Section 50.69 of the regulations of the Nuclear Regulatory Commission (NRC) provides an option for licensees of nuclear power plants to establish a program for risk-informed treatment of structures, systems, and components (SSCs), such as quality assurance and maintenance. Implementation of Section 50.69 should result in less burdensome treatment requirements for SSCs that have low safety significance, as determined through a risk-informed categorization process.
The industry has developed a draft template for license amendment requests (LARs) to implement 10 CFR 50.69. The purpose of the template is to expedite NRC review and approval of LARs submitted pursuant to Section 50.69.
On January 25, NRC staff held a public meeting to discuss its comments on the draft template. The staff had some significant comments on the draft template, mostly related to the categorization process for SSCs. In particular, NRC expressed concern with categorizations that are not based upon probabilistic risk assessments (PRAs) performed in accordance with Revision 2 of Regulatory Guide 1.200. This concern extended to the use of seismic margins analysis in lieu of seismic PRAs, as well as the use of Fire-Induced Vulnerability Evaluations (FIVE) in lieu of fire PRAs. NRC also expressed concern with the deterministic questions in the template used to supplement PRAs for the purpose of categorizing SSCs. More specifically, NRC questioned whether the deterministic questions are sufficiently clear and rigorous. In response, industry representatives stated that procedural guidance would be issued for answering the deterministic questions, and invited NRC to attend meetings of Integrated Decision-making Panels (IDPs) to verify the rigor with which IDPs answer the deterministic questions.
Overall, the NRC staff believes that the templates for LARs will prove valuable in expediting NRC’s reviews, and that the NRC should be able to complete its review of a LAR within one year. However, NRC would like the industry to “meter” its submission of LARs so that NRC is not inundated with dozens of LARs at one time. NRC stated that it would inform the industry in February regarding the number of LARs that the NRC could process per quarter.
Revisions to the draft template to account for NRC’s comments at the meeting are not anticipated. Instead, through the use of coordinating committees, industry representatives will help ensure that LARs address NRC’s comments and are consistent in scope and content to facilitate NRC’s reviews.