Recently, the United States conducted a subcritical nuclear test at Nevada. The experiment, the third under the administration of President Joe Biden, was carried out to collect essential data regarding the country’s nuclear warheads.
- According to the NNSA, a division of the US Energy Department, subcritical tests are relied upon to ensure the safety and effectiveness of nuclear warheads without conducting nuclear explosive testing.
- This type of test is termed “subcritical” because it uses fissile materials but there is no self-sustaining nuclear chain reaction.
- Most subcritical tests employ weapons grade plutonium (Pu-239) in various configurations. In recent years, subcritical tests have been conducted underground at the Nevada Test Site.
- Subcritical tests also can be conducted using an isotope of plutonium with a higher critical mass (Pu-242) which allows test devices to more closely resemble actual nuclear weapons triggers in size and shape.
- Both kinds of tests also can be conducted in some cases in vessels above ground.
