This subclass is indented under subclass 385. Subject matter
wherein the coolant is caused to traverse the reactor core a
plurality of times prior to its being sent to a heat
exchanger or other utilization means.
Subclass:
388
Re-entrant type:
This subclass is indented under subclass 387. Subject matter
wherein in the plural coolant passes, the coolant flows first
along one flow path in a fuel element structure in one
direction and then flows through a different flow path in the
same fuel element structure in the reverse direction.
(1) Note. The flow, for example, may first be along the
inner surface of the outer wall of the fuel assembly and then
reverse its direction and flow back through a center portion
of the fuel assembly.
Subclass:
389
With particular flow directing or diverting means (e.g., flow
baffle):
This subclass is indented under subclass 385. Subject matter
wherein structure is provided solely for the specific purpose
of altering the direction of coolant flow.
Subclass:
390
With core bypass means (e.g., passage along core barrel or
through shield structure):
This subclass is indented under subclass 389. Subject matter
wherein the flow path or pattern of the altered coolant flow
includes a path which bypasses the fuel assemblies in the
core.
Subclass:
391
Manipulated or used exterior of the reactor core:
This subclass is indented under subclass 383. Subject matter
wherein the fluid circulating within the reactor core area is
a coolant which has energy (e.g., thermal or kinetic) added
to or removed therefrom (e.g., by a heat exchanger, pump, or
turbine) exterior of the reactor core.
SEE OR SEARCH THIS CLASS, SUBCLASS:
210 wherein the manipulation involves modification of
coolant flow to control the reactor.
Subclass:
392
With jet pump:
This subclass is indented under subclass 391. Subject matter
wherein the coolant is caused to circulate with the aid of a
jet pump.
SEE OR SEARCH CLASS:
417, Pumps, subclass 151 for jet pumps, per se.
Subclass:
393
With coaxial flow:
This subclass is indented under subclass 391. Subject matter
wherein the coolant exterior of the core is caused to flow
through a concentric pipe arrangement such that the coolant
will flow in one direction through the inner pipe and
(generally) in the opposite direction through the annulus
between the inner and outer pipes.
Subclass:
394
With single structure component containment (e.g., pod
arrangement):
This subclass is indented under subclass 391. Subject matter
wherein components of the nuclear reactor system are placed
within bores of monolithic structure.
Subclass:
395
Having specified fluid flow path or pattern within reactor
core:
This subclass is indented under subclass 361. Subject matter
wherein the coolant is made to traverse a specified or
predetermined route or channel within the reactor core or the
route taken is such as to place the coolant into a pattern or
network which serves to exert a particular effect upon the
reactor or reaction.
(1) Note. The recitation of a coolant flowing or
circulating through the reactor core is not itself enough to
place a patent in this or indented subclasses.
Subclass:
396
Plural separate coolant loops through reactor core:
This subclass is indented under subclass 395. Subject matter
wherein the coolant is caused to traverse the reactor core
through separate and independent routes.
(1) Note. The coolant loops can be joined to a common
conduit outside of the reactor.
Subclass:
397
Plural passes:
This subclass is indented under subclass 395. Subject matter
wherein the coolant is caused to traverse the reactor core a
plurality of times prior to its being sent to a heat
exchanger or other utilization means.
Subclass:
398
Re-entrant type:
This subclass is indented under subclass 397. Subject matter
wherein the plural coolant passes, the coolant flows first
along one flow path in a fuel element structure in one
direction and then flows through a different flow path in the
same fuel element structure in the reverse direction.
(1) Note. The flow, for example, may first be along the
inner surface of the outer wall of the fuel assembly and then
reverses its direction and flow back through a center portion
of the fuel assembly.
Subclass:
399
With particular flow directing or diverting means (e.g., flow
baffle):
This subclass is indented under subclass 395. Subject matter
wherein structure is provided solely for the specific purpose
of altering the direction of coolant flow.
Subclass:
400
With core bypass means (e.g., passage along core barrel or
through shield structure):
This subclass is indented under subclass 399. Subject matter
wherein the flow path or pattern of the altered coolant flow
includes a path which bypasses the fuel assemblies in the
core.
