G21C NUCLEAR REACTORS
Introduced: September 1968
Classification Context
- Section:
- PHYSICS
- Class:
- NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- Subclass:
- NUCLEAR REACTORS
Description
G21C covers the design, construction, operation, and control of nuclear reactors used for power generation, research, or propulsion. This subclass encompasses reactor types (pressurized water, boiling water, gas-cooled, fast breeder reactors), core designs, fuel elements, coolant systems, and safety mechanisms including containment structures. It includes reactor control systems, neutron moderators, and instrumentation for monitoring reactor performance. Adjacent classes G21D (nuclear fuel elements) and G21F (physical protection of nuclear materials) address specialized fuel and security aspects separately.
Additional Content
Glossary
Core The central region of a reactor containing fuel and moderator elements, where nuclear fission occurs. Moderator moderators Material used in a thermal nuclear reactor to reduce the velocity of neutrons produced by nuclear fission in order to facilitate chain reaction. Shield shields Means surrounding a reactor to prevent radiation damage to operators etc.
Limiting references
Fusion reactors; hybrid fission-fusion reactors Treating radioactively contaminated materials; Decontamination arrangements therefor Nuclear explosives
Application references
Nuclear power plant Control of nuclear power plant Production of electric energy from fusion or fission reactions
Related Keywords
12 direct subcodes
Child Classifications
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- G21C 1/00 Reactor types
- G21C 11/00 Shielding structurally associated with the reactor
- G21C 13/00 Pressure vessels; Containment vessels; Containment in general
- G21C 15/00 Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
- G21C 17/00 Monitoring; Testing
- 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
- G21C 21/00 Apparatus or processes specially adapted to the manufacture of reactors or parts thereof
- G21C 23/00 Adaptations of reactors to facilitate experimentation or irradiation
- G21C 3/00 Reactor fuel elements or their assemblies; Selection of substances for use as reactor fuel elements
- G21C 5/00 Moderator or core structure; Selection of materials for use as moderator
- G21C 7/00 Control of nuclear reaction
- G21C 9/00 Emergency protection arrangements structurally associated with the reactor
Top Applicants
Top 10 applicants by patent filingsfor class G21, 2013–2023, worldwide · Source: EPO PATSTAT
- CHINA GENERAL NUCLEAR POWER CORPORATION 2,364
- CGN POWER COMPANY 1,899
- CHINA NUCLEAR POWER ENGINEERING COMPANY 1,870
- NUCLEAR POWER INSTITUTE OF CHINA 1,517
- KOREA ATOMIC ENERGY RESEARCH INSTITUTE KR 1,367
- WESTINGHOUSE ELECTRIC CORPORATION US 1,295
- KOREA HYDRO & NUCLEAR POWER COMPANY KR 1,196
- CHINESE ACADEMY OF SCIENCES 1,044
- CHINA INSTITUTE OF ATOMIC ENERGY 1,011
- HITACHI-GE NUCLEAR ENERGY 955