ML20239A949
| ML20239A949 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/26/2020 |
| From: | Lochbaum D Pacific Gas & Electric Co |
| To: | Samson Lee Plant Licensing Branch IV |
| Lee S, 301-415-3158 | |
| Shared Package | |
| ML20239A951 | List: |
| References | |
| Download: ML20239A949 (1) | |
Text
From:
David Lochbaum To:
Lee, Samson Cc:
Doane, Margaret; Morris, Scott; Linda Seeley; Lucy J Swanson; dcurran@harmoncurran.com; Nieh, Ho
Subject:
[External_Sender] Diablo Canyon Unit 1 AFW system piping Date:
Wednesday, August 26, 2020 12:18:30 PM Attachments:
20200826-dc-lochbaum-evaluation-unit-1-afw-piping.pdf Hello Sam:
Attached is my evaluation of the potential piping degradation of the AFW systemat Diablo Canyon Unit 1.
I found that the NRC has been asked four times prior to PG&E's recent request to extend the 72-hour LCO for one AFW train inoperable.
I hope it's still true, but the NRC has never granted relief from the 72-hour limit unless an AFW train was declared inoperable. In 2010, NRC denied Entergy's exigent LAR to extend the LCO for AFW Pump 32 from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 106 hours0.00123 days <br />0.0294 hours <br />1.752645e-4 weeks <br />4.0333e-5 months <br />. The NRC denied the request on grounds that AFW pump 32 was stated to remain operable by Entergy, thus removing the need for an urgent NRC relieffrom the non-applicable 572-hour limit.
To the best of my awareness, PG&E has not declared any AFW train on Unit 1 to be inoperable. If so, none of the NRC's reliefoptions shouldbe used. Instead, PG&E and follow Entergy's example by submitting a regular license amendment request with all the attendant public notifications.
- Thanks, Dave Lochbaum