Subclass:
401
One-fluid-type pressure tube reactor:
This subclass is indented under subclass 395. Subject matter
wherein the flow channels in the reactor are formed by a
plurality of spaced tubes or conduits, the interiors of which
are each at pressure substantially higher than the pressure
of the adjacent medium.
Subclass:
402
Manipulated or used exterior of reactor core:
This subclass is indented under subclass 361. Subject matter
wherein the fluid circulating within the reactor core area is
a coolant which has energy (e.g., thermal or kinetic) added
to or removed therefrom (e.g., by a heat exchanger, pump, or
turbine) exterior of the reactor core.
SEE OR SEARCH THIS CLASS, SUBCLASS:
210 wherein the manipulation involves modification of
coolant flow to control the reactor.
subclasses 369+ 378+, 380, and 391+, for similarly handling
gases for use exterior of reactor core.
SEE OR SEARCH CLASS:
165, Heat Exchange, appropriate subclasses for cooling
towers.
261, Gas and Liquid Contact Apparatus, appropriate subclasses
for cooling towers.
Subclass:
403
Including tank, pool, or reservoir (e.g., swimming pool):
This subclass is indented under subclass 402. Subject matter
wherein a relatively large mass of fluid is maintained within
a vessel which serves as a tank, pool, or reservoir.
(1) Note. Tank-type reactors, i.e., wherein the reactor
core, pumps, and heat exchanger are all immersed in the same
fluid, are proper subject matter for this and indented
subclasses.
Subclass:
404
Having reactor core and heat exchanger or pump therein:
This subclass is indented under subclass 403. Subject matter
having one vessel in which is situated the reactor core,
primary heat exchangers, or pump, all of which are immersed
in the liquid coolant.
Subclass:
405
With particular heat exchanger structure:
This subclass is indented under subclass 404. Subject matter
wherein the heat exchanger is more than nominally disclosed.
(1) Note. The mere disclosure of a fluid flowing through a
heat exchanger is insufficient basis for classification in
this subclass.
Subclass:
406
Compact or integral (e.g., heat exchanger, core, pumps in
same vessel):
This subclass is indented under subclass 402. Subject matter
wherein the components of the reactor circuit, e.g., heat
exchanger, core, pumps, are all contained with a common
vessel.
(1) Note. The vessel may be partitioned with the reactor
core in one part, heat exchanger in another and separate
part, etc.
Subclass:
407
With jet pumps:
This subclass is indented under subclass 402. Subject matter
wherein the coolant is caused to circulate with the aid of a
jet pump.
Subclass:
408
With means or structure to flash coolant into vapor:
This subclass is indented under subclass 402. Subject matter
wherein the coolant is caused to abruptly change to the vapor
phase, e.g., by sudden pressure reduction.
Subclass:
409
FUEL COMPONENT STRUCTURE:
This subclass is indented under the class definition. Subject
matter comprising an integral structure the constituent
material of which includes, at least in part, a nuclear
fuel*.
(1) Note. A patent to be placed as an original into this
and indented subclasses may be associated with another
reactor component when the other component is so associated
with the fuel component that the plural components are
treated or handled as one, as when within the fuel component
structure there is included some other component structure
such as a coolant, moderator, insulator, thermocouple, or
other structure.
(2) Note. For processes of fabricating or manufacturing
reactor fuel component, search appropriate manufacturing
class.
(3) Note. Patents that claim some particular handling of
the fuel component are placed as originals in the appropriate
subclasses in this class and may be crossed to this and
indented subclasses.
(4) Note. The fuel material itself may be solid, liquid, or
gaseous.
SEE OR SEARCH THIS CLASS, SUBCLASS:
subclasses 261+ for patents that claim some particular
handling of the fuel component.
347 for patents claiming a fuel separately associated in
some particular manner with another reactor component,
including a fluid component.
SEE OR SEARCH CLASS:
29, Metal Working, subclass 400.1 for methods of assembly
and disassembly of fuel elements, and subclass 723 for
apparatus for disassembly of fuel elements. See subclass 906
for a cross-reference art collection of documents reflecting
to nuclear device making.
