A Risk-based Methodology for Addressing Environmental Risk from a Wide Variety of Contaminated Sites at the Idaho National Engineering Laboratory

Abstract

The Idaho National Engineering Laboratory (INEL) is a multidisciplinary applied-engineering laboratory located in Southeastern Idaho, covering approximately 1430 km² of high semi-arid desert on the eastern Snake River Plain. The laboratory has a rich history of a wide variety of activities spanning over 45 years. The primary functions have been related to nuclear reactor research and development, and radioactive waste management treatment, storage, and disposal. The Navy was the first to use the site, as a gunnery range for testing 41-cm-diameter battleship guns; another area was used by the Army as an aerial gunnery range. During its first forty years, the INEL was home to fifty-two reactors, most of them first-of-a-kind. In addition to the testing of these reactors, fuel testing and reprocessing of Naval fuel was performed. As a result of many of these past operations, the INEL was placed on the Environmental Protection Agency’s (EPA’s) Superfund National Priorities List (NPL) in November of 1989. This action set into motion the requirements for performance of investigations to “determine fully the nature and extent of any threat to the public and the environment caused by... hazardous substances...”. This listing and the resultant actions identified over 400 potential hazardous waste sites that needed to be addressed. These sites ranged in complexity from a rubble pile with construction debris, to radioactively contaminated pond sediments, to a 0.4-km² burial ground consisting of large quantities of transuranic, low-level, and mixed transuranic and low-level wastes. It was quite obvious that the degree of attention and information that would be needed to make informed decisions about what remedial actions if any these sites might require should vary greatly. This paper describes the development and successful implementation of a graded and streamlined approach being used to provide the necessary and appropriate information needed by the decision makers to make sound and cost-effective cleanup decisions.

Work supported by the U.S. Department of Energy, under DOE Idaho Operations Contract DE-AC07-94ID13223.