IR 05000395/2021010
| ML21215A044 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 08/02/2021 |
| From: | James Baptist Division of Reactor Safety II |
| To: | Stoddard D Dominion Energy Virginia |
| References | |
| IR 2021010 | |
| Download: ML21215A044 (15) | |
Text
August 2, 2021
SUBJECT:
VIRGIL C. SUMMER NUCLEAR STATION, UNIT 1 - DESIGN BASIS ASSURANCE INSPECTION (PROGRAMS) INSPECTION REPORT 05000395/2021010
Dear Mr. Stoddard:
On June 25, 2021, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Virgil C. Summer Nuclear Station, Unit 1. On July 29, 2021, the NRC inspectors discussed the results of this inspection with Mr. G. Lippard and other members of your staff. The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; the Director, Office of Enforcement; and the NRC Resident Inspector at Virgil C. Summer Nuclear Station, Unit 1.
This letter, its enclosure, and your response (if any) 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 Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely,
/RA/
James B. Baptist, Chief Engineering Branch 1 Division of Reactor Safety Docket No. 05000395 License No. NPF-12
Enclosure:
As stated
Distribution via LISTSERV
SUNSI Review
X Non-Sensitive Sensitive
X Publicly Available Non-Publicly Available
OFFICE RII/DRS RII/DRS RII/DRS RII/DRS
NAME P. Braxton J. Nicely G. Ottenberg J. Baptist
DATE 7/30/2021 7/29/2021 7/30/2021 8/2/2021
Enclosure
U.S. NUCLEAR REGULATORY COMMISSION
Inspection Report
Docket Number:
05000395
License Number:
Report Number:
Enterprise Identifier: I-2021-010-0036
Licensee:
Dominion Energy
Facility:
Virgil C. Summer Nuclear Station, Unit 1
Location:
Jenkinsville, SC
Inspection Dates:
June 07, 2021 to June 25, 2021
Inspectors:
P. Braxton, Reactor Inspector
G. Nicely, Contractor
G. Ottenberg, Senior Reactor Inspector
Approved By:
James B. Baptist, Chief
Engineering Branch 1
Division of Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a design basis assurance inspection (programs) inspection at Virgil C. Summer Nuclear Station, Unit 1, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
Failure to Fully Address Previous NCV Related to Maximum Expected Differential Pressure for the XVG08811A(B)-SI and XVG08812A(B)-SI Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000395/2021010-01 Open/Closed None (NPP)71111.21N.
The inspectors identified a Green finding and associated Non-cited Violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, "Corrective Action," when the licensee failed to correct a condition adverse to quality associated with the calculation of the maximum expected differential pressure (DP) for the containment sump valves.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), inspectors were directed to begin telework. In addition, regional baseline inspections were evaluated to determine if all or a portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP.
REACTOR SAFETY
71111.21N.02 - Design-Basis Capability of Power-Operated Valves Under 10 CFR 50.55a Requirements POV Review (IP Section 03)
The inspectors:
a. Evaluated whether the sampled POVs are being tested and maintained in accordance with NRC regulations along with the licensees commitments and/or licensing bases.
b. Evaluated whether the sampled POVs are capable of performing their design-basis functions.
c. Evaluated whether testing of the sampled POVs is adequate to demonstrate the capability of the POVs to perform their safety functions under design-basis conditions.
d. Evaluated maintenance activities including a walkdown of the sampled POVs (if accessible).
