ML20089A008

From kanterella
Revision as of 13:03, 25 July 2023 by StriderTol (talk | contribs) (StriderTol Bot change)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

Relief Request GVRR-9 Associated with Pandemic Related Issues - Inservice Testing Interval Extension for Motor Operated Valves
ML20089A008
Person / Time
Site: Limerick Constellation icon.png
Issue date: 03/29/2020
From: David Helker
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML20089A008 (8)


Text

200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.55a March 29, 2020 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 1 Renewed Facility Operating License No. NPF-39 NRC Docket No. 50-352

Subject:

Relief Request GVRR-9 Associated with Pandemic Related Issues - Inservice Testing Interval Extension for Motor Operated Valves Based on the current situation associated with pandemic related issues, Exelon Generation Company, LLC (Exelon) is requesting a proposed alternative to the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), for the Inservice Testing Program. Attached is the proposed alternative associated with Inservice Testing Interval extension for certain Limerick Generating Station (LGS), Unit 1, Motor Operated Valves (MOVs).

At the current time, Exelon is reducing activities associated with the LGS, Unit 1, outage which began on Saturday, March 28, 2020, in order to limit the spread of the COVID-19 virus. As discussed in the relief request, many of these activities involve close contact and a limit to social distancing. Further review has determined that close contact required to perform the MOV testing would be detrimental to the occupational health and safety of the workforce and result in the potential to spread the virus. Additionally, the station may experience critical shortages of specially trained and qualified personnel due to illness which will greatly affect completion of these required tests during the current refuel outage.

Accordingly, Exelon is requesting approval of this relief on an expedited basis.

Due to the urgent nature of this situation, Exelon is requesting approval of the attached relief request by March 31, 2020.

There are no regulatory commitments in this letter.

U.S. Nuclear Regulatory Commission Relief Request GVRR-9 Associated with Pandemic Related Issues for MOVs Docket No. 50-352 March 29, 2020 Page 2 If you have any questions concerning this letter, please contact David Neff at (267) 533-1132.

Respectfully, David P. Helker Sr. Manager, Licensing Exelon Generation Company, LLC

Attachment:

Relief Request GVRR-9 Associated with Pandemic Related Issues - lnservice Testing Interval Extension for Motor Operated Valves cc: w/ Attachments Regional Administrator - NRG Region I NRG Senior Resident Inspector - Limerick Generating Station NRG Project Manager - Limerick Generating Station R. R. Janati, Pennsylvania Bureau of Radiation Protection

Attachment Relief Request GVRR-9 Associated with Pandemic Related Issues - Inservice Testing Interval Extension for Motor Operated Valves

EXELON GENERATION COMPANY, LLC IST PROGRAM - RELIEF REQUEST Limerick Generating Station Unit 1 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)

Associated with Pandemic Related Issues GVRR-9, Revision 0, Inservice Testing Interval Extension for Motor Operated Valves

1. ASME Code Component(s) Affected The following 17 active safety related motor operated valves (MOVs) are required by Subsection ISTC of the 2012 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) Code to be tested in accordance with ASME OM Code Mandatory Appendix Ill.

Component System Code Class Category Type 1 HV-013-106 Reactor Enclosure Cooling Water 2 A MO 2 HV-013-108 Reactor Enclosure Cooling Water 2 A MO 3 HV-013-111 Reactor Enclosure Cooling Water 2 A MO 4 HV-041-130B Nuclear Boiler 1 A MO 5 HV-041-140 Nuclear Boiler NC B MO 6 HV-046-125 Control Rod Drive Hydraulic NC B MO 7 HV-048-1F006B Standby Liquid Control 1 A/C MO 8 HV-051-1F008 Residual Heat Removal 1 A MO 9 HV-051-1F009 Residual Heat Removal 1 A MO 10 HV-057-162 Containment Atmospheric Control 2 A MO 11 HV-057-163 Containment Atmospheric Control 2 A MO 12 HV-059-101 Primary Containment Instrument Gas 2 A MO 13 HV-059-151A Primary Containment Instrument Gas 2 A MO 14 HV-059-151B Primary Containment Instrument Gas 2 A MO 15 HV-087-120A Drywell Chilled Water NC A MO 16 HV-087-121B Drywell Chilled Water NC A MO 17 HV-087-123 Drywell Chilled Water 2 A MO

2. Applicable Code Edition and Addenda

American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), 2012 Edition with no addenda.

