ML13066A627
| ML13066A627 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/19/2010 |
| From: | Wong S NRC/NRR/DRA |
| To: | Rosenberg S Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2012-0325 | |
| Download: ML13066A627 (1) | |
Text
Mitman, Jeffrey From:
Wong, See-Meng 9 A
ý Sent:
Friday, November 19, 29101 O0,8 AM To:
Rosenberg, Stacey(
Cc:
Lee, Samson; Rodriguez, Veronica; Ferrante, Fernando; Mitman, Jeffrey; Beaulieu, David
Subject:
New Information Notice (IN) on "Applicability of Historical Dam Failure Frequency Estimates in Probabilistic Risk Assessments" Attachments:
IN-DAM FAILURE FREQUENCY ESTIMATES IN PRA.DOCX; RE: Draft IN on Dam Failure Rates
- Stacey, DRA/APOB is submitting to PGCB for agency issuance of a new Information Notice (IN) on "Applicability of Historical Dam Failure Frequency Estimates in Probabilistic Risk Assessments." This proposed IN is to alert addressees of a non-conservative dam failure frequency estimate that may result in underestimating the plant baseline risk profile when used in external flood risk analyses. The dam failure frequency estimate originated in reference documents published in the 1980s. DRA/APOB staff reviewed the original reference report and found that the approach taken to evaluate external flood risks uses both generic and site-specific arguments to achieve a lower value than supported by similar studies available in specialized literature.
A draft of this IN was previously submitted to PGCB for consideration of issuance but the process was not concluded. Since then, in consultation with PGCB staff, DRA/APOB undertook significant steps to fully revise the draft IN (see attached). These efforts included discussions of any potential technical issues with a RES/DRA subject matter expert (see e-mail attached), and removal of overly-prescriptive language on dam failure rates in the IN text. Furthermore, DRA management were briefed on the current status of this IN on 11/18/2010, and concurred on proceeding with this effort under the expectation that APOB staff will be fully engaged in supporting PGCB in the expeditious issuance of this IN. Therefore, we would appreciate very much the help of PGCB to open a TAC for APOB support to prepare this IN for agency issuance. The lead APOB staff member for this IN effort is Fernando Ferrante.
If you have any questions, please do not hesitate to contact us directly. APOB looks forward to completing this action in a timely fashion with your support.
See Meng Wong Acting APOB Branch Chief 1