G21J NUCLEAR EXPLOSIVES; APPLICATIONS THEREOF
Introduced: September 1968
Classification Context
- Section:
- PHYSICS
- Class:
- NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- Subclass:
- NUCLEAR EXPLOSIVES; APPLICATIONS THEREOF
Description
G21J covers nuclear explosive devices and their practical applications. This includes designs for nuclear weapons, thermonuclear devices, and related triggering or detonation mechanisms. The classification also encompasses peaceful applications of nuclear explosions, such as industrial excavation, seismic research, or mineral extraction where controlled nuclear detonation is employed. Related classified research on nuclear weapon design itself typically falls within national security restrictions rather than patent literature.
Filing statistics
IPC subclass G21J recorded 58 patent applications worldwide between 2013 and 2023. Annual filings grew from 2 in 2013 to 2 in 2023 (+0%), peaking at 17 applications in 2019. The most active applicants in class G21 are CHINA GENERAL NUCLEAR POWER CORPORATION (2,364 applications), CGN POWER COMPANY (1,899 applications) and CHINA NUCLEAR POWER ENGINEERING COMPANY (1,870 applications).
Source: EPO PATSTAT, worldwide filings
In class comparison
G21J ranks 8th of 8 subclasses with filings in G21, with 58 applications between 2013 and 2023, 0.1% of the class.
| Rank | Subclass | Title | Applications | Share |
|---|---|---|---|---|
| 1 | G21C, Nuclear Reactors | Nuclear Reactors | 29,798 | 37.0% |
| 2 | G21F, Protection Against X-Radiation, Gamma Radiation, Corpuscular Radiation or Particle Bombardment; Treating Radioactively Contaminated Material; Decontamination Arrangements Therefor | Protection Against X-Radiation, Gamma Radiation, Corpuscular Radiation or Particle Bombardment; Treating Radioactively Contaminated Material; Decontamination Arrangements Therefor | 22,783 | 28.3% |
| 3 | G21K, Handling of Particles or Ionising Radiation Not Otherwise Provided for; Irradiation Devices; Gamma Ray or X-Ray Microscopes | Handling of Particles or Ionising Radiation Not Otherwise Provided for; Irradiation Devices; Gamma Ray or X-Ray Microscopes | 11,603 | 14.4% |
| 4 | G21D, Nuclear Power Plant | Nuclear Power Plant | 7,179 | 8.9% |
| 5 | G21G, Conversion of Chemical Elements; Radioactive Sources | Conversion of Chemical Elements; Radioactive Sources | 4,076 | 5.1% |
| 6 | G21B, Fusion Reactors | Fusion Reactors | 3,917 | 4.9% |
| 7 | G21H, Obtaining Energy From Radioactive Sources; Applications of Radiation From Radioactive Sources, Not Otherwise Provided for; Utilising Cosmic Radiation | Obtaining Energy From Radioactive Sources; Applications of Radiation From Radioactive Sources, Not Otherwise Provided for; Utilising Cosmic Radiation | 1,227 | 1.5% |
| 8 | G21J | Nuclear Explosives; Applications Thereof | 58 | 0.1% |
Source: EPO PATSTAT, worldwide filings
Additional Content
Uncontrollable reaction uncontrollable reactions Any fission or fusion reaction where event initiators (e.g. neutrons in the fission process) are produced in a number greater than required to sustain a chain reaction and where there is no mechanism to selectively moderate the reaction, e.g. a fission reactor where the operator has simply opted not to moderate or has failed to moderate the reaction is not a nuclear explosive device in the context of this subclass.
3 direct subcodes
Child Classifications
Navigate with arrow keys, Enter to open
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