IR 05000395/2018001

Nuclear Regulatory Commission Integrated Inspection Report 05000395/2018001

ML18131A073
Person / Time
Site:	Summer  (NPF-012)
Issue date:	05/10/2018
From:	Randy Musser NRC/RGN-II/DRP/RPB3
To:	Lippard G South Carolina Electric & Gas Co
References
IR 2018001
Download: ML18131A073 (17)

Text

May 10, 2018

SUBJECT:

VIRGIL C. SUMMER NUCLEAR STATION, UNIT 1 - NUCLEAR REGULATORY COMMISSION INTEGRATED INSPECTION REPORT 05000395/2018001

Dear Mr. Lippard:

On March 31, 2018, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Virgil C. Summer Nuclear Station, Unit 1. On April 30, 2018, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.

NRC inspectors documented one finding of very low safety significance (Green) in this report.

This finding involved a violation of NRC requirements. The NRC is treating this violation as an non-cited violation (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.

If you contest the violation or significance of this NCV, 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 the Virgil C. Summer Nuclear Station.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC resident inspector at the Virgil C. Summer Nuclear Station. 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 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Randall A. Musser, Chief

Reactor Projects Branch 3

Division of Reactor Projects

Docket Nos.: 50-395 License Nos.: NPF-12

Enclosure:

IR 05000395/2018001

REGION II==

Docket Nos:

50-395

License Nos:

NPF-12

Report Nos:

05000395/2018001

Licensee:

South Carolina Electric & Gas (SCE&G) Company

Facility:

Virgil C. Summer Nuclear Station, Unit 1

Location:

Jenkinsville, SC 29065

Dates:

January 1, 2018 through March 31, 2018

Inspectors:

J. Reece, Senior Resident Inspector E. Hilton, Resident Inspector R. Taylor, Senior Project Engineer (Section 92723)

Approved by:

Randall A. Musser, Chief Reactor Projects Branch 3 Division of Reactor Projects

Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring licensees performance by conducting a baseline 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. NRC and self-revealed findings, violations, and additional items are summarized in the table below.

List of Findings and Violations

Failure to Perform an Adequate Risk Assessment With Consequent Reactor Trip Cornerstone Significance Cross-cutting Aspect Report Section Initiating Events Green NCV 05000395/2018001-01 Opened/Closed

[H.5] - Work Management 71153 A self-revealed, Green NCV was identified for the licensees failure to adequately assess risk in accordance with 10 CFR 50.65(a)(4), Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, involving repairs to a non-safety related inverter, XIT-5905. This NCV closes LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main Turbine Trip.

Additional Tracking Items

Type Tracking number Title Report Section Status Licensee Event Report (LER)05000395/2017-002-01 Low Feedwater Flow to the 'B'

Steam Generator Causes Automatic Reactor Trip 71153 Closed LER 05000395/2017-003-00 Failed Lightning Arrester on Main Transformer Causes Reactor Trip 71153 Closed LER 05000395/2017-003-01 Failed Lightning Arrester on Main Transformer Causes Reactor Trip 71153 Closed LER 05000395/2017-005-00 Automatic Reactor Trip Due to Main Turbine Trip 71153 Closed

LER 05000395/2017-006-00 Technical Specification Action Not Met for Inoperable Oxygen Monitor 71153 Closed

PLANT STATUS

Unit 1 operated at or near rated thermal power for the entire inspection period.

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 performed plant status activities described in IMC 2515 Appendix D, Plant Status and conducted routine reviews using IP 71152, Problem Identification and Resolution. 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.

71111.04 - Equipment Alignment

Partial Walkdown (5 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) Walkdown motor driven emergency feedwater (MDEFW) pump B and turbine driven emergency feedwater (TDEFW) pump while A MDEFW pump was tagged out for maintenance; inspection was completed on January 8, 2018

(2) Walkdown B train engineered safety feature (ESF) power as a loss of A train offsite power circuit 115 kV line (1DA) was due to transmission maintenance; inspection was completed on January 18, 2018

(3) A and B MDEFW during scheduled maintenance on TDEFW on January 23, 2018

(4) A residual heat removal (RHR) pump while B RHR pump was tagged out for maintenance; inspection was completed on January 25, 2018

(5) B emergency diesel generator (EDG) during planned maintenance on A EDG; inspection was completed on February 27, 2018

71111.05AQ - Fire Protection Annual/Quarterly

Quarterly Inspection (6 Samples)

The inspectors evaluated fire protection program implementation in the following selected areas:

(1) Auxiliary building 374 foot

(ft) elevation (fire zones AB01.01.01, 01.01.02, AB01.02, AB01.03) ; inspection was completed on January 25, 2018

(2) Control room (fire zone CB17.01); inspection was completed on January 25, 2018

(3) 1DA switchgear room (fire zone IB01.20); inspection completed on February 22, 2018

(4) 1DB switchgear rooms and heating, ventilation, and air conditioning (HVAC) rooms (fire zones IB01.16, IB01.17, IB01.22.02); inspection was completed on February 22, 2018

(5) Control building cable spreading rooms 425 and 448 elevations (fire zones CB04, CB15); inspection was completed on February 22, 2018

(6) Service water pumphouse (fire zones SWPH01, 02, 03, 04.02, 05.01.01, 05.01.02, 05.01.03 and 05.02.01, 05.02.02, 05.02.03); inspection was completed on February 22, 2018

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Operator Requalification (1 Sample)

The inspectors observed an operator requalification simulator training scenario occurring on March 5, 2018, and involving multiple failures leading to entry into abnormal operating procedures followed by emergency operating procedures.

Operator Performance (3 Samples)

The inspectors observed and evaluated:

(1) Troubleshoot rad monitor RM-A14 Reactor Building (RB) Purge Supply Exhaust System degraded with digital display issues; inspection was completed on February 18, 2018

(2) A EDG surveillance test; observation was completed on March 1, 2018

(3) B EDG maintenance runs; observation was completed on March 16, 2018

71111.12 - Maintenance Effectiveness

Routine Maintenance Effectiveness (2 Samples)

The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions:

(1) Maintenance Rule (a)(1) evaluation for AC Vital Buses System; inspection was completed on February 5, 2018

(2) Emergent maintenance at Parr Substation resulted in loss of offsite power to emergency bus 1DA; inspection was completed on March 20, 2018

71111.13 - Maintenance Risk Assessments and Emergent Work Control

The inspectors evaluated the risk assessments for the following planned and emergent work activities:

(1) Yellow risk condition during work week 4 for scheduled maintenance of TDEFW pump; inspection was completed on January 23, 2018

