IR 05000336/2017004

Integrated Inspection Report 05000336/2017004 and 05000423/2017004

ML18032A330
Person / Time
Site:	Millstone
Issue date:	02/01/2018
From:	Daniel Schroeder Reactor Projects Branch 2
To:	Stoddard D Dominion Energy
Schroeder D
References
IR 2017004
Download: ML18032A330 (57)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION ary 1, 2018

SUBJECT:

MILLSTONE POWER STATION - INTEGRATED INSPECTION REPORT 05000336/2017004 AND 05000423/2017004

Dear Mr. Stoddard:

On December 31, 2017, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station (Millstone), Units 2 and 3. On January 17, 2018, the NRC inspectors discussed the results of this inspection with Mr. John Daugherty, Site Vice President, 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 a 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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Millstone. In addition, if you disagree with a cross-cutting aspect assignment, 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 I, and the NRC Resident Inspector at Millstone. 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 the NRC Public Document Room in accordance with 10 CFR 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely,

/RA/

Daniel L. Schroeder, Chief Reactor Projects Branch 2 Division of Reactor Projects Docket Nos. 50-336 and 50-423 License Nos. DPR-65 and NPF-49

Enclosure:

Inspection Report 05000336/2017004 and 05000423/2017004 w/Attachment:

Supplementary Information

REGION I==

Docket Nos. 50-336 and 50-423 License Nos. DPR-65 and NPF-49 Report Nos. 05000336/2017004 and 05000423/2017004 Licensee: Dominion Energy Nuclear Connecticut, Inc. (Dominion)

Facility: Millstone Power Station, Units 2 and 3 Location: P.O. Box 128 Waterford, CT 06385 Dates: October 1 through December 31, 2017 Inspectors: J. Fuller, Senior Resident Inspector L. McKown, Resident Inspector C. Highley, Resident Inspector H. Anagnostopoulos, Senior Health Physicist E. Burket, Reactor Inspector J. DeBoer, Emergency Preparedness Inspector P. Presby, Senior Operations Engineer J. Brand, Reactor Inspector Approved By: Daniel L. Schroeder, Chief Reactor Projects Branch 2 Division of Reactor Projects Enclosure

SUMMARY

IR 05000336/2017004 and 05000423/2017004; 10/01/2017 - 12/31/2017; Millstone Power

Station (Millstone), Units 2 and 3; Refueling and Other Outage Activities.

This report covered a three-month period of inspection by resident inspectors and announced baseline inspections performed by regional inspectors. The inspectors identified one non-cited violation (NCV), which was of very low safety significance (Green). The significance of most findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process, dated October 28, 2016. Cross-cutting aspects are determined using IMC 0310, Aspects Within the Cross-Cutting Areas, dated December 4, 2014. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated November 1, 2016.

The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 6.

Cornerstone: Barrier Integrity

Green.

A self-revealed NCV of very low safety significance (Green) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified wherein, on October 13, 2017, Dominion failed to accomplish an activity affecting quality, Plant Cooldown, in accordance with approved procedures.

Specifically, during solid plant cooldown, over the course of 18 seconds, reactor coolant system (RCS) pressure increased from 350 psia to 472 psia, which exceeded the limit of 435 psia established by Attachment 1, RCS Cooldown Curves, of operating procedure OP 3208, Plant Cooldown, Revision 028. Dominion operations staff took prompt actions to restore RCS pressure within limits and completed a required engineering evaluation to determine the effect of the out of limit condition on the structural integrity of the RCS.

Dominion entered this issue into the corrective action program (CAP) as condition report (CR) 1080842 and completed a root cause evaluation of the event.

This finding was determined to be more than minor because it adversely affected the configuration control attribute of the Barrier Integrity cornerstone objective to provide reasonable assurance that physical design barriers (RCS) protect the public from radionuclide releases caused by accidents or events. The inspectors evaluated the finding using IMC 0609, Appendix G, Attachment 1, Shutdown Operations Significance Determination Process Phase 1 Initial Screening and Characterization of Findings, and determined the finding to be of very low safety significance (Green). The finding had a cross-cutting aspect in the area of Human Performance related to Work Management because the licensee did not implement an adequate process of planning, controlling, and executing work activities such that nuclear safety was the overriding priority. Specifically,

Dominion failed to recognize the increased risk of isolating instrument air during solid plant operations. [H.5] (Section 1R20)

REPORT DETAILS

Summary of Plant Status

Unit 2 operated at or near 100 percent power for the entire operating period.

