AWE cooperates with the Los Alamos National Laboratory in the United States and other American nuclear weapons laboratories in carrying out subcritical nuclear tests at the Nevada underground test site to obtain scientific data to maintain the safety and reliability of nuclear weapons.
In 1929, a test boiler that had been built in 1927 began operating in the thermal power plant at Gartenfeld in Berlin for the first time in subcritical mode with a fully open throttle valve.