(2) Yellow risk condition for scheduled solid state protection system (SSPS) A surveillance test during work week 9; inspection was completed on March 2, 2018

71111.15 - Operability Determinations and Functionality Assessments

The inspectors evaluated the following operability determinations and functionality assessments:

(1) CR-17-06495, B EDG breaker failed to close; inspection was completed on January 24, 2018

(2) CR-18-00302, Evaluate immediate operability of LCV00115D-CS stroke time; inspection was completed on February 5, 2018

(3) CR-18-00233, B EDG cylinder number 11 petcock discovered open; inspection was completed on January 20, 2018

(4) CR-18-00783, Review qualification of spent fuel level instrument ILT09781; inspection was completed on March 21, 2018

(5) CR-17-04978, A train reactor building cooling unit (RBCU) condensate drain flow alarm did not clear during RBCU functional test; inspection was completed on March 6, 2018

(6) CR-18-01093, Both B EDG air start tanks have moisture and debris buildup; inspection was completed on March 23, 2018

71111.18 - Plant Modifications

The inspectors evaluated the following temporary or permanent modifications:

WO1801542, Bypass Authorization Request for RBCU drain flow switch problem; inspection was completed on February 7, 2018

71111.19 - Post Maintenance Testing

The inspectors evaluated the following post maintenance tests:

(1) WO1717009 and WO1715870, A charging pump preventive maintenance (PMT),replaced leaking outboard seal; inspection was completed on January 4, 2018

(2) WO1713073, Repair oil leaks at flanges on XVR11022-EF on TDEFW; inspection was completed on January 23, 2018

(3) WO1807327, A EDG jacket water leak repairs; inspection was completed on March 1, 2018

(4) WO1807963, B steam generator (SG) power operated relief valve (PORV) would not stroke during surveillance test; inspection was completed on March 20, 2018

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Routine

(1) STP 125.002A, Diesel Generator A Operability Test, Revision 2E; inspection was completed on March 1, 2018

(2) STP 345.037, Solid State Protection System Actuation Logic and Master Relay Test Train A, Revision 18D; inspection was performed on March 2 & 5, 2018

In-service (3 Samples)

(1) STP 205.003, Charging Safety Injection Pump and Valve Test, Revision 8B; inspection was completed on February 8, 2018

(2) STP 205.004, RHR Pump and Valve Operability Test, Revision 9B; inspection was completed on March 5, 2018

(3) STP 220.001A, Motor Driven Emergency Feedwater Pump and Valve Test, Revision 12; inspection was completed on March 9, 2018

71114.06 - Drill Evaluation

Emergency Planning Drill (2 Samples)

The inspectors evaluated the performance of an emergency preparedness (EP) drill on February 6, 2018. The drill involved an anticipated trip without scram (ATWS), faulted steam generator, EDG malfunctions, loss of offsite power, and steam generator tube rupture which required entry into increasing emergency action levels starting with an Alert and ending in a General Emergency.

On March 28, 2018, the inspectors reviewed and observed the performance of an EP drill that involved failure of an underground fire system header, damage to a loaded independent spent fuel storage installation (ISFSI) cask, grid disturbance, main transformer lightning arrestor failure, control rod ejection, and subsequent fuel failure which required entry into increasing emergency action levels starting with a Notification of Unusual Event and ending in a Site Area Emergency.

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below for the period from January 1, 2017, through December 31, 2017.===

(1) Unplanned Scrams per 7000 Critical Hours

(2) Unplanned Power Changes per 7000 Critical Hours

(3) Unplanned Scrams with Complications

71152 - Problem Identification and Resolution

Annual Follow-up of Selected Issues (1 Sample)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

CR-17-00198, A EDG service water discharge line pinhole leak; inspection was completed on March 27, 2018

71153 - Follow-up of Events and Notices of Enforcement Discretion Licensee Event Reports

The inspectors evaluated and closed the following LERs which can be accessed at the following website: https://lersearch.inl.gov/LERSearchCriteria.aspx

(1) LER 05000395/2017-002-01: Low Feedwater Flow to the 'B' Steam Generator Causes Automatic Reactor Trip

(2) LERs 05000395/2017-003-00, 01: Failed Lightning Arrester on Main Transformer Causes Reactor Trip

(3) LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main Turbine Trip

(4) LER 05000395/2017-006-00: Technical Specification Action Not Met for Inoperable Oxygen Monitor

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

92723 - Follow Up Inspection for Three or More Severity Level IV Traditional Enforcement Violations in the Same Area in a 12-Month Period

The inspector evaluated the licensees root cause evaluation 17-00537 and corrective actions associated with the Severity Level IV (SL IV) violations. The inspectors review included but were not limited to: 1) assurance that the causes of the violations were understood, 2) that the extent of condition and extent of cause for the violations were identified, and 3) that both completed and proposed corrective actions for the violations were appropriate and sufficient to address the causes.

INSPECTION RESULTS

Observations and Minor Violation for Review of CR-17-00198, A EDG service water discharge line pinhole leak 71152

Minor Violation: 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, for failure to promptly identify a condition adverse to quality (CAQ). Specifically, the licensee did not initiate a CR to document cavitation damage for on the downstream pipe reducer element for XVB03121A.

Screening: Because the licensee corrected the condition with their work order system under WO 1305828, the inspectors identified this as a minor violation of Criterion XVI.

Enforcement:

This failure to comply with 10 CFR 50, Appendix B, Criterion XVI constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy. The licensee entered this problem into their CAP as CR-18-01588.

The inspectors reviewed CR-17-00198 that was initiated on January 11, 2017, following the licensees discovery of a pinhole leak in the A EDG service water (SW) discharge pipe reducer element flanged to the SW return valve, XVB03121A-SW. The pipe reducer element was subsequently replaced during the refueling outage (RF) 23 completed in the Spring, 2017, and a vendor analysis report of pipe reducer element was completed and attached to CR-17-00198 on November 14, 2017. The inspectors noted that the report concluded the pinhole leak resulted in deep metal loss consistent with cavitation induced degradation. The inspectors noted that XVB03121A-SW is a butterfly valve and maintained in a throttled position to ensure the required SW flow through the A EDG heat exchangers; B train has a similar arrangement. The inspectors also noted that this configuration results in a near continuous conditions allowing cavitation since the licensee maintains continuous SW flow to both trains of EDGs even when they are not in service. The inspectors noted that the downstream piping below the reducer element on both trains is marked with a grid pattern to allow the licensee to monitor flow accelerated corrosion (FAC).

