at three sites on Wahluke Slope and one on what is now the Fitzner-Eberhardt Arid Lands Ecology Reserve. Each site had two underground missile storage magazines, twenty missiles and eight missile launchers. The Nike Ajax missiles were later replaced with Nike Hercules missiles. The development of intercontinental ballistic missiles made the missiles obsolete, and Camp Hanford became an outpost of Fort Lewis on July 1, 1959. The missile batteries were disbanded in 1960, and Camp Hanford was closed on March 31, 1961. Early expansion Cold War tensions escalated in April 1948 with the Berlin Airlift. Construction was under way on the new DRand HReactors, but the quickest way to increase production was to restart BReactor. This was authorized later that month. Shugg was recalled to Washington, DC, to serve as the AEC deputy general manager in August, and was succeeded by Frederick C. Schlemmer on September 16. In turn, he was succeeded by David F. Shaw on June 1, 1950. Shaw was succeeded by James E. Travis in June 1955, and he remained the site manager until June 1965. It was also possible to improve productivity. Zirconium was added to the cans to stabilize them under high exposures, and tests confirmed that they could withstand three times the exposure used in 1946 without rupture. In March 1950 GE was authorized to run the reactors at 305 MW instead of 250. This cut the use of raw materials by half, and yielded forty percent more plutonium per operating dollar. The Soviet Union detonated its first atomic bomb on August 29, 1949. The explosion was detected by a U.S. Air Force weather reconnaissance aircraft four days later. In response, President Harry S. Truman authorized a crash program to develop the hydrogen bomb. Preliminary designs called for large amounts of tritium. This could be produced in a reactor using target slugs loaded with lithium deuteride and fuel rods containing enriched uranium. One or more reactors would have to be set aside for tritium production. HReactor was chosen, and started producing tritium in 1950. For the longer term, the AEC decided to construct new reactors, of a different design using enriched uranium and heavy water as a moderator, at a new site, which became the Savannah River Site. The outbreak of the Korean War in September 1951 prompted the AEC to authorize a sixth reactor at Hanford on January 23, 1951. Construction began in