148, Metal Treatment, subclass 401 for heat-treated metal
stock which may be useful in the production of fuel elements;
and subclass 132 for heat-treated actinide metals or alloys.
252, Compositions, subclasses 625+ for compositions not
otherwise provided for that may be used as fuels or in
fabricating fuel elements.
420, Alloys or Metallic Compositions, particularly subclasses
1+.
423, Chemistry of Inorganic Compounds, subclasses 249+ for
inorganic compounds of the actinide series elements which may
be useful as fuel components.
427, Coating Processes, subclass 6 for processes of coating
nuclear fuel particles or elements.
501, Compositions: Ceramic, appropriate subclasses for
ceramic compositions useful as a nuclear reactor component or
fuel element material.
Subclass:
410
With means to prevent thinning of the cladding (e.g., amoeba
effect):
This subclass is indented under subclass 409. Subject matter
wherein the fuel component structure contains a material
which serves to inhibit the thinning of the fuel covering
(i.e., cladding) by diffusion during reactor operation (i.e.,
"amoeba effect").
Subclass:
411
Spherical particles:
This subclass is indented under subclass 409. Subject matter
wherein the fuel is in a spherically shaped form.
Subclass:
412
Encased with nonfuel component:
This subclass is indented under subclass 409. Subject matter
wherein a material (e.g., fluid) or structural element having
a reactor function different from that of the fuel (e.g.,
moderator, heat insulator, coolant) is encased, enclosed, or
sealed together with the fuel material within a single
container (i.e., a "cladding").
Subclass:
413
With internal pressurizer:
This subclass is indented under subclass 412. Subject matter
wherein a means is provided within the container (i.e.,
cladding) for maintaining the pressure within the fuel
component substantially constant during or throughout its
operating life, e.g., by releasing a gas subsequent to
fabrication of the fuel component.
Subclass:
414
Coated, preformed, or impregnated layer or part or adhesively
bonded layers or parts:
This subclass is indented under subclass 412. Subject matter
including a preformed layer or part having a coating thereon
or an impregnate therein, or plural preformed layers bonded
together.
(1) Note. The bonding may be either autogeneous or by means
of a bonding agent.
(2) Note. When the preform is porous, the coating or
impregnating material may be located or concentrated upon the
surface or may penetrate substantially the entire layer or
part.
Subclass:
415
Lubricating layer:
This subclass is indented under subclass 414. Subject matter
wherein the coating or impregnate comprises a lubricant.
Subclass:
416
Multiple or composite cladding-type layers:
This subclass is indented under subclass 414. Subject matter
wherein the cladding itself is comprised of a plurality of
layers.
Subclass:
417
Including getter layer or barrier layer:
This subclass is indented under subclass 416. Subject matter
wherein at least one of the cladding layers acts or functions
as an absorber or barrier with respect to the transport of
fuel or nuclear reaction products between the fuel and an
outer cladding layer.
Subclass:
418
Getter, fission product retainer or filter:
This subclass is indented under subclass 412. Subject matter
wherein the nonfuel component functions as an absorber or
complete or selective barrier with respect to the transport
of fuel or nuclear reaction products.
Subclass:
419
Burnable poison:
This subclass is indented under subclass 412. Subject matter
wherein the nonfuel component is a burnable poison*.
SEE OR SEARCH THIS CLASS, SUBCLASS:
447 for a burnable poison in fuel pack or bundle but not
encased with the fuel itself.
Subclass:
420
Interpellet spacing or positioning means:
This subclass is indented under subclass 412. Subject matter
wherein the encased material is a nonfuel material which is
positioned between two separate fuel bodies, i.e., pellets.
Subclass:
421
Homogeneously intermixed:
This subclass is indented under subclass 412. Subject matter
wherein the encased material is intermixed, more or less,
homogeneously throughout the fuel material.
(1) Note. The subject matter of this subclass type includes
fuel dissolved or dispersed in a fluid moderator; the fuel
and encased material may be a granulated mixture or in the
form of a solid solution, etc.
