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 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's new regulations will ensure that the safety of large-scale blended waste be evaluated before its disposal. Large-scale blending means mixing of waste from multiple generators at a third party location (i.e., a waste processing facility) prior to its disposal.

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

• NRC will publish regulatory guidance that addresses the characteristics of large-scale blended waste needed to ensure its safe disposal, including how uniform, or well mixed, the waste must be.

• NRC will update 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 will recognize this progress and acknowledge that other factors may be used in determining how nuclear facilities manage their LLRW.

• NRC will issue guidance to Agreement States on how to evaluate proposals to blend large quantities of waste until the staff guidance is updated. Agreement States should conduct case-by-case evaluations in the meantime. The guidance will also indicate to States that entities wishing to pursue large-scale blending should be advised that NRC guidance on blending is undergoing revisions and it may be advisable for them to wait until it is published in a final form.

NRC will aggressively solicit public and stakeholder input on the proposed rulemaking and guidance. Several public meetings will be conducted and the draft rule language and guidance will be published for comment. Schedules for development of the rule and guidance, including meetings and public comment periods, will be posted on NRC web site.

NRC Agreement States will have to adopt NRC's new regulation requiring a safety analysis of the disposal of large-scale blended waste. 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 will be developing, Agreement States are not required to use NRC guidance. However, they frequently follow NRC guidance in making decisions on their licensing requests.