L-2023-162, Response to 50.69 2nd Round of Rals

Response to 50.69 2nd Round of Rals

ML23326A006
Person / Time
Site:	Saint Lucie
Issue date:	11/21/2023
From:	Strand D Florida Power & Light Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-2023-162
Download: ML23326A006 (1)

Text

November 21, 2023 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk

SUBJECT:

DOCKET NO:

St. Lucie Units 1 and 2 50-335 and 50-389 Response to 50.69 2nd Round of RAls

References:

L-2023-162 10 CFR 50.90 10 CFR 50.69

1. Florida Power & Light Company letter L-2022-175, Application to Adopt 1 o CFR 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors," December 2, 2022 (ML22336A071)

2. Florida Power & Light Company letter L-2023-118, Response to Request for Additional Information Regarding License Amendment Request to Adopt 10 CFR 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors," September 11, 2023 (ML23255A041)

3. Florida Power & Light Company letter L-2023-136, Supplement to License Amendment Request to Adopt 10 CFR 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors," September 26, 2023 (M L23269A 150)

4. NRC Message from Natreon Jordan, Project Manager for St. Lucie Units 1 and 2, "50.69 2nd Round of RAls," October 31, 2023 In Reference 1, Florida Power & Light Company (FPL) submitted a license amendment request to modify the licensing basis by the addition of a license condition to allow for the implementation of the provisions of Title 10 of the Code of Federal Regulations (10 CFR),

Part 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors," to the licenses for St. Lucie Unit 1 and Unit 2.

Reference 2 provided a response to requested information that the NRC staff determined to be necessary to complete its review.

Reference 3 provided information that supplemented information provided in References 1 and 2 that the NRC staff determined to be necessary to complete its review.

St. Lucie Nuclear Plant Docket Nos. 50-335 and 50-389 L-2023-162 Page 2 of 2 Reference 4 transmitted a request for additional information that the NRC staff has determined is necessary to complete its review.

The enclosure to this letter provides the requested information.

This letter does not alter the conclusions in Reference 1 that the proposed change does not involve a significant hazards consideration pursuant to 10 CFR 50.92, and there are no significant environmental impacts associated with the change.

This letter contains no new or revised regulatory commitments.

If you should have any questions regarding this submittal, please contact Kenneth Mack, Licensing Manager, at (561) 904-3635.

I declare under penalty of perjury that the foregoing is true and correc,t.

Executed on the 2. / ~ day of November 2023.

Sincerely, General 1Manager Regulatory Affairs Florida Power & Light Company Enclosure cc:

USNRC Regional Administrator, Region II USNRC Project Manager, St. Lucie Nuclear Plant, Units 1 and 2 USNRC Senior Resident Inspector, St. Lucie Nuclear Plant, Units 1 and 2 Mr. John Williamson, Florida Department of Health

ENCLOSURE Response to Request for Additional Information

APLC RAI 03 - Alternate Seismic Approach Section 50.69(b)(2)(ii) of 10 CFR requires that the quality and level of detail of the systematic processes that evaluate the plant for internal and external events during operation are adequate for the categorization of SSCs.

In the LAR, the licensee proposes to address seismic hazard risk using the alternative seismic approach for seismic Tier 1 plants described in EPRI 3002017583. Case studies performed to derive seismic categorization insights in support of the alternative seismic approach are included in EPRI 3002017583, and the NRC staff reviewed and evaluated the technical acceptability of the PRAs used in case studies for Plants A, C, and D. The NRC staff has not endorsed EPRI 3002017583 as a topical report for generic use. As such, each licensee is required to perform a plant-specific evaluation of applicability of the EPRI alternative seismic approach to their plant, including applicability of the information used in the case studies.

Calvert Cliffs Nuclear Power Plant, Units 1 and 2, serves as the pilot plant for using the alternative seismic Tier 1 approach. The NRC staff reviewed and approved the Calvert Cliffs alternative seismic Tier 1 approach based on the information on Tier 1 plants included in EPRI 3002012988 (predecessor to EPRI 3002017583) and the information provided in the Calvert Cliffs 10 CFR 50.69 LAR (ADAMS Accession No. ML18333A022) and its supplements (ADAMS Accession Nos. ML19130A180, ML19183A012, ML19200A216, and ML19217A143). NRC staff's review and approval of the Calvert Cliffs alternative seismic Tier 1 approach is documented in its safety evaluation (ADAMS Accession No. ML19330D909). The NRC staff notes that the licensee's proposed alternative seismic Tier 1 approach is similar to that proposed by Calvert Cliffs.

In support of this review, the staff requests the following:

a. Confirm, in Section 3.2.3 of the LAR, whether the plant-specific EPRI 3002017583 test case information FPL is using from other licensees and being incorporated by reference into this application is described in Case Studies A, C, and D (and provide references associated with each case study). Otherwise, provide justification for exclusion of such information in the LAR.

b. Confirm whether the licensee's proposed alternative seismic Tier 1 approach is identical to that reviewed and approved in the NRC staff's Calvert Cliffs safety evaluation. If it is identical, the licensee may incorporate, by reference, the relevant information provided in the supplements to the Calvert Cliffs LAR to support NRC staff's review of the St.

Lucie alternative seismic Tier 1 approach. If not, identify and justify differences between the two plants.

In addressing the staff's request (a and b above), the licensee may consult recently issued 10 CFR 50.69 license amendments that involved alternative seismic Tier 1 approaches similar to that being used by St. Lucie (e.g., ADAMS Accession Nos. ML22094A107, ML21090A193).

