|  | G |
SECTION G — PHYSICS

NUCLEONICS

|  | G21 |
NUCLEAR PHYSICS; NUCLEAR ENGINEERING

|  | G21C |
NUCLEAR REACTORS (analogue computers therefor Fulltext... Hierarchy... Expanded...G06G 7/54; fusion reactors Fulltext... Hierarchy... Expanded...G21B; nuclear explosives Fulltext... Hierarchy... Expanded...G21J)

|  | G21C 1/00 |
Reactors

|  | G21C 1/01 |
· | General details not provided for in groups Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G21C 3/00-G21C 19/00 [3]

|  | G21C 1/02 |
· | Fast fission reactors, i.e. reactors not using a moderator

|  | G21C 1/04 |
· | Thermal reactors

|  | G21C 1/06 |
· · | Heterogeneous reactors, i.e. in which fuel and moderator are separated

|  | G21C 1/08 |
· · · | moderator being highly pressurised, e.g. boiling-water reactor, integral-superheat reactor, pressurised-water reactor (Fulltext... Hierarchy... Expanded...G21C 1/22 takes precedence)

|  | G21C 1/10 |
· · · · | moderator and coolant being different or separated

|  | G21C 1/12 |
· · · · · | moderator being solid, e.g. Magnox reactor

|  | G21C 1/14 |
· · · | moderator being substantially not pressurised, e.g. swimming-pool reactor (Fulltext... Hierarchy... Expanded...G21C 1/22 takes precedence)

|  | G21C 1/16 |
· · · · | moderator and coolant being different or separated, e.g. sodium-graphite reactor

|  | G21C 1/18 |
· · · · · | coolant being pressurised

|  | G21C 1/20 |
· · · · · · | moderator being liquid, e.g. pressure-tube reactor

|  | G21C 1/22 |
· · · | using fluid or fluent fuel

|  | G21C 1/24 |
· · | Homogeneous reactors, i.e. in which fuel and moderator present an effectively homogeneous medium to the neutrons

|  | G21C 1/26 |
· · · | Single-region reactors

|  | G21C 1/28 |
· · · | Two-region reactors

|  | G21C 1/30 |
· | Subcritical reactors

|  | G21C 1/32 |
· | Integral reactors, i.e. reactors wherein parts functionally associated with the reactor but not essential to the reaction, e.g. heat exchangers, are disposed inside the enclosure with the core (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G21C 1/02-G21C 1/30 take precedence) [3]

|  | G21C 3/00 |
Reactor fuel elements and their assemblies; Selection of substances for use as reactor fuel elements

|  | G21C 3/02 |
· | Fuel elements

|  | G21C 3/04 |
· · | Constructional details

|  | G21C 3/06 |
· · · | Casings; Jackets

|  | G21C 3/08 |
· · · · | provided with external means to promote heat-transfer, e.g. fins, baffles, corrugations

|  | G21C 3/10 |
· · · · | End closures

|  | G21C 3/12 |
· · · · | Means forming part of the element for locating it within the reactor core; External spacers for this purpose

|  | G21C 3/14 |
· · · · | Means forming part of the element for inserting it into, or removing it from, the core; Means for coupling adjacent elements

|  | G21C 3/16 |
· · · | Details of the construction within the casing

|  | G21C 3/18 |
· · · · | Internal spacers; Other non-active material within the casing, e.g. compensating for expansion of fuel rod (interlayers Fulltext... Hierarchy... Expanded...G21C 3/20)

|  | G21C 3/20 |
· · · · | with coating on fuel or on inside of casing; with non-active interlayer between casing and active material

|  | G21C 3/22 |
· · | Elements with fissile or breeder material in contact with coolant

|  | G21C 3/24 |
· · | Elements with fissile or breeder material in fluid form within a non-active casing

|  | G21C 3/26 |
· · | Elements with fissile or breeder material in powder form within a non-active casing

|  | G21C 3/28 |
· · | Elements with fissile or breeder material in solid form within a non-active casing

|  | G21C 3/30 |
· | Assemblies of a number of fuel elements in the form of a rigid unit

|  | G21C 3/32 |
· · | Bundles of parallel pin-, rod-, or tube-shaped fuel elements

