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Record of Decision System (RODS)



City & State:  IDAHO FALLS  ID  83401
EPA ID:  ID4890008952
EPA Region:  10
NPL Status:  Currently on the Final NPL
ROD Type:  Record of Decision
ROD ID:  EPA/ROD/R10-96/147
ROD Date:  12/01/1995
Operable Unit(s):  24
Media:  soil
Contaminant:  radionuclides, cesium-137, barium-137
Abstract:  Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.

The Idaho National Engineering Laboratory (INEL) is a government facility managed by the Department of Energy (DOE). The INEL occupies 880 square miles of the northeastern portion of the Eastern Snake River Plain. The stationary low-power reactor-1 (SL-1) and Boiling Water Reactor Experiment-1 (BORAX-1) burial grounds are approximately 38 and 52 miles west of Idaho Falls, Idaho.The SL-1 site is located about 1,600 feet northeast of the Auxiliary Reactor Area II and includes the surface soil area surrounding a 600- by 300-foot fenced burial ground. Approximately 99,000 cubic feet of radionuclide contaminated debris, soil, and gravel are disposed of in the burial ground. An estimated 2 feet of soil with a thick grass cover lies over the waste.The BORAX-1 burial ground is located about 2,730 feet northwest of the Experimental Breeder Reactor-1, a national monument. The BORAX-1 site includes a 200- by 420- foot surface soil contamination area surrounding the 100- by 100-foot fenced burial ground. The volume of buried radionuclide contaminated soil and debris is approximately 6,336 cubic feet. The area was covered with 6 inches of gravel in 1954, but grass, sagebrush, and other plants have reseeded the area since then.The INEL was originally established as the National Reactor Testing Station by the U.S. Atomic Energy Commission in 1949. The National Reactor Testing Station¿s mission was to build, test, and operate nuclear reactors, fuel processing plants, and support facilities. The INEL¿s current mission, as directed by the DOE, is the integration of engineering, applied science, and operations in an environmentally conscious, safe, and cost-effective manner.The SL-1 and BORAX-1 burial grounds are historical disposal areas and do not host any current programs. Current activities are limited to periodic observations for maintenance of the fences and grounds and monitoring for radioactivity.There are no residential communities within the INEL boundaries, and none of the 11,700 people employed at the INEL work full time at either burial ground. The nearest residential community is Atomic City, approximately 1 mile south of the INEL boundary.Most of the surrounding area is unimproved rangeland or farmland, and approximately 330,000 acres of the INEL are open to grazing by permit. However, grazing is prohibited within 2 miles of any nuclear facility, and no dairy cows are allowed. Approximately 95% of the INEL site has been withdrawn from the public domain by land transfer from the U.S. Bureau of Land Management to DOE.The SL-1 and BORAX-1 burial grounds were constructed to dispose of contaminated debris, soils, and gravel generated by the destruction of a small nuclear reactor at each location. The BORAX-1 burial ground was established in 1954 and the SL-1 burial ground was established in 1961. In January 1961, the SL-1 reactor was destroyed by an accidental nuclear excursion that resulted in a steam explosion. Very little contamination was released to the environment at the time of the accident due to the containment provided by the reactor building. Demolition and cleanup activities resulted in the spread of contamination over surface soils from Auxiliary Reactor Area II to the SL-1 burial ground. In 1954, the design mission of the BORAX-1 reactor was completed and the decision was made to conduct one final experiment that would result in the destruction of the reactor. The excursion contaminated approximately 84,000 square feet of ground. Following cleanup, the area was covered with soil.
Remedy:  The major components of the selected remedy include: containment by capping with an engineered barrier constructed primarily of native materials; for BORAX-1 implementation will include consolidation of surrounding contaminated surface soils for containment under the engineered cover; contouring and grading of surrounding terrain to direct surface water runoff away from the caps; periodic above ground radiological surveys following completion of the caps to assess the effectiveness of the remedial action; periodic inspection and maintenance following completion of the caps to ensure cap integrity and surface drainage away from the barriers; access restrictions consisting of fences, posted signs, and permanent markers; restrictions limiting land use to industrial applications for at least 100 years following completion of the caps; and review of the remedy no less often than every five years until determined by the regulatory agencies to be unnecessary.The selected remedy addresses the principal threats posed by the burial grounds by providing shielding from ionizing radiation, a barrier to inhibit ecological and human intrusion, and a long-lasting cover to diminish the effects of wind and water erosion.
Text:  View full-text ROD [ 147K ]
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