ML25275A001
| ML25275A001 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 10/02/2025 |
| From: | Ilka Berrios Plant Licensing Branch III |
| To: | Peter Dietrich DTE Electric Company |
| Arora S | |
| References | |
| EPID L-2025-LLR-0021 | |
| Download: ML25275A001 (1) | |
Text
October 2, 2025 Mr. Peter Dietrich Senior Vice President and Chief Nuclear Officer DTE Energy Company Fermi 2 - 260 TAC 6400 North Dixie Highway Newport, MI 48166
SUBJECT:
FERMI 2 - ALTERNATIVE REQUEST VRR-003, REVISION 1, FOR THE FOURTH 10-YEAR INTERVAL OF THE INSERVICE TESTING PROGRAM (EPID L-2025-LLR-0021)
Dear Mr. Dietrich:
By letter dated February 11, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25042A569), DTE Electric Company (DTE, licensee) submitted alternative request VRR-003, Revision 1, Alternative for Performance-Based Scheduling of Pressure Isolation Valve [PIV] Leakage Tests, to the U.S. Nuclear Regulatory Commission (NRC). The licensee proposed an alternative to certain inservice testing (IST) requirements of the 2012 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), for the Fourth 10-Year IST Interval at Fermi 2 Power Plant (Fermi 2).
Specifically, pursuant to subparagraph (1) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, in Title 10, Energy, of the Code of Federal Regulations (10 CFR 50.55a(z)(1)), the licensee requested to implement Alternative Request VRR-003, Revision 1, at Fermi 2 on the basis that the proposed alternative would provide an acceptable level of quality and safety.
The NRC staffs review and evaluation of the proposed alternative request concludes that DTE has adequately addressed all regulatory requirements set forth in 10 CFR 50.55a(z)(1). Based on its review, the NRC staff approves use of the proposed alternative for the valves listed in Table 1 of the enclosed safety evaluation.
All other ASME OM Code requirements as incorporated by reference in 10 CFR 50.55a for which the relief or an alternative was not specifically requested and approved in the subject request remain applicable.
If you have any questions, please contact the Project Manager, at 301-415-1421 or e-mail at Surinder.Arora@nrc.gov.
Sincerely, Ilka Berrios, Acting Chief Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-341
Enclosure:
Safety Evaluation cc: ListServ ILKA BERRIOS Digitally signed by ILKA BERRIOS Date: 2025.10.02 15:20:04 -04'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST VRR-003, REVISION 1 ALTERNATIVE FOR PERFORMANCE-BASED SCHEDULING OF PIV LEAKAGE TESTS FOURTH 10-YEAR INSERVICE TESTING INTERVAL DTE ELECTRIC COMPANY FERMI 2 DOCKET NO. 50-341
1.0 INTRODUCTION
By letter dated February 11, 2025 (Agencywide Documents Access and Management System Accession No. ML25042A569), DTE Electric Company (licensee) submitted Alternative Request VRR-003, Revision 1, Alternative for Performance-Based Scheduling of Pressure Isolation Valve [PIV] Leakage Tests, to the U.S. Nuclear Regulatory Commission (NRC). The licensee proposed an alternative to certain inservice testing (IST) requirements of the 2012 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), for the Fourth 10-Year IST Interval at Fermi 2 Power Plant (Fermi 2).
Specifically pursuant to subparagraph (1) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, in Title 10, Energy, of the Code of Federal Regulations (10 CFR 50.55a(z)(1)), the licensee requested to implement Alternative Request VRR-003, Revision 1, at Fermi 2 on the basis that the proposed alternative would provide an acceptable level of quality and safety.