The inspectors reviewed historical corrective actions and noted the following:

• CR-04-03364 was initiated on October 25, 2004, due to NRC observation of noise noted at the SW discharge butterfly valves, XVB03121A,B, which may be due to cavitation due to the throttled condition of the valves. During RF-16 in October 2006, both valves were subsequently removed for inspection and found to have cavitation damage to the valve body and the outlet flange which was documented in CR-06-03587 and CR-06-03758. The valves and associated reducer elements were replaced. Additionally, Action 10 of CR-06-03587 created a preventative maintenance (PM) task to inspect the valves every fifth RF and created WOs for the inspections.

XVB03121A was scheduled for inspection in RF-21, Spring 2014, and XVB03121B was scheduled for inspection in RF-22, Fall 2015.

• During RF-21, cavitation damage was identified on the downstream pipe reducer element for XVB03121A and it was replaced under WO 1305828. However, the inspectors noted the licensee did not initiate a CR for this CAQ per SAP-999, Corrective Action Program, Rev. 12, which is the licensees process for promptly identifying a CAQ as required by 10 CFR 50, Appendix B, Criterion XVI, Corrective Action.

• During RF-22 the licensee initiated CR-15-05473 due to cavitation damage found on the downstream piping reducer element for XVB03121B. The damaged reducer element was replaced during the outage. The inspectors noted that this CR did not perform any new evaluations relative to any changes to their periodicity of inspections.

The inspectors noted that the A train SW pinhole leak documented by CR-17-00198 and repaired in RF-23 occurred prior to the next scheduled inspection for XVB03121A during RF-26. The inspectors also verified the licensee had created new PM inspections to perform ultrasonic examination of the pipe reducer elements every 6 months. However, the inspectors also observed that the licensee did not address the use of a butterfly valve for throttling resulting in cavitation conditions as opposed to a more suitable valve design. Following discussion with the licensee, Action 14 to CR-17-00198 was initiated for a design review and presentation to the Plant Health Committee.

Observations for LER 05000395/2017-002-01: Low Feedwater Flow to the 'B' Steam Generator Causes Automatic Reactor Trip

71153 The inspectors reviewed and closed LER 05000395/2017-002-00 in NRC integrated inspection report 05000395/2017004.

Inspectors noted that a vendor concluded the solenoid valve failure was due to a manufacturing defect relating to lack of solder at a wiring junction. The inspectors determined that the licensee had not performed a Part 21 evaluation. The licensee added Action 26 to CR-17-03674 to complete the Part 21 evaluation which concluded there was no substantial safety hazard. This LER is closed.

Observations for LERs 05000395/2017-003-00, 01: Failed Lightning Arrester on Main Transformer Causes Reactor Trip

71153 The inspectors reviewed LERs 05000395/2017-003-00, 01. On August 28, 2017, the failure of a surge arrestor on the center phase of the main transformer, XTF-1, resulted in an automatic turbine trip that initiated an automatic reactor trip. Subsequent examination revealed that the surge arrestor failed as a result of moisture ingress past the upper housing seal leading to a flash-over of the internal metal oxide varistors. The inspectors reviewed industry data regarding testing of surge arrestors which indicate that single test results may not indicate an impending failure, but trending of multiple tests can indicate degradation of the internal components. The inspectors determined that the licensee does perform testing but on a periodicity of every two refueling outages. The inspectors concluded that more frequent testing may provide better trend results, and the licensee took this information into consideration. The inspectors reviewed the licensees corrective actions documented in CR-17-04597. This LER is closed.

Failure to Perform an Adequate Risk Assessment With Consequent Reactor Trip Cornerstone Significance Cross-cutting Aspect Report Section Initiating Events Green NCV 05000395/2018001-01 Opened/Closed

[H.5] - Work Management 71153 A self-revealed, Green NCV was identified for the licensees failure to adequately assess risk in accordance with 10 CFR 50.65(a)(4), Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, during repairs to a non-safety related inverter, XIT-5905.

This NCV closes LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main Turbine Trip.

Description:

On November 7, 2017, a loss of XIT-5905 caused a loss of power to the feedwater digital control system (DCS) which led to a loss of all three feedwater pumps and subsequent main turbine trip and an automatic reactor trip. The licensee entered the event into their CAP as CR-17-05860 and later performed a root cause analysis (RCA) documented by CR-17-05908, which addressed the programmatic, behavioral, and organizational aspects of planning, maintenance, operation and risk management of components leading to the reactor trip. The inspectors reviewed the RCA and noted the following:

• Direct cause stated, Maintenance was performed on-line on single point vulnerability (SPV) equipment without proper controls (i.e., less than adequate mitigating strategies, vendor oversight, and retest requirements), with subsequent component failure resulting in a plant trip.

• Root cause (RC01) stated, VCS-SAP-1315, [Process Requirements for Obtaining Services], was not followed correctly, resulting in no assessment of risk, mitigating strategies, or vendor oversight.

• RC02 stated, Implementation of the planning process failed to ensure station expectations were met associated with adherence to SSP-001, such that proper assessment of the scope of work, vendor oversight, and retest requirement were not provided for the work performed.

• RC03 stated, Less than adequate oversight and reinforcement of standards and expectations associated with Maintenance review of scope of work for corrective maintenance, use of HU tools, and vendor oversight.

• Contributing cause (CC1) stated, Implementation of the planning and scheduling process failed to ensure station expectations were met associated with adherence to SSP-001, such that single point vulnerability was not identified for the planning of WO 1705755 Step 2.

• CC2 stated, Engineering resources were not allocated for the inverter work, due to subject matter expert (SME) involvement with an emergent activity and SME understanding of expected work scope, which contributed to inadequate vendor oversight, inadequate identification of the scope of work, and inadequate retest of the work performed.

The inspectors reviewed additional actions in CR-17-05860 and noted that Action 005 was initiated to scope XIT-5905 into the maintenance rule (MRule). Following additional inspector inquiries, the licensee initiated CR-18-00533 to perform the maintenance rule evaluation and CR-18-00651 to document that the evaluation originally documented in Action 005 of CR-17-05860 did not follow CAP procedure requirements.

The inspectors reviewed design calculation, DC00300-156, Eighth Major Update of the PRA Model, Revision 3A, which included a change to add XIT-5905 to the equipment out of service (EOOS) computer model used by the licensee to perform risk evaluations in accordance with 10 CFR 50.65(a)(4). DC00300-156 was issued on November 13, 2017, six days after the unit trip.

The inspectors performed additional research and discovered relevant information not discussed in the RCA. The inspectors concluded the licensee had the opportunity to mitigate or eliminate the SPV aspects in 2011 or approximately six years prior to the unit trip on November 7, 2017. The licensee initiated CR-18-00954 to determine why CR-09-05101 was not reviewed or discussed in the RCA documented in CR-17-05908.

