ML20034F784
| ML20034F784 | |
| Person / Time | |
|---|---|
| Site: | Fermi  |
| Issue date: | 02/07/2020 |
| From: | Nancy Salgado NRC/NRR/DORL/LPL3 |
| To: | Peter Dietrich DTE Electric Company |
| Venkataraman B | |
| References | |
| EPID L-2020-LLR-0011 | |
| Download: ML20034F784 (9) | |
Text
February 7, 2020 Mr. Peter Dietrich Senior Vice President and Chief Nuclear Officer DTE Electric Company Fermi 2 - 260 TAC 6400 North Dixie Highway Newport, MI 48166
SUBJECT:
FERMI 2 - ISSUANCE OF RELIEF RE: PROPOSED ALTERNATIVE REQUESTS NOS. VRR-010 AND VRR-011 ASSOCIATED WITH FOURTH TEN YEAR INTERVAL INSERVICE TESTING OF VARIOUS VALVES (EPID L-2020-LLR-0011)
Dear Mr. Dietrich:
By letter dated January 24, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20024F137), DTE Electric Company (DTE, the licensee) submitted proposed alternative request Nos. VRR-010, and VRR-011, to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with valve inservice testing (IST) for certain valves associated with the fourth 10-year interval IST program at Fermi 2.
Specifically, pursuant to subparagraph (2) 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, to Title 10, Energy, of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternatives in requests VRR-010 and VRR-011 on the basis that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality or safety.
As set forth in the enclosed safety evaluation (SE), the U.S. Nuclear Regulatory Commission (NRC) staff determined that the proposed alternative requests VRR-010 and VRR-011, provide reasonable assurance that the motor-operated valves listed in Tables 1 and 2 of the SE are operationally ready until the planned refueling outage in the spring of 2020. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes the use of the alternative requests VRR-010 and VRR-011 for Fermi 2 from the beginning of the fourth 10-year IST interval, which is currently scheduled for February 17, 2020, until the end of the refueling outage, RF20, which is scheduled for the spring of 2020.
All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject requests remain applicable.
If you have any questions, please contact the project manager, Booma Venkataraman, at (301) 415-2934 or Booma.Venkataraman@nrc.gov.
Sincerely,
/RA/ Robert F. Kuntz for Nancy L. Salgado, Chief, Plant Licensing Branch III Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-341
Enclosure:
Safety Evaluation cc: Listserv
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO PROPOSED ALTERNATIVE REQUEST NOS. VRR-010 AND VRR-011 FOR THE FOURTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM DTE ELECTRIC COMPANY FERMI 2 DOCKET NO. 50-341
1.0 INTRODUCTION
By letter dated January 24, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20024F137), DTE Electric Company (DTE, the licensee) submitted proposed alternative request Nos. VRR-010, and VRR-011, to the requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), associated with valve inservice testing (IST) for certain valves associated with the fourth 10-year interval IST program at Fermi 2.
Specifically, pursuant to subparagraph (2) 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, to Title 10, Energy, of the Code of Federal Regulations (10 CFR) 50.55a(z)(2), the licensee requested to use the proposed alternatives in requests VRR-010 and VRR-011 on the basis that the ASME OM Code requirements present an undue hardship without a compensating increase in the level of quality or safety.
2.0 REGULATORY EVALUATION
Regulation 10 CFR 50.55a(f), states, in part, that 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.
Regulation 10 CFR 50.55a(z) states that alternatives to the requirements of 10 CFR 50.55a(f) may be used, when authorized by the U.S. Nuclear Regulatory Commission (NRC), if the licensee demonstrates: (1) the proposed alternatives would provide an acceptable level of quality and safety, or (2) compliance with the specified requirements 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-010 In VRR-010, the licensee requested an alternative to the valve testing requirements in Mandatory Appendix III, Preservice and Inservice Testing of Active Electric Motor Operated Valve Assemblies in Light-Water Reactor Power Plants, of the ASME OM Code (2012 Edition).