Previously, the NRC authorized Alternative Request VRR-003, Revision 0, by letter dated January 24, 2020 (ML20014E731). The licensee prepared Alternative Request VRR-003, Revision 1, to add valves E4100F005 (High Pressure Coolant Injection Main Pump Discharge Check Valve) and E5100F014 (Reactor Core Isolation Cooling [RCIC] Pump Discharge Check Valve), and deleted E5100F012 (RCIC Pump Discharge Isolation Valve) because this valve no longer has a safety function to close for pressure isolation. Also on February 24, 2021, the Fermi 2 refueling outage interval was updated from 18 months to 24 months per License Amendment No. 218 (ML20358A155).
2.0 REGULATORY EVALUATION
The NRC regulations in 10 CFR 50.55a(f), Preservice and inservice testing requirements, state, in part:
Throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the ASME OM Code must meet the IST requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in 10 CFR 50.55a(f)(2) and (3) and that are incorporated by reference in 10 CFR 50.55a(a)(1)(iv), to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The NRC regulations in 10 CFR 50.55a(z) state that:
Alternatives to the requirements of paragraphs (b) through (h) of [10 CFR 50.55a]
or portions thereof may be used when authorized by the Director, Office of Nuclear Reactor Regulation. A proposed alternative must be submitted and authorized prior to implementation. The applicant or licensee must demonstrate that:
(1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or (2) Hardship without a compensating increase in quality and safety. Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
3.0 TECHNICAL EVALUATION
3.1 Licensees Alternative Request VRR-003, Revision 1 Applicable ASME OM Code Edition The applicable code of record for the Fourth 10-Year IST Interval at Fermi 2 is the 2012 Edition of ASME OM Code as incorporated by reference in 10 CFR 50.55a. The Fermi 2 Fourth IST interval began on February 17, 2020, and is scheduled to end on February 16, 2030.
Applicable ASME OM Code Components Alternative testing is requested for the following valves:
Table 1 Valve ID Function ASME Code Class OM Valve Category E1100F050A Residual Heat Removal (RHR) Div. 1 Inboard Isolation Testable Check Valve 1
A/C E1100F050B RHR Div. 2 Inboard Isolation Testable Check Valve 1
A/C E1150F008 RHR Div. 1 & 2 Shutdown Cooling Outboard Containment Isolation Valve 1
A E1150F009 RHR Div. 1 & 2 Shutdown Cooling Inboard Containment Isolation Valve 1
A E1150F015A RHR Div. 1 Low Pressure Coolant Injection (LPCI)
Inboard Isolation Valve 1
A E1150F015B RHR Div. 2 LPCI Inboard Isolation Valve 1
A E1150F608 RHR Shutdown Cooling Inboard Inlet Isolation Bypass Valve 1
A E2100F006A Core Spray (CS) Div. 1 Inboard Primary Containment Check Valve 1
A/C E2100F006B CS Div. 2 Inboard Primary Containment Check Valve 1
A/C E2150F005A CS Div. 1 Inboard Isolation Valve 1
A E2150F005B CS Div. 2 Inboard Isolation Valve 1
A E4100F005 HPCI Main Pump Discharge Check Valve 2
A/C E4150F006 HPCI Main Pump Outlet to Feedwater Isolation Valve 1
A E4150F007 HPCI Main Pump Discharge Isolation Valve 2
A E5100F014 RCIC Pump Discharge Check Valve 2
A/C E5150F013 RCIC Pump Supply to Feedwater Header Isolation Valve 1
A Applicable ASME OM Code Requirements The requirements in the ASME OM Code (2012 Edition), Subsection ISTC, Inservice Testing of Valves in Light-Water Reactor Nuclear Power Plants, as incorporated by reference in 10 CFR 50.55a, related to this alternative request are as follows:
Paragraph ISTC-3630, Leakage Rate for other than Containment Isolation Valves, states:
Category A valves with a leakage requirement not based on an Owners 10 CFR 50, Appendix J program, shall be tested to verify their seat leakages within acceptable limits. Valve closure before seat leakage testing shall be by using the valve operator with no additional closing force applied.
Subparagraph ISTC-3630(a), Frequency, states that tests shall be conducted at least once every 2 yr [years].
