ML24036A140
| ML24036A140 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 01/31/2024 |
| From: | Hang Vu NRC/NRR/DEX/EICB |
| To: | |
| References | |
| EPID L-2023-LLA-0096 | |
| Download: ML24036A140 (2) | |
Text
REGULATORY AUDIT
SUMMARY
FOR NOVEMBER 8, 2023 AUDIT BY THE OFFICE OF NUCLEAR REACTOR REGULATION INSTRUMENTATION AND CONTROLS BRANCH JAMES A. FITZPATRICK NUCLEAR POWER PLANT LICENSE AMENDMENT REQUEST TO AMEND THE TECHNICAL SPECIFICATIONS SECTION 3.3.1.2, THE SOURCE RANGE MONITORS INSTRUMENTATION DOCKET NUMBER 50-333 (EPID No. L-2023-LLA-0096)
LOCATION: Remote AUDIT TEAM MEMBERS:
Hang Vu, Audit Team Leader, NRR/DEX/EICB
1.0 INTRODUCTION
By letter dated June 28, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23179A021), the Constellation Energy Generation, LLC (Constellation, the licensee), submitted a license amendment request (LAR) to revise James A.
FitzPatrick Nuclear Power Plant (JAF) Technical Specifications (TSs). The requested change would modify TS Section 3.3.1.2, Source Range Monitors (SRM) Instrumentation. Specifically, the proposed change would allow a lower required count rate for Surveillance Requirement (SR) 3.3.1.2.4 of 0.7 counts per second (cps) with a signal to noise ratio (S/N) 20:1.
In this LAR, the licensee proposed to modify SR 3.3.1.2.4 to add an additional acceptance criterion that is based on a higher S/N ratio (minimum count rate of 0.7 cps is based on a S/N ratio of greater than 20:1), as provided in General Electric Service Information Letter (GE SIL) 478 dated December 16, 1988 (Reference 1 of LAR). The licensee also performed a S/N ratio determination test using procedure for ST-5H test (Reference 2 of LAR).
However, the LAR did not include the GE SIL 478 and ST-5H. The U.S. Nuclear Regulatory Commission (NRC) staff determined that a regulatory audit of these documents is needed to complete the review of the LAR. The audit plan is documented in a letter dated October 27, 2023 (ML23289A244).
To support the audit, the licensee provided GE SIL 478 and ST-5H on the Constellation Energy Generations portal and the audit took place remotely.
The NRC staff conducted the regulatory audit in accordance with the NRR procedure as described in LIC-111, Regulatory Audits (ML19226A274).
2.0 AUDIT ACTIVITIES During the week of November 8, 2923, the NRC staff conducted a regulatory audit with the objectives to review the additional acceptance criterion that is based on a higher S/N ratio (minimum count rate of 0.7 cps is based on a S/N ratio of 20:1), as provided in GE SIL 478, to reach a licensing or regulatory decision.
3.0 DOCUMENT REVIEWED AS PART OF AUDIT
- 1. General Electric (GE) Service Information Letter (SIL) No. 478, SRM Minimum Count Rate Dated December 16, 1988 (Reference 1 of LAR)
- 2. James A. FitzPatrick Nuclear Power Plant Operation Surveillance Procedure - SRM Signal to Noise Ratio Determination Test ST-5H, Revision 5 (Reference 2 of LAR) 4.0 NRC STAFF OBSERVATION AND DECISION The NRC staff performed an audit to review GE SIL 478 and ST-5H to verify that:
The results of the GE study 478: (1) ensure that SRMs could monitor neutron counts with the same confidence of 95 percent as in the original design basis with the minimum count rate of 0.7 cps and a signal to noise ratio greater than 20:1 and (2) show that the higher S/N ratio is required so that the SRM can effectively distinguish between actual counts and noise at lower count rates.
The performance of the ST-5H test (SRM signal to noise ratio determination test) demonstrates that a 20:1 S/N ratio is possible at the lower count rates, minimum of 0.7 cps, for all four SRMs. If the 20:1 S/N ratio could not be demonstrated, the S/N ratio 2:1 will demonstrate operability.
The licensees proposed change incorporated the results of the study in GE SIL 478 by adding a criterion that is based on a higher S/N ratio (minimum count rate of 0.7 cps is based on a signal-to-noise ratio of 20:1) into the current JAF SR 3.3.1.2.4.
5.0 AUDIT CONCLUSION The NRC staff concluded the Audit on November 8, 2023, and found that the information provided by the licensee during the audit is sufficient to support the NRC staff in reaching a regulatory decision.
Audit Team Leader: Hang Vu, NRR/DEX/EICB