Paragraph III-3200, Preservice Test, of Mandatory Appendix III states, in part, that each motor-operated valve (MOV) shall be tested during the preservice test period or before implementing IST. Paragraph III-3200 also states that testing that meets the requirements of the Mandatory Appendix but conducted before implementation of the Mandatory Appendix may be used.
The licensee has requested to use the proposed alternative described below for the MOVs listed in Table 1.
Table 1 Valve Identification (PIS) No.
Description ASME Code Class OM Valve Category Plant Drawing E1150F006A Residual Heat Removal (RHR)
Division 1 Pump A Shutdown Cooling Isolation MOV 2
B M-5706-2 E1150F006B RHR Division 2 Pump B Shutdown Cooling Isolation MOV 2
B M-5706-1 E1150F006C RHR Division 1 Pump C Shutdown Cooling Isolation MOV 2
B M-5706-2 E1150F006D RHR Division 2 Pump D Shutdown Cooling Isolation MOV 2
B M-5706-1 The Fermi 2 fourth 10-year IST program interval begins February 17, 2020, and is scheduled to end on February 16, 2030. The applicable ASME OM Code edition for the Fermi 2 fourth 10-year IST program interval is the 2012 Edition, which is incorporated by reference in 10 CFR 50.55a with conditions.
=
Reason for Request===
The Code of Record for the Fermi 2 fourth 10-year IST program interval is the 2012 Edition of the ASME OM Code which includes Mandatory Appendix III. The licensee determined that the MOVs in Table 1 were not in the existing scope of the Fermi 2 MOV program implemented in response to Generic Letter (GL) 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves, and that those MOVs should be included in the Mandatory Appendix III scope for the fourth 10-year IST interval at Fermi 2. The licensee stated that preservice testing that meets the requirements of Mandatory Appendix III has not been performed for these MOVs. The licensee also determined that the preservice testing for these MOVs should not be performed when the plant is online due to the operational risk involved in performing diagnostic testing for these MOVs when the plant is operating. In particular, an
inadvertent electrical short circuit during diagnostic testing of these MOVs could result in the loss of safety function of the low pressure coolant injection (LPCI) system. During plant shutdown conditions, this situation would not cause a safety concern because the LPCI loop select logic is not required in that plant mode.
Proposed Alternative The licensee proposes to perform the diagnostic testing for the MOVs listed in Table 1 during refueling outage, RF20, in the spring of 2020 as part of the fourth 10-year IST program interval.
This diagnostic testing will serve as the preservice testing for these MOVs.
The MOVs in Table 1 are normally closed and have a closed safety function to remain closed during design basis events. They have an open safety function to allow alignment of RHR system to the shutdown cooling mode. The MOVs are cycled quarterly for IST stroke time testing and this recent testing has been successful. The MOVs will be stroke time tested once more prior to RF20. The MOVs are controlled by a torque switch in the closing direction and a limit switch in the opening direction. Full MOV actuator capability is sufficient to open the valves during design basis conditions.
All four MOVs underwent thrust testing in the early 1990s. There has been no internal work performed on the valves since then. For three of the MOVs, the torque switches have not been adjusted since the thrust testing. The torque switch setting on the fourth MOV was increased slightly since the thrust testing, which improves its closing capability. Also, motor control center-based testing has been conducted periodically since the thrust tests and the tests have been successful.
NRC Staff Evaluation
The MOVs listed in Table 1 were not included in the existing scope of the GL 96-05 MOV program at Fermi 2. However, these MOVs should be included in the scope of Mandatory Appendix III of the ASME OM Code for the fourth 10-year IST program interval at Fermi 2. The licensee determined that preservice testing for these MOVs that meets the Mandatory Appendix III requirements has not been performed. The licensee determined that these MOVs cannot be tested online because there is a potential that the LPCI safety function might be lost.
These MOVs are stroke time tested quarterly and were thrust tested in the early 1990s, with all tests being successful. The MOVs are in the closed position and will stay in the closed position until RF20, except for one stroke time test.
