Background

On July 18, 2013, NRC staff requested Commission approval to publish a proposed rule in the Federal Register that would amend 10 CFR Part 61. (See LLW Notes, July/August 2013, pp. 1, 32-38. NOTE: This link is only accessible to LLW Forum Members.)

The proposed amendments would revise 10 CFR Part 61 to require low-level radioactive waste disposal licensees and license applicants to conduct updated and new site-specific analyses and to permit the development of criteria for future low-level radioactive waste acceptance based on the results of these analyses. According to NRC staff, these amendments would ensure that low-level radioactive waste streams that are significantly different from those considered during the development of the current regulations will be disposed of safely and meet the performance objectives for land disposal of LLRW.

The proposed rule would update the existing technical analysis requirements for protection of the general population (i.e., performance assessment) to include a 10,000-year compliance period; add a new site-specific technical analysis for the protection of inadvertent intruders (i.e., intruder assessment) that would include a 10,000-year compliance period and a dose limit; add a new analysis for certain long-lived low-level radioactive waste (i.e., performance period analysis) that would include a post-10,000 year performance period; and revise the technical analyses required at closure.

NRC would also add a new requirement to develop criteria for the acceptance of low-level radioactive waste for disposal based on either the results of these technical analyses or on the existing low-level radioactive waste classification requirements. This would facilitate consideration of whether a particular disposal site is suitable for future disposal of depleted uranium (DU), blended low-level radioactive waste, or any other previously unanalyzed low-level radioactive waste stream. Additionally, the NRC is proposing amendments to facilitate implementation and better align the requirements with current health and safety standards. This rule would affect low-level radioactive waste disposal licensees and license applicants that are regulated by the NRC or the Agreement States.

For additional information regarding the P61WG report, please contact LLW Forum Executive Director Todd D. Lovinger at (754) 779-7551 or LLWForumInc@aol.com.

NRC Commission Direction

On February 20, 2014, NRC released a Staff Requirements Memorandum (SRM-SECY-13-0075) in which the Commission approves publication of the proposed Part 61 rule and the associated draft guidance for public comment, subject to the following comments and changes:

    • The proposed rule should be revised to include a regulatory compliance period of 1,000 years.
    • The proposed rule should be published with a compatibility category “B” applied to the most significant provisions of the revised rule, including the Period of Compliance; the Protective Assurance Analysis Period and its analytical threshold, which, as it is approached, requires the applicant to propose remedial changes to the disposal site design, or impose inventory limits, or propose alternative methods of disposal; and the Waste Acceptance Criteria.
    • The Commission has approved staff’s proposal to require a 10,000 year intruder assessment analysis, built upon the same assumptions as the compliance and protective assurance analyses contained in the rule, which should be detailed in guidance documents.
    • The site-specific analysis for protection of the general public within the 1,000-year compliance period should set a specific dose limit of 25 mrem/yr.
    • The staff should focus on ensuring a thorough review of the draft guidance by the limited community of disposal operations in the U.S. This includes the licensees, Agreement States, and interested public. The staff should also ensure the draft guidance is reviewed by the broader scientific and academic community and other government agencies with disposal experience.
    • The proposed rule should clearly indicate that the intruder assessment should be based on intrusion scenarios that are realistic and consistent with expected activities in and around the disposal site at the time of site closure.
    • A further protective assurance analysis should be performed for the period from the end of the compliance period through 10,000 years. Given the significant uncertainties inherent in these long timeframes, and to ensure a reasonable analysis, this performance assessment should reflect changes in features, events, and processes of the natural environment such as climatology, geology, and geomorphology only if scientific information compelling such changes from the compliance period is available. In general, this analysis should strive to minimize radiation dose with the goal of keeping doses below a 500 mrem/yr analytical threshold. The radiation doses should be reduced to a level that is reasonably achievable based on technological and economic considerations.
    • The Commission has approved the staff’s proposal for applicants to provide a qualitative analysis covering a performance period of 10,000 years or more after site closure to evaluate the ability of the disposal system to mitigate long-term risks associated with the disposal of long-lived low-level radioactive waste.
    • The proposed rule should include a clear statement that licensing decisions are based on defense in depth (DID) protections, such as siting, waste forms and radionuclide content, engineered features, natural geologic features of the disposal site, and on performance assessment (PA) goals and insights, as well as scientific judgment. This combination of DID and PA should be identified as the “safety case” for licensing. The staff should clearly describe the attributes of the safety case in the proposed rule, as modified by this SRM, in terms of the types of DID protections and the role of the PA in satisfying performance criteria and establishing a safety case. Confirming changes should be made throughout the rulemaking package.
    • The staff should develop a specific question for the Federal Register notice that introduces this proposed rule regarding whether the compatibility designations assigned to the various sections of the proposed rule as modified by this SRM are appropriate and solicit comments on whether changes should be considered and for what reason. Although the Commission has assigned Compatibility “B” for the Compliance Period and the Protective Assurance Analysis Period, the staff should specifically solicit comment on that designation. In addition, a question should be added to the FRN regarding whether 500 mrem/yr is an appropriate analytical threshold for the Protective Assurance Analysis period.
    • The Advisory Committee on Reactor Safeguards (ACRS) is encouraged to continue to provide their independent review and recommendations on the technical basis supporting this rule, and the accompanying draft guidance, during the rulemaking period.
    • The public comment period should be extended to 120 days.
  • The revised Federal Register Notice arising from the direction in the staff requirements memorandum should be provided to the Commission for its review no later than 10 business days prior to its transmittal for publication.

A copy of SRM-SECY-13-0075 is available at http://www.nrc.gov/reading-rm/doc-collections/commission/srm/2013/2013-0075srm.pdf.   The proposed rule (SECY-13-0075) can also be found in the NRC’s Agencywide Documents Access and Management System (ADAMS) using accession number ML13129A268. The following enclosures were submitted along with the proposed rule: a draft Federal Register notice (ML13129A262); draft regulatory analysis (ML13129A264); and, summary of stakeholder feedback (ML13129A266).   To locate the proposed rule and enclosures on NRC’s web site, please go to www.nrc.gov and click on “Adams Public Documents” on the right-hand column.  Then, click on “Begin Web-Based ADAMS Search.”  When you open that page, click on “Advance Search” tab near the top. Then, for “document properties” enter “Accession Number” as the property, “is equal to” as the operator, and the specific ML number for the desired document.   For additional information, please contact Andrew Carrera in the NRC’s Office of Federal and State Materials and Environmental Management at (301) 415-1078 or at Andrew.Carrera@nrc.gov.