Corrective Action(s): The licensee implemented CR-17-05860 and CR-17-5908 to identify causes and appropriate corrective actions.

Corrective Action Reference(s): The licensee entered this issue into their CAP as CR-17-05860 and CR-17-05908.

Performance Assessment:

Performance Deficiency: The licensees failure to adequately assess the risk in accordance with 10 CFR 50.65(a)(4) for an activity involving repairs to inverter XIT-5905 was a performance deficiency (PD).

Screening: The inspectors determined the PD was more than minor because it adversely affected the initiating events cornerstone objective to limit the likelihood of events that upset plant stability and challenge safety functions during power operations and the associated attribute of equipment performance relative to maintenance and reliability. Specifically, the licensee failed to consider the SPV significance of maintenance on inverter XIT-5905 during power operations, and the failure of the inverter led to an automatic reactor trip.

Significance: The inspectors assessed the significance of the finding using IMC 0609, 4, Initial Characterization of Findings, dated October 7, 2016, and IMC 0609, Appendix K, Maintenance Risk Assessment and Risk Management Significance Determination Process, dated May 19, 2005. The baseline core damage frequency (CDF)was 3.3208E-6 and the increase in CDF due to the turbine trip was 3.5260E-6 resulting in an incremental core damage frequency (ICDF) involving the reactor/turbine trip was 2.0520E-7.

The duration of the work on XIT-5905 was approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> resulting in an incremental core damage probability (ICDP) of 2.811E-10. Since the licensee performed no actual risk assessment for the work on XIT-5905, the ICDP is equal to the incremental core damage probability deficit (ICDPD) or risk deficit. The finding was therefore determined to be of very low safety significance (Green) using flowchart 1 of IMC0609, Appendix K, because the risk deficit was less than 1E-6.

Cross-cutting Aspect: The inspectors determined the finding had a cross-cutting aspect of work management (H.5) in the area of human performance, because the licensee did not perform an adequate risk assessment in accordance with their procedures.

Enforcement:

Violation: 10 CFR 50.65(a)(4) requires, in part, that before performing maintenance activities the licensee shall assess and manage the increase in risk that may result from the proposed maintenance activities. Contrary to the above, on November 7, 2017, the licensee failed to adequately assess the risk for maintenance on inverter XIT-5905.

Disposition: This violation is being treated as an NCV consistent with Section 2.3.2.a of the Enforcement Policy.

Minor Violation for LER 05000395/2017-006-00: Technical Specification Action Not Met for Inoperable Oxygen Monitor 71153

Minor Violation: Technical Specification (TS) 3.3.3.9, Explosive Gas Monitoring Instrumentation, for failure perform a grab sample and analysis at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Screening: Subsequent grab sample and analysis performed on October 31, 2017 determined that oxygen levels were satisfactory. Therefore the inspectors determined the TS violation was minor. The licensee entered the issue into the CAP as CR-17-05725.

Enforcement:

The failure to comply with TS 3.3.3.9, Explosive Gas Monitoring Instrumentation,constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.

The inspectors reviewed LER 05000395/2017-006-00 and identified the above information.

This LER is closed.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

The inspectors confirmed that proprietary information was controlled to protect from public disclosure.

On April 30, 2018, the inspector presented the quarterly resident inspector inspection results to Mr. George Lippard and other members of the licensee staff.

DOCUMENTS REVIEWED

71111.04 - Equipment Alignment

E-302-641, Residual Heat Removal, Rev, 21

SOP-115, Residual Heat Removal, Rev. 22D

SOP-306, Emergency Diesel Generator, Rev. 19E

SOP-211, Emergency Feedwater System, Revision 14G

D-302-085, Emergency Feedwater System Flow Diagram, Rev. 41

FSAR 8.3.1.1.2, Onsite Standby Power Supplies

SOP-304, 115kV, 7.2 kV Operations, Rev. 14A

71111.05AQ - Fire Protection Annual/Quarterly

VC Summer Unit 1 Fire Pre-Plans

STP-728.040, Auxiliary Building Fire Barrier Inspection, Elevations 400, 397, 388 and 374,

Rev. 4C

STP-728.042, Control Building Elevation 463 Fire Barrier Inspection, Rev. 7B

STP-728.043, Control Building Elevation 448 Fire Barrier Inspection, Rev. 5C

STP-728.045, Control Building Elevation 425 Fire Barrier Inspection, Rev. 4G

STP-728.047, Intermediate Building Elevations 476, 463, and 451 Fire Barrier Inspection, Rev.

4C

STP-728.048, Intermediate Building Elevations 436 Fire Barrier Inspection, Rev. 4G

71111.12 - Maintenance Effectiveness

ES-514, Maintenance Rule Program Implementation, Rev. 7

SAP-0157, Maintenance Rule Program, Rev. 2

71111.13 - Maintenance Risk Assessments and Emergent Work Control

SSP-001, Planning and Scheduling Maintenance Activities, Rev. 24H

OAP-100.6, Control Room Conduct and Control of Shift Activities, Rev. 4L

OAP-102.1, Conduct of Operations Scheduling Unit, Rev. 8E

71111.18 - Plant Modifications

Drawing 1MS-28-058, Train A XPN-6091, Rev. 21

Drawing B-208-060, Leak Detection System, Rev. 17

SAP-148, Attachment 1, Bypass Authorization Request #18-01, Rev 9

Special Order 18-01, RBCU Operation Impact on RBCU Drain Flow Alarm, Rev. 0

UNITED STATES

NUCLEAR REGULATORY COMMISSION

REGION II

245 PEACHTREE CENTER AVENUE NE, SUITE 1200

ATLANTA, GEORGIA 30303-1257

May 10, 2018

Mr. George A. Lippard III

Vice President, Nuclear Operations

South Carolina Electric & Gas Company

Virgil C. Summer Nuclear Station

Bradham Blvd & Hwy 215

P.O. Box 88, Mail Code 800

Jenkinsville, SC 29065

SUBJECT:

VIRGIL

C. SUMMER NUCLEAR STATION, UNIT 1 - NUCLEAR REGULATORY

COMMISSION INTEGRATED INSPECTION REPORT 05000395/2018001

Dear Mr. Lippard:

On March 31, 2018, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection

at your Virgil

C. Summer Nuclear Station, Unit 1. On April 30, 2018, the NRC inspectors

discussed the results of this inspection with you and other members of your staff. The results of

this inspection are documented in the enclosed report.

NRC inspectors documented one finding of very low safety significance (Green) in this report.

This finding involved a violation of NRC requirements. The NRC is treating this violation as an

non-cited violation (NCV) consistent with Section 2.3.2.a of the Enforcement Policy.

