In this section, the following term is used with the meaning indicated:
"variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes).
Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05.
Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...G05).
The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.
Reactor fuel elements or 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 3/07
· · · ·
characterised by their material, e.g. alloys [5]
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 3/17
· · · ·
Means for storage or immobilisation of gases in fuel elements [5]
G21C 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 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
· ·
with fissile or breeder material in contact with coolant
G21C 3/24
· ·
with fissile or breeder material in fluid form within a non-active casing
G21C 3/26
· ·
with fissile or breeder material in powder form within a non-active casing
G21C 3/28
· ·
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 3/322
· · ·
Means to influence the coolant flow through or around the bundles [5]
G21C 3/324
· · ·
Coats or envelopes for the bundles [5]
G21C 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]
G21C 3/328
· · · ·
Relative disposition of the elements in the bundle lattice [5]
G21C 3/33
· · ·
Supporting or hanging of elements in the bundle (spacer grids Fulltext... Hierarchy... Expanded...G21C 3/34); Means forming part of the bundle for inserting it into, or removing it from, the core; Means for coupling adjacent bundles [5]
being provided with fuel element supporting members [5]
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
P:100
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
for tubes, e.g. standpipes; Locking devices for plugs [5]
G21C 13/073
· · ·
Closures for reactor-vessels, e.g. rotatable [5]
G21C 13/08
·
Vessels characterised by the material; Selection of materials for pressure vessels
G21C 13/087
· ·
Metallic vessels [5]
G21C 13/093
· ·
Concrete vessels [5]
G21C 13/10
·
Means for preventing contamination in event of leakage
P:50
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, e.g. for coolant circulation through the supports of the fuel elements
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 ducts conducting a hot fluid; from ducts comprising auxiliary apparatus, e.g. pumps, cameras
Partitions or thermal insulation between fuel channel and moderator, e.g. in pressure tube reactors
G21C 15/22
·
Structural association of coolant tubes with headers or other pipes, e.g. in pressure tube reactors (joints of tubes in general Fulltext... Hierarchy... Expanded...F16L) [4]
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 radioactivity, strain
G21C 17/104
· ·
Measuring reactivity [5]
G21C 17/108
· ·
Measuring reactor flux [5]
G21C 17/112
· ·
Measuring temperature [5]
G21C 17/116
· ·
Passages or insulators, e.g. for electric cables [5]
G21C 17/12
· ·
Sensitive element forming part of control element
G21C 17/14
·
Period meters
P:60
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
· ·
Means for supporting or storing fuel elements or control elements [4]
G21C 19/07
· · ·
Storage racks; Storage pools [5]
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 19/105
· · ·
with grasping or spreading coupling elements [5]
G21C 19/11
· · ·
with revolving coupling elements, e.g. socket coupling [5]
G21C 19/115
· · ·
with latching devices and ball couplings [5]
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
Recombination devices for radiolytic dissociation products [5]
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)
by separating into pieces both the canning or the casing and the fuel element, e.g. by cutting or shearing [5]
G21C 19/375
· · ·
Compacting devices, e.g. for fuel assemblies [5]
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
P:110
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