June. The new reactor was built in the Barea and called CReactor. The same basic graphite-moderated design was used, with improvements to give it a rated power of 750 MW. The new reactor became operational in November 1952. On February 25, 1952, Truman authorized two more reactors at the Hanford Site. These were called K West and K East, and were sited at Coyote Rapids between the Band Dareas. They were known as "Jumbo" reactors for their much larger size. They still used the same graphite-moderator technology, but had improvements to allow them to operate at 1,800 MW. Each used of graphite, over a thousand tons more than the three wartime reactors, and had concrete shields instead of steel and masonite. They had more feed tubes and reduced spacing between them. Improvements in water-pump design allowed them to have eighteen pumps instead of the fifty in the wartime reactors, but were capable of pumping . As with the other reactors, the cooling water was collected in ponds, allowed to cool, and then tipped back into the river. An innovation was that heat from the cooling water was used to heat the work places. Each Jumbo reactor required about 300 operators to run it, compared with 400 for HReactor. This represented a saving of a million dollars a year (equivalent to $million in ). Although capable of being run at up to 4,400 MW, the AEC imposed an administrative limit of 4,000 MW on them. Since plutonium239 has a half-life of 24,100 years, AEC chairman Gordon Dean calculated that sufficient plutonium would be produced by the mid-1960s. With this in mind, the reactors were designed with a life of twenty years. Separation facilities In addition to the new reactors there were also new separation facilities. The AEC had long been dissatisfied with the wasteful bismuth phosphate separation process. GE conducted research into an alternative, reduction-oxidation (REDOX) process. This used methyl isobutyl ketone (hexone) as a solvent. It was developed at the Hanford Site in the 3706 Building and tested in the 321 Building. The AEC approved the REDOX process in May 1949, and work began on the new plant the following year. Construction ran behind schedule, and it did not commence operation until January 1952. Known as the 202-S Building or the SPlant, it was long and wide, and could process up to twelve metric tons of uranium per day, compared