|  | G21C 3/34 |
· · · | Spacer grids

|  | G21C 3/36 |
· · | Assemblies of plate-shaped fuel elements or coaxial tubes

|  | G21C 3/38 |
· | Fuel units consisting of a single fuel element in a supporting sleeve

|  | G21C 3/40 |
· | Structural combination of fuel element with thermoelectric element for direct production of electric energy from fission heat (for temperature measurement Fulltext... Hierarchy... Expanded...G21C 17/10)

|  | G21C 3/42 |
· | Selection of substances for use as reactor fuel

|  | G21C 3/44 |
· · | Fluid or fluent reactor fuel

|  | G21C 3/46 |
· · · | Aqueous compositions

|  | G21C 3/48 |
· · · · | True or colloidal solutions of the active constituent

|  | G21C 3/50 |
· · · · | Suspensions of the active constituent; Slurries

|  | G21C 3/52 |
· · · | Liquid metal compositions

|  | G21C 3/54 |
· · · | Fused salt, oxide, or hydroxide compositions

|  | G21C 3/56 |
· · · | Gaseous compositions; Suspensions in a gaseous carrier

|  | G21C 3/58 |
· · | Solid reactor fuel

|  | G21C 3/60 |
· · · | Metallic fuel; Intermetallic dispersions

|  | G21C 3/62 |
· · · | Ceramic fuel

|  | G21C 3/64 |
· · · · | Ceramic dispersion fuel, e.g. cermet

|  | G21C 5/00 |
Moderator or core structure; Selection of materials for use as moderator

|  | G21C 5/02 |
· | Details

|  | G21C 5/04 |
· · | Spatial arrangements allowing for Wigner growth

|  | G21C 5/06 |
· · | Means for locating or supporting fuel elements

|  | G21C 5/08 |
· · | Means for preventing undesired asymmetric expansion of the complete structure

|  | G21C 5/10 |
· · | Means for supporting the complete structure

|  | G21C 5/12 |
· | characterised by composition, e.g. the moderator containing additional substances which ensure improved heat resistance of the moderator

|  | G21C 5/14 |
· | characterised by shape

|  | G21C 5/16 |
· · | Shape of its constituent parts

|  | G21C 5/18 |
· | characterised by the provision of more than one active zone

|  | G21C 5/20 |
· · | wherein one zone contains fissile material and another zone contains breeder material

|  | G21C 5/22 |
· · | wherein one zone is a superheating zone

|  | G21C 7/00 |
Control of nuclear reaction

|  | G21C 7/02 |
· | by using self-regulating properties of reactor materials (arrangements that involve temperature stability Fulltext... Hierarchy... Expanded...G21C 7/32)

|  | G21C 7/04 |
· · | of burnable poisons

|  | G21C 7/06 |
· | by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section

|  | G21C 7/08 |
· · | by displacement of solid control elements, e.g. control rods

|  | G21C 7/10 |
· · · | Construction of control elements

|  | G21C 7/12 |
· · · | Means for moving control elements to desired position

|  | G21C 7/14 |
· · · · | Mechanical drive arrangements

|  | G21C 7/16 |
· · · · | Hydraulic or pneumatic drive arrangements

|  | G21C 7/18 |
· · · | Means for obtaining differential movement of control elements

|  | G21C 7/20 |
· · · | Disposition of shock-absorbing devices (shock-absorbers in general Fulltext... Hierarchy... Expanded...F16F)

|  | G21C 7/22 |
· · | by displacement of a fluid or fluent neutron-absorbing material

|  | G21C 7/24 |
· · | Selection of substances for use as neutron-absorbing material

|  | G21C 7/26 |
· | by displacement of the moderator or parts thereof

|  | G21C 7/28 |
· | by displacement of the reflector or parts thereof

|  | G21C 7/30 |
· | by displacement of reactor fuel or fuel elements

|  | G21C 7/32 |
· | by varying flow of coolant through the core

|  | G21C 7/34 |
· | by utilisation of a primary neutron source

|  | G21C 7/36 |
· | Control circuits

|  | G21C 9/00 |
Emergency protection arrangements structurally associated with the reactor (emergency cooling arrangements Fulltext... Hierarchy... Expanded...G21C 15/18)

