ML22242A288
| ML22242A288 | |
| Person / Time | |
|---|---|
| Issue date: | 09/30/2022 |
| From: | Michael Orenak NRC/NRR/DANU/UAL1 |
| To: | Steven Lynch NRC/NRR/DANU/UARP |
| Orenak M | |
| Shared Package | |
| ML22242A289 | List: |
| References | |
| EPID N-2022-ADV-0004 | |
| Download: ML22242A288 (4) | |
Text
MEMORANDUM TO:
Steven Lynch, Chief Advanced Reactors Policy Branch Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation FROM:
Michael Orenak, Project Manager Advanced Reactor Licensing Branch 1 Division of Advanced Reactors and Non-Power Production and Utilization Facilities Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE AUGUST 3, 2022, CLOSED MEETING TO DISCUSS THE INDUSTRY DEVELOPED OBSERVATIONS AND ACTIONS TAKEN FROM THE X-ENERGY AND NATRIUM TIRICE TABLETOP EXERCISES (EPID N-2022-ADV-0004)
On August 3, 2022, a closed meeting was held to discuss the industrys observations and actions taken from the X-energy TIRICE tabletop exercises held June 13-15, 2022, and the Natrium TIRICE tabletop exercises held July 18-20, 2022. These tabletop exercises were held to exercise the Title 10 Code of Federal Regulations (CFR) 50.59-like process outlined in Revision D of the white paper, Technology Inclusive Risk Informed Change Evaluation (TIRICE) for Non-Light Water Reactors, that is to be applied by reactor applicants using a risk-informed, performance-based licensing strategy outlined in Nuclear Energy Institute (NEI) 18-04, Revision 1, Risk-Informed Performance-Based Guidance for Non Light Water Reactor Licensing Basis Development. Revision D of the TIRICE white paper was submitted to the NRC on July 7, 2022 and can be found in the Agencywide Documents Access and Management System (ADAMS) at Accession Nos. ML22244A035. The U.S. Nuclear Regulatory Commission (NRC) staff provided comments to industry on Revision D of the TIRICE paper on August 2, 2022 and those comments can be found at ML22244A046. NEI 18-04, Revision 1, can be found at ML19241A336.
The closed meeting notice and agenda, dated June 27, 2022, are available at ML22208A170.
The industrys presentation slides are available at ML22242A286. The Enclosure provides the list of meeting attendees.
Meeting Summary After introductions, the meeting proceeded into the discussion of the X-energy tabletop observations and actions taken. For slide 2 of the presentation, a discussion arose around when a probabilistic risk assessment (PRA) change should be controlled by a PRA standard and when it should be controlled by the TIRICE process. The NRC asked if changes in computer codes used in a PRA analysis are considered a change to methods of evaluation under 10 CFR 50.59. The industry responded the change in methods would be applicable to design basis September 28, 2022 Signed by Orenak, Michael on 09/28/22
S. Lynch 2
accidents (DBAs), but changes to methods for other licensing basis events would be controlled under the PRA standard American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) RA-S-1.4-2021, Probabilistic Risk Assessment Standard for Advanced Non-Light Water Reactor Nuclear Power Plants. Industry also reiterated that changes to PRAs should be controlled differently than other changes in licensing documents. The NRC commented that a possible solution to controlling changes to PRAs (since they are more important in plants licensed using NEI 18-04, Revision 1, process) is to have a separate program document to specify how changes to methods, key insights, results for the PRA, parts of the PRA, etc. are identified and analyzed for the need for a license amendment before implementation. The industry disagreed with the NRCs proposal because they said scope creep would occur. The industry concluded the discussion by stating that they continued to desire to have all PRA changes occur using ASME/ANS RA-S-1.4-2021 change control process and provided a reminder that just because an aspect of the licensing basis is in the FSAR, it doesnt mean that its under a change control process.
For slide 3, an NRC contractor asked if a change in reliability would be considered a PRA assumption in the TIRICE process. The industry responded that a change in reliability would not be considered a PRA assumption in the same way that assumptions are treated in deterministic analyses for a DBA.
Slide 5 was the start of the discussion of the Natrium tabletop exercises. For slide 5, industry stated that they were trying to develop non-light water reactor examples to put into the TIRICE guidance document to support the end users. The NRC staff agreed that examples are very valuable for the end users and also help the NRC staff.
For slide 7, item 9, industry stated that they are still developing their response to this item.
Industry is unsure if a change from non-safety related with special treatment to non-safety related with no special treatment would require a TIRICE evaluation because of the lower safety impact of the change.
Enclosure:
List of Attendees CONTACT: Michael Orenak, NRR/DANU 301-415-3229
Package ML22242A289 NRC-001 OFFICE NRR/DANU/UAL1/PM NRR/DANU/UAL1/LA NRR/DANU/UARP/BC NRR/DANU/UAL1/PM NAME MOrenak DGreene SLynch MOrenak DATE 9/1/2022 9/14/2022 9/28/2022 9/28/2022
Enclosure List of Attendees CLOSED MEETING TO DISCUSS THE INDUSTRY OBSERVATIONS AND ACTIONS TAKEN FROM THE X-ENERGY AND NATRIUM TIRICE TABLETOP EXERCISES Wednesday, August 3, 2022 Name Organization Michael Orenak U.S. Nuclear Regulatory Commission (NRC)
Bill Reckley NRC Chris VanWert NRC Joe Sebrosky NRC Steve Lynch NRC Amy Cubbage NRC Scott Tonsfeldt NRC Michelle Hart NRC Eric Bowman NRC Jim Kinsey Idaho National Labs (INL)
Thomas Hicks INL Tom King INL Michael Tschiltz Consultant to Southern Company Steve Nesbit LMNT Consulting Justin Wheat Enercon Amir Afzali Southern Company Pete Lablond LeBlond & Associates Brandon Chisolm Southern Company Services Steve Vaughn (X-energy portion only)
X Energy, LLC Dennis Henneke (Natrium portion only)
GE Power