France conducted Xouthos, its 210th and final live nuclear test, detonating a slot thermonuclear warhead beneath the Fangataufa lagoon in the southern Pacific Ocean. The test had a yield of between 20 and 120 kilotons of TNT, potentially 8 times as explosive as the bomb the United States dropped on Hiroshima in 1945.

Xouthos marked the end of France’s nuclear tests but not the end of its nuclear stockpile maintenance. To ensure that the country’s warheads are in working order, France is working with Lawrence Livermore National Laboratory in the United States to develop a super-cooled laser ignition test facility.There are eight other nations with nuclear weapons:

The United States, Russia, the United Kingdom, France, China, Israel, India, and Pakistan. In the 21st century, only North Korea has conducted live nuclear weapons tests. For the other countries, maintaining and sustaining nuclear warheads

without real-world tests is an engineering challenge. One way to manage this is through computer modeling, which lets nuclear laboratories refine warhead design and study new types of warhead refurbishment.