NRC-25-0002, Submittal of Revised IST Valve Relief Request, VRR-003 Rev. 1, for the Fourth Ten Year Interval
| ML25042A569 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 02/11/2025 |
| From: | Domingos C DTE Electric Company |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NRC-25-0002 | |
| Download: ML25042A569 (1) | |
Text
Christopher P. Domingos Site Vice President DTE Electric Company 6400 N. Dixie Highway, Newport, MI 48166 Tel: 734.586.5025 Fax: 734.586.5295 Email: christopher.domingos@dteenergy.com 10 CFR 50.55a February 11, 2025 NRC-25-0002 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Fermi 2 Power Plant NRC Docket No. 50-341 NRC License No. NPF-43
Subject:
Submittal of Revised IST Valve Relief Request, VRR-003 Rev. 1, for the fourth Ten Year Interval Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(1), DTE Electric Company (DTE) hereby requests NRC approval of the enclosed revised relief request, VRR-003 (Alternative for Performance-Based Scheduling of PIV Leakage Tests) for the Fermi 2 plant. The fourth 10-year interval of the Fermi 2 Inservice Testing (IST) Program, began on February 17, 2020, and ends on February 16, 2030.
In Reference 1, DTE submitted relief requests for the fourth IST Program 10-year interval at Fermi 2 for NRC review and approval. The NRC approved relief request, VRR-003 rev. 0, per Reference 2.
Due to the third consecutive satisfactory leak test during a refueling outage, relief request VRR-003 rev. 1 is revised to add the following two valves: E4100F005 (HPCI Main Pump
References:
- 1) DTE Letter NRC-19-0025, Submittal of Valve Relief Requests for the Inservice Testing Program Fourth 10-Year Interval, dated May 29, 2019 (ML19149A329)
- 2) NRC Letter to DTE, Fermi 2 - Issuance of Relief Re: Proposed Alternative Request Nos. VRR-002, VRR-003, VRR-006, VRR-008, and VRR-009 Associated with Fourth Ten Year Interval Inservice Testing of Various Valves (EPID L-2019-LLR-0048, EPID L-2019-LLR-0049, EPID L-2019-LLR-0057, EPID L-2019-LLR-0051 and EPID L-2019-LLR-0059) dated January 24, 2020 (ML20014E731)
- 3) NRC Letter to DTE, Fermi 2 - Issuance of Amendment No. 218 - Revision to Technical Specifications to Change Certain Surveillance Intervals to Accommodate a 24-Month Fuel Cycle (EPID L-2019-LLA-0249) dated February 24, 2021 (ML202358A155)
USNRC NRC-25-0002 Page2 Discharge Check Valve) and E5100F014 (RCIC Pump Discharge Check Valve). VRR-003 rev. I removed valve E5l50F012 (Reactor Core Isolation Cooling [RCIC] Pump Discharge Isolation Valve) from the table of affected components and data table because this valve no longer has a safety function to close for pressure isolation. Based on ASME OM Code ISTC-1200 Part C, this valve is exempt from 1 ST testing since it is normally deenergized and administratively controlled in its open safety position. VRR-003 rev. 1 also updated the refueling outage period from 18 months to 24 months per license amendment no. 218 (per Reference 3).
NRC approval of the proposed alternative is requested for the remaining duration of the Fermi 2 Fourth IST 10-Year Interval, which started on February 17, 2020. DTE requests NRC approval of relief request VRR-003 rev. 1 by January 21, 2026 to support Refueling Outage 23.
No new commitments are being made in this submittal.
Should you have any questions or require additional information, please contact Mr. Eric Frank, Manager - Nuclear Licensing, at (734) 586-4 772.
Enclosure:
Christopher P. Domingos Site Vice President
- 1. Revised 10 CFR 50.55a Relief Request, VRR-003 Rev. 1, Alternative for Performance-Based Scheduling of PIV Leakage Tests cc: NRC Project Manager NRC Resident Office Regional Administrator, Region III
to NRC-25-0002 Fermi 2 NRC Docket No. 50-341 Operating License No. NPF-43 Revised 10 CFR 50.55a Relief Request, VRR-003 Rev. 1, Alternative for Performance-Based Scheduling of PIV Leakage Tests to NRC-25-0002 Page 1 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests Proposed Alternative in Accordance with 10 CFR 50.55a(z)(1)
Alternative Provides Acceptable Level of Quality and Safety Revision Summary: Added valves E4100F005 and E5100F014 to the table of affected components and data table. Removed valve E5150F012 from the table of affected components and data table because this valve no longer has a safety function to close for pressure isolation.
Based on ASME OM Code ISTC-1200 Part C, this valve is exempt from 1ST testing since it is normally deenergized and administratively controlled in its open safety position (LCR 20-025-ISI). Updated language to reflect change in refueling outage frequency from 18 months to 24 months. Minor grammatical changes.