SEE OR SEARCH CLASS:
252, Compositions, subclasses 625+ for radioactive
compositions which may include the nuclear fuel material.
501, Compositions: Ceramic, appropriate subclasses for
ceramic compositions useful as a nuclear reactor component or
fuel element material.
Subclass:
422
Alloyed fuel:
This subclass is indented under subclass 421. Subject matter
wherein the fuel or a part thereof is metallic which is
alloyed with the encased material which is also metallic.
Subclass:
423
Moderator or reflector:
This subclass is indented under subclass 412. Subject matter
wherein the encased material is a neutron moderator or
reflector material.
Subclass:
424
Coolant or heat exchange material:
This subclass is indented under subclass 412. Subject matter
wherein the encased material is a coolant* or heat exchange
material.
Subclass:
425
Heat insulating material:
This subclass is indented under subclass 412. Subject matter
wherein the encased material is not transmissive of thermal
energy, i.e., is a heat insulating material.
Subclass:
426
Plural fuel segments or elements:
This subclass is indented under subclass 409. Subject matter
wherein the fuel component structure is comprised of either
(a) a plurality of fuel segments which are sealed, enclosed,
or contained within a single container, or (b) a plurality of
elements assembled together with each element itself
consisting of an enclosed, sealed, or contained integral mass
of fuel or a plurality of fuel segments.
Subclass:
427
In solid moderator block:
This subclass is indented under subclass 426. Subject matter
wherein the structure for attenuating neutron energy takes
the form of a given volume, usually a parallelepiped, which
contains nuclear fuel either as an admixture or discrete
bodies, positioned therein.
SEE OR SEARCH THIS CLASS, SUBCLASS:
421 for fuel homogeneously mixed with moderator.
423 for fuel encased with moderator.
Subclass:
428
Wherein the fissile content varies radially or axially within
the same container (e.g., plural fuel layers):
This subclass is indented under subclass 426. Subject matter
wherein the plural segments are so constituted and arranged
within a container that the fissile* content of the container
varies radially or axially.
SEE OR SEARCH THIS CLASS, SUBCLASS:
435 for plural fuel elements in a pack or bundle, the
fissile content of which varies radially or axially.
Subclass:
429
Complementary segments within same container:
This subclass is indented under subclass 426. Subject matter
wherein a plurality of fuel segments are included within a
container with the segments being constructed or shaped to
complement or mate with each other.
(1) Note. The mere use of a flat surface on the segments
(which would allow stacking) is not sufficient for placement
in this subclass.
Subclass:
430
Spherically shaped segments within same container:
This subclass is indented under subclass 426. Subject matter
wherein the fuel segments are approximately spherically
shaped pellets and are randomly positioned within a
container.
Subclass:
431
Concentric cylindrical elements:
This subclass is indented under subclass 426. Subject matter
comprising at least two tubular fuel elements one of which is
nested inside the other.
Subclass:
432
Plate-type fuel elements:
This subclass is indented under subclass 426. Subject matter
wherein the fuel elements are in the form of plates which are
at least in part, spaced from and substantially parallel to
each other.
Subclass:
433
Stacked (e.g., candu type reactor fuel components):
This subclass is indented under subclass 426. Subject matter
wherein plural fuel segments, elements, or components are
assembled in a linear normally vertically relationship, e.g.,
one above the other.
Subclass:
434
In pack or bundle:
This subclass is indented under subclass 426. Subject matter
wherein the plural segments or elements are held together in
a pack or bundlelike relationship relative to each other or
to a container or to other structure, by a spacing,
supporting, or securing means.
Subclass:
435
Wherein the fissile content varies radially or axially across
the pack or bundle:
This subclass is indented under subclass 434. Subject matter
wherein the amount or concentration of fissile* material
varies radially and/or axially across the pack or bundle.
(1) Note. The variation of fissile isotope includes the use
of one fissile isotope, e.g., plutonium 239 in some fuel
members, and another fissile isotope, e.g., Uranium 235, in
other fuel members.
