ML25021A204
| ML25021A204 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/21/2025 |
| From: | Sean Meighan NRC/NRR/DRA |
| To: | Southern Nuclear Operating Co |
| References | |
| Download: ML25021A204 (1) | |
Text
U.S. NRC Staff Presentation - Items to Help the Review of the Proposed LAR Pre-Submittal Meeting regarding a Proposed LAR for AST using RG 1.183, Revision 1 at Vogtle 1 and 2 February 6, 2025 Sean Meighan Radiation Protection and Consequence Branch Division of Risk Assessment Office of Nuclear Reactor Regulation
Introduction
- The items discussed will help make the NRC staff review more efficient.
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Values Table For each accident, will SNC provide a values table which lists all initial conditions, inputs, and assumptions?
In the table, will SNC provide 3 categories/columns (example ML22181B066, Attachment 11)?
o Value in the License Amendment Request (LAR) o The Current Licensing basis value (CLB) o Change/no change column If there is a change from CLB, describe why the change.
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Values Table Continued
- If there is a change in assumed unfiltered in-leakage to the control room from the CLB (or more specifically) - will SNC provide tracer gas tests? The last 3 tests would be best for trending.
- CLB may include changes made under 50.59 and could include changes that the NRC staff has not seen.
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RADTRAD
Will SNC provide the RADTRAD decks (ensure that TSC is included if applicable)?
Will SNC provide the RADTRAD output (*.pdf) attached to end of LAR?
Which version of RADTRAD is SNC using?
Will SNC provide the following statement in the proposed LAR (or something similar)?
Unless otherwise noted below all initial conditions, inputs, and assumptions for each leakage pathway used for the analysis remain the same as used in the current UFSAR Chapter 15 and/or in the AST LOCA analysis of record. (this should go just before the Values Table described above) - inclusion of this statement allows us to focus on the initial conditions, inputs, and assumptions that have changed from CLB.
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Margins and Defense-in-Depth Will SNC provide a tabulation/treatment of major margins (e.g., unfiltered control room leakage, containment leakage, ESF leakage)?
Will SNC provide a tabulation/treatment of major contributors to defense-in-depth, diversity, and redundancy (e.g. assuming additional failure outside of single failure, modeling only 2 MSLs (deposition and holdup), assuming additional passive failures)?
Will SNC be noting the other design basis accidents (DBAs) that did not meet criteria for submitting in the LAR? (Those DBAs that were affected by the change in the LAR, but did not trip the more than minimal increase in dose and can be addressed in 50.59 space.)
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Exceptions and Deviations from Revision 1 Will SNC be taking any exceptions or deviations RG 1.183, Revision 1?
Will SNC be retaining any elements of RG 1.183, Revision 0?
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Conclusion
- The NRC staff is not making any regulatory decision at todays meeting.
- Once the proposed LAR is received, the NRC staff will make any regulatory decisions in writing in a timely manner.
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