Proposed Alternative and Basis for Use As summarized by the NRC staff, the licensee proposes in Revision 1 to Alternative Request VRR-003 to perform leakage testing of pressure isolation valves (PIVs) at intervals ranging from every 30 months up to every 75 months. The specific test interval for each valve would be a function of its seat leakage performance and would be established in a manner consistent with the containment isolation valves (CIVs) process under 10 CFR Part 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, Option B Performance-Based Requirements.
Eleven of the 16 valves within the scope of this alternative request are classified as CIVs and 9 of those valves are leakrate tested with air at intervals determined by 10 CFR Part 50, Appendix J, Option B. As part of this alternative request, the licensees IST Leak Rate Program will be established such that if any of those 9 valves fail either their CIV test or their PIV test, the test interval for both tests will be reduced to every 30 months until they can be re-classified as good performers per the 10 CFR Part 50, Appendix J, Option B, requirements. The licensee will determine the leak test intervals for the valves with a PIV-only function in the same manner as is conducted for CIV testing under Appendix J, Option B. That is, the test interval may be extended up to every 3 refueling outages (not to exceed 75 months) upon completion of 3 consecutive periodic PIV tests with results within prescribed acceptance criteria. Any PIV test failure will require a return to the initial (every 30 months) interval until good performance can be re-established.
The licensee states that the primary basis for this relief request is the historically good performance of the PIVs. The licensee reports that there have been no PIV failures due to the seating surface condition of the valves. Several of the valves within the scope of this request have passed the as-found PIV water test, but experienced failures of as-found CIV air leakage tests due to seat imperfections. The licensee considers that CIV air-testing is a more challenging and accurate measurement of seat condition, and it is more likely to identify any seat condition degradation. The licensee provided a sample of recent PIV leak rate test performance in Revision 1 to Alternative Request VRR-003.
The licensee notes that it received approval of License Amendment No. 205 (ML16351A460) on March 9, 2017, for Fermi 2 to implement Nuclear Energy Institute (NEI) 94-01, Revision 3-A, Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J (ML12221A202) and the conditions and limitations specified in NEI 94-01, Revision 2-A, to implement the performance-based leakage-testing program in accordance with 10 CFR Part 50, Appendix J, Option B. The license amendment increased the CIV leakage test intervals (i.e.,
Type C tests) from 60 months to 75 months. Valves whose leakage test results indicate good performance may have their interval of testing increased based on these test results. The Fermi 2 program for 10 CFR Part 50, Appendix J, Option B, requires individual CIVs to be good performers before they can be placed on extended seat leakage testing intervals.
The licensee states that the intent of this request is to allow a performance-based approach to the scheduling of PIV leakage testing. The licensee asserts that the Fermi 2 PIVs have an excellent performance history in terms of seat leakage testing. The risks associated with extending the leakage test interval to a maximum of 75 months are extremely low. The licensee has determined that this alternative will provide significant reductions in radiation dose.
Licensees Reason for Request As summarized by the NRC staff, the licensees reason for submitting Revision 1 to Alternative Request VRR-003 is to reduce outage dose and to align the PIV test frequency to the Appendix J, Option B, test frequency. The radiation exposure and the personnel time involved will be significantly reduced by performing the PIV and position indication test (PIT) at the same interval as the 10 CFR Part 50, Appendix J, Option B, seat leakage test. The licensee reported that historical data collected during the third 10-year interval identified that PIV testing alone each refueling outage results in a significant cumulative radiation exposure dose to plant personnel.
3.2
NRC Staff Evaluation
At nuclear power plants, PIVs are defined as two valves in series within the reactor coolant pressure boundary which separate the high pressure reactor coolant system from an attached lower pressure system. Failure of a PIV could result in an over-pressurization event which could lead to a system rupture and possible release of fission products to the environment. This type of failure event was analyzed under NUREG/CR-5928, ISLOCA [Inter-System Loss Of Coolant Accident] Research Program, dated July 1993 (ML20046D097) to quantify the risk associated with an ISLOCA event. NUREG/CR-5928 analyzed the potential for an ISLOCA in boiling water reactor and pressurized water reactor designs.
