NL-20-0108, Supplemental Response to Request for Additional Information Regarding the License Amendment Request to Transition to 10 CFR 50.48(c)- NFPA-805 Performance Based Standard for Fire Protection for Light.
| ML20036F588 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 02/05/2020 |
| From: | Gayheart C Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-20-0108 | |
| Download: ML20036F588 (5) | |
Text
J!. Southern Nuclear FFR 0 ~ 2070 Docket Nos.: 50-321 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Cheryl A. Gayheart Regulatory Affairs Director Edwin I. Hatch Nuclear Plant - Units 1 and 2
- 1535 Co l o nn ad~ Parkway Rirminghnm. AL 35243 205 992 53 16 cngayhen@:-.outhernco.etllll NL-20-01 08 Supplemental Response to Request for Additional Information Regarding the License Amendment Request to Transition to 10 CFR 50.48(c)- NFPA -805 Performance Based Standard for Fire Protection for Light Water Reactor Generating Plants Ladies and Gentlemen:
By letter dated April 4, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18096A936), Southern Nuclear Operating Company (SNC) submitted a license amendment request (LAR) for the Edwin I. Hatch Nuclear Plant (HNP),
Units 1 and 2, to adopt National Fire Protection Association Standard 805 (NFPA 805),
"Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition (ADAMS Accession No. ML010800360), as incorporated into Title 10 of the Code of Federal Regulations, Part 50, Section 50.48(c). This LAR was supplemented by letters dated May 28, 2019, August 9, 2019, October 7, 2019, and December 13, 2019.
On January 30, 2020, a clarification call was held between SNC and the U.S. Nuclear Regulatory Commission (NRC) regarding the December 13, 2019 response to Probabilistic Risk Assessment (PRA) Request for Additional Information (RAI) 03. During this call, SNC agreed to provide a supplemental clarification to this RAI response.
The conclusions of the No Significant Hazards Consideration and Environmental Consideration contained in the original LAR have been reviewed and are unaffected by this RAI response.
This letter contains no NRC commitments. If you have any questions, please contact Jamie Coleman at 205.992.6611.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the O'S day of February 2020.
Respectfully submitted, art Director, Regulatory Affairs Southern Nuclear Operating Company CAG/RMJ
U.S. Nuclear Regulatory Commission NL-20-0108 Page 2
Enclosure:
Supplemental Response to PRA RAI 03 cc:
Regional Administrator, Region II NRR Project Manager-Hatch Senior Resident Inspector-Hatch Director, Environmental Protection Division - State of Georgia RType: CHA02.004
Edwin I. Hatch Nuclear Plant - Units 1 and 2 Supplemental Response to Request for Additional Information Regarding the License Amendment Request to Transition to 10 CFR 50.48(c)- NFPA -805 Performance Based Standard for Fire Protection for Light Water Reactor Generating Plants Enclosure Supplemental Response to PRA RAI 03
Enclosure to NL-20-01 08 Supplemental Response to PRA RAI 03 NRC Request:
The following two items were not included in the licensee's response to Probabilistic Risk Assessment (PRA) Request for Additional Information (RAI) 03, dated December 13, 2019 (ADAMS Accession No. ML19351D130):
In its response to NFPA 805 PRA RAI 07.01 (a), dated October 7, 2019 (ADAMS Accession No. ML19280C812), SNC stated that the Fire PRA (FPRA) methodology for treatment of enclosed sensitive electronics will be updated, so that electrical cabinets that contain sensitive electronics will not be screened, based on the function of the electrical cabinet. Electrical cabinets that contain enclosed sensitive electronics will be treated as such in the FPRA. The results will be included in the aggregate analysis in response to PRA RAI 03.
In its response to NFPA 805 PRA RAI 15.b.01.b.ii, dated October 7, 2019 (ADAMS Accession No. ML19280C812), SNC stated that a surrogate Main Control Room (MCR) abandonment Conditional Core Damage Probability (CCDP) limit will no longer be used in the compliant model. The change in risk will be based on the calculated risk of the compliant and post transition plant models. This is consistent with the other fire area risk evaluations. These results will be included with the response to RAI 03.
SNC Response to NRC Request:
These two items were included in the changes to the PRA made in response to previous NRC RAis. The table below is an updated version from that provided in the December 13, 2019 response to PRA RAI 03(b) to clarify the NRC's concern. New additions from the December 13, 2019 table are provided in bold.
PRA RAI PRA Resolution PRA Upgrade Comment 02.b No change required N/A N/A 04.b No change required N/A N/A 07.01.a The FPRA methodology for No No new failures were treatment of enclosed sensitive identified as a result of electronics no longer screens this change.
out electrical cabinets that contain sensitive electronics based on the function of the cabinet.
07.b No chanQe required N/A N/A 08 The FPRA was revised to No No new or change in incorporate the changes to the method.
transient weighting factors.
E-1
Enclosure to NL-20-01 08 Supplemental Response to PRA RAI 03 PRA RAI PRA Resolution PRA Upgrade Comment 09.c The FPRA was changed to use a No The minimum JHEP floor minimum JHEP floor value of 1 E-value approach was 5
used in the peer reviewed model; however, exceptions were justified. These exceptions have been replaced with the recommended floor value.
10 No change required N/A N/A 11.e No change required N/A N/A 11.h No change required N/A N/A 12.e No change required N/A N/A 13.f No change required N/A N/A 13.i No change required N/A N/A 15.b.01.b.ii A surrogate MCR No The revised delta risk abandonment CCDP limit is no is included in the table longer used in the compliant in PRA RAI 3.a and in model.
the updated Attachment W Tables.
16.c No change required N/A N/A 16.d No change required N/A N/A E-2