Unit 3 began the inspection period at 100 percent power and operated at full power until October 12, when operators reduced power and shutdown the reactor to start the 3R18 refueling outage. Unit 3 returned to 100 percent power on November 17, after the completion of the 3R18 refueling outage, and operated at or near 100 percent power for the remainder of the inspection period.

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R01 Adverse Weather Protection

.1 Readiness for Seasonal Extreme Weather Conditions

a. Inspection Scope

The inspectors performed a review of Dominions readiness for the onset of seasonal cold temperatures at Unit 2 and Unit 3. The review focused on safety-related equipment including condensate storage tanks, refueling water storage tanks, and diesel generator fuel oil storage, as well as heating for the buildings. The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR), technical specifications (TSs), control room logs, and the CAP to determine what temperatures or other seasonal weather could challenge these systems, and to ensure Dominions personnel had adequately prepared for these challenges. The inspectors reviewed station procedures, including Dominions seasonal weather preparation procedure and applicable operating procedures. The inspectors performed walkdowns of the selected systems to ensure station personnel identified issues that could challenge the operability of the systems during cold weather conditions. Documents reviewed for each section of this inspection report are listed in the Attachment.

b. Findings

No findings were identified.

.2 External Flooding

a. Inspection Scope

During the week of October 29, the inspectors performed an inspection of the external flood protection measures for Millstone. The inspectors reviewed TSs, procedures, design documents, and the UFSAR, which depicted the design flood levels and protection areas containing safety-related equipment to identify areas that may be affected by external flooding. The inspectors conducted a general site walkdown of all external areas of the plant, including the emergency diesel generator (EDG) enclosures, turbine building, auxiliary building, and berm to ensure that Dominion erected flood protection measures in accordance with design specifications. Where applicable, the inspectors determined installed flood seal service life and verified that adequate procedures existed for inspecting the installed seals.

b. Findings

No findings were identified.

1R04 Equipment Alignment

.1 Partial System Walkdowns

a. Inspection Scope

The inspectors performed partial walkdowns of the following systems:

Unit 2

'B' high pressure safety injection (HPSI) train during inoperability of 'A' HPSI train, 'D' RCS loop injection valve on October 5 B EDG fuel Injection during Unit 3 reserve station service transformer (RSST)outage on October 25 Emergency core cooling system (ECCS)/low pressure safety injection (LPSI) line following discovery of gas voiding on October 31 Unit 3 Reactor plant closed cooling water to residual heat removal during reactor draindown on October 17 B EDG fuel oil and air start systems as the protected diesel on October 25 The inspectors selected these systems based on their risk-significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors reviewed applicable operating procedures, system diagrams, the UFSAR, TS, work orders, CRs, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted the systems performance of its intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. The inspectors also reviewed whether Dominion staff had properly identified equipment issues and entered them into the CAP for resolution with the appropriate significance characterization.

b. Findings

No findings were identified.

.2 Full System Walkdown

a. Inspection Scope

On October 24, the inspectors performed a complete system walkdown of accessible portions of the Unit 3 LPSI system to verify the existing equipment lineup would allow for successful implementation of Dominions operating procedures. The inspectors reviewed procedures, drawings, and the UFSAR to verify that the system was aligned to perform its required safety functions. The inspectors also reviewed electrical power availability, component lubrication and equipment cooling, hanger and support functionality, and operability of support systems. The inspectors performed field walkdowns of accessible portions of the systems to verify as-built system configuration matched plant documentation. The inspectors confirmed that systems and components were aligned correctly, environmentally qualified, and protected against external threats.

The inspectors also examined the material condition of the components for degradation and observed operating parameters of equipment to verify that there were no deficiencies. Additionally, the inspectors reviewed a sample of related CRs to ensure Dominion appropriately evaluated and resolved any deficiencies.

b. Findings

No findings were identified.

