ML22236A545
| ML22236A545 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/26/2022 |
| From: | Thomas Wengert NRC/NRR/DORL/LPL4 |
| To: | Entergy Operations |
| Wengert T, NRR/DORL/LPL4 | |
| References | |
| EPID L-2021-LLA-0106 | |
| Download: ML22236A545 (5) | |
Text
August 26, 2022 ANO Site Vice President Arkansas Nuclear One Entergy Operations, Inc.
N-TSB-58 1448 S.R. 333 Russellville, AR 72802
SUBJECT:
ARKANSAS NUCLEAR ONE, UNIT 2 - CORRECTION TO ISSUANCE OF AMENDMENT NO. 331 RE: ADOPTION OF 10 CFR 50.69, RISK-INFORMED CATEGORIZATION AND TREATMENT OF STRUCTURES, SYSTEMS AND COMPONENTS FOR NUCLEAR POWER REACTORS (EPID L-2021-LLA-0106)
Dear Sir or Madam:
By letter dated July 19, 2022 (Agencywide Documents Access and Management System Accession No. ML22165A244), the U.S. Nuclear Regulatory Commission (NRC) issued Amendment No. 331 to Renewed Facility Operating License (RFOL) No. NPF-6 for Arkansas Nuclear One, Unit 2 (ANO-2). The amendment consisted of changes to the RFOL in response to your application dated May 26, 2021 (ML21147A264), as supplemented by letters dated March 9, 2022 (ML22068A170), and May 18, 2022 (ML22138A380).
The amendment modified the ANO-2 licensing basis by adding a license condition to allow for the implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.69, Risk-informed categorization and treatment of structures, systems and components for nuclear power reactors.
Subsequent to the issuance of Amendment No. 331, an error was identified in the supporting safety evaluation (SE). Your staff informed the NRC staff that on page 19 of the SE, it states in part:
The licensee provided a list of 22 doors, hatches, and other flood protection features that are credited to allow the external flooding hazard to screen (emphasis added)
However, the sentence should read:
The licensee provided a list of 15 doors, hatches, and other flood protection features that are credited to allow the external flooding hazard to screen (emphasis added)
The NRC staff determined that the error was inadvertently introduced during the preparation of the license amendment and is entirely editorial in nature.
The correction does not change any of the conclusions in the SE associated with the issuance of this amendment and does not affect the associated notice to the public.
The enclosure to this letter contains the corrected version of page 19 of the SE. The revised page contains a marginal line indicating the area of change. Please replace the corresponding page issued by Amendment No. 331 for ANO-2.
The NRC staff regrets any inconvenience this may have caused. If you have any questions, please contact me at (301) 415-4037 or by email at Thomas.Wengert@nrc.gov.
Sincerely,
/RA/
Thomas J. Wengert, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-368
Enclosure:
Corrected page 19 of the SE cc: Listserv
ENCLOSURE CORRECTED PAGE 19 FOR SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 331 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-6 ENTERGY OPERATIONS, INC.
ARKANSAS NUCLEAR ONE, UNIT 2 DOCKET NO. 50-368
During its review, the NRC staff noted that the licensees performance monitoring program for 10 CFR 50.69 has the capability to identify significant changes to the plant risk profile as well as instances in which a RISC-3 or RISC-4 SSC may fail to perform a safety significant function, resulting in an immediate evaluation and review for such instances. Based on its review, the NRC staff finds that the requirements in 10 CFR 50.69(e) are met for the proposed alternative seismic approach.
In summary, the NRC staff determined that: (1) the licensees programs provide reasonable assurance that the existing seismic capacity of LSS components would not be significantly impacted by alternative treatments permitted by 10 CFR 50.69, and (2) the monitoring and configuration control program ensures that potential degradation of the seismic capacity would be detected and addressed before it significantly impacts the plant risk profile. Therefore, the NRC staff finds reasonable confidence that the licensees proposed alternative seismic approach is a systematic process for evaluating seismic hazards for their impact on SSC categorization, which meets the requirements in 10 CFR 50.69(c)(2)(iv).
Conclusion for the Proposed Alternative Seismic Approach Based on its review, the NRC staff concludes that the licensees proposed alternative seismic approach for ANO-2, as described in the licensees LAR and its supplemental letters, is acceptable for considering seismic risk in the licensees categorization process under 10 CFR 50.69.
3.3.1.2.3 Non-Seismic External Hazards and Other Hazards This hazard category includes all non-seismic external hazards such as high winds, external floods, and other hazards. In section 3.2.4, Other External Hazards, of enclosure 1 to the LAR, the licensee stated, in part, that all other external hazards, except for seismic, were screened from applicability to ANO-2 per a plant-specific evaluation in accordance with Generic Letter 88-20, and updated to use the criteria in ASME/ANS PRA standard RA-Sa-2009.
The licensee stated, in its supplement dated March 9, 2022, that SSCs will be evaluated during categorization of the SSC using guidance in NEI 00-04, figure 5-6 to confirm that the SSC is not credited in screening an external hazard. The licensee stated that ANO-2 will assess the risk from all other external hazards consistent with figure 5-6 of NEI 00-04. The licensee further stated, in the supplement, that SSCs important to safety are flood protected either because of their location above the postulated maximum flood level or because they are enclosed in reinforced concrete Seismic Class 1 structures. The licensee provided a list of 15 doors, hatches, and other flood protection features that are credited to allow the external flooding hazard to screen, and that will be considered HSS in accordance with NEI 00-04, figure 5-6.
In summary, the use of the ANO-2 IPEEE results described by the licensee in the LAR, the supplemental letters, and the licensees assessment of the other external hazards (i.e., high winds, tornadoes, and external floods) is consistent with section 5 of NEI 00-04, Revision 0. The NRC staff concludes that the licensees treatment of non-seismic external hazards and other hazards is acceptable and meets the requirements of 10 CFR 50.69(c)(1)(ii).
- By email OFFICE NRR/DORL/LPL4/PM*
NRR/DORL/LPL4/LA*
NRR/DRA/APLA/BC*
NAME TWengert PBlechman RPascarelli DATE 8/25/2022 8/25/2022 8/25/2022 OFFICE NRR/DORL/LPL4/BC*
NRR/DORL/LPL4/PM*
NAME JDixon-Herrity TWengert DATE 8/25/2022 8/26/2022