DEVELOPMENT OF A LONG-TERM DISPOSITION OPTION FOREXCESS RADIOACTIVE SEALED SOURCES

摘要

In medicine, medical research, and numerous other fields, the use of sealed radioactivesources has greatly improved human living conditions. However, many of these sealedsources become obsolete, or excess. If improperly managed, these once beneficialsources can cause serious injury, or death. In the U.S., the most problematic of thesesealed sources are those held by state and Federal licensees for several years with nooption for disposal. As radioactive waste, this backlog of sealed sources would beclassified as Greater-than-Class-C (GTCC) low-level waste by the U.S. NuclearRegulatory Commission (NRC).Recognizing these hazards, the U.S. Department of Energy (DOE) has implemented theOff-Site Source Recovery (OSR) Project to (a) recover, (b) store, and (c) dispose of theGTCC LLW sealed sources and other similar materials as designated by the DOE. Thenear-term objective of the DOE’s OSR Project is to reduce the risk to the general publicand the environment from excess and unwanted sealed sources that are not now underDOE control. This paper emphasizes the OSR Project’s (a) near-term activities that willestablish a technical basis for developing disposal options, (b) the activities necessary toselect a disposal option, or options through the National Environmental Policy Act(NEPA) process and, (c) provides a summary of current activities. As this mortgage ofsealed sources in storage at DOE sites builds, the need to implement a viable disposaloption becomes more acute.The Low-Level Radioactive Waste Policy Amendments Act of 1985 dictates that (a) thefederal government, and specifically DOE, is responsible for disposal of GTCC LLW,and (b) the GTCC LLW disposal facility must be licensed by the NRC.GTCC LLW is not generally suitable for near-surface disposal, and disposal in a geologicrepository is the NRC’s default option for GTCC LLW disposal, although the NRC willconsider alternative disposal methods that the DOE might propose. As a generalization,in a storage or disposal facility, the GTCC LLW actinides could pose a health threat forthousands of years, and the GTCC LLW non-actinides will pose a health threat for a fewhundred years. This general division of the GTCC LLW may lead the OSR Project todevelop two separate disposal options.Because the NRC has never licensed a GTCC LLW disposal site, the NRC will have todevelop the licensing process and the review criteria for the license application. Inaddition to the NRC’s licensing standards, a GTCC LLW disposal facility may also haveto meet EPA disposal standards. One regulatory outlier is the co-disposal of GTCC LLWin the Waste Isolation Pilot Plant (WIPP), which is an EPA certified geologic repositoryfor defense transuranic (TRU) wastes. Many of the GTCC LLWs from NRC licenseesare identical in character to defense TRU wastes that have been approved for disposal inWIPP. The OSR Project will explore the option of disposal in WIPP of those GTCCLLWs that are similar in character to the TRU wastes destine for WIPP.An options analysis will be performed to define the disposal option(s) that will beimplemented. The analysis can be divided into three stages: (1) define the criteria thatwill be used to screen the options and a strategy for implementing the analysis; (2) gatherinformation on each option; and (3) implement a broad screening analysis. The screeninganalysis will be implemented by the DOE through the NEPA process. This work willlead to the development of a viable GTCC LLW disposal option for sealed sources by2006.