- 1. ASME Code Component(s) Affected Valve Identification (PIS) No.
Noun Description ASME Code Class OM Valve Category Appendix J, Option B Air Tested E1100F050A Residual Heat Removal (RHR) Div. 1 Inboard Isolation Testable Check Valve 1
A/C N
E1100F050B RHR Div. 2 Inboard Isolation Testable Check Valve 1
A/C N
E1150F008 RHR Div. 1 & 2 Shutdown Cooling Outboard Containment Isolation Valve 1
A Y
E1150F009 RHR Div. 1 & 2 Shutdown Cooling Inboard Containment Isolation Valve 1
A Y
E1150F015A RHR Div. 1 Low Pressure Coolant Injection (LPCI) Inboard Isolation Valve 1
A N
E1150F015B RHR Div. 2 LPCI Inboard Isolation Valve 1
A N
E1150F608 RHR Shutdown Cooling Inboard Inlet Isolation Bypass Valve 1
A Y
E2100F006A Core Spray (CS) Div. 1 Inboard Primary Containment Check Valve 1
A/C Y
E2100F006B CS Div. 2 Inboard Primary Containment Check Valve 1
A/C Y
E2150F005A CS Div.1 Inboard Isolation Valve 1
A Y
E2150F005B CS Div.2 Inboard Isolation Valve 1
A Y
to NRC-25-0002 Page 2 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests Valve Identification (PIS) No.
Noun Description ASME Code Class OM Valve Category Appendix J, Option B Air Tested E4100F005 HPCI Main Pump Discharge Check Valve 2
A/C N
E4150F006 High Pressure Coolant Injection (HPCI) Main Pump Outlet to Feedwater Isolation Valve 1
A Y
E4150F007 HPCI Main Pump Discharge Isolation Valve 2
A N
E5100F014 RCIC Pump Discharge Check Valve 2
A/C N
E5150F013 RCIC Pump Supply to Feedwater Header Isolation Valve 1
A Y
2. Applicable Code Edition and Addenda
ASME OM Code 2012 Edition, No Addenda
3. Applicable Code Requirement
ISTC-3630, Leakage Rate for other than Containment Isolation Valves, states that 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.
ISTC-3630(a), Frequency, states that tests shall be conducted at least once every 2 yr.
4. Reason for Request
Pursuant to 10 CFR 50.55a, Codes and Standards, paragraph (z)(1), relief is requested from the requirement of ASME OM Code ISTC-3630(a). The basis of the relief request is that the proposed alternative will provide an acceptable level of quality and safety.
ISTC-3630(a) requires that leakage rate testing (water) for pressure isolation valves (PIV) be performed at least once every two years. 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 (frequency) as the 10 CFR 50 Appendix J Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, Option B Performance-Based Requirements, seat leakage test. Historical data collected during the third 10-year interval identified that PIV testing alone each refueling outage (each 24 months) incurs a to NRC-25-0002 Page 3 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests total dose of approximately 900 mRem. The reason for this relief request is to reduce outage dose and to align the PIV test frequency to the Appendix J, Option B test frequency.
For the third 10-year interval, the NRCs approval of the relief request in VRR-013, Revision 0, resulted in the PIV test frequency being aligned with the Fermi 2 performance-based leakage-test program outlined in 10 CFR 50 Appendix J, Option B but with a test interval limit of 60 months. VRR-013, Revision 1, was subsequently approved to perform PIV testing with a test interval limit of 75 months (see Section 7, Precedent). This frequency is commensurate with the 10 CFR 50 Appendix J, Option B performance-based leakage testing program at Fermi 2, which incorporates NEI 94-01, Revision 3-A (ADAMS Accession No. ML12221A202), and the conditions and limitations specified in NEI 94-01, Revision 2-A.
The Fermi 2 program which implements 10 CFR 50 Appendix J, Option B requires individual containment isolation valves to be good performers before they can be placed on extended seat leakage testing frequency. As documented in the third 10-year interval relief request VRR-013, Revision 1, the total dose saving was estimated to be 2700 mRem for the extended test intervals.
5. Proposed Alternative and Basis for Use
Pressure isolation valves (PIVs) are not included in the scope for performance-based testing as provided for in 10 CFR 50 Appendix J, Option B. The concept behind the Option B alternative for containment isolation valves is that licensees should be allowed to adopt cost effective methods for complying with regulatory requirements. NEI 94-01 describes the risk-informed basis for the extended test intervals under Option B. That justification shows that for valves which have demonstrated good performance by passing their leak rate tests for three consecutive cycles, further failures appear to be governed by the random failure rate of the component. NEI 94-01 also presents the results of a comprehensive risk analysis, including the statement that the risk impact associated with increasing [leak rate] test intervals is negligible (less than 0.1% of total risk). The valves identified in this relief request are all in water applications. The PIV testing is performed with water pressurized to normal plant operating pressures. This relief request is intended to provide for a performance-based scheduling of PIV tests at Fermi 2.
