WASHINGTON – The United States will dismantle this week the last of its Cold War-era B53 nuclear bombs, the most destructive weapon in the country’s arsenal, the National Nuclear Safety Administration said Monday.

The 10,000-pound bomb is the size of a minivan and contains about 300 pounds of high explosive surrounding a uranium core. It was designed to be dropped from a B-52 bomber and produce an explosion 600 times more powerful than the bomb that destroyed Hiroshima, Japan, in 1945, according to the Federation of American Scientists website.

The weapon was being disassembled by Babcock & Wilcox Technical Services Pantex LLC, the contractor that operates the agency’s plant in Amarillo, Texas. Dismantling nuclear weapons is part of President Obama’s goal to reduce the role of atomic weapons in U.S. national security, Thomas D’Agostino, under secretary of energy for nuclear security, said in a statement.