Subclass:
436
Wire-wrapped fuel elements:
This subclass is indented under subclass 434. Subject matter
wherein the spacing means comprises a wire wrapped around a
fuel element.
(1) Note. The wire may be wrapped in a helical fashion.
Subclass:
437
Having the fuel element ends positioned on or attached to
rails:
This subclass is indented under subclass 434. Subject matter
wherein the fuel elements have at least one of their ends
attached to or positioned on a bar (rail).
(1) Note. The pack or bundle will normally have a plurality
of such rails with the rails being generally parallel to one
another.
(2) Note. The rails are not to be considered grids.
Subclass:
438
Including grid:
This subclass is indented under subclass 434. Subject matter
wherein a multiaperture structure holds or maintains the
plural fuel segments or elements in a spaced array.
(1) Note. The multiaperture structure may be a grating or
egg cratelike structure.
SEE OR SEARCH CLASS:
52, Static Structures (e.g., Buildings), subclass 664, 666,
and 668 for similar grid structures, per se.
211, Supports: Racks, subclass 60.1 for similar grid
structures, per se.
248, Supports, subclass 68.1 for similar grid structures,
per se.
Subclass:
439
With coolant flow path deflecting means:
This subclass is indented under subclass 438. Subject matter
wherein the grid is provided with structure for the specific
purpose of altering (deflecting) the direction of coolant
flow.
Subclass:
440
For ends of fuel elements:
This subclass is indented under subclass 438. Subject matter
wherein the grid contacts and engages the ends of the fuel
elements.
(1) Note. Subject matter of this subclass type may include
tie rod end plates which engage the ends of the fuel
elements.
Subclass:
441
With nonintegral fuel element contacting means:
This subclass is indented under subclass 438. Subject matter
wherein the grid is provided with a separable component and
this component is utilized to contact and maintain the fuel
pins in the spaced apart array.
Subclass:
442
With fuel element contacting protuberance or projection:
This subclass is indented under subclass 438. Subject matter
wherein the grid comprises walls defining fuel element
compartments, at least one wall of which is provided with
means extending away from the wall into the compartment to
position the fuel element therein.
Subclass:
443
With coolant flow path deflecting means:
This subclass is indented under subclass 434. Subject matter
wherein structure is provided for the specific purpose of
altering (deflecting) the direction of coolant flow.
Subclass:
444
With coolant flow bypass means:
This subclass is indented under subclass 443. Subject matter
wherein structure is provided such that a portion of the
coolant does not come into direct contact with the nuclear
fuel containing members.
Subclass:
445
With thermal expansion compensating means:
This subclass is indented under subclass 434. Subject matter
with means to compensate for changes in dimension of at least
a part of the pack or bundle due to thermal expansion.
Subclass:
446
With removable member:
This subclass is indented under subclass 434. Subject matter
wherein the pack or bundle includes a member which is
removable from the rest of the pack or bundle, e.g., a fuel
pin, moderator pin, poison pin, a grid, a sheath, etc.
Subclass:
447
Including separate burnable poison or moderator:
This subclass is indented under subclass 434. Subject matter
wherein the pack or bundle contains burnable poison* or
moderator which is not encased together with the fuel, that
is, the burnable poison or moderator will be in its own
separate pin or element, in a grid, in the sheath, etc.
SEE OR SEARCH THIS CLASS, SUBCLASS:
419 for burnable poison encased with the fuel.
423 for moderator encased with the fuel.
Subclass:
448
With means for spacing apart adjacent packs or bundles:
This subclass is indented under subclass 434. Subject matter
wherein the assemblies or bundles contain structure which
serves to maintain the outer surfaces of adjacent packs or
bundles spaced apart from one another.
Subclass:
449
Having provision or structure for insertion of control
elements therein:
This subclass is indented under subclass 434. Subject matter
wherein the pack or bundle has provision or structure which
allows control elements to be inserted therein.
Subclass:
450
With condition sensing or indicating means:
This subclass is indented under subclass 409. Subject matter
wherein the fuel component includes a structure or material
for sensing or indicating some condition of the fuel
component.
