Hanford Tank Farm

Hanford Tank Farm
Name	Hanford Tank Farm
Location	Hanford Site, Benton County, Washington, United States
Coordinates	46°21′N 119°34′W
Established	1940s
Operator	United States Department of Energy
Status	Active cleanup

Hanford Tank Farm is a complex of underground storage tanks at the Hanford Site in Benton County, Washington that stored high-level radioactive waste from plutonium production during the Manhattan Project and the Cold War. The facility became central to environmental and public-health controversies involving the United States Department of Energy, the Environmental Protection Agency, the Washington State Department of Ecology, and tribal nations including the Confederated Tribes of the Umatilla Indian Reservation. The site has driven litigation under the Comprehensive Environmental Response, Compensation, and Liability Act, oversight by the Nuclear Regulatory Commission-related entities, and technological development in vitrification and waste retrieval in partnership with national laboratories such as Pacific Northwest National Laboratory and Savannah River National Laboratory.

History

Construction at the Hanford Site began under the Manhattan Project with the mission to produce plutonium for the Trinity test and the Fat Man bomb used at Nagasaki. Irradiated fuel from reactors such as the B Reactor was chemically processed at separations facilities including T Plant and U Plant, generating liquid high-level waste stored in tanks clustered in zones known as 200 East and 200 West. Throughout the Cold War, operations expanded under the United States Army Corps of Engineers handoff and subsequent management by General Electric contractors and private firms such as Westinghouse Electric Company and Bechtel National. Reports of tank leaks emerged in the 1950s and were documented in internal records and later investigations by the Government Accountability Office and the Department of Energy inspector general, prompting enforcement actions under the Resource Conservation and Recovery Act and consent decrees negotiated with the Washington State Attorney General.

Infrastructure and Tank Types

The Tank Farm comprises single-shell tanks and double-shell tanks arrayed in tank farms including 241-AW, 241-AN, 241-AZ, and 241-SX, constructed from carbon steel with concrete encasements on the Hanford Site mesa. Single-shell tanks, built in the 1940s–1960s, typically hold 55,000–1,000,000 gallons and were susceptible to corrosion and leakage; double-shell tanks, completed later under programs involving Rockwell International and IHI Corporation designs, add an inner liner and secondary containment. Ancillary infrastructure includes evaporators, transfer pipelines, pumpable retrieval systems, mixer pumps developed with contractors like URS Corporation and Washington Closure Hanford, and evaporator-crystallizer units connected to electrical distribution maintained by the Bonneville Power Administration. Monitoring technology incorporates borehole logging, seismic arrays, and geophysical surveys coordinated with United States Geological Survey expertise.

Radioactive Waste Inventory and Chemistry

Contents include highly radioactive sludge, salt cakes, and supernatant liquids containing isotopes such as cesium-137, strontium-90, plutonium-239, americium-241, and various fission products and activation products from reactors like N Reactor. Chemical constituents include complexants, hydroxides, nitrates, nitrites, ferrocyanides, and organic degradation products derived from separation reagents used at PUREX and legacy processes at REDOX and B Plant. Radiochemical and chemical stratification leads to challenges in retrieval and waste-form stabilization being addressed by vitrification programs developed with Lawrence Livermore National Laboratory, Argonne National Laboratory, and private partners such as AREVA and Bechtel. Inventory estimates and tank characterization rely on core sampling, grab samples, and nonintrusive methods validated against standards from National Institute of Standards and Technology.

Environmental and Health Impacts

Leaking single-shell tanks have contaminated vadose zone sediments and contributed to plumes of contamination moving toward the Columbia River, raising concerns among downstream stakeholders including the Yakama Nation, Nez Perce Tribe, and the City of Richland, Washington. Contaminants of concern include long-lived radionuclides such as iodine-129 and technetium-99 along with chromium and other hazardous constituents regulated under Safe Drinking Water Act frameworks. Epidemiological and ecological studies by institutions like Fred Hutchinson Cancer Research Center and University of Washington researchers have examined occupational exposures among workers employed by contractors such as Fluor Corporation and community exposures, informing compensation regimes under laws like the Energy Employees Occupational Illness Compensation Program Act. Environmental monitoring is conducted by the Pacific Northwest Site Office and citizen groups including Hanford Watch.

Cleanup and Remediation Efforts

Cleanup efforts are coordinated through DOE's Office of River Protection and executed by contractors including Bechtel National and others under milestone agreements established in legal settlements with the State of Washington and the Environmental Protection Agency. Central features include retrieval of tank waste, pretreatment to remove high-activity fractions, and immobilization by vitrification at the Waste Treatment and Immobilization Plant (the "Vit Plant"). Pilot projects involve supplemental treatment technologies, grout and cementitious stabilization, and interim storage strategies informed by research at Pacific Northwest National Laboratory. Challenges include technical failures, cost overruns, schedule slips, and lessons learned similar to remediation programs at Savannah River Site and Oak Ridge National Laboratory. Community engagement includes tribal consultations with the Colville Confederated Tribes and public comment processes overseen by the Hanford Advisory Board.

Regulation, Oversight, and Legal Issues

Regulatory oversight is shared among the United States Department of Energy (owner/operator), the Environmental Protection Agency (CERCLA authority), and the Washington State Department of Ecology (RCRA and state consent decrees), with litigation resulting in enforceable milestones codified in federal court consent decrees and settlement agreements adjudicated in the United States District Court for the Eastern District of Washington. Congressional oversight committees such as the United States House Committee on Energy and Commerce and the United States Senate Committee on Energy and Natural Resources and watchdog reports by the Government Accountability Office have scrutinized budgetary and technical performance. International comparisons cite remediation precedents at Sellafield and policy lessons drawn from Chernobyl and Fukushima Daiichi responses regarding institutional control, long-term stewardship, and intergovernmental trust.

Category:Hanford Site Category:Nuclear waste repositories in the United States Category:Environmental remediation in the United States