The EVS Division prepared a draft environmental impact statement (EIS) for disposal of greater-than-Class C low-level radioactive waste (GTCC LLRW) for the DOE Office of Environmental Management. DOE is now finalizing this EIS and is including a preferred alternative. DOE intends that the final EIS will provide information to support the selection of disposal method(s) and site(s) for GTCC LLRW and GTCC-like waste.
In general, GTCC LLRW is not acceptable for near-surface disposal. Typically, the waste form and disposal methods must be different from and more stringent than those specified for Class C LLRW. For GTCC LLRW, the Nuclear Regulatory Commission (NRC) requires disposal in a geologic repository, unless proposals for an alternative method are approved. The concentrations of radionuclides in LLRW of Classes A, B, and C limit the periods during which these wastes are generally considered to be hazardous to about 500-1,000 years.
An NRC regulation notes that near-surface disposal site characteristics for Class A, B, and C wastes should be considered for the indefinite future and evaluated for a time frame of at least 500 years. Radioactive decay and the slow migration of radionuclides from the disposal units should reduce the hazard from the radionuclides to safe levels at that time. In contrast, some of the radionuclides in the GTCC wastes either have long half-lives (in excess of 10,000 years) or are present in high concentrations.
Consistent with legislated NRC and DOE authorities, the NRC LLRW classification system does not apply to radioactive waste that is owned or generated by DOE and disposed of in DOE facilities. However, DOE owns or generates both LLRW and non-defense-generated transuranic waste, which have characteristics similar to those of GTCC LLRW and for which there may be no path for disposal. DOE has included these wastes for evaluation in the GTCC EIS, because a common approach and/or facility could be used. For the EIS, DOE is referring to these wastes as “GTCC-like” wastes, although the use of this term does not create a new DOE classification of radioactive waste.
The combined GTCC LLRW and GTCC-like waste inventory addressed in this EIS has a packaged volume of about 12,000 m3 (420,000 ft3) and contains a total activity of about 160 million curies (MCi). The GTCC LLRW and GTCC-like wastes addressed in the EIS include both stored inventory (already generated) and projected inventory (to be generated in the future). The stored inventory consists of the three waste types considered in the EIS (activated metals, sealed sources, and other waste) and includes waste in storage at sites licensed by the NRC or states authorized to do so (GTCC LLRW) and at certain DOE sites (GTCC-like waste).
The draft EIS evaluates the potential environmental impacts associated with constructing and operating one or more new facilities, or using an existing facility, for disposal of GTCC LLRW and GTCC-like waste. The EIS evaluates disposal methods including geologic repository, intermediate-depth borehole, enhanced near-surface trench, and above-grade vault, as well as locations including the Hanford Site in Washington; the Idaho National Laboratory in Idaho; the Los Alamos National Laboratory, the Waste Isolation Pilot Plant (WIPP), and the WIPP vicinity in New Mexico; the Nevada National Security Site (formerly the Nevada Test Site) in Nevada; and the Savannah River Site in South Carolina. The draft EIS also evaluates generic commercial disposal sites and the no-action alternative.
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