NUREG-0933, Resolution of Generic Safety Issues, Issue 105, Interfacing Systems LOCA at LWRs, discussed the need for PIV leak rate testing based primarily on three pre-1980 historical failures of applicable valves industry-wide. These failures all involved human errors in either operations or maintenance. None of these failures involved inservice equipment degradation. The performance of PIV leak rate testing provides assurance of acceptable seat leakage with the valve in a closed position. Typical PIV testing does not identify functional problems which may inhibit the valves ability to re-position from open to to NRC-25-0002 Page 4 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests closed. For check valves, such functional testing is accomplished per ASME OM Code Sections ISTC-3522 Category C Check Valves, ISTC-5221 Valve Obturator Movement, and ISTC-5222 Condition-Monitoring Program. Motor operated valves are routinely full stroke tested in accordance with ASME OM Code Section ISTC-5120, Motor Operated Valves, to ensure their functional capabilities. At Fermi 2, these functional tests for PIVs have historically been performed at a Quarterly, Cold Shutdown, or Refuel outage frequency.
In the fourth interval, the motor operated valves will follow the frequencies and testing required by Mandatory Appendix III, Preservice and In-service Testing of Active Electric Motor Operated Valve Assemblies in Light-Water Reactor Power Plants. The functional testing of the PIVs is adequate to identify any abnormal condition that might affect closure capability. Performance of the separate 24-month PIV leak rate testing does not contribute any additional assurance of functional capability as it only verifies the seat tightness of the closed valves.
Fermi 2 proposes to perform PIV testing at intervals (frequencies) ranging from every 30 months up to every 75 months. The specific 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 50 Appendix J Option B. Eleven of the sixteen valves listed are classified as CIVs and nine of those valves are leak rate tested with air at intervals determined by 10 CFR 50 Appendix J, Option B (hereto referred to as Option B). IST Leak Rate Program guidance will be established such that if any of those nine 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 50 Appendix J, Option B requirements.
The test intervals for the valves with a PIV-only function will be determined in the same manner as is done for CIV testing under Option B. That is, the test interval may be extended up to every three 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 primary basis for this relief request is the historically good performance of the PIVs.
There have been no PIV failures due to seating surface condition of the valves. Several of the valves covered by this relief request have passed the as found PIV water test but experienced failures of as found CIV air leakage tests due to seat imperfections. There is industry-wide consensus that CIV air-testing is a more challenging and accurate measurement of seat condition, and more likely to identify any seat condition degradation. A sample of recent PIV leak rate test performance is provided in Attachment 1 to this Enclosure.
to NRC-25-0002 Page 5 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests NUREG/CR-5928, Final Report of the NRC-sponsored ISLOCA Research Program, evaluated the likelihood and potential severity of ISLOCA events in BWRs and PWRs. The BWR design used as a reference for this analysis was a BWR-4 with a Mark 1 containment.
Fermi 2 was listed in Section 4.1 of the document as one of the applicable plants. The applicable BWR systems were individually analyzed and in each case this report concluded that the system was not at risk with respect to ISLOCA risk. Section 4.3 concluded the BWR portion of the analysis by saying ISLOCA is not a risk concern for the BWR plant examined here.
On March 9, 2017, Fermi 2 received approval of License Amendment No. 205 (ADAMS Accession No. ML16351A460) to implement NEI 94-01, Revision 3-A (ADAMS Accession No. 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 50 Appendix J, Option B. This License Amendment increased the containment isolation valves 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 which implements 10 CFR 50 Appendix J, Option B requires individual containment isolation valves be good performers before they can be placed on extended seat leakage testing frequency. Based on the data contained in Attachment 1 to this Enclosure, almost all of the listed valves have passed their last three PIV Leak Rate Tests and would currently qualify for extended frequency.
Summary of the bases and rationale for this relief request:
Performance-based PIV testing would yield a dose reduction of approximately 2700 mRem over a 75-month period based on historical data.
Performance of functional stroke testing of PIVs is per the ASME Code.
PIV testing for the applicable valves has excellent historical performance results.
There is a very low likelihood of valve mispositioning during power operations (procedures, interlocks).
Some valves are also air tested and degrading seat conditions are identified much sooner with air testing.
The low pressure piping typically has relief valves. These relief valves may not provide ISLOCA mitigation for inadvertent PIV mispositioning (gross leakage) but their relief capacity can easily accommodate conservative PIV seat leakage rates.
