Low-level waste and mixed low-level waste

LLW is radioactively contaminated material that is not HLW, SNF, TRU, byproduct material, or naturally occurring radioactive material (DOE, 2009). Under the AEA, the DOE is self-regulating with regard to LLW. Mixed low-level waste (MLLW) is LLW that also contains a hazardous component and is, therefore, subject to a dual regulatory framework, under the AEA, including DOE Order 435.1, Radioactive Waste Management, as well as federal or state hazardous waste requirements promulgated under RCRA (DOE, 1999 ).

The strategy to deal with LLW and MLLW is:

• continue to utilize a combination of DOE onsite, DOE regional, and commercial disposal facilities

• complete an Environmental Impact Statement (EIS) for commercial GTCC waste and issue ROD for GTCC disposal facility

• reuse/disposition contaminated nickel

• build new onsite CERCLA cells

• continue to pursue treatment alternatives for wastes currently inciner­ated at the Toxic Substances Control Act Incinerator at the Oak Ridge Reservation in Tennessee

• continue to develop disposition plans for remaining legacy MLLW and LLW, eliminating waste acceptance and/or transportation barriers.

The DOE produced the Final Waste Management Programmatic Environ­mental Impact Statement (EIS) for Management, Treatment, Storage, and Disposal of Hazardous Waste in 1997 (DOE, 1997). The associated complex­wide decisions for treatment and disposal of LLW and MLLW were issued in 2000. These documents described the approach EM would use to elimi­nate the inventory of legacy LLW and MLLW, the latter in accordance with applicable regulatory agreements. As Table 18.5 illustrates, the DOE has an estimated 1.2 million m3 of LLW and MLLW.

While treatment and disposal of most LLW and MLLW are now routine, the DOE has inventories of both that lack readily available disposition options. The DOE is focusing on developing pathways for this waste. One category of waste for which a disposal solution has been developed is ‘silo material’, generated at the Fernald Site in Ohio. This waste was a byproduct of uranium processing, and the radium it contained emitted large amounts of radon. As a result, it was stored in heavily shielded concrete silos. Because of the nature of this material and the regulatory framework surrounding it, it required a specialized license.

The DOE worked closely with a vendor and state regulators in Texas to allow storage of the Fernald silo material at a Texas commercial facility. Removal of the silo material allowed the DOE to close the Fernald site on schedule in 2006 and greatly reduce the environmental risk of continued storage there. The vendor subsequently applied for a disposal license for this type of material and received the requested permit from Texas regula-

Table 18.5 Disposal of low-level waste and mixed low-level waste

Facility

Waste type

Amount of waste

Onsite disposal — INL, SRS, ORR, and LANL

Regional disposal — Hanford and NNSS

Commercial disposal facilities (when cost effective and in the interest of the federal government)

LLW

LLW and MLLW LLW and MLLW

Legacy and newly generated waste in the DOE Environmental Management program

LLW and MLLW

1.2 million m3

Environmental restoration cleanup (DOE sites) — Fernald, Hanford, INL, and ORR

LLW and MLLW

6 million m3

Environmental restoration cleanup (commercial sites)

LLW and MLLW

3 million m3

INL = Idaho National Laboratory; SRS = Savannah River Site; ORR = Oak Ridge Reservation; LANL = Los Alamos National Laboratory; NNSS = Nevada National Security Site.

tors in 2008. The disposition path for the Fernald silo material is now final­ized and approved.

To complete cleanup of the Rocky Flats Plant in Colorado, the DOE supported technology development to decontaminate 1,500 gloveboxes suf­ficiently to allow equipment to be disposed of as MLLW or LLW. Glove — boxes are sealed chambers in which workers handle plutonium using long rubber gloves that extend through portholes. They range in size and can be as large as a bus. Previous disposition plans called for the gloveboxes to be reduced in size (cut into smaller pieces), packaged, characterized, and certi­fied for disposal at WIPP. This revised approach significantly reduced work exposure to contamination, workplace hazards, and associated costs.

DOE EM has the lead for developing the EIS for the disposal of GTCC low-level radioactive waste and GTCC-like waste. GTCC waste is LLW resulting from US NRC-licensed activities with radionuclides that would be dangerous to humans beyond 500 years. This waste stream comprises materials such as radioactive sources commonly used to sterilize medical products, detect flaws and failures in pipelines and metal welds, and serve other industrial and medical purposes. These materials were generated, owned, or managed by commercial entities rather than the DOE. However, the Low-level Radioactive Waste Policy Amendments Act of 1985 assigned the federal government responsibility for the disposal of certain GTCC radioactive waste resulting from US NRC-licensed activities.

GTCC waste is the highest radiological activity waste with no planned disposition path. The DOE is preparing an EIS to evaluate disposal options for commercial GTCC LLW as well as LLW similar in character to GTCC generated by the DOE. The DOE issued a Notice of Intent to prepare the EIS in July 2007. A draft EIS was issued by the DOE in February 2011, and a final EIS is expected to be released in 2013. By law, before the DOE makes a final decision on the disposal alternative(s) to be implemented, the agency must submit a report to Congress and await Congressional action before making a final disposal decision.

Contaminated nickel from the shutdown of gaseous diffusion plants is a potentially valuable asset. The DOE is evaluating the feasibility of recover­ing the nickel for potential sale to an end user rather than disposing of it as LLW.

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