3. Applicable Code Requirement

The ASME OM Code Mandatory Appendix III, Preservice and lnservice testing of Active Electric Motor-Operated Valve Assemblies in Water Cooled Reactor Nuclear Power Plants.

The following Appendix Ill Paragraphs are affected by this Relief Request (RR) for a one-time IST Program interval extension to the next refueling outage for specific Limerick Generating Station (LGS), Unit 1, MOVs.

Page 1 of 5

EXELON GENERATION COMPANY, LLC IST PROGRAM - RELIEF REQUEST Limerick Generating Station Unit 1 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)

Associated with Pandemic Related Issues GVRR-9, Revision 0, Inservice Testing Interval Extension for Motor Operated Valves III-3310 Inservice Test Interval. (c) The maximum inservice test interval shall not exceed 10 yr. MOV inservice tests conducted per para. III-3400 may be used to satisfy this requirement.

III-3722 LSSC MOVs. (d). LSSC MOVs shall be inservice tested at least every 10 yr in accordance with para. III-3310.

4. Reason for Request

In accordance with 10 CFR 50.55a(z)(2), Exelon Generation Company, LLC (Exelon) is requesting approval for a one-time IST Program interval extension to the next refueling outage for specific LGS, Unit 1, MOVs due to occupational health and safety concerns associated with pandemic related issues. The next refueling outage is currently scheduled for the spring of 2022 (Li1R19). For each of the identified applicable paragraphs, relief is being sought for alternative treatments described in Section 5 of this RR based on the existence of satisfactory MOV performance and capability and that compliance would involve activities that would be detrimental to the occupational health and safety of the workforce and result in the potential to spread the virus. The basis of the request is that compliance results in hardship or unusual difficulty without a compensating increase in level of quality or safety during the current pandemic.

At the current time, Exelon is reducing activities associated with the LGS, Unit 1 outage which began on Saturday, March 28, 2020, in order to limit the spread of the COVID-19 virus. As discussed in this RR, many of these activities involve close contact and a limit to social distancing. Further review has determined that close contact required to perform the MOV testing would be detrimental to the occupational health and safety of the workforce and result in the potential to spread the virus. Additionally, the station may experience critical shortages of specially trained and qualified personnel due to illness which will greatly affect completion of these required tests during the current refueling outage. These tests require several valve maintenance technicians, and other support personnel (e.g., scaffold builders, radiation protection technicians, and other maintenance personnel). Accordingly, Exelon is requesting approval of this relief on an expedited basis.

The United States government declared a national emergency associated with the COVID-19 outbreak on March 13, 2020. In addition, the state of Pennsylvania, where LGS is located, made an Emergency Disaster Declaration on March 5, 2020, to take actions necessary to reduce exposure to the virus associated with the COVID-19 outbreak. The Centers for Disease Control (CDC) is recommending social distancing as it applies to COVID-19. The CDC defines social distancing as "remaining out of congregate settings, avoiding mass gatherings, and maintaining distance (approximately 6 feet or 2 meters) from others when possible." In the case of performing the MOV testing at a nuclear power plant, which requires work in close spaces, this recommendation cannot be effectively implemented.

Due to the COVID-19 pandemic and in an effort to comply with CDC guidance, Exelon is requesting relief associated with performing certain MOV testing. Section 5 of this RR demonstrates that there is reasonable assurance that the design function of each identified Page 2 of 5

EXELON GENERATION COMPANY, LLC IST PROGRAM - RELIEF REQUEST Limerick Generating Station Unit 1 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)

Associated with Pandemic Related Issues GVRR-9, Revision 0, Inservice Testing Interval Extension for Motor Operated Valves MOV will be maintained through the next refuel outage currently scheduled for the spring of 2022 (Li1R19). The technical justification utilizes available detailed data from the most recent MOV test, the corresponding MOV Functional Margin, and a review of the maintenance history for each MOV. This provides the technical justification necessary to show that the proposed alternative is acceptable, and that deferral of the MOV testing in 2020 will not result in an adverse consequence to safety.

5. Proposed Alternative and Basis for Use

Exelon is requesting relief associated with performing the identified MOV testing in accordance with 10 CFR 50.55a(z)(2) on the basis that compliance results in hardship or unusual difficulty without a compensating increase in level of quality or safety during the current pandemic. Exelon proposes a one-time extension to IST Program intervals for specific LGS, Unit 1, MOVs to the next refueling outage currently scheduled for the spring of 2022 (Li1R19). An evaluation was performed for each identified MOV that utilized detailed data from the most recent MOV test, the corresponding MOV Functional Margin, and a review of the maintenance history for each MOV. This evaluation concluded that the proposed alternative is acceptable, and that deferral of the specific MOV testing in 2020 will not result in an adverse consequence to safety.

