Blending of Low-Level Radioactive Waste

At the direction of the Commission, the U.S. Nuclear Regulatory Commission (NRC) staff is working to improve and strengthen the agency's standards for blending of low-level radioactive waste (LLRW). The goal is to make NRC's regulation of LLRW blending more risk-informed, performance-based, and in general more consistent with the agency's overall policy for regulating the nuclear industry.

Blending, as defined here, refers to mixing of LLRW of different concentrations. It does not mean mixing radioactive waste with non-radioactive waste (i.e., dilution) and concerns only disposal of the blended waste in a licensed facility, not its release to the general environment.

NRC's previous position discouraged blending under some conditions, without a health and safety basis, but did not discourage blending if a nuclear facility's operational efficiency could be improved. This position was not fully risk-informed or performance-based.

The new agency position is risk-informed – it is tied to how LLRW blending might affect the protection of public health and safety.

The new position is performance-based - NRC's decision making involving blending will above all be based on performance and results. Performance means that the blended waste must meet the limits on radiation exposures at the disposal facility and limits on how much the radioactivity concentration may vary (i.e., how well-mixed it must be).

NRC is developing new regulations that will ensure that the safety of blended waste, as well as other types of LLRW, are evaluated before their disposal.

In addition to a new regulation that will address disposal of blended waste, NRC is taking or has taken three other regulatory actions:

• NRC will publish regulatory guidance that addresses the characteristics of blended waste needed to ensure its safe disposal, including how uniform, or well mixed, the waste must be. A draft of this guidance, NRC's Branch Technical Position on Concentration Averaging and Encapsulation, was noticed for comment on June 11, 2012 (77 FR 34411).

• NRC has updated its “Policy Statement on Low-Level Waste Volume Reduction.” Since its publication in 1981, nuclear facility operators have made significant progress in reducing LLRW volumes. The revised Policy Statement recognizes this progress and acknowledges that other factors may be used in determining how nuclear facilities manage their LLRW. The final policy statement can be found in (77 FR 25760)

• NRC issued interim guidance to the NRC Agreement States on how to evaluate proposals to blend large quantities of waste until the Concentration Averaging and Encapsulation BTP is updated. Agreement States should conduct case-by-case evaluations in the meantime.

NRC has obtained public and stakeholder input on the proposed revisions to the Concentration Averaging and Encapsulation BTP in workshops and  formal notices for comment in the Federal Register.  For the rulemaking that will address blended waste, NRC has also held several workshops and public meetings and will obtain public comments on the proposed rule when it is published.  Schedules for development of the rule and guidance, including meetings and public comment periods, will be posted on NRC web site.

Further, in consideration of stakeholder concerns expressed regarding potential environmental impacts associated with the blending of certain LLRW, on September 20, 2012, (77 FR 58416), NRC issued the following report for public comment: "Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste Spent Ion Exchange Resins from Commercial Nuclear Power Plants." In this report, the staff identified and compared potential environmental impacts of six alternatives, including options involving blending, long-term storage, direct disposal, and volume reduction of LLRW spend ion exchange resins.

The NRC Agreement States will have to adopt NRC's new regulation requiring a safety analysis of the disposal of blended and other LLRW. The Commission directed that the staff work closely with the Agreement States to ensure maximum State flexibility in drafting the rule language. With respect to the new guidance NRC is developing, Agreement States are not required to use NRC guidance. However, they frequently follow NRC guidance in making decisions on their licensing requests.