ML20183A319
| ML20183A319 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 07/01/2020 |
| From: | Mel Gray Engineering Region 1 Branch 1 |
| To: | Bryan Hanson Exelon Generation Co, Exelon Nuclear |
| Gray M | |
| References | |
| IR 2020014 | |
| Download: ML20183A319 (8) | |
See also: IR 05000352/2020014
Text
July 1, 2020
Mr. Bryan C. Hanson
Senior Vice President
Exelon Generation Company, LLC
President and Chief Nuclear Officer
Exelon Nuclear
4300 Winfield Road
Warrenville, IL 60555
SUBJECT:
LIMERICK GENERATING STATION, UNITS 1 AND 2 - INFORMATION
REQUEST TO SUPPORT TRIENNIAL BASELINE DESIGN-BASIS CAPABILITY
OF POWER-OPERATED VALVES INSPECTION; INSPECTION REPORT
05000352/2020014 AND 05000353/2020014
Dear Mr. Hanson:
The purpose of this letter is to notify you that the U.S. Nuclear Regulatory Commission (NRC)
Region I staff will conduct a team inspection at your Limerick Generating Station, Units 1 and 2.
Amar Patel, a Senior Reactor Inspector from the NRCs Region I Office, will lead the inspection
team. The inspection will be conducted in accordance with Inspection Procedure
71111.21N.02, Design-Basis Capability of Power-Operated Valves Under 10 CFR 50.55a
Requirements, dated July 26, 2019 (ADAMS Accession No. ML19067A240).
The inspection will assess the reliability, functional capability, and design bases of risk-important
power-operated valves (POVs) as required by Title 10 of the Code of Federal Regulations (10
CFR) 50.55a, and Appendix A and B requirements. The inspectors will select a sample of
POVs based on risk insights, safety significance, and operating margin.
During a telephone conversation on June 30, 2020, with Mr. Charles Wheeler, a member of
your Limerick staff, we confirmed arrangements for an information gathering site visit and the
two-week onsite inspection. The schedule is as follows:
Information gathering visit: Week of August 17, 2020
Onsite weeks: Weeks of September 14 and September 28, 2020
The purpose of the information gathering visit is to meet with members of your staff and to
become familiar with your programs and procedures intended to ensure compliance with 10
CFR 50.55a for POVs. The lead inspector will discuss aspects of the programs including any
specific applicable regulatory commitments made by your facility and your use of NRC
Regulatory Guides or industry standards. Frank Arner, a Region I Senior Risk Analyst, will
support Amar Patel during the information-gathering visit to review probabilistic risk assessment
data and identify the final POV samples to be examined during the inspection.
Experience with previous design basis team inspections of similar depth and length has shown
this type of inspection is resource intensive, both for NRC inspectors and licensee staff. In
B. Hanson
2
order to minimize the inspection impact on the site and to ensure a productive inspection for
both parties, we have enclosed a request for information needed for the inspection.
Insofar as possible, this information should be provided electronically to the lead inspector at the
NRC Region I office by August 10, 2020. Additional documents may be requested during the
information gathering visit and/or during team preparation week (the week prior to the first onsite
inspection week). The inspectors will minimize your administrative burden by specifically
identifying only those documents required for the inspection.
If there are any questions about the inspection or the material requested in the enclosure,
please contact the lead inspector at 610-337-5220 or via e-mail at amar.patel@nrc.gov.
This letter does not contain new or amended information collection requirements subject to the
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). Existing information collection
requirements were approved by the Office of Management and Budget, Control Number 3150-
0011. The NRC may not conduct or sponsor, and a person is not required to respond to, a
request for information or an information collection requirement unless the requesting document
displays a currently valid Office of Management and Budget Control Number.
This letter and its enclosure will be made available for public inspection and copying at
http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in
accordance with 10CFR Part 2.390, Public Inspections, Exemptions, Requests for
Withholding.
Thank you in advance for supporting this resource intensive but important engineering
inspection.
Sincerely,
X /RA/
Signed by: Melvin K. Gray
Mel Gray, Chief
Engineering Branch 1
Division of Reactor Safety
Docket Nos. 05000352 and 05000353
License Nos. NPF-39 and NPF-85
Enclosure:
Document Request for Power-Operated
Valves Inspection
cc: Distribution via ListServ
SUNSI Review
Non-Sensitive
Sensitive
Publicly Available
Non-Publicly Available
OFFICE
RI/DRS
RI/DRS
NAME
APatel
MGray
DATE
6/30/20
7/1/20
DOCUMENT REQUEST FOR POWER-OPERATED VALVES INSPECTION
Enclosure
Inspection Report: 05000352/2020014 and 05000353/2020014
Onsite Inspection Dates:
September 14 through September 18, 2020; and
September 28 through October 2, 2020
Inspection Procedure:
Inspection Procedure 71111.21N.02, Design-Basis Capability of
Power-Operated Valves Under 10 CFR 50.55a Requirements
Lead Inspector:
Amar Patel, Senior Reactor Inspector
610-337-5220
amar.patel@nrc.gov
I.
