Uploaded April 2026 | Updated September 2026, 11 hours ago
Video recording of RIC2026 Technical Session: T2 - Multi-Unit Risk: Are We Ready for This?
Note: the subtitles are 90% accurate.
This session will explore the topic of multi-unit (MU) risk for both the existing fleet of light water reactors and advanced reactor designs. Susan Cooper (NRC Office of Nuclear Regulatory Research (RES)) will summarize the integrated site risk approach and results from the NRC’s Level 3 probabilistic risk assessment (PRA) project, including MU Level 1, 2, and 3 results. The Electric Power Research Institute has been involved in developing and applying MU PRA guidance for both U.S. and international nuclear power plants (NPPs). The current approach and status for developing an MU PRA standard will be presented by a member of the Joint Committee on Nuclear Risk Management MU PRA Standard Working Group. Given that some countries outside the United States have many units on a single site, a different perspective on MU risk will be provided by a representative from the international community for which most NPP sites have more than two reactors. Finally, efforts to model MU risk for advanced reactor designs will be summarized by a member from industry.
SESSION CHAIR(S):
Jonathan Evans, Chief of the Probabilistic Risk Assessment Branch, RES/NRC
Opening Remarks
SPEAKER(S):
Shahen Poghosyan, Senior Nuclear Safety Officer, International Atomic Energy Agency
Multi‑unit Risk: Understanding the Big Picture - Opportunities and Challenges
Mark Wishart, Senior Technical Leader, Electric Power Research Institute
EPRI's Perspective on Multi-Unit Risk Assessments
Susan Cooper, Senior Reliability and Risk Engineer, Probabilistic Risk Assessment Branch, Division of Risk Analysis, RES/NRC
Insights from NRC's Level 3 PRA Project's Multi-Unit and Integrated Site Risk Results
Ricky Summitt, Senior Principal PRA Consultant, Enercon Services, Inc.
Challenges in Defining a Multi-Unit PRA
SESSION COORDINATORS(S):
Temitope Williams, Reliability and Risk Analyst, RES/NRC tel: (301) 415-1564, e-mail: temitope.williams@nrc.gov
Video recording of RIC2026 Technical Session: T2 - Multi-Unit Risk: Are We Ready for This?
Note: the subtitles are 90% accurate.
This session will explore the topic of multi-unit (MU) risk for both the existing fleet of light water reactors and advanced reactor designs. Susan Cooper (NRC Office of Nuclear Regulatory Research (RES)) will summarize the integrated site risk approach and results from the NRC’s Level 3 probabilistic risk assessment (PRA) project, including MU Level 1, 2, and 3 results. The Electric Power Research Institute has been involved in developing and applying MU PRA guidance for both U.S. and international nuclear power plants (NPPs). The current approach and status for developing an MU PRA standard will be presented by a member of the Joint Committee on Nuclear Risk Management MU PRA Standard Working Group. Given that some countries outside the United States have many units on a single site, a different perspective on MU risk will be provided by a representative from the international community for which most NPP sites have more than two reactors. Finally, efforts to model MU risk for advanced reactor designs will be summarized by a member from industry.
SESSION CHAIR(S):
Jonathan Evans, Chief of the Probabilistic Risk Assessment Branch, RES/NRC
Opening Remarks
SPEAKER(S):
Shahen Poghosyan, Senior Nuclear Safety Officer, International Atomic Energy Agency
Multi‑unit Risk: Understanding the Big Picture - Opportunities and Challenges
Mark Wishart, Senior Technical Leader, Electric Power Research Institute
EPRI's Perspective on Multi-Unit Risk Assessments
Susan Cooper, Senior Reliability and Risk Engineer, Probabilistic Risk Assessment Branch, Division of Risk Analysis, RES/NRC
Insights from NRC's Level 3 PRA Project's Multi-Unit and Integrated Site Risk Results
Ricky Summitt, Senior Principal PRA Consultant, Enercon Services, Inc.
Challenges in Defining a Multi-Unit PRA
SESSION COORDINATORS(S):
Temitope Williams, Reliability and Risk Analyst, RES/NRC tel: (301) 415-1564, e-mail: temitope.williams@nrc.gov
