Results of NRC's Analysis of Use of Intentional Mixing of Contaminated Soil for Decommissioning Sites

摘要

The U.S. Nuclear Regulatory Commission (NRC) Staff's analysis of issues related to the License Termination Rule (LTR) included an evaluation of the use of intentional mixing of contaminated soil to meet the radiologicalrncriteria for license termination at 10 CFR 20, Subpart E. NRC's objective in conducting this analysis was to providernadditional options for meeting the criteria for license termination in the rule, particularly for sites that would need to meetrnthe criteria for restricted release, at 10 CFR 20.1403. The results of this analysis (along with the results of the evaluations ofrnother LTR issues) provide clarity and flexibility to licensees and NRC staff for completing remediation and terminatingrnlicenses at several complex decommissioning sites.rnThe NRC staff conducted a two-part evaluation to ensure that the issue of the use of intentional mixing was thoroughly researched and a solid basis was included to develop and support the set of options. The first evaluation was arnthorough identification and analysis of the policies, regulations, guidance, and experiences of the NRC, other U.S.rngovernment agencies, international organizations, and other domestic sources (e.g., Health Physics Society) with the use ofrnintentional mixing or related activities. This first evaluation provided significant issues, facts, and positions associated withrnthe use of intentional mixing that would be factored into the decision process in the second evaluation.rnThe second evaluation was an analysis of a set of options for the use of intentional mixing to meet the release criteria of the LTR. In May 2004, the Commission approved the intentional mixing of soil to meet the LTR criteria on a case-by-case basis, with some minimum conditions that were necessary to bound approval decisions that were based on the evaluations. The Commission also allowed continuation of approvals of mixing to meet waste acceptance criteria of disposal facilities and for certain special disposals conducted under 10 CFR 20.2002.rnMany specifics about the limited circumstances under which NRC would consider a proposal to use intentional mixing andrnhow it will be implemented in an actual situation still need to be addressed. Much of this will be covered in guidance whichrnwill be issued in draft form later this year. Other issues will also be considered, and policies determined, as actual proposalsrnto use intentional mixing are considered.