RESPONSE

a. Section 3.2.3 of the LAR states, "Test cases described in Section 3 of EPRI Report 3002017583 (LAR Reference 6) showed that it would be unusual even for moderate hazard plants to exhibit any unique seismic insights, including due to correlated failures."

For clarity, Case Study A (References 1, 2, and 3) Case Study C (References 4 and 5),

and Case Study D (References 6, 7, 8, 9, and 10) are being incorporated by reference.

Therefore, while it is prudent to perform additional evaluations to identify conditions where correlated failures may occur for Tier 2 sites, for Tier 1 sites such as PSL, correlation studies would not lead to new seismic insights or affect the site risk results in any significant way.

b. The Calvert Cliffs Safety Evaluation is based on EPRI Report 3002012988 whereas the St. Lucie LAR relies upon EPRI Report 3002017583 (LAR Reference 6). Section 3.2.3 of the LAR states, "The overall seismic risk is relatively low compared to total plant risk.

The seismic risk contributions are consistent with those approved by the NRC for the RE. Ginna Nuclear Power Plant's adoption of 10 CFR 50.69 (LAR Reference 21)."

EPRI Report 3002017583 has incorporated the information and follow up actions from the Calvert Cliffs LAR RAI submittal that was agreed upon by the NRC staff's review of the alternative seismic approach for Tier 1 plants. Therefore, Attachment 2 of ML19200A216 (Reference 14) is applicable to St. Lucie since it is using the updated EPRI Report 3002017583.

There are no differences identified between the proposed St. Lucie alternative seismic Tier 1 approach and that reviewed and approved in the NRC staff's Calvert Cliffs safety evaluation (Reference 16); therefore, References 11 through 15 are being incorporated by reference.

REFERENCES

1. Peach Bottom Atomic Power Station Seismic Probabilistic Risk Assessment Report, "Response to NRC Request Regarding Recommendation 2.1 of the Near Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," August 28, 2018 (RS-18-098)

(ML18240A065).

2. Peach Bottom Atomic Power Station, Units 2 and 3 - Staff Review of Seismic Probabilistic Risk Assessment, "Associated with Reevaluated Seismic Hazard Implementation of the Near-Term Task Force Recommendation 2.1: Seismic," (EPID NO. L-2018-JLD-0010),

June 10, 2019 (ML19053A469).

3. Peach Bottom Atomic Power Station, Units 2 and 3 - Correction Regarding Staff Review of Seismic Probabilistic Risk Assessment, "Reevaluated Seismic Hazard Implementation of the Near-Term Task Force Recommendation 2.1: Seismic," (EPID NO. L-2018-JLD-0010),

October 8, 2019, (ML19248C756).

4. Plant C Nuclear Plant, Units 1 and 2, License Amendment Request to Modify Approved 10 CFR 50.69 Categorization Process, June 22, 2017 (ML17173A875).

5. Plant C Nuclear Plant, Units 1 and 2, "Issuance of Amendments Regarding Application of Seismic Probabilistic Risk Assessment Into the Previously Approved 1 O CFR 50.69 Categorization Process (EPID L-2017-LLA-0248)," August 10, 2018 (M:18180A062).

6. Seismic Probabilistic Risk Assessment for Plant D Nuclear Plant, Units 1 and 2, "Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.1 of the NTTF Review of Insights from the Fukushima Dai-ichi Accident," June 30, 2017 (ML 1718A485).

7. Plant D Nuclear Plant, Units 1 and 2, Seismic Probabilistic Risk Assessment Supplemental Information, April 10, 2018 (M:18100A966).

8. Plant D Nuclear Plant, Units 1 and 2 - Staff Review of Seismic Probabilistic Risk Assessment Associated with Reevaluated Seismic Hazard Implementation of the NTTF Recommendation 2.1: Seismic (CAC NOS. MF9879 AND MF9880; EPID NO. L-2017-JLD-0044) July 10, 2018 (ML18115A138).

9. Plant D Nuclear Plant, Units 1 and 2, Application to Adopt 10 CFR 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors," November 29, 2018 (ML18334A363)

10. Plant D Nuclear Plant, Units 1 and 2 - Issuance of Amendment Nos. 134 and 38 Regarding Adoption of 10 CFR 50.69, "Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Reactors" (EPID NO. L-2018-LLA-0493) April 30, 2020 (ML20076A194) 11. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Application to Adopt 10 CFR 50.69, 'Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors,"' dated November 28, 2018 (ML18333A022)

12. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Revised submittal to Application to Adopt 1 O CFR 50.69, 'Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors,"' dated May 10, 2019 (ML19130A180)

13. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, 'Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors,"' dated July 1, 2019 (ML19183A012)

14. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, 'Risk-informed categorization and treatment of structures, systems, and components for nuclear power reactors,"' dated July 19, 2019 (ML19200A216)

15. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Response to Request for Additional Information Regarding the Application to Adopt 10 CFR 50.69, 'Risk-informed categorization

and treatment of structures, systems, and components for nuclear power reactors, "' dated August 5, 2019 (ML19217A143)

16. Calvert Cliffs Nuclear Power Plant, Units 1 and 2, "Issuance of Amendment Nos. 332 and 310 RE: Risk-Informed Categorization and Treatment of Structures, Systems, and Components FOR Nuclear Power Reactors (EPID L-2018-LLA-0482)" (ML193300909)