Rocky Flats Plant – Building #707

AddressRocky Flats Environmental Technology Site, Hwy. 93, Golden 80402
QuadLouisville, 1965 (1979)
SectionS10 & 11, T2S, R70W
Elevationc. 6000
SourceHistoric Building Inventory Record #5JF1014.36, 1995, Colorado Historical Society.
Initialdate1999-01-07 00:00:00-07
HistoryDesigned by C.F. Braun & Co. of Alhambra, California, and built by Swinerton & Walberg of San Francisco in 1970, this two-story, 93,800 sq. ft. building housed plutonium manufacturing and plutonium storage. It is "L" shaped with two one-story ells extending from the east side. The exterior walls are precast concrete panels on a reinforced concrete foundation with a flat roof and no windows in the building. The main floor is divided into eight modules for specific manufacturing processes. Construction began in 1967, and was completed in 1970, with plutonium operations beginning on May 20, 1970. In 1969, construction had been accelerated following the fire in Building #776/777 and to accommodate the Part V weapons design. Building #707 was the only facility in the weapons complex that was capable of producing pit assemblies for the United States nuclear weapons stockpile. In 1989, all operations involving radioactive materials ceased.