The Commissioners were briefed today by NRC staff and stakeholders on Generic Safety Issue 191, Assessment of Debris Accumulation on Pressurized Water Reactor Sump Performance
– Source NRC –
Good morning. The Commission meets this morning to discuss Generic Safety Issue-191. During today’s meeting, we will hear from the staff on the agency’s work to ensure that sumps for pressurized water reactors meet their required safety performance, as well as to discuss how we move forward to achieve closure on this longstanding issue. The Commission also will hear from a panel of industry representatives regarding their views of how to resolve this issue.
This has not been an easy issue. The fact that even small amounts of debris can significantly affect the emergency core cooling system is part of the reason why it has been so challenging. The issue involves many complexities, which is why researchers have experienced difficulty in modeling the chemical effects involved.
But in recent years, we have made progress on this issue. Over half of pressurized water reactors have resolved their strainer performance issues, but there are 33 remaining plants that still have issues to resolve. As the staff will discuss during their presentations, these outstanding issues potentially raise significant safety concerns in the event of a loss of coolant accident. Although the probability of this occurring may be low, we have to be cognizant of the magnitude of the potential safety consequences when we look at the risk that this issue poses.
This is an important safety issue for the Commission to resolve. I want to encourage both the staff and industry representatives to highlight the policy issues that they think may require Commission consideration to do so. I look forward to today’s discussion.