Resolution of Generic Safety Issues: NMSS-0015. Adequacy of 10 CFR 150 Criticality Requirements (Rev. 1) ( NUREG-0933, Main Report with Supplements 1–34 )
As of July 1998, SNM-bearing low-level waste was being disposed of at the following three facilities: (1) Envirocare in Clive, Utah; (2) U.S. Ecology in Hanford, Washington; and (3) Chem-Nuclear in Barnwell, South Carolina. Until 1997, the Hanford and Barnwell facilities were licensed by NRC under 10 CFR 70 to possess and dispose of greater than critical mass quantities of SNM. These facilities requested that the SNM possession limits be reduced to the 10 CFR 150.11 limits and that the NRC licenses be transferred to the respective Agreement States. The licenses were amended as requested and transferred to the respective Agreement States. Thus, all three facilities are currently regulated by Agreement States.
Emplacement criticality safety was addressed in 10 CFR 61.16(b)2 which requires licensees to describe proposed procedures for avoiding accidental criticality for both storage and emplacement. However, at the time this issue was identified, this portion of 10 CFR 61 was not a compatibility requirement for Agreement States. In conjunction with considering changing the compatibility requirement of 10 CFR 61.16(b), NRC planned to develop guidance on emplacement criticality which could be used at existing and future low-level disposal sites. This issue was identified1723 by NMSS to develop guidance on emplacement criticality that could be used at existing and future low-level waste disposal sites by licensees, Agreement States, and the NRC.
The issue was given a medium priority ranking and resolution was pursued. SECY-99-272 was issued with recommendations to revise the Agreement State compatibility requirements in 10 CFR 61 and issue new emplacement criticality guidance. In an SRM dated January 5, 2000, the Commission disapproved the staff's proposal and directed the staff to cease work on the issue. The Commission concluded that the theoretical scenarios developed by the staff were unrealistic and failed to justify further efforts. Thus, the issue was resolved546 with the Commission's decision.