If you contest the violation or significance of this NCV, 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 the Virgil C. Summer Nuclear Station.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a

response within 30 days of the date of this inspection report, with the basis for your

disagreement, to the

U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk,

Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; and the NRC

resident inspector at the Virgil C. Summer Nuclear Station.

G. Lippard

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 10 CFR 2.390, Public Inspections, Exemptions, Requests for

Withholding.

Sincerely,

/RA/

Randall

A. Musser, Chief

Reactor Projects Branch 3

Division of Reactor Projects

Docket Nos.: 50-395

License Nos.: NPF-12

Enclosure:

IR 05000395/2018001

cc: Distribution via ListServ

ML18131A073

OFFICE

RII:DRP

RII:DRP

RII:DRP

RII:DRP

RII:DRP

NAME

JReece

EHilton

LPressley

RMusser

RTaylor

DATE

05/10/18

05/ 10 /18

05/03/18

05/10/18

05/10/18

U.S. NUCLEAR REGULATORY COMMISSION

REGION II

Docket Nos:

50-395

License Nos:

NPF-12

Report Nos:

05000395/2018001

Licensee:

South Carolina Electric & Gas (SCE&G) Company

Facility:

Virgil

C. Summer Nuclear Station, Unit 1

Location:

Jenkinsville, SC 29065

Dates:

January 1, 2018 through March 31, 2018

Inspectors:

J. Reece, Senior Resident Inspector

E. Hilton, Resident Inspector

R. Taylor, Senior Project Engineer (Section 92723)

Approved by:

Randall

A. Musser, Chief

Reactor Projects Branch 3

Division of Reactor Projects

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring licensees performance

by conducting a baseline 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. NRC and self-

revealed findings, violations, and additional items are summarized in the table below.

List of Findings and Violations

Failure to Perform an Adequate Risk Assessment With Consequent Reactor Trip

Cornerstone

Significance

Cross-cutting

Aspect

Report

Section

Initiating Events

Green NCV 05000395/2018001-01

Opened/Closed

[H.5] - Work

Management

71153

A self-revealed, Green NCV was identified for the licensees failure to adequately assess risk

in accordance with 10 CFR 50.65(a)(4), Requirements for Monitoring the Effectiveness of

Maintenance at Nuclear Power Plants, involving repairs to a non-safety related inverter, XIT-

5905. This NCV closes LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main

Turbine Trip.

Additional Tracking Items

Type

Tracking number

Title

Report Section

Status

Licensee

Event

Report

(LER) 05000395/2017-002-01

Low Feedwater

Flow to the 'B'

Steam Generator

Causes Automatic Reactor Trip

71153

Closed

LER 05000395/2017-003-00

Failed Lightning

Arrester on Main

Transformer

Causes Reactor

Trip

71153

Closed

LER 05000395/2017-003-01

Failed Lightning

Arrester on Main

Transformer

Causes Reactor

Trip

71153

Closed

LER 05000395/2017-005-00

Automatic Reactor Trip Due to Main

Turbine Trip

71153

Closed

LER 05000395/2017-006-00

Technical

Specification

Action Not Met for

Inoperable

Oxygen Monitor

71153

Closed

PLANT STATUS

Unit 1 operated at or near rated thermal power for the entire inspection period.

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 performed plant status activities described in

IMC 2515 Appendix D, Plant Status and conducted routine reviews using IP 71152, Problem

Identification and Resolution. 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.

REACTOR SAFETY

71111.04 - Equipment Alignment

Partial Walkdown (5 Samples)

The inspectors evaluated system configurations during partial walkdowns of the following

systems/trains:

(1) Walkdown motor driven emergency feedwater (MDEFW) pump B and turbine driven

emergency feedwater (TDEFW) pump while A MDEFW pump was tagged out for

maintenance; inspection was completed on January 8, 2018

(2) Walkdown B train engineered safety feature (ESF) power as a loss of A train offsite

power circuit 115 kV line (1DA) was due to transmission maintenance; inspection was

completed on January 18, 2018

(3) A and B MDEFW during scheduled maintenance on TDEFW on January 23, 2018

(4) A residual heat removal (RHR) pump while B RHR pump was tagged out for

maintenance; inspection was completed on January 25, 2018

(5) B emergency diesel generator (EDG) during planned maintenance on A EDG;

inspection was completed on February 27, 2018

71111.05AQ - Fire Protection Annual/Quarterly

Quarterly Inspection (6 Samples)

The inspectors evaluated fire protection program implementation in the following selected

areas:

(1) Auxiliary building 374 foot (ft) elevation (fire zones AB01.01.01, 01.01.02, AB01.02,

AB01.03) ; inspection was completed on January 25, 2018

(2) Control room (fire zone CB17.01); inspection was completed on January 25, 2018

(3) 1DA switchgear room (fire zone IB01.20); inspection completed on February 22, 2018

(4) 1DB switchgear rooms and heating, ventilation, and air conditioning (HVAC) rooms (fire

zones IB01.16, IB01.17, IB01.22.02); inspection was completed on February 22, 2018

(5) Control building cable spreading rooms 425 and 448 elevations (fire zones CB04,

CB15); inspection was completed on February 22, 2018

(6) Service water pumphouse (fire zones SWPH01, 02, 03, 04.02, 05.01.01, 05.01.02,

05.01.03 and 05.02.01, 05.02.02, 05.02.03); inspection was completed on February 22,

2018

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Operator Requalification (1 Sample)

The inspectors observed an operator requalification simulator training scenario occurring on

March 5, 2018, and involving multiple failures leading to entry into abnormal operating

procedures followed by emergency operating procedures.

Operator Performance (3 Samples)

The inspectors observed and evaluated:

(1) Troubleshoot rad monitor RM-A14 Reactor Building (RB) Purge Supply Exhaust System

degraded with digital display issues; inspection was completed on February 18, 2018

(2) A EDG surveillance test; observation was completed on March 1, 2018

(3) B EDG maintenance runs; observation was completed on March 16, 2018

71111.12 - Maintenance Effectiveness

Routine Maintenance Effectiveness (2 Samples)

The inspectors evaluated the effectiveness of routine maintenance activities associated

with the following equipment and/or safety significant functions:

(1) Maintenance Rule (a)(1) evaluation for AC Vital Buses System; inspection was

completed on February 5, 2018

(2) Emergent maintenance at Parr Substation resulted in loss of offsite power to emergency

bus 1DA; inspection was completed on March 20, 2018

71111.13 - Maintenance Risk Assessments and Emergent Work Control (2 Samples)

The inspectors evaluated the risk assessments for the following planned and emergent

work activities:

