of nuclear explosions for large excavation projects such as harbors or canals. The 100 kiloton Sedan shot dug out a crater 320 feet deep and with an average diameter of 1280 feet and displaced almost 7.5 million cubic yards, or 12 million tons of earth, 4° The Cold War Heats Up The Commission conducted the 1961 and 1962 tests as the inter_NMational situation became more tense. Heating up the Cold War, Soviet Union began a series of confrontations over Berlin in 1961. the But the worst crisis came in October 1962, when President Kennedy demanded that the Soviet Union withdraw missiles it had deployed in Cuba. Although Chairman Krushchev removed the missiles, the world seeme< close to the brink of nuclear war before the crisis ended. The Cuban missile crisis profoundly affected test ban negot: -tions which had resumed in Geneva. Doubtlessly the ‘erisis made =... the United States and the Soviet Union more willing to compromis: *’ on October 11, 1963, the two powers formally entered into a treaty Danning nuclear testing in the atmosphere, under water, and in outer space. Thereafter all American nuclear testing was conducted underground. ‘Three months later in his first State of the Union address, Si- dent Lyndon B. Johnson announced that the United states would reduce ics production of enriched uranium by 25 percent and shut down four production reactors. stockpile arms The United States, the President declared, would not beyond its needs. Indeed, hac wc production complexes operated that the Commission had put only c- new reactor into production since the mid-1950's. so efficiently Called the New Pros °=ticn Reactor and added to the Hanford complex, the unit was symbolic -<: che