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Title: FINAL FRONTIER AT HANFORD TACKLING THE CENTRAL PLATEAU

Journal Article · · RADWASTE SOLUTIONS MAGAZINE
OSTI ID:924803

The large land area in the center of the vast Department of Energy (DOE) Hanford Site in southeast Washington State is known as 'the plateau'--aptly named because its surface elevations are 250-300 feet above the groundwater table. By contrast, areas on the 585-square mile Site that border the Columbia River sit just 30-80 feet above the water table. The Central Plateau, which covers an ellipse of approximately 70 square miles, contains Hanford's radiochemical reprocessing areas--the 200 East and 200 West Areas--and includes the most highly radioactive waste and contaminated facilities on the Site. Five 'canyons' where chemical processes were used to separate out plutonium (Pu), 884 identified soil waste sites (including approximately 50 miles of solid waste burial trenches), more than 900 structures, and all of Hanford's liquid waste storage tanks reside in the Central Plateau. (Notes: Canyons is a nickname given by Hanford workers to the chemical reprocessing facilities. The 177, underground waste tanks at Hanford comprise a separate work scope and are not under Fluor's management). Fluor Hanford, a DOE prime cleanup contractor at the Site for the past 12 years, has moved aggressively to investigate Central Plateau waste sites in the last few years, digging more than 500 boreholes, test pits, direct soil 'pushes' or drive points; logging geophysical data sets; and performing electrical-resistivity scans (a non-intrusive technique that maps patterns of sub-surface soil conductivity). The goal is to identify areas of contamination areas in soil and solid waste sites, so that cost-effective and appropriate decisions on remediation can be made. In 2007, Fluor developed a new work plan for DOE that added 238 soil waste-site characterization activities in the Central Plateau during fiscal years (FYs) 2007-2010. This number represents a 50 percent increase over similar work previously done in central Hanford. Work Plans are among the required steps in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) cleanup process. The CERCLA process is used to oversee the investigation, decision-making and remediation of 'past practices' (historical) sites, as opposed to sites in active use. For the first several years of Hanford's cleanup work, everyone concerned--the Department, contractors, regulatory agencies, stakeholders and Indian nations and tribes--focused efforts on the rivershore. The magnificent Columbia River--eighth largest in the world--flows through and by the Hanford Site for 52 miles. Two million people live downstream from Hanford along the Columbia before it empties into the Pacific Ocean. Further, the part of the river known as the 'Hanford Reach' is a prime habitat for salmon, steelhead, sturgeon and other species of fish. In fact, it provides a spawning ground to more salmon than any other stretch of river in the United States outside of Alaska. For these reasons, protecting the Columbia by cleaning up waste directly along its shoreline was an early priority in Hanford's Federal Facility Agreement and Consent Order (or Tri-Party Agreement) signed in 1989 among the DOE, U.S. Environmental Protection Agency (EPA) and Washington State to govern cleanup. However, Tri-Party Agreement signatories and others concerned with Hanford and the Columbia River, knew that the waste located in, and beneath, the Central Plateau could also pose dangers to the waterway. While the waste in central Hanford might move more slowly, and pose fewer immediate threats, it would have to be dealt with as cleanup progressed.

Research Organization:
Hanford Site (HNF), Richland, WA (United States)
Sponsoring Organization:
USDOE - Office of Environmental Management (EM)
DOE Contract Number:
DE-AC06-96RL13200
OSTI ID:
924803
Report Number(s):
HNF-36881 Rev 0; TRN: US0802939
Journal Information:
RADWASTE SOLUTIONS MAGAZINE, Vol. 15, Issue MAY/JUNE
Country of Publication:
United States
Language:
English