- (1) XVG03111B-SW; RBCU 1B & 2B CI System Return Isolation Valve
- (2) XVG08811B-SI; Containment Sump RH Pump B Suction Isolation Valve
- (3) LCV00115C-CS; Volume Control Tank Outlet Isolation Valve
- (4) XVG08000A-RC; Pressurizer PORV Inlet Isolation Valve
- (5) XVB03116A-SW; Service Water Pump A Discharge Valve
- (6) XVB09503A-CC; RH Heat Exchanger A CC Inlet Valve
- (7) PCV00444B-RC; Pressurizer Power Operated Relief Valve (PORV)
- (8) IFV02030-MS; EF Pump Turbine Steam Supply Flow Control Valve
- (9) XVG06067-HR; Alternate Purge Exhaust Isolation Valve
INSPECTION RESULTS
Failure to Fully Address Previous NCV Related to Maximum Expected Differential Pressure for the XVG08811A(B)-SI and XVG08812A(B)-SI Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000395/2021010-01 Open/Closed
None (NPP)71111.21N.0 The inspectors identified a Green finding and associated Non-cited Violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, "Corrective Action," when the licensee failed to correct a condition adverse to quality associated with the calculation of the maximum expected differential pressure (DP) for the containment sump valves.
Description:
One of the required safety functions of the residual heat removal (RHR) system is to establish long-term recirculation reactor cooling after loss of coolant accidents (LOCAs). The RHR pump containment sump suction valves, XVG08811A/B-SI and XVG08812A/B-SI, must open to establish a suction path from the containment sump to the RHR pumps. NRC inspection report 2006008 (ADAMS ML062080036) identified a 10 CFR 50, Appendix B, Criterion XVI violation (NCV 2006008-01), for the licensee's failure to identify a condition adverse to quality that was discussed in industry OE20884. The OE identified that small break (SB) LOCAs could produce more limiting DP scenarios for the RHR pump containment sump suction valves due to the potential for the RHR pump to operate under minimum flow conditions. The higher DPs require higher MOV actuator thrust to successfully operate.
Condition report, CER 06-02041, was written in response to NCV 2006008-01, but it was closed relying on actions to be taken in another condition report, CER-05-03241. Following issuance of NCV 2006008-01, CER-05-03241 re-evaluated the increase in differential pressure across the XVG08811A/B-SI and XVG08812A/B-SI valves, and stated:
The maximum possible SBLOCA opening differential pressures was re-estimated to be ~
460 psid for XVG08812A/B-RH & ~ 455 psid for XVG08811A/B-RH assuming the RHR pump suction pressure is controlled at the RHR inlet relief valve setpoint. Based on current design basis assumptions, all of the RHR sump MOVs, except XVG08811B, were found to have sufficient open thrust capability for their maximum expected differential pressure. Further review indicates that the voltage drop calculations for XVG08811B are overly conservative and that the use of more realistic assumptions results in a 30 V increase in terminal voltage. When crediting the higher terminal voltage, the open thrust capability for XVG08811B was found to exceed the minimum required opening thrust for the SBLOCA scenario by approximately 4.35%. This re-confirmed the prior conclusion that the existing containment sump valves/actuators can successfully perform their design function of opening during the transition to CL recirculation during a SBLOCA.
At the time of this inspection, the station's record calculation identified the maximum expected DP in the open direction as 49 psid as opposed to the 460 & 455 psid identified above.
While the higher DP condition had been evaluated in CER-05-03241 as acceptable, it initially resulted in negative calculated margin for the XVG08811B-SI valve. The DP calculation, DC01520-049, the associated minimum required thrust calculation, DC01520-059, and the actuator capability calculation, DC01520-067, were planned to be updated to reflect the evaluation in CER-05-03241. However, the calculations were never updated because engineering change request ECR 72009 was not implemented as intended, explaining why the station's record calculation still incorrectly identified 49 psid as the design basis assumption. As a result, the licensee was over-estimating the margin available for the MOVs to perform their safety functions. The MOV program relies on the calculated margins to determine valve operability and the required periodic verification test intervals.
Corrective Actions: Upon the inspector's discovery, the licensee reconfirmed that the XVG08811A/B-SI and XVG08812A/B-SI valves remained capable of performing their intended functions, and would have positive margin after accounting for the higher DP and taking credit for adjustments to the actuator capability.
Corrective Action References: CR -21-01620
Performance Assessment:
Performance Deficiency: The licensees failure to correct a condition adverse to quality associated with the calculation of maximum expected differential pressure for the containment sump valves, was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the licensee had to change assumptions to obtain favorable results as they revised the actuator capability calculations for the XVG08811B-SI valve in order to demonstrate the valve had positive design margin.
Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Specifically, the inspectors used IMC 0609, Appendix A, Exhibit 2, "Mitigating Systems Screening Questions," and determined the finding was a deficiency affecting the design or qualification of a mitigating structure, system, or component (SSC), and the SSC maintained its operability or PRA functionality.
Cross-Cutting Aspect: Not Present Performance. No cross cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.
Enforcement:
Violation: 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, required Measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected. Contrary to this, the licensee failed to assure that a condition adverse to quality was promptly identified and corrected. Specifically, previously identified incorrect calculation of the maximum expected differential pressures was not corrected.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On July 29, 2021, the inspectors presented the design basis assurance inspection (programs) inspection results to Mr. G. Lippard and other members of the licensee staff.
- On June 25, 2021, the inspectors presented the initial inspection results to Mr. R. Justice and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.21N.02 Calculations
DC 08200-001
ESF Degraded Voltage Logic and Settings
Rev. 29
DC01520-035
Maximum Differential Pressures for SW GL 89-10 Motor
Operated Butterfly Valves
Rev. 3
DC01520-039
Maximum Differential Pressures for CCWS Quarter-turn
MOV Operation
Rev. 1
DC01520-049
Maximum Differential Pressure for Safety Injection System
MOV Operation
Revs. 3, 4, &
DC01520-050
Motor Operated Valve Weak Link Analysis Reports
Revs. 0, 1, &
DC01520-059
Minimum Required Thrust for Rising Stem MOVs in the
Safety Injection System
Rev. 12
DC01520-062
Minimum Required Thrust for Rising Stem MOVs - RC
System,
Rev. 10
DC01520-065
Design, Review and Capability of Rising Stem MOVs
Rev. 14
DC01520-065
Design, Review and Capability of Rising Stem MOVs
Rev. 14
DC01520-066
Minimum Required Thrust for Rising Stem MOVs
Rev. 11
DC01520-067
Design, Review and Capability of Rising Stem MOVs
Rev.16
DC01520-067
Design, Review and Capability of Rising Stem MOVs in
Rev. 16
DC01520-069
MOV Thermal Overload Calculation
Rev. 3
DC01520-089
GL-89-10 MOV Scope, Grouping and Engineering
Justification
Revs. 6 & 11
DC01520-090
Design, Review and Capability of Henry Pratt Generic Letter 89-10 Motor Operated Butterfly Valves
Rev. 5
DC01520-093
Measurement Conversions and Error Determination for
MOV Parameters
Rev.3
DC01520-093
Measurement Conversions and Error Determination for
MOV Parameters Obtained Per ES-513
Rev. 3
DC01520-094
Max Operating Torque for Henry Pratt GL89-10 Motor
Operated Butterfly Valves
Rev. 3
DC01520-102
Force Required to Overcome Pressure Locking
XVG08000A
Rev. 1
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
DC01521-011
Determination of the Limiting Line Pressure and Maximum
Expected Differential Pressure for Category 1 Air
Operated Valves In The MS System
Rev. 1
DC0152A-007
Determination of Limiting Line Pressure and Maximum
Expected Differential Pressure for Air-Operated Valves,
Rev. 1
DC0152A-008
KVAP Analysis for Air Operated Valves
XVG06056/6057/6066/6067-HR
Rev. 1
DC0152A-012
KVAP Analysis for Air-Operated Valves IFV02030-MS,
IPV/02000/0210/2020-MS & XVM02801A/B/C-MS
Rev. 1
DC08200-003
Class 1E 460V MOV Starting Voltages
Rev. 8
DC08760-007
MCC Control Circuit Analysis
Rev. 2
Corrective Action
Documents
CR-11-01045,
CR-11-00991,
CR-11-01027,
CR-11-00631,
CR-11-00750,
CR-11-00782,
CR-11-00956,
CR-20-03556,
CR-20-03557,
CR-20-03560,
CR-21-00678,
CR-05-03241,
CR-06-02041,
CR-20-02322,
CR-20-02274
Corrective Action
Documents
Resulting from
Inspection
21-011679
Review appropriateness of Commonwealth Edison White
Paper 125 Revision 3 in the VCS actuator capability
calculations.