Information Gathering Visit
During this visit, we plan to obtain sufficient insights to finalize POV samples for this
inspection. We would like to meet with POV specialists to discuss the upcoming
inspection and our sample selection process. The primary valve types to be reviewed
for this inspection include motor-operated valves (MOVs) and air-operated valves
(AOVs); and additional valve types include hydraulic-operated valves (HOVs), solenoid-
operated valves (SOVs), and pyrotechnic-actuated (squib) valves. During this visit, the
lead inspector will (a) discuss the scope of the planned inspection; (b) identify additional
information needed to review in preparation for the inspection; (c) ensure that the
information to be reviewed is available at the beginning of the inspection; and (d) verify
that logistical issues will be identified and addressed prior to the teams arrival. Please
reserve a room during the site visit with a telephone, wireless internet access, and a
licensee computer with access to procedures, corrective action program documents, and
a printer.
II.
Information Requested for Selection of Power-Operated Valves
The following information is requested by August 10, 2020, to facilitate inspection
preparation. Feel free to contact the lead inspector if you have any questions regarding
this information request. Please provide the information electronically in pdf files,
Excel, or other searchable formats, preferably on some portable electronic media (e.g.,
CD-ROM, DVD). The files should contain descriptive names, and be indexed and
hyperlinked to facilitate ease of use. Information in lists should contain enough
information to be easily understood by someone who has knowledge of light water
reactor technology and POVs.
1. A word-searchable Update Final Safety Analysis Report. If not available in a single
file per unit, please ensure a collective table of contents is provided.
2. Site (and corporate if applicable) procedures associated with implementation of the
MOV program required by 10 CFR 50.55a(b)(3)(ii) and/or ASME OM Code
Mandatory Appendix III; and site (corporate) procedure for AOV program.
3. Site response(s) to NRC Generic Letter (GL) 95-07, Pressure Locking and Thermal
Binding of Safety-Related Power-Operated Gate Valves.
DOCUMENT REQUEST FOR POWER-OPERATED VALVES INSPECTION
2
4. Site evaluation of NRC Information Notice 2012-14, MOV Inoperable due to Stem-
Disc Separation.
5. List of corrective action documents related to the MOV and AOV programs since
9/2015 (include document No., title/short description, date).
6. List of corrective action documents related to each of the 30 POVs listed below since
9/2015 (include document No., title/short description, date).
7. List of significant modifications, repairs, or replacement of safety related POVs
completed since 9/2015, including date completed (include document No., title, date
completed).
8. Any self-assessments or quality assurance type assessments of the MOV/AOV
programs (performed since 9/2015).
9. Most recent POV (e.g., MOV, AOV, SOV) program health report, if available.
10. List and electronic copy of all Emergency Operating Procedures.
11. List of Abnormal Operating Procedures.
12. Identify the edition of the ASME Operation and Maintenance of Nuclear Power Plants
(OM Code) that is the Code of Record for the current 10-year Inservice Test Program
interval, as well as any standards to which the station has committed with respect to
POV capability and testing.
13. For each of the following MOVs, provide the information listed in the table below
(further information on what/how to provide was discussed during the June 30th
phone call with Mr. Charles Wheeler).
Containment Atmospheric Control, FV-DO-101A
Containment Atmospheric Control, HV-57-163
High Pressure Coolant Injection, HV-55-1F002
High Pressure Coolant Injection, HV-55-1F003
High Pressure Coolant Injection, HV-55-2F001
High Pressure Coolant Injection, HV-55-2F004
Reactor Core Isolation Cooling, HV-49-2F008
Reactor Core Isolation Cooling, HV-49-1F013
Reactor Core Isolation Cooling, HV-50-2F045
Reactor Water Clean-Up, HV-44-1F004
Residual Heat Removal, HV-51-1F014B
Residual Heat Removal, HV-51-1F017B
Residual Heat Removal, HV-51-1F068B
Residual Heat Removal Service Water, HV-12-032A
Residual Heat Removal Service Water, HV-12-032C
Residual Heat Removal, HV-51-2F014A
Residual Heat Removal, HV-51-2F015A
Residual Heat Removal, HV-C-51-2F048A
DOCUMENT REQUEST FOR POWER-OPERATED VALVES INSPECTION
3
Item Parameter/Information*
1
MOV Identification
2
Safety Function
3
Valve manufacturer, type, and size
4
Actuator manufacturer, type, and size
5
Motor manufacturer, type (AC/DC), and size
6
Valve ASME Class
7
Risk Significance
8
Control Switch Trip (CST) Application (Close/Open)
9
Design-Basis Differential Pressure (DBDP) and Flow (Close/Open)
10
Rising-Stem Valve: Assumed Valve Factor (VF)
11
Quarter-Turn Valve: Assumed bearing torque coefficient
12
Assumed Stem Friction Coefficient (SFC)
13
Assumed Load Sensitive Behavior (LSB) (%)
14
% Uncertainties (e.g., diagnostic equipment, CST repeatability, etc.)