|  | G21C 9/02 |
· | Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse (control elements per se Fulltext... Hierarchy... Expanded...G21C 7/00)

|  | G21C 9/04 |
· | Means for suppressing fires

|  | G21C 11/00 |
Shielding structurally associated with the reactor

|  | G21C 11/02 |
· | Biological shielding (in general Fulltext... Hierarchy... Expanded...G21F)

|  | G21C 11/04 |
· · | on waterborne craft

|  | G21C 11/06 |
· | Reflecting shields, i.e. for minimising loss of neutrons

|  | G21C 11/08 |
· | Thermal shields; Thermal linings, i.e. for dissipating heat from gamma radiation which would otherwise heat an outer biological shield

|  | G21C 13/00 |
Pressure vessels; Containment vessels; Containment in general (for chemical or physical processes Fulltext... Hierarchy... Expanded...B01J 3/00; pressure vessels in general Fulltext... Hierarchy... Expanded...F16J 12/00)

|  | G21C 13/02 |
· | Details

|  | G21C 13/04 |
· · | Arrangements for expansion and contraction

|  | G21C 13/06 |
· · | Sealing-plugs (for pressure vessels in general Fulltext... Hierarchy... Expanded...F16J 13/00)

|  | G21C 13/08 |
· | Vessels characterised by the material; Selection of materials for pressure vessels

|  | G21C 13/10 |
· | Means for preventing contamination in event of leakage

|  | G21C 15/00 |
Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants

|  | G21C 15/02 |
· | Arrangement or disposition of passages in which heat is transferred to the coolant

|  | G21C 15/04 |
· · | from fissile or breeder material

|  | G21C 15/06 |
· · · | in fuel elements

|  | G21C 15/08 |
· · | from moderating material

|  | G21C 15/10 |
· · | from reflector or thermal shield

|  | G21C 15/12 |
· · | from pressure vessel; from containment vessel

|  | G21C 15/14 |
· · | from headers; from joints in ducts

|  | G21C 15/16 |
· | comprising means for separating liquid and steam (separating in general Fulltext... Hierarchy... Expanded...B01D; steam traps Fulltext... Hierarchy... Expanded...F16T)

|  | G21C 15/18 |
· | Emergency cooling arrangements; Removing shut-down heat

|  | G21C 15/20 |
· | Partitions or thermal insulation between fuel channel and moderator

|  | G21C 15/22 |
· | Structural association of coolant tubes with headers (joints of tubes in general Fulltext... Hierarchy... Expanded...F16L)

|  | G21C 15/24 |
· | Promoting flow of the coolant (electrodynamic pumps Fulltext... Hierarchy... Expanded...H02K 44/02)

|  | G21C 15/26 |
· · | by convection, e.g. using chimneys, using divergent channels

|  | G21C 15/28 |
· | Selection of specific coolants (if serving as the moderator Fulltext... Hierarchy... Expanded...G21C 5/12; compositions per se Fulltext... Hierarchy... Expanded...C09K 5/00)

|  | G21C 17/00 |
Monitoring; Testing (measuring in general Fulltext... Hierarchy... Expanded...G01)

|  | G21C 17/02 |
· | Devices or arrangements for monitoring coolant or moderator

|  | G21C 17/04 |
· · | Detecting burst slugs

|  | G21C 17/06 |
· | Devices or arrangements for monitoring or testing fuel or fuel elements, e.g. for burn-up, for contamination, for leak-tightness (Fulltext... Hierarchy... Expanded...G21C 17/08, Fulltext... Hierarchy... Expanded...G21C 17/10 take precedence)

|  | G21C 17/08 |
· | Structural combination of reactor core or moderator structure with viewing means, e.g. with television camera, periscope, window

|  | G21C 17/10 |
· | Structural combination of fuel element, control rod, reactor core, or moderator structure with sensitive instruments, e.g. for measuring temperature, reactivity, radioactivity, strain, neutron flux

|  | G21C 17/12 |
· · | Sensitive element forming part of control element

|  | G21C 17/14 |
· | Period meters

|  | G21C 19/00 |
Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel [2]

|  | G21C 19/02 |
· | Details of handling arrangements

|  | G21C 19/04 |
· · | Means for controlling flow of coolant over objects being handled; Means for controlling flow of coolant through channel being serviced

