IPC 6 English version G21C 7/00-G21C 17/14

IPC ⁶ English version

G21C - G21C 5/22

G21C00700-G21C01714

G21C 19/00 - G21C 23/00

SECTION G– PHYSICS

G 21

NUCLEAR PHYSICS; NUCLEAR ENGINEERING

G 21 C

NUCLEAR REACTORS (analogue computers therefor G 06 G 7/54; fusion reactors G 21 B; nuclear explosives G 21 J)

Control of nuclear reaction

by using self-regulating properties of reactor materials (arrangements that involve temperature stability G 21 C 7/32)

of burnable poisons (burnable poisons in fuel rods G 21 C 3/326) [5]

by application of neutron-absorbing material, i.e. material with absorption cross-section very much in excess of reflection cross-section

by displacement of solid control elements, e.g. control rods

Construction of control elements

103

Control assemblies containing one or more absorbants as well as other elements, e.g. fuel or moderator elements [5]

107

Control elements adapted for pebble-bed reactors [5]

Deformable control elements, e.g. flexible, telescopic, articulated [5]

113

Control elements made of flat elements; Control elements having cruciform cross-section [5]

117

Clusters of control rods; Spider construction [5]

Means for moving control elements to desired position (dropping rods in an emergency G 21 C 9/02)

Mechanical drive arrangements

Hydraulic or pneumatic drive arrangements

Means for obtaining differential movement of control elements

Disposition of shock-absorbing devices (shock-absorbers in general F 16 F)

by displacement of a fluid or fluent neutron-absorbing material

Selection of substances for use as neutron-absorbing material

by displacement of the moderator or parts thereof

Spectral shift control [5]

by displacement of the reflector or parts thereof

by displacement of reactor fuel or fuel elements

by varying flow of coolant through the core

by utilisation of a primary neutron source

Control circuits

Emergency protection arrangements structurally associated with the reactor (emergency cooling arrangements G 21 C 15/18)

004

Pressure suppression [5]

008

by rupture-discs or -diaphragms [5]

012

by thermal accumulation or by steam condensation, e.g. ice condensers [5]

016

Core catchers [5]

Means for effecting very rapid reduction of the reactivity factor under fault conditions, e.g. reactor fuse

027

by fast movement of a solid, e.g. pebbles [5]

033

by an absorbent fluid [5]

Means for suppressing fires

Means for preventing accumulation of explosives gases, e.g. recombiners [5]

11/

Shielding structurally associated with the reactor

11/

Biological shielding (in general G 21 F)

11/

on waterborne craft

11/

Reflecting shields, i.e. for minimising loss of neutrons

11/

Thermal shields; Thermal linings, i.e. for dissipating heat from gamma radiation which would otherwise heat an outer biological shield

13/

Pressure vessels; Containment vessels; Containment in general (for chemical or physical processes B 01 J 3/00; pressure vessels in general F 16 J 12/00)

13/

Details

13/

024

Supporting constructions for pressure vessels or containment vessels [5]

13/

028

Seals, e.g. for pressure vessels or containment vessels [5]

13/

032

Joints between tubes and vessel walls, e.g. taking into account thermal stresses [5]

13/

036

the tube passing through the vessel wall, i.e. continuing on both sides of the wall [5]

13/

Arrangements for expansion and contraction

13/

Sealing-plugs (for pressure vessels in general F 16 J 13/00)

13/

067

for tubes, e.g. standpipes; Locking devices for plugs [5]

13/

073

Closures for reactor-vessels, e.g. rotatable [5]

13/

Vessels characterised by the material; Selection of materials for pressure vessels

13/

087

Metallic vessels [5]

13/

093

Concrete vessels [5]

13/

Means for preventing contamination in event of leakage

15/

Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants

15/

Arrangement or disposition of passages in which heat is transferred to the coolant, e.g. for coolant circulation through the supports of the fuel elements

15/

from fissile or breeder material

15/

in fuel elements

15/

from moderating material

15/

from reflector or thermal shield

15/

from pressure vessel; from containment vessel

15/

from ducts conducting a hot fluid; from ducts comprising auxiliary apparatus, e.g. pumps, cameras

15/

comprising means for separating liquid and steam (separating in general B 01 D; steam traps F 16 T)

15/

Emergency cooling arrangements; Removing shut-down heat

15/

Partitions or thermal insulation between fuel channel and moderator, e.g. in pressure tube reactors

15/

Structural association of coolant tubes with headers or other pipes, e.g. in pressure tube reactors (joints of tubes in general F 16 L) [4]

15/

Promoting flow of the coolant (electrodynamic pumps H 02 K 44/02)

15/

243

for liquids [5]

15/

247

for liquid metals [5]

15/

using jet pumps [5]

15/

253

for gases, e.g. blowers [5]

15/

257

using heat-pipes [5]

15/

by convection, e.g. using chimneys, using divergent channels

15/

Selection of specific coolants (if serving as the moderator G 21 C 5/12; compositions in general C 09 K 5/00)

17/

Monitoring; Testing (measuring in general G 01)

17/

003

Remote inspection of vessels, e.g. pressure vessels [5]

17/

007

Inspection of the outer surfaces of vessels [5]

17/

Inspection of the inner surfaces of vessels [5]

17/

013

Inspection vehicles [5]

17/

017

Inspection or maintenance of pipe-lines or tubes in nuclear installations [5]

17/

Devices or arrangements for monitoring coolant or moderator

17/

022

for monitoring liquid coolants or moderators [5]

17/

025

for monitoring liquid metal coolants [5]

17/

028

for monitoring gaseous coolants [5]

17/

032

Reactor-coolant flow measuring or monitoring [5]

17/

035

Moderator- or coolant-level detecting devices [5]

17/

038

Boiling detection in moderator or coolant [5]

17/

Detecting burst slugs

17/

Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination (G 21 C 17/08, G 21 C 17/10 take precedence; detecting leaking fuel elements during reactor operation G 21 C 17/04)

17/

Leak testing [5]

17/

Structural combination of reactor core or moderator structure with viewing means, e.g. with television camera, periscope, window

17/

Structural combination of fuel element, control rod, reactor core, or moderator structure with sensitive instruments, e.g. for measuring radioactivity, strain

17/

104

Measuring reactivity [5]

17/

108

Measuring reactor flux [5]

17/

112

Measuring temperature [5]

17/

116

Passages or insulators, e.g. for electric cables [5]

17/

Sensitive element forming part of control element

17/

Period meters

G21C - G21C 5/22

G21C 19/00 - G21C 23/00