(1) Note. Sensing structure includes, for example,
thermocouples and strain gages; indicating material may
include a gas. The conditions sensed or indicated may
include the integrity of the cladding, temperature, etc.
SEE OR SEARCH THIS CLASS, SUBCLASS:
247 for temperature or pressure measurement.
251 for apparatus for or process of detecting, sensing, or
monitoring a leaking fuel element.
Subclass:
451
Having particular end closure or seal (e.g., weld, plug, cap,
etc.):
This subclass is indented under subclass 409. Subject matter
including a particular or specific means for closing the
end(s) of a fuel element or component, e.g., weld, cap, etc.
Subclass:
452
With indexing means:
This subclass is indented under subclass 451. Subject matter
wherein the fuel element end cap has a particular
distinguishing feature or structure associated therewith for
discerning its identity among other fuel elements.
Subclass:
453
Fuel support or covering provided with fins, projections,
prongs, etc.:
This subclass is indented under subclass 409. Subject matter
having means to contain, cover, or support the fuel, which
means is provided with internal or external projections,
protuberances, prongs, fins, or other similar structure.
(1) Note. The fins, etc., may serve such diverse functions
as spacing members, support, dividers, aligning of or with
heat exchange and fluid flow passages, etc.
SEE OR SEARCH THIS CLASS, SUBCLASS:
436 for wire-wrapped fuel pins in a pack or bundle.
Subclass:
454
With external fins, projections, prongs, etc.:
This subclass is indented under subclass 453. Subject matter
wherein the fins, etc., are on the outer surface of the fuel
container, support, or covering.
Subclass:
455
Hollow, annular, or graduated fuel layers or members (e.g.,
concentric, helical, etc.):
This subclass is indented under subclass 409. Subject matter
wherein at least the portion containing the fuel material
itself is in the form of a sheet or tube which may be
arranged or associated with itself concentrically or
helically.
Subclass:
456
Vented fuel:
This subclass is indented under subclass 409. Subject matter
wherein the fuel component includes a means to release
fission products therefrom during normal operation of a
nuclear reactor.
Subclass:
457
Nonconventional jacket or can material:
This subclass is indented under subclass 409. Subject matter
wherein the fuel is covered or clad by a material other than
the conventional cladding materials of Al, Zr, steel, etc.
Subclass:
458
MODERATOR OR REFLECTOR COMPONENT STRUCTURE FOR A FISSION
REACTOR:
This subclass is indented under the class definition. Subject
matter comprising structure whose proximate function is to
attenuate the energy of an incident neutron (moderator) or to
alter the trajectory of an incident neutron (reflector) in a
nuclear fission reactor.
Subclass:
459
With means for keying or assembling moderator blocks
together:
This subclass is indented under subclass 458. Subject matter
wherein the material for reducing neutron energy is formed
into a given volume, usually a parallelepiped, which is so
shaped as to facilitate the interconnection of the given
volumes one with another.
Subclass:
460
ROTATING PLUG-TYPE COVER:
This subclass is indented under the class definition. Subject
matter comprising a closure for a fission reactor vessel
which closure is capable of rotary movement.
Subclass:
461
VESSEL SUPPORTS (E.G., CORE VESSEL-SUPPORTS):
This subclass is indented under the class definition. Subject
matter wherein load-bearing means are provided to accommodate
the weight of a fission reactor vessel in a fixed position.
Subclass:
462
GRIDS:
This subclass is indented under the class definition. Subject
matter wherein a multiaperature structure holds or maintains
reactor components in a spaced array.
SEE OR SEARCH CLASS:
52, Static Structures (e.g., Buildings), subclass 664, 666,
and 668 for similar type grid structures, per se.
211, Supports: Racks, subclass 60.1 for similar grid
structures.
248, Supports, subclass 68.1 for similar grid structures.
Subclass:
463
MISCELLANEOUS:
This subclass is indented under the class definition. Subject
matter comprising material not provided for elsewhere.
CROSS-REFERENCE ART COLLECTIONS
Subclass:
900
PARTICULAR MATERIAL OR MATERIAL SHAPES FOR FISSION REACTORS.
This subclass is indented under the class definition.