|  | G21C 19/06 |
· · | Magazines for holding fuel elements or control elements

|  | G21C 19/08 |
· · | Means for heating fuel elements before introduction into the core; Means for heating or cooling fuel elements after removal from the core

|  | G21C 19/10 |
· · | Lifting devices or pulling devices adapted for co-operation with fuel elements or with control elements (manipulators Fulltext... Hierarchy... Expanded...B25J)

|  | G21C 19/12 |
· · | Arrangements for exerting direct hydraulic or pneumatic force on fuel element or on control element

|  | G21C 19/14 |
· | characterised by their adaptation for use with horizontal channels in the reactor core

|  | G21C 19/16 |
· | Articulated or telescopic chutes or tubes for connection to channels in the reactor core

|  | G21C 19/18 |
· | Apparatus for bringing fuel elements to the reactor charge area, e.g. from a storage place

|  | G21C 19/19 |
· | Reactor parts specifically adapted to facilitate handling, e.g. to facilitate charging or discharging of fuel elements [3]

|  | G21C 19/20 |
· | Arrangements for introducing objects into the pressure vessel; Arrangements for handling objects within the pressure vessel; Arrangements for removing objects from the pressure vessel

|  | G21C 19/22 |
· · | Arrangements for obtaining access to the interior of a pressure vessel whilst the reactor is operating

|  | G21C 19/24 |
· · · | by using an auxiliary vessel which is temporarily sealed to the pressure vessel

|  | G21C 19/26 |
· | Arrangements for removing jammed or damaged fuel elements or control elements; Arrangements for moving broken parts thereof

|  | G21C 19/28 |
· | Arrangements for introducing fluent material into the reactor core; Arrangements for removing fluent material from the reactor core (pumping coolant Fulltext... Hierarchy... Expanded...G21D)

|  | G21C 19/30 |
· · | with continuous purification of circulating fluent material, e.g. by extraction of fission products

|  | G21C 19/32 |
· | Apparatus for removing radioactive objects or materials from the reactor discharge area, e.g. to a storage place; Apparatus for handling radioactive objects or materials within a storage place or removing them therefrom (disposal of waste material Fulltext... Hierarchy... Expanded...G21F 9/00)

|  | G21C 19/33 |
· | Apparatus or processes for dismantling strings of spent fuel elements (Fulltext... Hierarchy... Expanded...G21C 19/34 takes precedence) [2]

|  | G21C 19/34 |
· | Apparatus or processes for removing canning or casings from fuel (shielded cells Fulltext... Hierarchy... Expanded...G21F 7/00)

|  | G21C 19/36 |
· · | Mechanical means only

|  | G21C 19/38 |
· · | Chemical means only

|  | G21C 19/40 |
· | Arrangements for preventing occurrence of critical conditions, e.g. during storage

|  | G21C 19/42 |
· | Reprocessing of irradiated fuel

|  | G21C 19/44 |
· · | of irradiated solid fuel

|  | G21C 19/46 |
· · · | Aqueous processes

|  | G21C 19/48 |
· · · | Non-aqueous processes

|  | G21C 19/50 |
· · | of irradiated fluid fuel

|  | G21C 21/00 |
Apparatus or processes specially adapted to the manufacture of reactors or parts thereof (in general, Section B, e.g. Fulltext... Hierarchy... Expanded...B23)

|  | G21C 21/02 |
· | Manufacture of fuel elements or breeder elements contained in non-active casings

|  | G21C 21/04 |
· · | by vibrational compaction or tamping

|  | G21C 21/06 |
· · | by swaging

|  | G21C 21/08 |
· · | by a slip-fit cladding process

|  | G21C 21/10 |
· · | by extrusion, drawing, or stretching

|  | G21C 21/12 |
· · | by hydrostatic or thermo-pneumatic canning

|  | G21C 21/14 |
· · | by plating in a fluid

|  | G21C 21/16 |
· · | by casting or dipping techniques

|  | G21C 21/18 |
· | Manufacture of control elements covered by group Fulltext... Hierarchy... Expanded...G21C 7/00

|  | G21C 23/00 |
Adaptations of reactors to facilitate experimentation or irradiation [3]