U.S. scientists are conducting new subcritical tests to ensure the reliability of aging nuclear weapons.

For the first time in years, U.S. officials have conducted new nuclear weapons experiments—without detonating an actual bomb. The tests, carried out deep underground at the Nevada National Security Site, are part of ongoing efforts to assess the safety and reliability of the nation’s aging nuclear arsenal. Known as “subcritical” tests, they use high explosives and plutonium but stop short of triggering a nuclear chain reaction. The data helps scientists verify that America’s warheads remain stable without full-scale explosions.