Collections of patents that claim or disclose a specific or
particular reactor component by its material make-up
(composition, etc.) or when in some particular shape, and not
amounting to structure provided for in the main schedule
above.
Subclass:
901
Fuel:
This subclass is indented under subclass 900. Subject matter
wherein the fuel is defined by its material makeup.
Subclass:
902
With external lubricating or absorbing material:
This subclass is indented under subclass 901. Subject matter
wherein the outer surface of the fuel element is provided
with a material which facilitates assembly of the fuel
elements with their spacing, supporting, or scuring means by
reducing the friction on the fuel elements or is provided
with an absorber to facilitate handling during refueling.
Subclass:
903
Shapes:
This subclass is indented under subclass 901. Subject matter
wherein the fuel is formed into a specific or peculiar
shape.
Subclass:
904
Moderator, reflector, or coolant materials:
This subclass is indented under subclass 900. Subject matter
wherein a specific moderator or coolant material is claimed
or disclosed which goes beyond such normal materials as
graphite, Be, [supscrpt]H[end supscrpt][subscrpt]2[end
subscrpt]O, [supscrpt]D[end supscrpt][subscrpt]2[end
subscrpt]O, etc.
Subclass:
905
Organic:
This subclass is indented under subclass 904. Subject matter
wherein the material is organic.
Subclass:
906
Metal:
This subclass is indented under subclass 904. Subject matter
wherein the material is a metal.
Subclass:
907
Dissociative coolants:
This subclass is indented under subclass 904. Subject matter
wherein the coolant is a material which dissociates upon
heating.
Subclass:
908
REACTOR GEOMETRY (OR PART THEREOF) DEFINED IN TERMS OF
NUMERICAL VALUES:
Subject matter involving numerical relationship between
various parameters of a nuclear fission reactor.
Subclass:
909
MOBILE REACTORS:
Subject matter involving a nuclear power generating system
which is portable.
SEE OR SEARCH THIS CLASS, SUBCLASS:
318 for nuclear plants which provide propulsion.
406 for nuclear plants which are compact or integral.
Subclass:
910
ROTATING REACTORS:
Subject matter involving a nuclear reactor wherein the core
(or at least a portion thereof) revolves or rotates about an
axis.
Subclass:
911
PLURAL REACTOR SYSTEMS:
Subject matter involving at least two reactors which are
associated together in some manner so as to present an
overall single system.
Subclass:
912
NUCLEAR REACTOR SYSTEMS SITUATED IN THE OCEAN:
Subject matter involving a nuclear reactor system which is
designed for operation and situation directly in a large body
of water.
Subclass:
913
ANTIMATTER DEVICES AND METHODS:
Subject matter involving reactions which produce annihilation
radiation.
Subclass:
914
NUCLEAR EXPLOSIVES:
This subclass is indented under the class definition.
Collection of patents that claim or disclose an uncontrolled
nuclear reaction structure, e.g., a bomb.
Subclass:
915
FUSION REACTOR FUELS:
Subject matter involving fuels (materials, compositions) for
use in nuclear fusion reactions.
Subclass:
916
METHODS OF MAKING FUSION FUEL TARGETS:
Subject matter involving methods of manufacturing bodies or
elements containing fusion fuel material.
Subclass:
917
UTILIZING DIFFERENT FUELS OR FUELS IN DIFFERENT FORMS, IN
DIFFERENT REACTOR REGIONS IN RELATION TO AMOUNTS OF HEAT
PRODUCED IN SAID REGIONS:
Subject matter involving the utilization of different fuels
or fuels in different forms in relation to amounts of heat
produced in the regions.
Subclass:
918
ENTIRE REACTOR CORE OF SINGLE INTEGRAL STRUCTURE:
Subject matter wherein the entire reactor core is comprised
of a unitary structure.
Information Products Division -- Contacts
Questions regarding this report should be directed to:
U.S. Patent and Trademark Office
Information Products Division
PK3- Suite 441
Washington, DC 20231
tel: (703) 306-2600
FAX: (703) 306-2737
email: oeip@uspto.gov
Last Modified: 6 October 2000