R Reactor

R Reactor. The R Reactor was a plutonium production nuclear reactor constructed at the Savannah River Site in South Carolina as part of the United States Cold War nuclear weapons complex. It was one of five similar heavy water reactors built at the site during the early 1950s to augment and eventually replace the aging graphite reactors at the Hanford Site in Washington. Operated by the DuPont company for the United States Atomic Energy Commission, the reactor produced weapons-grade plutonium-239 and other nuclear materials essential for the nation's nuclear arsenal until its shutdown in the mid-1960s.

History

Authorized in 1950 amidst escalating tensions of the Cold War and following the Soviet Union's first atomic bomb test, the construction of the Savannah River Site and its reactors was a direct response by the United States Department of Defense. The R Reactor, alongside its sister reactors P Reactor, K Reactor, L Reactor, and C Reactor, was built rapidly, with groundbreaking in 1951 and achieving criticality in December 1953. Its operation was part of a massive industrial effort that involved thousands of workers and transformed the rural landscape near Aiken, South Carolina. Throughout its operational life, the reactor supported key national security initiatives, including the production of materials for the hydrogen bomb and, in later campaigns, tritium for thermonuclear weapon secondaries. The reactor's operational history was also marked by technical challenges and modifications to improve safety and output, reflecting the evolving standards of the nuclear industry.

Design and operation

The R Reactor was a heavy water-moderated, light water-cooled production reactor, a design selected for its efficient neutron economy and ability to produce significant quantities of plutonium-239 from uranium-238 targets. Its core consisted of an array of aluminum-clad fuel and target tubes, surrounded by a massive calandria vessel containing the heavy water moderator. Primary cooling was provided by pumping Savannah River water through the core, with the heated water then discharged to large artificial basins like Par Pond for cooling before release. This design shared key features with contemporary CANDU reactor designs but was optimized for material production rather than electricity generation. The reactor operated at a thermal power level of approximately 600 MW, and its operations were supported by extensive ancillary facilities, including radioactive waste management buildings, fuel fabrication plants, and chemical separation facilities like the nearby F Canyon and H Canyon, where irradiated fuel was processed to extract plutonium.

Decommissioning and legacy

Following a strategic reassessment of plutonium needs and the increasing efficiency of newer reactors, the United States Atomic Energy Commission permanently shut down the R Reactor in 1964. Initial decommissioning activities involved the removal of nuclear fuel, heavy water, and other readily accessible radioactive materials. The reactor building was placed in a long-term surveillance and maintenance status for decades. In the 1990s, under the oversight of the United States Department of Energy and in accordance with modern environmental regulations, more comprehensive decommissioning began. This included the partial dismantlement of structures, removal of contaminated components, and remediation of associated soils. Today, the site of the R Reactor, within the larger Savannah River Site, is a monitored industrial area, with its history representing a significant chapter in the Manhattan Project legacy and the environmental challenges of early nuclear weapons production. The story of the reactor is preserved and interpreted by the Savannah River Site Museum and forms part of the historical narrative managed by the United States Department of Energy's Office of Environmental Management.

See also

* P Reactor * K Reactor * Hanford Site * Nuclear weapons of the United States * Heavy water * Plutonium

Category:Nuclear reactors in the United States Category:Savannah River Site Category:Cold War military equipment of the United States Category:Nuclear weapons production reactors