On January 24, 2020 (ML20014E731), the NRC staff authorized Alternative Request VRR-003 for Fermi 2, which was a continuation of a previous request for the Third IST Interval at Fermi 2.
In Revision 1 to Alternative Request VRR-003, the licensee reports that based on the third consecutive satisfactory leak test during a refueling outage, two additional valves E4100F005 (HPCI Main Pump Discharge Check Valve) and E5100F014 (RCIC Pump Discharge Check Valve) have been added to the scope of this proposal. The licensee also states that valve E5l50F012 (RCIC Pump Discharge Isolation Valve) has been removed from the scope of the alternative request because this valve no longer has a safety function to close for pressure isolation. Also, in Revision 1 to Alternative Request VRR-003, the licensee updated the refueling outage interval from 18 months to 24 months based on a recent license amendment for Fermi 2.
In Revision 1 to Alternative Request VRR-003, the licensee proposes to perform PIV testing of the specific16 PIVs at intervals ranging from every 30 months up to every 75 months in lieu of the requirements in 2012 Edition of the ASME OM Code, paragraph ISTC-3630(a). The specific interval for each valve would be a function of its seat leakage performance and would be established in a manner consistent with 10 CFR Part 50, Appendix J, Option B. Eleven of the 16 valves within the scope of this request are classified as CIVs and 9 of those valves are leak rate tested with air at intervals determined by 10 CFR Part 50, Appendix J, Option B. As part of this alternative request, the licensees IST Leak Rate Program will be established such that if any of those 9 valves fail either their CIV test or their PIV test, the test interval for both tests will be reduced to every 30 months until they can be re-classified as good performers per the 10 CFR Part 50, Appendix J, Option B, requirements. The licensee will determine the test intervals for the valves with a PIV-only function in the same manner as is performed for CIV testing under Appendix J, Option B. That is, the test interval may be extended up to every 3 refueling outages (not to exceed 75 months) upon completion of three consecutive periodic PIV tests with results within prescribed acceptance criteria. Any PIV test failure will require a return to the initial (every 30 months) interval until good performance can be re-established.
The licensee has determined that this alternative will provide a significant reduction in radiation exposure dose to plant personnel.
Based on its review, the NRC staff has determined that the proposal in Revision 1 to Alternative Request VRR-003 is essentially a continuation of a recently authorized alternative request for PIV leakage testing. The NRC staff has determined that the proposed alternative continues to provide reasonable assurance of the operational readiness with respect to leakage testing of the valves within the scope of the request. Therefore, the NRC staff finds that Revision 1 to Alternative Request VRR-003 may be authorized in accordance with 10 CFR 50.55a(z)(1) as providing an acceptable level of quality and safety.
4.0 CONCLUSION
As described above, the NRC staff has determined that Revision 1 to Alternative Request VRR-003 for performance-based leakage testing of specific valves listed in Table 1 provides an acceptable level of quality and safety. Accordingly, the NRC staff concludes that the licensee has adequately addressed all the regulatory requirements set forth in 10 CFR 50.55a(z)(1).
Therefore, the NRC staff authorizes the use of Revision 1 to Alternative Request VRR-003 for the Fourth 10-Year IST Interval at Fermi 2, which began on February 17, 2020.
All other ASME OM Code requirements as incorporated by reference in 10 CFR 50.55a for which relief or an alternative was not specifically requested, and granted or authorized (as appropriate), in the subject request remain applicable.
Principal Contributors: Thomas G. Scarbrough, NRR Gurjendra S. Bedi, NRR Date: October 2, 2025
ML25275A001 NRR-028 OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DNRL/NVIB/BC NRR/DORL/LPL3/BC(A)
NAME SArora SLent Bailey IBerrios DATE 10/01/2025 10/02/2025 08/06/2025 10/02/2025