15
Calculated Required Thrust/Torque (Close/Open)
16
Least Available Output (e.g., actuator, CST, rating, spring pack, weak link)
17
Test Conditions (e.g., fluid differential pressure (DP), system pressure, flow,
and temperature; ambient temperature; and motor voltage) (Close/Open)
18
Thrust and torque required to overcome dynamic conditions (Close/Open)
19
Rising-Stem Valve: Measured VF (Close/Open)
20
Rising-Stem Valve: Available VF (Close/Open)
21
Measured SFC (Close/Open)
22
Measured LSB (%)
23
Quarter-Turn Valve: Measured bearing torque coefficient (Close/Open)
24
Determined % Margin (Close/Open)
25
Basis for Design-Basis Capability:
25.a Dynamic test performed at design-basis DP/flow conditions
25.b Extrapolation of dynamic test data
25.c Justification from normal operation at or above design-basis conditions
25.d Industry dynamic test methodology (such as EPRI MOV PPM)
25.e Grouped with similar valves dynamically tested at plant
25.f
Grouped with similar valves dynamically tested at other plants
25.g Valve qualification testing (such as ASME QME-1-2007)
25.h Other (such as large calculated margin)
- Specify Not Applicable (NA) as appropriate
14. For each of the following AOVs, provide the information listed in the table below.
Emergency Service Water, HV-11-041
Emergency Service Water, HV-11-047
Emergency Service Water, HV-11-123
Nuclear Boiler, HV-41-1F022C
Nuclear Boiler, HV-41-1F028D
Reactor Core Isolation Cooling, FV-50-113
Containment Atmospheric Control, HV-57-204
Containment Atmospheric Control, HV-57-221
Control Rod Drive Hydraulic, XV-47-2F181
Emergency Service Water, HV-11-201H
DOCUMENT REQUEST FOR POWER-OPERATED VALVES INSPECTION
4
Item Parameter/Information*
1
AOV Identification
2
Safety Function
3
Fail safe position (open/close)
4
Valve manufacturer, type, and size
5
Actuator manufacturer, type, and size
6
Valve ASME Class
7
Risk Significance
8
Design-Basis Differential Pressure (DBDP) and Flow (Close/Open)
9
Rising-Stem Valve: Assumed Valve Factor (VF)
10
Quarter-Turn Valve: Assumed bearing torque coefficient
11
% Uncertainties (e.g., diagnostic equipment, CST repeatability, etc.)
12
Calculated Required Thrust/Torque (Close/Open)
13
Minimum allowable air pressure (Beginning/End Stroke)
14
Maximum allowable air pressure (Beginning/End Stroke)
15
Minimum allowable spring preload (Beginning/End Stroke)
16
Maximum allowable spring preload (Beginning/End Stroke)
17
Least Available Actuator Output (e.g., actuator capability, actuator limit, valve
weak link limitation)
18
Test Conditions (e.g., fluid differential pressure (DP), system pressure, flow,
and temperature; and ambient temperature) (Close/Open)
19
Thrust and torque required to overcome dynamic conditions (Close/Open)
20
Rising-Stem Valve: Measured VF (Close/Open)
21
Quarter-Turn Valve: Measured bearing torque coefficient (Close/Open)
22
Determined Margin (%) (Least margin for air stroke operation, spring stroke
operation, maximum spring load, and structural capability)
23
Basis for Design-Basis Capability:
24.a Dynamic test performed at design-basis DP/flow conditions
24.b Extrapolation of dynamic test data
24.c Justification from normal operation at or above design-basis conditions
24.d Industry dynamic test methodology
24.e Grouped with similar valves dynamically tested at plant
24.f
Grouped with similar valves dynamically tested at other plants
24.g Valve qualification testing (such as ASME QME-1-2007)
24.h Other (such as large calculated margin)
- Specify Not Applicable (NA) as appropriate
15. For each of the following miscellaneous POVs, provide the information listed in the
table below.
Core Spray SV-52-239
Standby Liquid Control XV-48-2F004C
Item Parameter/Information*
1
Safety Function
2
Fail safe position (open/close/as-is)
3
Valve manufacturer, type, and size
4
Actuator manufacturer, type, and size
5
Valve ASME Class
6
Risk significance
DOCUMENT REQUEST FOR POWER-OPERATED VALVES INSPECTION
5
7
Design-basis differential pressure and flow (close/open)
8
Minimum required Voltage at the POV
9
Available voltage at the POV
10
Environmental Qualification harsh environment (Y/N)
11
Normally energized (Y/N)
12
Time in service
- Specify Not Applicable (NA) as appropriate