Assessing radiological contamination at the Green River Site in Utah
This fall, the S&K Aerospace Technical Assistance Contract (TAC) Team was contracted by the U.S. Army Corps of Engineers to conduct a survey of buildings and infrastructure at the Green River Test Site in Utah. The test site covers more than 3,500 acres and is managed by White Sands Missile Range in New Mexico. The demolition of 37 buildings, underlying slabs, and associated infrastructure on 350 acres at the test site is scheduled as part of the Army Facilities Reduction Program. However, during the preparation of an environmental assessment for the demolition, the possibility was raised that some of the buildings and infrastructure may be radiologically contaminated.
During the 1950s and 1960s, builders commonly used mill tailings materials in concrete for mineral aggregate during construction of buildings. Because test site facilities were built about 1962, readily accessible contaminated mill tailings may have been used for the construction of foundations, slabs, and sub-grade material at the site. The test site is adjacent to a former uranium mill, though much smaller than the former mill in Moab. The Green River mill was remediated in the late 1980s. The test site was also used as a launch, observation, and radar tracking facility for rockets, including those in the Pershing and Athena programs.
The Team’s scope of work was to develop a plan for the radiological assessment of 37 buildings scheduled for demolition and to perform the assessment on 30 of them. The plan also addressed how to determine whether the remaining facilities/infrastructure at the test site have any radiological contamination. The buildings to be surveyed were identified in 14 vicinity areas, including the 43-acre cantonment (quarters) owned by the White Sands Missile Range.
In late November and early December, the Team conducted the assessment of the buildings, which were all in disrepair and have been extensively vandalized. The assessment consisted of conducting gamma radiation exposure-rate surveys of the interior of the buildings and surrounding exterior areas, excavating shallow (6- to 8-inch) test holes adjacent to some of the foundations, and/or taking large-area wipes, or direct static readings using survey equipment, to determine the level of contamination. The vast majority of the buildings and infrastructure assessed were not contaminated. Naturally occurring radioactive material (uranium ore) was identified at two locations within the test site.
The TAC is currently evaluating the assessment results and will prepare a report to document the recommended removal actions and disposal requirements for the demolition debris.