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Background: Union Carbide Corporation (UCC) built and operated the facility in the early 1960s to burn uraniferous lignite coal. The plant had a capacity of 100 tons of ore per day and was operated from July 1965 to November 1967. The plant site was located near the mines to decrease the freight haulage costs. Burning the lignite concentrated the uranium values in the ash product that was directly amenable to further processing at the company’s Rifle, Colorado, uranium mill. The raw lignite ore, which contained 35-50 percent moisture by weight, was burned in a natural gas fired, rotary kiln to decompose and drive off the organic constituents and carbon. The kiln was 8 feet in diameter by 125 feet in length, and it operated at 1,300°F to 1,600°F depending on the lignite feed quality. The lignite ore averaged about 0.37 percent U3O8, and the uranium values were concentrated in the ash by the burning process. Uranium recovery in the ash product averaged 93 percent. During burn operations, ash dust from the kiln was collected by a wet scrubber and was returned to the rotary cooler/discharge unit where the hot ash emerged from the kiln. The original plant site covered about 11 acres. In 1980, a U.S. Department of Energy survey of the area showed that an additional 21 acres contiguous to the site were contaminated by low amounts of a wind-blown ash residue, apparently released during plant operations. The volume of contaminated soil at the site is estimated to be about 57,000 cubic yards. No clearly defined process-residue piles or waste ponds exist at the site Sludge-pit areas may possibly be buried at the site. The Belfield site is owned by private interests.
UMTRA Surface Remediation: After closing the facility in 1967, UCC cleaned and decontaminated the facility and site to specifications required by the U.S. Atomic Energy Commission’s then-current regulations. Site stabilization was not performed at that time. The site was subsequently leased for other industrial uses, and a portion was later covered with gravel for vehicle parking. When studied in 1980, the site had a well-established cover of indigenous plant species. No obvious tailings pile remained at the site.
The Belfield site was not included on the original congressional list of processing sites designated under UMTRCA for remediation. The Dakota Resources Council nominated the site for cleanup (1979) and the site was designated by the Secretary of Energy. Based on its relatively low public-health impact, the site was initially assigned a low cleanup priority. North Dakota requested (1995) revocation of the site’s designation citing low public support, limited State funding, and the very small public and environmental risk. The site designation was then revoked by the Secretary of Energy. An Environmental Assessment and Finding of No Significant Impact was prepared by the DOE as required by the National Environmental Policy Act. The Belfield site was not remediated. An estimated 58,000 cubic yards of contaminated soil remain at the original site. Seven vicinity properties were identified as potentially contaminated by residual radioactive material: none was cleaned up under UMTRCA, since the Belfield site’s designation was revoked.
Responsibility for Remdiation: The State of North Dakota, 100 percent.
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