|  | 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 characterised by the selection of fissile material or breeder material or moderating material; Reactors characterised by the disposition of the fuel elements, e.g. in the form of the lattice

|  | 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 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 structure; Selection of substances 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 11/00)

|  | G21C 13/02 |
· | Details

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

|  | G21C 13/06 |
· · | Sealing-plugs (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...H02N 4/20)

|  | 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 handling, fuel or other materials which are used within the reactor, e.g. within its pressure vessel [2]

|  | G21C 19/02 |
· | Details

|  | 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 19/20 |
· | 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 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