G21J - Definition 
Definition statement
This subclass covers:
Devices specially adapted to cause or facilitate uncontrollable fission or fusion reactions of atoms of the device and to release the explosive energy created thereby to an area outside the devices.
The peaceful or belligerent use of such devices.
Arrangements for detecting nuclear explosions.
Informative references
Attention is drawn to the following places, which may be of interest for search:
Explosive chemical compositions | C06B |
Methods for stimulating production of oil, gas, water, soluble or meltable materials or a slurry of minerals from wells by use of explosives | E21B 43/263 |
Conventional explosive devices | F42B |
So-called "dirty bombs" where conventional explosives are used to dispense radioactive substances | F42B 12/46 |
Individual measuring devices may be classified as the measuring device per se | G01 |
Analogue computers for simulating nuclear explosions | G06G 7/54 |
Controlled fusion reactors | G21B |
Controlled fission reactors | G21C |
Nuclear power plant | G21D |
Glossary of terms
In this subclass, the following terms or expressions are used with the meaning indicated:
| Uncontrollable reaction | 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. |
Synonyms and Keywords
In patent documents the following terms "bomb" and "device" are often used as synonyms. Also, these terms can be used as keywords.
In patent documents the following terms "H-bomb", "fusion bomb", "hydrogen bomb" and "thermonuclear bomb" are often used as synonyms. Also, these terms can be used as keywords.