G
SECTION G — PHYSICS
  
NUCLEONICS
 G21
NUCLEAR PHYSICS; NUCLEAR ENGINEERING
 G21C
NUCLEAR REACTORS (analogue computers therefor G06G 7/54; fusion reactors G21B; nuclear explosives G21J)
 G21C 1/00
Reactors
 G21C 1/01
·  General details not provided for in groups 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 (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 (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 (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 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 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 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 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 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 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 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 B01J 3/00; pressure vessels in general 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 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 B01D; steam traps 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 F16L)
 G21C 15/24
·  Promoting flow of the coolant (electrodynamic pumps 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 G21C 5/12; compositions per se C09K 5/00)
 G21C 17/00
Monitoring; Testing (measuring in general 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 (G21C 17/08, 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 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 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 G21F 9/00)
 G21C 19/33
·  Apparatus or processes for dismantling strings of spent fuel elements (G21C 19/34 takes precedence)  [2]
 G21C 19/34
·  Apparatus or processes for removing canning or casings from fuel (shielded cells 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. 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 G21C 7/00
 G21C 23/00
Adaptations of reactors to facilitate experimentation or irradiation  [3]