An experiment to determine the reliability of the U.S. nuclear stockpile has been conducted at the Nevada test site, drawing criticism from Japanese leaders.
The experiment conducted Saturday 960 feet underground remained subcritical, meaning no self-sustaining nuclear chain reaction occurred, according to the Energy Department. Such experiments have been conducted since a moratorium on nuclear testing went into effect in 1992.
The Energy Department contends the experiments are essential to the nation's program to maintain the safety and reliability of the stockpile in the absence of underground nuclear testing.
The mayors of Hiroshima and Nagasaki, the only cities ever to suffer atomic bombings, said the test will impede nuclear disarmament.