After the Cold War, the department's attention also turned to radioactive waste disposal and environmental quality maintenance.

Chu also served as the longest-serving secretary of energy and was the first individual to join the Cabinet after having received a Nobel Prize.

[6] Former Michigan governor, Jennifer Granholm, confirmed on February 25, 2021 under President Joe Biden, was the second woman to lead the Department of Energy.

This arrangement is intended to maintain full civilian control over strategic weapons, except as directed by the president for specific military uses.

[10] Under the terms of several successive treaties, most recently New START, the United States has reduced its strategic arsenal to 1,500 deployed weapons.