Commission Decision on LLRW Blending
On October 13, 2010, the Commission issued its Staff Requirements Memorandum for SECY-10-0043. In it, the Commission approved the option to develop a risk-informed, performance-based position on blending, and provided specific guidance on certain issues, such as compatibility, public outreach, and blending of Greater Than Class C waste (GTCC).
The approved option contains the following components:
"Piggybacking" blending onto an ongoing rulemaking for the disposal of "unique waste streams." The Commission directed the staff to start this rulemaking in its March 18, 2009, Staff Requirements Memorandum for SECY-08-0147. SECY-08-0147 is the staff's analysis of the disposal of depleted uranium (DU) from enrichment plants. Neither enrichment plant DU nor large-scale blended wastes were analyzed in the original technical basis for NRC's disposal regulations in 10 CFR Part 61 (1982). The staff has characterized these waste streams as "unique," requiring additional analysis to ensure their safe disposal in a 10 CFR Part 61 facility. A new requirement for a site-specific intruder analysis would be mandated in the rulemaking, to ensure that these new waste streams not previously analyzed in the 10 CFR Part 61 technical basis can be safely disposed of. As part of this option, the staff committed to conduct an additional analysis of the environmental impacts, including non-radiological impacts such as transportation, for blended waste. Disposal of blended ion exchange resins from a central processing facility would be compared to direct disposal of the resins, onsite storage of certain wastes when disposal is not possible, and further volume reduction of the Class B and C concentration resins.
Revising the Concentration Averaging BTP to be more risk-informed and performance-based. NRC's current guidance on waste blending is contained in the BTP and therefore needs to be revised to incorporate the Commission's new position. In addition, the BTP addresses others areas, such as mathematical averaging of radioactivity concentrations in nuclear power plant components and hardware. The staff had previously planned to revise these other areas of the BTP, and with the Commission decision on blending, can now proceed with those revisions.
Revising the Commission's 1981 Volume Reduction Policy Statement. The Policy Statement encourages licensees to take steps to reduce the amount of waste generated and to reduce its volume once generated. That position was issued when disposal space was scarce, since two of the three operating LLRW disposal sites had threatened to close at that time, and one had recently reduced by half the annual amount authorized for disposal. Further, volume reduction techniques were not yet in widespread use and NRC's Policy Statement was meant to encourage the use of these techniques. Although the Policy Statement does not address blending directly, some stakeholders have argued that blending is contrary to the policy and to the goal of achieving reduced waste volumes. Class B/C concentrations of waste blended to Class A waste for subsequent disposal would not utilize existing volume reduction techniques for Class B/C wastes. These techniques can reduce the volume of B/C waste by 80%. Thus, although blending does not increase the volume of waste, it also does not employ all of the volume reduction technology that is currently available.
Notwithstanding NRC's policy, volume reduction is widely practiced today, in large part because disposal costs have risen significantly in the last 30 years and it is economical to reduce disposal volumes. The staff believes that the Policy Statement could be updated to recognize the progress that has been achieved, and to acknowledge that other factors may be used by licensees in determining how best to manage their LLRW. Specifically, the Policy Statement could be revised to acknowledge that volume reduction continues to be important, but that risk-informed, performance-based approaches to managing waste are also appropriate in managing LLRW safely and that volume reduction should be evaluated in this light.
Issuing interim guidance to Agreement States on how to evaluate proposed disposal of large quantities of blended waste until the rulemaking is completed. The guidance would recommend a case-by-case evaluation of blended waste for each site that plans to accept this type of waste for disposal. Factors such as intruder protection, the need for mitigative measures, and homogeneity would need to be evaluated by the appropriate regulator. In its SRM, the Commission encouraged entities wishing to pursue large-scale blending to wait until the revised BTP is published in final form, and this message also needs to be conveyed to the Agreement States.