(1) Yellow risk condition during work week 4 for scheduled maintenance of TDEFW pump;

inspection was completed on January 23, 2018

(2) Yellow risk condition for scheduled solid state protection system (SSPS) A surveillance

test during work week 9; inspection was completed on March 2, 2018

71111.15 - Operability Determinations and Functionality Assessments (6 Samples)

The inspectors evaluated the following operability determinations and functionality

assessments:

(1) CR-17-06495, B EDG breaker failed to close; inspection was completed on January 24,

2018

(2) CR-18-00302, Evaluate immediate operability of LCV00115D-CS stroke time; inspection

was completed on February 5, 2018

(3) CR-18-00233, B EDG cylinder number 11 petcock discovered open; inspection was

completed on January 20, 2018

(4) CR-18-00783, Review qualification of spent fuel level instrument ILT09781; inspection

was completed on March 21, 2018

(5) CR-17-04978, A train reactor building cooling unit (RBCU) condensate drain flow alarm

did not clear during RBCU functional test; inspection was completed on March 6, 2018

(6) CR-18-01093, Both B EDG air start tanks have moisture and debris buildup; inspection

was completed on March 23, 2018

71111.18 - Plant Modifications (1 Sample)

The inspectors evaluated the following temporary or permanent modifications:

WO1801542, Bypass Authorization Request for RBCU drain flow switch problem; inspection

was completed on February 7, 2018

71111.19 - Post Maintenance Testing (4 Samples)

The inspectors evaluated the following post maintenance tests:

(1) WO1717009 and WO1715870, A charging pump preventive maintenance (PMT),

replaced leaking outboard seal; inspection was completed on January 4, 2018

(2) WO1713073, Repair oil leaks at flanges on XVR11022-EF on TDEFW; inspection was

completed on January 23, 2018

(3) WO1807327, A EDG jacket water leak repairs; inspection was completed on March 1,

2018

(4) WO1807963, B steam generator (SG) power operated relief valve (PORV) would not

stroke during surveillance test; inspection was completed on March 20, 2018

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Routine (2 Samples)

(1) STP 125.002A, Diesel Generator A Operability Test, Revision 2E; inspection was

completed on March 1, 2018

(2) STP 345.037, Solid State Protection System Actuation Logic and Master Relay Test

Train A, Revision 18D; inspection was performed on March 2 & 5, 2018

In-service (3 Samples)

(1) STP 205.003, Charging Safety Injection Pump and Valve Test, Revision 8B; inspection

was completed on February 8, 2018

(2) STP 205.004, RHR Pump and Valve Operability Test, Revision 9B; inspection was

completed on March 5, 2018

(3) STP 220.001A, Motor Driven Emergency Feedwater Pump and Valve Test, Revision

2; inspection was completed on March 9, 2018

71114.06 - Drill Evaluation

Emergency Planning Drill (2 Samples)

The inspectors evaluated the performance of an emergency preparedness (EP) drill on

February 6, 2018. The drill involved an anticipated trip without scram (ATWS), faulted

steam generator, EDG malfunctions, loss of offsite power, and steam generator tube

rupture which required entry into increasing emergency action levels starting with an Alert

and ending in a General Emergency.

On March 28, 2018, the inspectors reviewed and observed the performance of an EP drill

that involved failure of an underground fire system header, damage to a loaded

independent spent fuel storage installation (ISFSI) cask, grid disturbance, main

transformer lightning arrestor failure, control rod ejection, and subsequent fuel failure

which required entry into increasing emergency action levels starting with a Notification of

Unusual Event and ending in a Site Area Emergency.

OTHER ACTIVITIES - BASELINE

71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below for the

period from January 1, 2017, through December 31, 2017. (3 Samples)

(1) Unplanned Scrams per 7000 Critical Hours

(2) Unplanned Power Changes per 7000 Critical Hours

(3) Unplanned Scrams with Complications

71152 - Problem Identification and Resolution

Annual Follow-up of Selected Issues (1 Sample)

The inspectors reviewed the licensees implementation of its corrective action program

related to the following issues:

CR-17-00198, A EDG service water discharge line pinhole leak; inspection was completed

on March 27, 2018

71153 - Follow-up of Events and Notices of Enforcement Discretion

Licensee Event Reports (4 Samples)

The inspectors evaluated and closed the following LERs which can be accessed at the

following website: https://lersearch.inl.gov/LERSearchCriteria.aspx

(1) LER 05000395/2017-002-01: Low Feedwater Flow to the 'B' Steam Generator Causes

Automatic Reactor Trip

(2) LERs 05000395/2017-003-00, 01: Failed Lightning Arrester on Main Transformer

Causes Reactor Trip

(3) LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main Turbine Trip

(4) LER 05000395/2017-006-00: Technical Specification Action Not Met for Inoperable

Oxygen Monitor

OTHER ACTIVITIES - TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

2723 - Follow Up Inspection for Three or More Severity Level IV Traditional Enforcement

Violations in the Same Area in a 12-Month Period

The inspector evaluated the licensees root cause evaluation 17-00537 and corrective

actions associated with the Severity Level IV (SL IV) violations. The inspectors review

included but were not limited to: 1) assurance that the causes of the violations were

understood, 2) that the extent of condition and extent of cause for the violations were

identified, and 3) that both completed and proposed corrective actions for the violations

were appropriate and sufficient to address the causes.

INSPECTION RESULTS

Observations and Minor Violation for Review of CR-17-00198, A EDG service

water discharge line pinhole leak

71152

Minor Violation: 10 CFR 50, Appendix B, Criterion XVI, Corrective Action, for failure to

promptly identify a condition adverse to quality (CAQ). Specifically, the licensee did not

initiate a CR to document cavitation damage for on the downstream pipe reducer element for

XVB03121A.

Screening: Because the licensee corrected the condition with their work order system under

WO 1305828, the inspectors identified this as a minor violation of Criterion XVI.

Enforcement: This failure to comply with 10 CFR 50, Appendix B, Criterion XVI constitutes a

minor violation that is not subject to enforcement action in accordance with the NRCs

Enforcement Policy. The licensee entered this problem into their CAP as CR-18-01588.

The inspectors reviewed CR-17-00198 that was initiated on January 11, 2017, following the

licensees discovery of a pinhole leak in the A EDG service water (SW) discharge pipe

reducer element flanged to the SW return valve, XVB03121A-SW. The pipe reducer element

was subsequently replaced during the refueling outage (RF) 23 completed in the Spring,

2017, and a vendor analysis report of pipe reducer element was completed and attached to

CR-17-00198 on November 14, 2017. The inspectors noted that the report concluded the

pinhole leak resulted in deep metal loss consistent with cavitation induced degradation. The

inspectors noted that XVB03121A-SW is a butterfly valve and maintained in a throttled

position to ensure the required SW flow through the A EDG heat exchangers; B train has a

similar arrangement. The inspectors also noted that this configuration results in a near

continuous conditions allowing cavitation since the licensee maintains continuous SW flow to

both trains of EDGs even when they are not in service. The inspectors noted that the

downstream piping below the reducer element on both trains is marked with a grid pattern to

allow the licensee to monitor flow accelerated corrosion (FAC).