06/21/2021
21-01559
TR01520-001 stated in the notes for XVG08811A&B-SI
that this valve did not have a closed safety function.
06/08/2021
21-01574
MOV program needs to update it engineering review of
static test data to include the refined gate unwedging
6/10/2021
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
equation.
21-01586
Evaluate the need to revise SAP-143 to resolve the
potentially contradictory guidance and revise SAP-143 as
required
06/10/2021
21-01620
ECR 72009 not completed and the calculations updated in
a timely manner.
6/14/2021
21-01629
Procedure Enhancement of EMP0445.007 to include QSS
check prior to MOVATs
06/15/2021
21-01657
Magnesium rotor degradation
06/17/2021
21-01678
Track review and revision of MOV calculations and
program documents as needed regarding degraded
voltage MOV calculation and MOV diagnostic test data.
6/21/2021
21-01680
Calculation DC0152A-008 needs to be updated
06/21/2021
21-01685
review the application of IEEE 741-2017 in DC08200-001
and determine if it is applies to DC08200-003 Section 7.1
06/21/2021
21-01698
Difference in COF numbers between DC01520-090 and
DC01520-094
06/23/2021
21-01699
Two maximum differential pressure values (30 psid and 75
psid) are reflected in various 152 series MOV calculations
(DC01520-050,-090) and program documents for
XVB09503A-CC.
06/23/2021
21-01700
Issues with design calculation DC01520-102
06/23/2021
21-01701
Drawing or maintenance procedure doesn't provide
installation orientation regarding flow and flow direction not
physically marked on valve.
06/23/2021
Drawings
ASME Assembly Drawing MOV LCV00115C-CS
Rev. 6
ASME Assembly Drawing MOV XVG08000A
Rev. 5
Motor Operated Gate Valve Model 14000GM84FEH00
Rev. 5
inch 150 Gate Valve-R.S. Bolted Bonnet-Butt Welds
Ends Motor Oper-Sgl Pack
Rev. B
16" thru 24" 1100 Nuclear Valve Cross-section and
Materials List ASME Section III Class Flange X Flange
Rev. 2
ASME Assembly Drawing AOV PCV00444B-RC
Rev. 3
Emergency Feedwater Pump Turbine Control Valve
Rev. 10
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
B-201-359
Electrical MCC Listing XMC1DA2Y, Sht 1
Rev. 12
B-201-362
Electrical MCC Listing XMC1DB2Y, Sht 1
Rev. 10
B-208-011
Electrical-Elementary Diagram RHR Heat Exchanger Inlet
Valve (XVB9503A)
Rev. 5
B-208-021
Electrical Elementary Diagram LCV-115C, Sheet 34
Rev. 10
B-208-054
inch Continuous Purge Line to HR System Isolation
Valve XVG-6067 & 6057, Sht 23
Rev.8
B-208-067
Main Steam to EFW Pump Turbine Isolation Valve IFV-
2030, Sht 46
Rev. 11
B-208-082
Electrical Elementary Diagram XVG08000A,Sht 10
Rev. 8
B-208-095
Electrical-Elementary Diagram Recirc Sump to RHR
Pump B Isol VV 8811B (XVG8811B)
Rev. 12
B-208-101
Electrical-Elementary Diagram Service Water Pump A
Discharge Valve (XVB3116A)
Rev. 9
B-208-101
Isolation Valve XVG3111B, Sht 40
Rev. 7
B-816-083
Instrument Air Supply Diagram
Rev. 9
B-817-130
PORV Control Air Signal Diagram
Rev. 5
C-4454
