Fast fission reactors, i.e. reactors not using a moderator
1
/
03
•
•
cooled by a coolant not essentially pressurised, e.g. pool-type reactors [5]
1
/
04
•
Thermal reactors
1
/
06
•
•
Heterogeneous reactors, i.e. in which fuel and moderator are separated
1
/
07
•
•
•
Pebble-bed reactors; Reactors with granular fuel [5]
1
/
08
•
•
•
moderator being highly pressurised, e.g. boiling-water reactor, integral-superheat reactor, pressurised-water reactor (G 21 C 1/22 takes precedence)
1
/
09
•
•
•
•
Pressure regulating arrangements, i.e. pressurisers [5]
1
/
10
•
•
•
•
moderator and coolant being different or separated
1
/
12
•
•
•
•
•
moderator being solid, e.g. Magnox reactor
1
/
14
•
•
•
moderator being substantially not pressurised, e.g. swimming-pool reactor (G 21 C 1/22 takes precedence)
1
/
16
•
•
•
•
moderator and coolant being different or separated, e.g. sodium-graphite reactor
1
/
18
•
•
•
•
•
coolant being pressurised
1
/
20
•
•
•
•
•
•
moderator being liquid, e.g. pressure-tube reactor
1
/
22
•
•
•
using liquid or gaseous fuel
1
/
24
•
•
Homogeneous reactors, i.e. in which fuel and moderator present an effectively homogeneous medium to the neutrons
1
/
26
•
•
•
Single-region reactors
1
/
28
•
•
•
Two-region reactors
1
/
30
•
Subcritical reactors
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 (G 21 C 1/02 to G 21 C 1/30 take precedence) [3]
3
/
00
Reactor fuel elements or their assemblies; Selection of substances for use as reactor fuel elements
3
/
02
•
Fuel elements
3
/
04
•
•
Constructional details
3
/
06
•
•
•
Casings; Jackets
3
/
07
•
•
•
•
characterised by their material, e.g. alloys [5]
3
/
08
•
•
•
•
provided with external means to promote heat-transfer, e.g. fins, baffles, corrugations
3
/
10
•
•
•
•
End closures
3
/
12
•
•
•
•
Means forming part of the element for locating it within the reactor core; External spacers for this purpose
3
/
14
•
•
•
•
Means forming part of the element for inserting it into, or removing it from, the core; Means for coupling adjacent elements
3
/
16
•
•
•
Details of the construction within the casing
3
/
17
•
•
•
•
Means for storage or immobilisation of gases in fuel elements [5]
3
/
18
•
•
•
•
Internal spacers or other non-active material within the casing, e.g. compensating for expansion of fuel rods or for compensating excess reactivity (interlayers G 21 C 3/20)
3
/
20
•
•
•
•
with coating on fuel or on inside of casing; with non-active interlayer between casing and active material
3
/
22
•
•
with fissile or breeder material in contact with coolant
3
/
24
•
•
with fissile or breeder material in fluid form within a non-active casing
3
/
26
•
•
with fissile or breeder material in powder form within a non-active casing
3
/
28
•
•
with fissile or breeder material in solid form within a non-active casing
3
/
30
•
Assemblies of a number of fuel elements in the form of a rigid unit
3
/
32
•
•
Bundles of parallel pin-, rod-, or tube-shaped fuel elements
3
/
322
•
•
•
Means to influence the coolant flow through or around the bundles [5]
3
/
324
•
•
•
Coats or envelopes for the bundles [5]
3
/
326
•
•
•
comprising fuel elements of different composition; Comprising, in addition to the fuel elements, other pin-, rod-, or tube-shaped elements, e.g. control rods, grid support rods, fertile rods, poison rods or dummy rods [5]
3
/
328
•
•
•
•
Relative disposition of the elements in the bundle lattice [5]
3
/
33
•
•
•
Supporting or hanging of elements in the bundle (spacer grids G 21 C 3/34); Means forming part of the bundle for inserting it into, or removing it from, the core; Means for coupling adjacent bundles [5]
3
/
332
•
•
•
•
Supports for spacer grids [5]
3
/
334
•
•
•
Assembling the bundles [5]
3
/
335
•
•
•
Exchanging elements in irradiated bundles [5]
3
/
336
•
•
•
Spacer elements for fuel rods in the bundle (spacer grids G 21 C 3/34) [5]
3
/
338
•
•
•
•
Helicoidal spacer elements [5]
3
/
34
•
•
•
Spacer grids
3
/
344
•
•
•
•
formed of assembled tubular elements [5]
3
/
348
•
•
•
•
formed of assembled non-intersecting strips [5]
3
/
352
•
•
•
•
formed of assembled intersecting strips [5]
3
/
356
•
•
•
•
being provided with fuel element supporting members [5]
3
/
36
•
•
Assemblies of plate-shaped fuel elements or coaxial tubes
3
/
38
•
Fuel units consisting of a single fuel element in a supporting sleeve
3
/
40
•
Structural combination of fuel element with thermoelectric element for direct production of electric energy from fission heat (for temperature measurement G 21 C 17/10)
3
/
42
•
Selection of substances for use as reactor fuel
3
/
44
•
•
Fluid or fluent reactor fuel
3
/
46
•
•
•
Aqueous compositions
3
/
48
•
•
•
•
True or colloidal solutions of the active constituent
3
/
50
•
•
•
•
Suspensions of the active constituent; Slurries
3
/
52
•
•
•
Liquid metal compositions
3
/
54
•
•
•
Fused salt, oxide, or hydroxide compositions
3
/
56
•
•
•
Gaseous compositions; Suspensions in a gaseous carrier