Over the past twenty years, Exelon MOV Programs have demonstrated many margin stable MOVs that are being considered for extension of their current MOV Program maximum inservice test intervals of ten years. Exelon submitted a RR for Limerick to permit implementation of the approved Code Case OMN-26 (Reference 1) and the NRC has accepted the requested licensing action (Reference 2). However, the one-time RR contained in this current submittal does not rely on the approval of the Code Case OMN-26 RR.

Table 1 below contains the calculated MOV Functional Margin, after accounting for uncertainties and degradation factors, based on the most current MOV test. An MOVs functional margin is a composite margin that defines the functional capability of the MOV to perform its design basis safety function. Each of these MOVs has a Functional Margin of high (> 10% and < 20%) or very high (> 20%) indicating that there is existing safety margin to assure reliable operation of these MOVs. The evaluation for this RR also included a review of the maintenance history of each MOV. No deficiencies, adverse trends or open maintenance work orders were identified that would impact or degrade each valves performance capability and exclude it from this interval extension RR. Each MOV in the scope of this RR is currently on a standard testing interval with acceptable performance.

Considering the valves current acceptable performance and the high or very high MOV functional margin, there is reasonable assurance that each MOV will continue to be capable of performing its design function during the use of this RR.

In summary, extending the MOV testing interval for each MOV in the scope of this RR to the next refueling outage scheduled for the spring of 2022 (Li1R19) would not adversely impact the function of the MOV or result in a reduction in plant safety. In the current pandemic environment, performing the required tests would result in an increased risk of virus exposure to plant personnel and a reduction in occupational health and safety without a Page 3 of 5

EXELON GENERATION COMPANY, LLC IST PROGRAM - RELIEF REQUEST Limerick Generating Station Unit 1 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)

Associated with Pandemic Related Issues GVRR-9, Revision 0, Inservice Testing Interval Extension for Motor Operated Valves compensating benefit. Therefore, this RR meets the criteria for relief on the basis that compliance results in hardship or unusual difficulty without a compensating increase in level of quality or safety during the current pandemic.

6. Duration of Proposed Alternative

This submittal requests a one-time IST Program interval extension for specific LGS, Unit 1, MOVs to the next refueling outage that is currently scheduled for the spring of 2022 (Li1R19).

7. Precedent None
8. References
1. Exelon letter to NRC, "Proposed Alternative to Utilize Code Case OMN-26," dated January 31, 2020 (ADAMS Accession No. ML20034C819)
2. NRC email to Exelon, "Code Case OMN-26 (EPID L-2020-LLR-0012)," dated February 25, 2020 (ADAMS Accession No. ML20056F345)

Page 4 of 5

EXELON GENERATION COMPANY, LLC IST PROGRAM - RELIEF REQUEST Limerick Generating Station Unit 1 Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)

Associated with Pandemic Related Issues GVRR-9, Revision 0, Inservice Testing Interval Extension for Motor Operated Valves Table 1 Comparison of MOV Testing Interval Functional Current MOV ID Last Requested

  1. Margin Max Number Tested Outage (Year)

Interval 1 HV-013-106 78.5 2010 10 L1R19 (2022) 2 HV-013-108 219.1 2010 10 L1R19 (2022) 3 HV-013-111 226.7 2010 10 L1R19 (2022) 4 HV-041-130B 180.6 2010 10 L1R19 (2022) 5 HV-041-140 74.9 2010 10 L1R19 (2022) 6 HV-046-125 102.3 2010 10 L1R19 (2022) 7 HV-048-1F006B 61.1 2010 10 L1R19 (2022) 8 HV-051-1F008 40.3 2010 10 L1R19 (2022) 9 HV-051-1F009 35.6 2010 10 L1R19 (2022) 10 HV-057-162 98.7 2010 10 L1R19 (2022) 11 HV-057-163 361.0 2010 10 L1R19 (2022) 12 HV-059-101 97.6 2010 10 L1R19 (2022) 13 HV-059-151A 97.1 2010 10 L1R19 (2022) 14 HV-059-151B 283.5 2010 10 L1R19 (2022) 15 HV-087-120A 10.2 2010 10 L1R19 (2022) 16 HV-087-121B 22.7 2010 10 L1R19 (2022) 17 HV-087-123 10.1 2010 10 L1R19 (2022)

Page 5 of 5