Pratt 1100 Nuclear Water Valve HB Operator SMB000
Motor Replaceable Packing Bonnet Flange X Flange
Rev. 2
D-302-011
Rev. 41
D-302-611
System Flow Diagram Component Cooling
Rev. 24
E-302-69
System Flow Diagram Safety Injection
Rev. 23
IMS-25-756-1-0
inch 150 Weld End Gate Valve, Sht 1
Rev. 0
Engineering
Evaluations
0310-0028-
CALC-001
Calculation of EDG Voltage and Frequency Variations on
Safety-Related MOVs
Rev. 2
2865C
V. C. Summer Nuclear Station JOG MOV Periodic
Verification Classification
Rev. 0
R015239
Comanche Peak MOVs VS VCSNS MOVs
07/23/1997
Miscellaneous
Power Operated Valves Self-Assessment
Rev. 0
DBD-MV2
Motor Operated Valve Design Review, Capability and
Setup Volume 2 (MV2)
Rev. 6
ECR 50316
Automatic Transfer to the RB Sump
Rev. A
ECR 70460
Limitorque SMB-000 Motor Replacement
Rev. 0
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
EI-3-009
Teledyne Check-out Procedure for Quick Stem Sensors
Rev.0
ER-AA-IST-10
ASME Inservice Testing Program
Rev. 7
MRF 22765B
Pressure Locking of SI Sump Recirc Valves
11/13/1995
TEP-3-023
Teledyne In-Situ Calibration of Thrust/Torque Strain
Gages
Rev. 3
TR-01520-004
AOV Setup, Test and Performance Validation Summary
Report
Rev. 9
TR-01520-007
PORV Qualification for Inadvertent Safety Injection
Rev. 0
TR01520-001
GL 89-10 MOV Setup, Test and Performance Validation
Summary Report
Rev. 9
TR01520-004
SAP-0159 Air Operated Valve ( Category 1) Setup, Test,
and Performance Validation Summary Report
2/10/2021
TWR RO15239
Comanche Peak MOVs vs. VCSNS MOVs
07/23/1997
SAFETY INJECTION SYSTEM (SI)
Rev. 16
VCSNS - EDBD -
Component Cooling Water System CC
Rev. 13
VCSNS-DBD-ES
Electric Power System
Rev. 6
VCSNS-DBD-HS
Post-Accident Sampling, Nuclear Sampling, and Hydrogen
Removal Systems
04/08/21
VCSNS-DBD-MS
05/03/2021
VCSNS-DBD-RC
Reactor Cooling System
Rev. 13
VCSNS-DBD-SW Service Water System
07/25/19
System Operating Basis for Motor Operated Valves
Rev. 0
Procedures
EMP-445.007
Testing of Motor Operated Valves
Rev. 15
EMP-445.019
MOV Magnesium Rotor Inspection
Rev. 1
ER-AA-IST-102
ASME IST Program - Inservice Testing of Valves
Rev. 8
ER-AA-IST-107
ASME IST Program - Inservice Testing of Active Motor
Operated Valves
Rev. 0
Sizing of Thermal Overloads
Rev. 2
MOV Program Implementation
Rev. 2
Control and Maintenance of the Plant Lubrication Manual
Database
Rev. 1
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
GTP-302
Inservice Testing of Valves Fourth Ten Year Interval
Rev. 17
ICP-240.169
Valve Diagnostic Procedure
Rev. 4
MMP-445.057
Maintenance of IFV02030-MS and IFV02030-O-MS
Rev. 3
Preventive Maintenance Program
Rev. 16C
Corrective Action Program
Rev. 19C
Motor Operated Valve Program
Rev. 1
Work Orders
1602584-
001,1711121-
001, 217450041,
1716500-001,
1716501-001,
2017872-001,
2100008-001,
1902265-001,
1902451-001,
1902989,
2100011-001,
1902989-001,
1711218-001,
1711217-002,
1712429-001,
1712429-003,
1712429-004,
1711219-001,
2017465-001,
2008733-002,
2101920-001,
1109922-001