1R05 Fire Protection

.1 Resident Inspector Quarterly Walkdowns

a. Inspection Scope

The inspectors conducted tours of the areas listed below to assess the material condition and operational status of fire protection features. The inspectors verified that Dominion controlled combustible materials and ignition sources in accordance with administrative procedures. The inspectors verified that fire protection and suppression equipment was available for use as specified in the area pre-fire plan, and passive fire barriers were maintained in good material condition. The inspectors also verified that station personnel implemented compensatory measures for out of service, degraded, or inoperable fire protection equipment, as applicable, in accordance with procedures.

Unit 2 Upper 6.9 kV and 4.16 kV switchgear area (Fire Area T-10) on October 30 Operating floor and turbine deck 546 elevation (Area T1-F) on November 20 Auxiliary building HPSI pump room (Fire Area A-4) on December 13 Auxiliary building charging pump room (Fire Area A-6A) on December 13 Unit 3 Containment (Fire Area R) on October 20

b. Findings

No findings were identified.

.2 Fire Protection - Drill Observation

a. Inspection Scope

The inspectors observed a fire brigade drill scenario conducted on November 20 that involved a simulated fire in the Unit 2 turbine building at the 546 elevation. The simulated fire was at the turbine bearing. The inspectors evaluated the readiness of the plant fire brigade to fight fires. The inspectors verified that Dominion personnel identified deficiencies, openly discussed them in a self-critical manner at the drill critique, and took appropriate corrective actions as required. The inspectors evaluated specific attributes as follows:

Proper wearing of turnout gear and self-contained breathing apparatus Proper use and layout of fire hoses Employment of appropriate fire-fighting techniques Sufficient fire-fighting equipment brought to the scene Effectiveness of command and control Search for victims and propagation of the fire into other plant areas Smoke removal operations Utilization of pre-planned strategies Adherence to the pre-planned drill scenario Drill objectives met The inspectors also evaluated the fire brigades actions to determine whether these actions were in accordance with Dominions fire-fighting strategies

b. Findings

No findings were identified.

1R06 Flood Protection Measures

.1 Annual Review of Cables Located in Underground Bunkers/Manholes

a. Inspection Scope

The inspectors conducted an inspection of underground bunkers/manholes subject to flooding that contain cables whose failure could affect risk-significant equipment. The inspectors performed walkdowns of risk-significant areas, including Unit 3 east and west switchgear areas (4-6), to verify that the cables were not submerged in water, that cables and/or splices appeared intact, and to observe the condition of cable support structures. When applicable, the inspectors verified proper sump pump operation and verified level alarm circuits were set in accordance with station procedures and calculations to ensure that the cables will not be submerged. The inspectors also ensured that drainage was provided and functioning properly in areas where dewatering devices were not installed.

b. Findings

No findings were identified.

1R07 Heat Sink Performance (711111.07A - 1 sample)

a. Inspection Scope

The inspectors reviewed the Unit 2 C reactor building closed cooling water heat exchanger readiness and availability to perform its safety functions. The inspectors reviewed the design basis for the component and verified Dominions commitments to NRC Generic Letter 89-13, Service Water System Requirements Affecting Safety-Related Equipment. The inspectors observed in-process eddy current testing (ECT),performed an independent visual inspection of the heat exchanger, and reviewed the results of previous inspections. The inspectors discussed the results of the most recent inspection with engineering staff and verified that Dominion initiated appropriate corrective actions for identified deficiencies. The inspectors also verified that the number of tubes plugged within the heat exchanger did not exceed the maximum amount allowed.

b. Findings

No findings were identified.

1R08 In-service Inspection

Unit 3

a. Inspection Scope

From October 23 to November 2, the inspectors conducted an inspection of Dominions third period, third interval in-service inspection activities during the Millstone Unit 3 refueling outage (3R18). Inspection samples were chosen based on the procedure objectives and areas where degradation would result in a significant increase in the risk of core damage. The inspectors observed in-process non-destructive examinations (NDEs), reviewed documentation, and interviewed Dominion personnel to verify that the NDE activities were conducted in accordance with the requirements of American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (BPV) Code Section XI, 2004 Edition, no addenda.

