ML15238B704
| ML15238B704 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/10/2015 |
| From: | Tekia Govan Japan Lessons-Learned Division |
| To: | Braun R Public Service Enterprise Group |
| Govab, Tekia NRR/JLD 415-6197 | |
| Shared Package | |
| ML15244B266 | List: |
| References | |
| TAC MF3790, TAC MF3791 | |
| Download: ML15238B704 (8) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 10, 2015 Mr. Robert Braun President and Chief Nuclear Officer PSEG Nuclear LLC-N09 P. 0. Box 236 Hancocks Bridge, NJ 08038
SUBJECT:
SALEM NUCLEAR GENERATING STATION, UNITS 1 AND 2 INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST-FLOOD-CAUSING MECHANISM REEVALUATION {TAC NOS. MF3790 AND MF3791)
Dear Mr. Braun:
The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRG) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14071A401, flood hazard reevaluation report (FHRR) submitted by PSEG Nuclear LLC (PSEG, the licensee) for Salem Nuclear Generating Station, Units 1 and 2 (Salem), as well as supplemental information resulting from requests for additional information and audits.
By letter dated March 12, 2012, the NRG issued a request for information pursuant to Title 1 O of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter)
(ADAMS Accession No. ML12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRG Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SAM) (ADAMS Accession No. ML15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards, dated November 21, 2014 (ADAMS Accession No. ML14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events.
The NRG staff has reviewed the information submitted by the licensee and has summarized the results of the review in the tables provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Table 2 provides the reevaluated flood hazard mechanisms; however, the reevaluated flood hazard mechanisms bounded by the current design-basis {Table 1) are not included.
The NRG staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information
described in guidance documents currently being finalized by the industry and NRC staff) for Salem. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time.
In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood event duration parameters and applicable flood associated effects should be considered as part of the Salem MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood-related associated effects developed by the licensee during the NRC staff's review of the MSA.
As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan forthe Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML15209A682).
If you have any questions, please contact me at (301) 415-6197 or e-mail at Tekia.Govan@nrc.gov.
Docket Nos. 50-272 and 50-311
Enclosure:
Summary of Results of Flooding Hazard Re-Evaluation Report cc w/encl: Distribution via Listserv Tekia V. Govan, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation
ENCLOSURE:
SUMMARY
TABLES OF REEVALUATED FLOOD HAZARD LEVELS
Salem, Units 1 and 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism Local Intense Precipitation Streams and Rivers Failure of Dams and Onsite Water Control/Storage Structures Stillwater Waves/
Elevation Run up Not included Not included in DB in DB Not included Not included in DB in DB Not included i Not included I Slorm Su~e - ----
_ITT:
I 8
Auxiliary Building 24.0 ft I
6.6 ft Service Water Intake Structure Seiche Tsunami Ice-Induced Flooding NAVD88 I
24.0 ft NAVD88 No Impact on the Site Identified No Impact on the Site Identified No Impact on the Site Identified 13.5 ft No Impact on the Site Identified No Impact on the Site Identified No Impact on the Site Identified I
i I
Design Basis 1
Hazard Elevation Not included in DB Not included in DB Not included in DB 30.6 ft NAVD88 37.5 ft NAVD88 No Impact on the Site Identified No Impact on the Site Identified No Impact on the Site Identified Reference FHRR Section 1.2.1 FHRR Section 1.2.2 FHRR Section 1.2.3 FHRR Section 1.2.4 FHRR Section 1.2.4 and Table 3-1 FHRR Section 1.2.5 FHRR Section 1.2.6 FHRR Section 1.2.7
Salem, Units 1 and 2 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism Stillwater Waves/
Design Basis Elevation Run up Hazard Elevation
--1 Reference Channel Migrations/Diversions No Impact No Impact No Impact FHRR Section 1.2.8 on the Site on the Site on the Site Identified Identified Identified Note 1: Reported values are rounded to the nearest one-tenth of a foot.
Note 2: Based on the NRC staffs independent (deterministic) hazard assessment using present-day regulatory guidance and methodologies of storm surge, the staff concludes that the site's current design basis remains bounded. For this reason, the staff concludes it is appropriate to utilize the current design basis storm surge elevation in conjunction with the mitigating strategies assessment.
I
Salem, Units 1 and 2 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/
Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation 12.2 ft I
Minimal 12.2 ft FHRR Section 3.1 NAVD88 l NAVD88 Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA.
Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table.
Note 3: Reported values are rounded to the nearest one-tenth of a foot.
I I
PKG ML15244B266;LTR: ML152388704; ENCL: ML15243A447 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA NRO/DSEA/RHM1/TR*
NAME TGovan Slent Mlee DATE 09/02/15 09/01/15 09/09/15 OFFICE NRO/DSEA/RHM1/TL
- NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME KErwin MShams TGovan DATE 09/09/15 09/10/15 09/10/15