Alarms are typically provided to identify high pressure to low pressure leakage.
Operators are highly trained to recognize symptoms of a present or incipient ISLOCA and to take appropriate actions.
The intent of this relief request is to allow a performance-based approach to the scheduling of PIV leakage testing. Fermi 2 PIVs have an excellent performance history in terms of seat to NRC-25-0002 Page 6 of 8 10 CFR 50.55a Relief Request VRR-003 Revision 1 Alternative for Performance-Based Scheduling of PIV Leakage Tests leakage testing. The risks associated with extending the leakage test interval to a maximum of 75 months are extremely low. This relief will provide significant reductions in radiation dose.
6. Duration of Proposed Alternative
This proposed alternative will be utilized for the entire fourth 10-year interval. The fourth interval began on February 17, 2020 and ends on February 16, 2030.
- 7. Precedent Fermi 2 currently has an approved relief request for containment isolation valves for the fourth 10-year interval. The current relief request is identified as VRR-003 in the approval documents below:
DTE Letter NRC-19-0025, Submittal of Valve Relief Requests for the Inservice Testing Program Fourth 10-Year Interval, dated May 29, 2019 (ML19149A329)
NRC Letter to DTE, Fermi 2 - Issuance of Relief Re: Proposed Alternative Request Nos. VRR-002, VRR-003, VRR-006, VRR-008, and VRR-009 Associated with Fourth Ten Year Interval Inservice Testing of Various Valves (EPID L-2019-LLR-0048, EPID L-2019-LLR-0049, EPID L 2019-LLR-0057, EPID L-2019-LLR-0051 and EPID L 2019 LLR 0059) dated January 24, 2020 (ML20014E731)
Fermi 2 had an approved relief request for containment isolation valves for the third 10-year interval. The previous relief request is identified as VRR-013 in the approval documents listed below:
Fermi 2 - Evaluation of In-Service Testing Program Relief Request VRR-011, VRR-012, and VRR-013, dated September 28, 2010, Accession No. ML102360570.
Fermi, Unit 2 - Relief from the Requirements of the ASME OM Code, dated March 7, 2018, Accession No. ML17354B002.
- 8. Attachments (1) Historical Pressure Isolation Valves Leakage Test Performance (Last Three Tests)
[2 pages]
to NRC-25-0002 Page 7 of 8 ATTACHMENT 1 TO VRR-003 Revision 1 Historical Pressure Isolation Valves Leakage Test Performance (Last Three Tests)
Page 1 Valve Number Date of Test Acceptance Criteria (gpm)
Measured Value (gpm)
E1100F050A 03/24/2020 10.00 0.04 02/15/2014 0.00 03/29/2009 0.21 E1100F050B 03/27/2024 10.00 0.12 03/26/2022 0.00 05/17/2020 0.02 E1150F008 06/22/2020 5.00 0.04 03/12/2014 0.14 04/17/2009 0.06 E1150F009 and E1150F608*
06/22/2020 5.00 0.00 03/12/2014 0.12 04/17/2009 0.00 E1150F015A 03/24/2020 0.40 0.02 02/14/2014 0.00 03/29/2009 0.02 E1150F015B 03/29/2024 0.40 Unsat**
04/07/2020 0.00 02/27/2014 0.00 E2100F006A 02/17/2022 5.00 0.00 03/21/2017 0.00 04/18/2012 0.00 E2100F006B 03/28/2024 5.00 0.00 02/25/2022 0.00 04/03/2017 0.00 E2150F005A 03/31/2020 5.00 0.00 02/13/2014 0.00 03/30/2009 0.00 E2150F005B 10/06/2018 5.00 0.00 02/24/2014 0.01 04/06/2009 0.00 E4100F005 04/04/2024 5.00 0.08 05/01/2022 0.02 04/12/2020 0.03 to NRC-25-0002 Page 8 of 8 ATTACHMENT 1 TO VRR-003 Revision 1 Historical Pressure Isolation Valves Leakage Test Performance (Last Three Tests)
Page 2 Valve Number Date of Test Acceptance Criteria (gpm)
Measured Value (gpm)
E4150F006 04/04/2024 5.00 0.01 04/13/2020 0.00 02/19/2014 0.00 E4150F007 04/12/2020 5.00 0.04 02/19/2014 0.00 04/01/2009 0.00 E5100F014 03/02/2024 3.00 0.01 02/14/2022 0.03 04/12/2020 0.00 E5150F013 04/17/2020 3.00 0.00 02/15/2014 0.00 04/01/2009 0.00 Legend:
gpm is gallons per minute Group tested together
- As-found test of E1150F015B was unsat due to degradation of the disc / wedge mating surface. Corrective Actions: The wedge was replaced. As-left leak rate was 0.00 gpm.