Non-destructive Examination and Welding Activities (IMC Section 02.01)

The inspectors performed direct observations of NDE activities in-process and reviewed records of NDEs listed below. The inspectors verified that the NDE activities were performed in accordance with the ASME BPV Code applicable examination procedures and industry guidance.

Remote observation of a sample of bare metal visual (BMV) examinations performed of the reactor vessel upper head penetrations performed in accordance with ASME Code Case N-729-4; Remote observation of a sample of ultrasonic testing (UT) of the reactor vessel upper head penetrations performed in accordance with ASME Code Case N-729-4; Direct observation of manual UT of the D RCS loop stop valve bonnet studs (component ID RCS-V-8-XX);

Record review of the BMV examinations of 1B and 1D steam generator (SG) channel head drain lines performed in accordance with ASME Code Case N-722-1 (component ID SG-1B(D) CH drain);

Record review of the BMV examination of the reactor vessel head vent line weld performed in accordance with ASME Code Case N-722-1 (component ID RV head vent FW-1); and Record review of manual UT of B RCS branch line welds performed in accordance with industry initiative MRP-146, Management of Thermal Fatigue in Normally Stagnant Non-Isolable Reactor Coolant System Branch Lines, (component ID RCS-10-FW-24-1, RCS-10-FW-25-1, and RCS-10-FW-26-1).

The inspectors reviewed certifications of the NDE technicians performing the examinations to verify the examinations were performed by qualified individuals in accordance with approved procedures and the results were reviewed and evaluated by certified NDE personnel as required by the ASME Code or Dominion procedures.

Modification/Repair/Replacements Consisting of Welding on Pressure Boundary Risk Significant Systems The inspectors performed direct observation and record review of the Millstone Unit 3 repair/replacement activity associated with the replacement of the A reactor plant component cooling water heat exchanger (M33CCP*E1A). The inspectors observed in-field welding of the reconnecting of the service water-side piping to the replacement heat exchanger. The inspectors reviewed the ASME Section XI Repair/Replacement Program procedure, work order 53103005951, procedure qualification record, welder performance qualifications, welding technique sheet for welding technique 4204, and penetrant testing NDE examination report. The inspectors reviewed the repair activity to verify the welding and applicable NDE activities were performed in accordance with ASME Section XI requirements.

Pressurized Water Reactor Vessel Upper Head Penetration Inspection Activities (IMC Section 02.02)

Dominion performed BMV and UT examinations of the reactor vessel head penetrations at Millstone Unit 3 during the 2017 refueling outage (3R18). The inspectors reviewed the examination procedures, observed portions of the examinations, and reviewed post examination records to verify that activities were performed in accordance with ASME BPV Code Case N-729-4 and 10 CFR 50.55a(g)(6)(ii)(D) requirements. The inspectors also reviewed the personnel qualifications of the examiners performing the inspections and the Dominion NDE Level III personnel evaluating and accepting the results.

Boric Acid Corrosion Control Inspection Activities (IMC Section 02.03)

The inspectors reviewed the boric acid corrosion control program procedure and discussed the program with engineers that perform boric acid corrosion evaluations.

The inspectors independently performed a walk down in containment to evaluate Dominions ability to identify boric acid. The inspectors also reviewed a sample of evaluations and corrective actions associated with boric acid found on safety significant piping and components inside containment during the 3R18 refueling outage to verify that evaluations met industry guidelines and that corrective actions assigned were consistent with the requirements of IWA-5250 of Section XI of the ASME Code and 10 CFR Part 50, Appendix B, Criterion XVI.

Steam Generator Tube Inspection Activities (IMC Section 02.04)

The inspectors reviewed the Millstone Unit 3 SG inspection plan, degradation assessment, and the condition monitoring and operational assessment for the 3R18 refueling outage. The SG inspection plan included ECT of all in-service tubes in the A and C SGs during the 3R18 refueling outage. The inspectors observed a sample of ECT of the C SG tubes, reviewed ECT data of various tubes, and observed data analysis and resolution activities. The inspectors also reviewed the examination technique specification sheets used for the ECT examinations of the SG tubes to ensure the examination techniques being applied could accurately detect and size areas of degradation.