The inspectors reviewed historical corrective actions and noted the following:

CR-04-03364 was initiated on October 25, 2004, due to NRC observation of noise

noted at the SW discharge butterfly valves, XVB03121A,B, which may be due to

cavitation due to the throttled condition of the valves. During RF-16 in October 2006,

both valves were subsequently removed for inspection and found to have cavitation

damage to the valve body and the outlet flange which was documented in CR-06-

03587 and CR-06-03758. The valves and associated reducer elements were

replaced. Additionally, Action 10 of CR-06-03587 created a preventative maintenance

(PM) task to inspect the valves every fifth RF and created WOs for the inspections.

XVB03121A was scheduled for inspection in RF-21, Spring 2014, and XVB03121B

was scheduled for inspection in RF-22, Fall 2015.

During RF-21, cavitation damage was identified on the downstream pipe reducer

element for XVB03121A and it was replaced under WO 1305828. However, the

inspectors noted the licensee did not initiate a CR for this CAQ per SAP-999,

Corrective Action Program, Rev. 12, which is the licensees process for promptly

identifying a CAQ as required by 10 CFR 50, Appendix B, Criterion XVI, Corrective

Action.

During RF-22 the licensee initiated CR-15-05473 due to cavitation damage found on

the downstream piping reducer element for XVB03121B. The damaged reducer

element was replaced during the outage. The inspectors noted that this CR did not

perform any new evaluations relative to any changes to their periodicity of inspections.

The inspectors noted that the A train SW pinhole leak documented by CR-17-00198 and

repaired in RF-23 occurred prior to the next scheduled inspection for XVB03121A during RF-

26. The inspectors also verified the licensee had created new PM inspections to perform

ultrasonic examination of the pipe reducer elements every 6 months. However, the inspectors

also observed that the licensee did not address the use of a butterfly valve for throttling

resulting in cavitation conditions as opposed to a more suitable valve design. Following

discussion with the licensee, Action 14 to CR-17-00198 was initiated for a design review and

presentation to the Plant Health Committee.

Observations for LER 05000395/2017-002-01: Low Feedwater Flow to the 'B'

Steam Generator Causes Automatic Reactor Trip

71153

The inspectors reviewed and closed LER 05000395/2017-002-00 in NRC integrated

inspection report 05000395/2017004.

Inspectors noted that a vendor concluded the solenoid valve failure was due to a

manufacturing defect relating to lack of solder at a wiring junction. The inspectors determined

that the licensee had not performed a Part 21 evaluation. The licensee added Action 26 to

CR-17-03674 to complete the Part 21 evaluation which concluded there was no substantial

safety hazard. This LER is closed.

Observations for LERs 05000395/2017-003-00, 01: Failed Lightning Arrester on

Main Transformer Causes Reactor Trip

71153

The inspectors reviewed LERs 05000395/2017-003-00, 01. On August 28, 2017, the failure

of a surge arrestor on the center phase of the main transformer, XTF-1, resulted in an

automatic turbine trip that initiated an automatic reactor trip. Subsequent examination

revealed that the surge arrestor failed as a result of moisture ingress past the upper housing

seal leading to a flash-over of the internal metal oxide varistors. The inspectors reviewed

industry data regarding testing of surge arrestors which indicate that single test results may

not indicate an impending failure, but trending of multiple tests can indicate degradation of the

internal components. The inspectors determined that the licensee does perform testing but

on a periodicity of every two refueling outages. The inspectors concluded that more frequent

testing may provide better trend results, and the licensee took this information into

consideration. The inspectors reviewed the licensees corrective actions documented in CR-

17-04597. This LER is closed.

Failure to Perform an Adequate Risk Assessment With Consequent Reactor Trip

Cornerstone

Significance

Cross-cutting

Aspect

Report

Section

Initiating Events

Green NCV 05000395/2018001-01

Opened/Closed

[H.5] - Work

Management

71153

A self-revealed, Green NCV was identified for the licensees failure to adequately assess risk

in accordance with 10 CFR 50.65(a)(4), Requirements for Monitoring the Effectiveness of

Maintenance at Nuclear Power Plants, during repairs to a non-safety related inverter, XIT-

5905.

This NCV closes LER 05000395/2017-005-00: Automatic Reactor Trip Due to Main Turbine

Trip.

Description: On November 7, 2017, a loss of XIT-5905 caused a loss of power to the

feedwater digital control system (DCS) which led to a loss of all three feedwater pumps and

subsequent main turbine trip and an automatic reactor trip. The licensee entered the event

into their CAP as CR-17-05860 and later performed a root cause analysis (RCA) documented

by CR-17-05908, which addressed the programmatic, behavioral, and organizational aspects

of planning, maintenance, operation and risk management of components leading to the

reactor trip. The inspectors reviewed the RCA and noted the following:

Direct cause stated, Maintenance was performed on-line on single point vulnerability

(SPV) equipment without proper controls (i.e., less than adequate mitigating

strategies, vendor oversight, and retest requirements), with subsequent component

failure resulting in a plant trip.

Root cause (RC01) stated, VCS-SAP-1315, [Process Requirements for Obtaining

Services], was not followed correctly, resulting in no assessment of risk, mitigating

strategies, or vendor oversight.

RC02 stated, Implementation of the planning process failed to ensure station

expectations were met associated with adherence to SSP-001, such that proper

assessment of the scope of work, vendor oversight, and retest requirement were not

provided for the work performed.

RC03 stated, Less than adequate oversight and reinforcement of standards and

expectations associated with Maintenance review of scope of work for corrective

maintenance, use of HU tools, and vendor oversight.

Contributing cause (CC1) stated, Implementation of the planning and scheduling

process failed to ensure station expectations were met associated with adherence to

SSP-001, such that single point vulnerability was not identified for the planning of

WO 1705755 Step 2.

CC2 stated, Engineering resources were not allocated for the inverter work, due to

subject matter expert (SME) involvement with an emergent activity and SME

understanding of expected work scope, which contributed to inadequate vendor

oversight, inadequate identification of the scope of work, and inadequate retest of the

work performed.