Based on this evaluation, the NRC staff finds that testing these MOVs online would result in a hardship or unusual difficulty without an increase in the level of quality and safety. The NRC staff also finds that because of the past successful testing of the MOVs, the proposed alternative to delay the preservice testing of these MOVs until the end of RF20 (approximately 3 months) will not have an adverse impact on safety during the operation of Fermi 2 until the next refueling outage in the spring of 2020.
3.2 Licensees Alternative Request VRR-011 In VRR-011, the licensee requested an alternative to the valve testing requirements in Mandatory Appendix III of the ASME OM Code.
In particular, paragraph III-3200 of Mandatory Appendix III states, in part, that each MOV shall be tested during the preservice test period or before implementing IST. In addition, paragraph III-320 states that testing that meets the requirements of the Mandatory Appendix, but conducted before implementation of the Mandatory Appendix, may be used.
The licensee has requested to use the proposed alternative described below for the MOVs listed in Table 2.
Table 2 Valve Identification (PIS) No.
Description ASME Code Class OM Valve Category Plant Drawing E4150F007 High Pressure Coolant Injection (HPCI) Main Pump Discharge Isolation MOV 2
A M-5708-1 E5150F012 Reactor Core Isolation Cooling (RCIC) Pump Discharge Isolation MOV 2
A M-5709-1 The Fermi 2 fourth 10-year IST program interval begins on February 17, 2020, and is scheduled to end on February 16, 2030. The applicable ASME OM Code edition for the Fermi 2 fourth 10-year IST program interval is the 2012 Edition, which is incorporated by reference in 10 CFR 50.55a with conditions.
=
Reason for Request===
The Code of Record for the Fermi 2 fourth 10-year IST program interval is the 2012 Edition of the ASME OM Code, which includes Mandatory Appendix III. The licensee determined that the MOVs listed in Table 2 were not in the existing scope of the GL 96-05 MOV program at Fermi 2.
However, these MOVs are currently within the Mandatory Appendix III scope. Preservice testing per Mandatory Appendix III has not been performed on the MOVs. The licensee is planning an effort to reclassify these MOVs as passive valves to be able to remove them from the Mandatory Appendix III scope. The licensee stated that this reclassification effort is not part of the scope of this alternative request.
The MOVs, E4150F007 and E5150F012, are currently designated as pressure isolation valves (PIVs) at Fermi 2. The licensee plans to justify reassigning the safety functions of MOVs E4150F007 and E5150F012 to check valves E4100F005 and E5100F014, respectively. In order to accomplish this reassignment, the check valves must be seat leakage tested. The licensee has determined that the seat leakage testing of these check valves should not be performed online. The next opportunity for testing the check valves is during RF20, which is scheduled for the spring of 2020. This will occur after the start of the fourth 10-year IST program interval on February 17, 2020. Because of this, the MOVs in Table 2 must maintain their safety function until the check valves are justified to perform the PIV safety functions of the MOVs, including leak testing of the check valves in RF20. As a result, the licensee will not be in compliance with Mandatory Appendix III, paragraph III-3200, preservice testing requirements, during this time period.
Proposed Alternative The licensee proposes to defer the diagnostic testing of the MOVs in Table 2 until the RF20 outage in the spring of 2020. At that time, the licensee plans to justify the reassignment of the safety function of these MOVs to check valves E4100F005 and E5100F014, including the performance of check valve leakage testing. Assuming successful justification of the reassignment of the safety function of these MOVs to the check valves, Mandatory Appendix III requirements will then not be applicable to the MOVs.
The MOVs, E4150F007 and E5150F012, have successfully passed their recent seat leakage testing, and meet all technical specification requirements for leakage once closed. They are also exercised and stroke time tested quarterly in both the open and closed directions, and are position indication tested every 2 years. These tests have also been successful.