During the 3R18 refueling outage, Dominion staff determined that two tubes met or exceeded the 40 percent through wall TS plugging limit in the A SG and that neither of the tubes required in-situ pressure testing. The inspectors reviewed the ECT data for the two tubes and compared that data to the in-situ pressure testing criteria described in the degradation assessment. The inspectors concluded that although the two tubes exceeded the TS limit for through wall degradation, the threshold for in-situ pressure testing was not exceeded. The inspectors noted that plugging these two tubes brought the total percentage of tubes plugged in A SG to 0.91, which is below the design plugging limit of 10 percent for the SG.

The inspectors verified that the SG examination and repair activities were performed in accordance with the Dominion Steam Generator Program, TS for Millstone Unit 3, Electric Power Research Institute Pressurized Water Reactor Steam Generator Examination Guidelines, and the ASME Boiler and Pressure Vessel Code, Section XI.

Identification and Resolution of Problems (IMC Section 02.05)

The inspectors reviewed a sample of Millstone Unit 3 CRs associated with NDE activities, welding, boric acid corrosion control, and SG primary and secondary side issues since the previous outage and during the current outage. The inspectors verified that nonconforming conditions were identified and dispositioned in accordance with Dominions CAP procedure, and that corrective actions were assigned based on the safety significance of the issue.

b. Findings

No findings were identified.

1R11 Licensed Operator Requalification Program and Licensed Operator Performance

(71111.11Q - 4 samples,

==71111.11A - 2 samples, 71111.11B - 1 sample)

.1

==

Quarterly Review of Licensed Operator Requalification Testing and Training

a. Inspection Scope

Unit 2 The inspectors observed Unit 2 control room simulator licensed operator requalification training on December 12. The inspectors evaluated operator performance during the ATWS, LOCA and SGTR events and verified completion of risk significant operator actions, including the use of alarm response and abnormal and emergency operating procedures. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and degrading plant conditions, and the oversight and direction provided by the control room supervisor. The inspectors verified the accuracy and timeliness of the emergency classifications made by the shift manager and the TS action statements entered by the unit supervisor. Additionally, the inspectors assessed the ability of the crew and training staff to identify and document crew performance problems.

Unit 3 The inspectors observed Unit 3 simulator Just-In-Time training on October 3. The training included both classroom training and time on the simulator. Specifically, the inspectors observed licensed operators practicing feedwater maneuvers, power reductions while removing one feed pump from service, and placement of residual heat removal in service in preparation for the Unit 3 refueling outage. The inspectors evaluated operator performance through these activities and verified completion of risk significant operator actions, including the use of abnormal and emergency operating procedures where applicable. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and degrading plant conditions, and the oversight and direction provided by the control room supervisor.

Additionally, the inspectors assessed the ability of the crew and training staff to identify and document crew performance problems.

b. Findings

No findings were identified.

.2 Quarterly Review of Licensed Operator Performance in the Main Control Room

(2 samples)

a. Inspection Scope

Unit 2 The inspectors observed Unit 2 operator performance during an emergent downpower to support moisture separator reheater drain tank level control valve failure on November 1.

The inspectors evaluated operator performance during the actual power maneuvers to verify the use of normal and abnormal operating procedures. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and changing plant conditions, as well as the oversight and direction provided by the control room supervisor. Additionally, the inspectors assessed the ability of the crew to identify and document crew performance problems.

Unit 3 The inspectors observed Unit 3 operator performance during shutdown activities on October 12. The inspectors also observed operations personnel conduct low power physics testing during initial startup of the reactor core on November 12 and 13. The inspectors observed infrequently performed test or evolution briefings, pre-shift briefings, and reactivity control briefings to verify that the briefings met the criteria specified in procedure OP-AA-100, Conduct of Operations, and procedure OP-AA-106, Infrequently Conducted or Complex Evolutions.

b. Findings

No findings were identified.