The inspectors reviewed additional actions in CR-17-05860 and noted that Action 005 was

initiated to scope XIT-5905 into the maintenance rule (MRule). Following additional inspector

inquiries, the licensee initiated CR-18-00533 to perform the maintenance rule evaluation and

CR-18-00651 to document that the evaluation originally documented in Action 005 of CR-17-

05860 did not follow CAP procedure requirements.

The inspectors reviewed design calculation, DC00300-156, Eighth Major Update of the PRA

Model, Revision 3A, which included a change to add XIT-5905 to the equipment out of

service (EOOS) computer model used by the licensee to perform risk evaluations in

accordance with 10 CFR 50.65(a)(4). DC00300-156 was issued on November 13, 2017, six

days after the unit trip.

The inspectors performed additional research and discovered relevant information not

discussed in the RCA. The inspectors concluded the licensee had the opportunity to mitigate

or eliminate the SPV aspects in 2011 or approximately six years prior to the unit trip on

November 7, 2017. The licensee initiated CR-18-00954 to determine why CR-09-05101 was

not reviewed or discussed in the RCA documented in CR-17-05908.

Corrective Action(s): The licensee implemented CR-17-05860 and CR-17-5908 to identify

causes and appropriate corrective actions.

Corrective Action Reference(s): The licensee entered this issue into their CAP as CR-17-

05860 and CR-17-05908.

Performance Assessment:

Performance Deficiency: The licensees failure to adequately assess the risk in accordance

with 10 CFR 50.65(a)(4) for an activity involving repairs to inverter XIT-5905 was a

performance deficiency (PD).

Screening: The inspectors determined the PD was more than minor because it adversely

affected the initiating events cornerstone objective to limit the likelihood of events that upset

plant stability and challenge safety functions during power operations and the associated

attribute of equipment performance relative to maintenance and reliability. Specifically, the

licensee failed to consider the SPV significance of maintenance on inverter XIT-5905 during

power operations, and the failure of the inverter led to an automatic reactor trip.

Significance: The inspectors assessed the significance of the finding using IMC 0609,

4, Initial Characterization of Findings, dated October 7, 2016, and IMC 0609,

Appendix KProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 0609,</br></br>Appendix K" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., Maintenance Risk Assessment and Risk Management Significance

Determination Process, dated May 19, 2005. The baseline core damage frequency (CDF)

was 3.3208E-6 and the increase in CDF due to the turbine trip was 3.5260E-6 resulting in an

incremental core damage frequency (ICDF) involving the reactor/turbine trip was 2.0520E-7.

The duration of the work on XIT-5905 was approximately 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> resulting in an incremental

core damage probability (ICDP) of 2.811E-10. Since the licensee performed no actual risk

assessment for the work on XIT-5905, the ICDP is equal to the incremental core damage

probability deficit (ICDPD) or risk deficit. The finding was therefore determined to be of very

low safety significance (Green) using flowchart 1 of IMC0609, Appendix K, because the risk

deficit was less than 1E-6.

Cross-cutting Aspect: The inspectors determined the finding had a cross-cutting aspect of

work management (H.5) in the area of human performance, because the licensee did not

perform an adequate risk assessment in accordance with their procedures.

Enforcement:

Violation: 10 CFR 50.65(a)(4) requires, in part, that before performing maintenance activities

the licensee shall assess and manage the increase in risk that may result from the proposed

maintenance activities. Contrary to the above, on November 7, 2017, the licensee failed to

adequately assess the risk for maintenance on inverter XIT-5905.

Disposition: This violation is being treated as an NCV consistent with Section 2.3.2.a of the

Enforcement Policy.

Minor Violation for LER 05000395/2017-006-00: Technical Specification Action

Not Met for Inoperable Oxygen Monitor

71153

Minor Violation: Technical Specification (TS) 3.3.3.9, Explosive Gas Monitoring

Instrumentation, for failure perform a grab sample and analysis at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Screening: Subsequent grab sample and analysis performed on October 31, 2017 determined

that oxygen levels were satisfactory. Therefore the inspectors determined the TS violation

was minor. The licensee entered the issue into the CAP as CR-17-05725.

Enforcement: The failure to comply with TS 3.3.3.9, Explosive Gas Monitoring

Instrumentation,constitutes a minor violation that is not subject to enforcement action in

accordance with the NRCs Enforcement Policy.

The inspectors reviewed LER 05000395/2017-006-00 and identified the above information.

This LER is closed.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

The inspectors confirmed that proprietary information was controlled to protect from public

disclosure.

On April 30, 2018, the inspector presented the quarterly resident inspector inspection results to

Mr. George Lippard and other members of the licensee staff.

DOCUMENTS REVIEWED

71111.04 - Equipment Alignment

E-302-641, Residual Heat Removal, Rev, 21

SOP-115, Residual Heat Removal, Rev. 22D

SOP-306, Emergency Diesel Generator, Rev. 19E

SOP-211, Emergency Feedwater System, Revision 14G

D-302-085, Emergency Feedwater System Flow Diagram, Rev. 41

FSAR 8.3.1.1.2, Onsite Standby Power Supplies

SOP-304, 115kV, 7.2 kV Operations, Rev. 14A

71111.05AQ - Fire Protection Annual/Quarterly

VC Summer Unit 1 Fire Pre-Plans

STP-728.040, Auxiliary Building Fire Barrier Inspection, Elevations 400, 397, 388 and 374,

Rev. 4C

STP-728.042, Control Building Elevation 463 Fire Barrier Inspection, Rev. 7B

STP-728.043, Control Building Elevation 448 Fire Barrier Inspection, Rev. 5C

STP-728.045, Control Building Elevation 425 Fire Barrier Inspection, Rev. 4G

STP-728.047, Intermediate Building Elevations 476, 463, and 451 Fire Barrier Inspection, Rev.

4C

STP-728.048, Intermediate Building Elevations 436 Fire Barrier Inspection, Rev. 4G

71111.12 - Maintenance Effectiveness

ES-514, Maintenance Rule Program Implementation, Rev. 7

SAP-0157, Maintenance Rule Program, Rev. 2

71111.13 - Maintenance Risk Assessments and Emergent Work Control

SSP-001, Planning and Scheduling Maintenance Activities, Rev. 24H

OAP-100.6, Control Room Conduct and Control of Shift Activities, Rev. 4L

OAP-102.1, Conduct of Operations Scheduling Unit, Rev. 8E

71111.18 - Plant Modifications

Drawing 1MS-28-058, Train A XPN-6091, Rev. 21

Drawing B-208-060, Leak Detection System, Rev. 17

SAP-148, Attachment 1, Bypass Authorization Request #18-01, Rev 9

Special Order 18-01, RBCU Operation Impact on RBCU Drain Flow Alarm, Rev. 0