IN BTP, NRC MAKES CHANGES IN WASTES ACCEPTABLE FOR MIXING

After several preliminary drafts, the Nuclear Regulatory Commission’s proposed final Branch Technical Position on Concentration Averaging was released to the public for a 120-day public comment period yesterday. The BTP is being updated as part of ongoing NRC efforts to address unique waste streams such as blended radioactive waste in regulations. Major changes were made to the section governing what wastes would be considered acceptable for blending or mixing, and how the NRC or Agreement State regulators could determine whether mixed low-level radioactive wastes are homogeneous. The section, now titled “Classifying Mixable and Homogeneous Wastes,” defines waste streams NRC  considers mixable, and made the parameters of what is considered homogenous more liberal in the proposed version. “Mixable” waste is defined as “waste that is amenable to physical mixing to relatively uniform radionuclide concentrations,” and NRC staff wrote that “mixable waste is not necessarily homogeneous.” Waste is homogeneous under the proposed BTP if “the concentrations of the ‘nuclide(s) of concern are likely to approach uniformity in the context of reasonably foreseeable intruder scenarios. Thus, mixability is a physical property of the waste, whereas homogeneity, as used in this guidance, is a radiological property.”