The licensees new application of the GL 96-05 methodology to MOV E4150F007 indicates that it would not be able to fully close under a differential pressure corresponding to full reactor pressure vessel (RPV) design pressure above1000 pounds per square inch (psi). However, the upstream check valve E4150F005 would reduce the differential pressure across the MOV and would allow it to close. During the third 10-year IST program interval, the licensee has performed open and close exercising of check valve E4150F005 in accordance with the ASME OM Code requirements. Check valve E4150F005 was also exercised during quarterly HPCI surveillances. All recent exercising of the check valve has been successful. Also, periodic inspections have been conducted on the check valve that provide confidence in its material condition.
The licensees new application of the GL 96-05 methodology to MOV E5150F012 indicates that it would not be able to fully close under a differential pressure corresponding to full RPV design pressure above1000 psi. However, the upstream check valve E5150F014 would reduce the differential pressure across the MOV and would allow it to close. During the Third 10-year IST program interval, the licensee has performed open exercising of check valve E4150F014 in accordance with the ASME OM Code requirements. Check valve E5150F014 was also exercised during quarterly RCIC surveillances. All recent exercising has been successful. The check valve was disassembled and inspected in 1994 and a new disc was installed. A satisfactory post-installation verification of its sealing surface was performed.
NRC Staff Evaluation
The MOVs listed in Table 2 were not included in the existing scope of the GL 96-05 MOV program at Fermi 2. However, the MOVs should be included in the scope of Mandatory Appendix III for the fourth 10-year IST program interval. The licensee determined that preservice testing for these MOVs that meets Mandatory Appendix III requirements has not been performed. The MOVs are currently classified as PIVs but the licensee is planning an effort to justify reassignment of their safety function to check valves E4150F005 and E5150F014. The licensee cannot complete this reclassification effort until the two check valves are seat leak tested during RF20, because the licensee determined that the check valves cannot be seat leak tested while the plant is online. Also, the MOVs cannot be diagnostically tested online because of the operational risk of the required testing lineup. The licensee is proposing to continue to rely on the safety function of the MOVs in Table 2 until the check valves are seat leak tested during RF20 in the spring of 2020, which is approximately 3 months after the start of the fourth 10-year IST program interval at Fermi 2.
Based on this evaluation, the NRC staff finds that testing these MOVs online would result in a hardship or unusual difficulty without increase in the level of quality and safety. The NRC staff also finds that because of the past successful testing of the MOVs and past exercising of the check valves, the proposed alternative to not perform the preservice testing of the MOVs from the start of the fourth 10-year IST program interval until the end of RF20 (approximately 3 months) will not have an adverse impact on safety during the operation of Fermi 2 until the next refueling outage in the spring of 2020. If the licensee is unsuccessful in justifying the reassignment of the PIV safety function from the MOVs in Table 2 to the applicable check valves during RF20, the IST requirements in Mandatory Appendix III will continue to be applicable to the MOVs in Table 2.
4.0 CONCLUSION
As set forth above, the NRC staff determined that the proposed alternative request Nos. VRR-010 and VRR-011 for Fermi 2 provide reasonable assurance that the MOVs listed in Tables 1 and 2 of this SE are operationally ready until the planned refueling outage in the spring of 2020.
Accordingly, the NRC staff concludes that the licensee has adequately addressed all the regulatory requirements set forth in 10 CFR 50.55a(z)(2) for alternative requests VRR-010 and VRR-011. Therefore, the NRC staff authorizes the use of the alternative requests VRR-010 and VRR-011 for Fermi 2 from the beginning of the fourth 10-year IST interval, which is scheduled for February 17, 2020, until the end of the next refueling outage, RF20, which is scheduled for the spring of 2020.
All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject requests remain applicable.
Principal Contributor: Robert Wolfgang, NRR/DEX/EMIB Date: February 7, 2020
(*)by e-mail and Memo OFFICE NRR/DORL/LPL3/PM NRR/DORL/LPL3/LA NRR/DEX/EMIB NRR/DORL/LPL3/BC NAME BVaidya SRohrer TScarbrough (A)(*)
NSalgado (RKuntz for)
DATE 02/06/2020 02/05/2020 02/03/2020 02/07/2020