.3 Licensed Operator Requalification

a. Inspection Scope

On December 27, an NRC region-based inspector conducted an in-office review of results of the Unit 2 and Unit 3 licensee-administered annual operating test for operators.

Examination Results Requalification exam results (annual operating test) for 2017 were reviewed to determine if pass/fail rates were consistent with the guidance of NUREG-1021, "Operator Licensing Examination Standards for Power Reactors," Revision 11, and NRC Inspection Manual Chapter 0609, Appendix I, Operator Requalification Human Performance Significance Determination Process (SDP). The review verified that the failure rate (individual or crew) did not exceed 20 percent.

Unit 2 The overall individual failure rate was 2.3 percent.

The overall crew failure rate was 0.0 percent.

Unit 3 The overall individual failure rate was 0.0 percent.

The overall crew failure rate was 0.0 percent.

b. Findings

No findings were identified

.4 Licensed Operator Requalification

Unit 3

a. Inspection Scope

The following Unit 3 inspection activities were performed using NUREG-1021, "Operator Licensing Examination Standards for Power Reactors," Revision 11, and Inspection Procedure Attachment 71111.11, Licensed Operator Requalification Program and Licensed Operator Performance.

Written Examination Quality The inspectors reviewed three written examinations (reactor operator and senior reactor operator) administered during the 2016 examination cycle for qualitative and quantitative attributes as specified in Appendix B of Attachment 71111.11, Licensed Operator Requalification.

Operating Test Quality The inspectors reviewed eight scenarios and ten job performance measures (JPMs) for qualitative and quantitative attributes as specified in Appendix C of 71111.11, Licensed Operator Requalification Program.

Licensee Administration of Operating Tests Observations were made of the Unit 3 dynamic simulator exams and JPMs administered during the week of November 27. These observations included facility evaluations of crew and individual performance during the dynamic simulator exams and individual performance of JPMs.

Examination Security The inspectors assessed whether facility staff properly safeguarded exam material.

JPMs, scenarios, and written examinations were checked for excessive overlap of test items.

Remedial Training and Re-Examinations The inspectors reviewed one complete remediation package to assess the effectiveness of the remedial training.

Conformance with Operator License Conditions Medical records for ten licensed operators were reviewed to assess conformance with license conditions. All records reviewed were satisfactory.

Proficiency watch standing records for an operating crew of licensed operators were reviewed. All active licensed operators met the watch standing requirements to maintain an active license.

The reactivation plans for three licensed operators were reviewed to assess the effectiveness of the reactivation process. The reactivation was successfully processed in accordance with site procedures.

Records were reviewed for the participation of an operating crew of licensed operators in the requalification program from January 2016 through September 2017.

Simulator Performance Simulator performance and fidelity was reviewed for conformance to the reference plant control room. A sample of simulator deficiency reports was reviewed to ensure facility staff addressed identified modeling problems. Simulator test documentation was also reviewed.

Problem Identification and Resolution A review was conducted of recent operating history documentation found in inspection reports, Dominions CAP, and the most recent NRC plant issues matrix. The inspectors also reviewed specific events from Dominions CAP that indicated possible training deficiencies to verify that they had been appropriately addressed. These reviews did not detect any operational events that were indicative of possible training deficiencies.

b. Findings

No findings were identified.

1R12 Maintenance Effectiveness

a. Inspection Scope

The inspectors reviewed the samples listed below to assess the effectiveness of maintenance activities on structure, system, and component (SSC) performance and reliability. The inspectors reviewed system health reports, CAP documents, maintenance work orders, and maintenance rule basis documents to ensure that Dominion was identifying and properly evaluating performance problems within the scope of the maintenance rule. For each sample selected, the inspectors verified that the SSC was properly scoped into the maintenance rule in accordance with 10 CFR 50.65 and verified that the (a)(2) performance criteria established by Dominion staff was reasonable. As applicable, for SSCs classified as (a)(1), the inspectors assessed the adequacy of goals and corrective actions to return these SSCs to (a)(2). Additionally, the inspectors ensured that Dominion staff was identifying and addressing common cause failures that occurred within and across maintenance rule system boundaries.

Unit 2 B EDG fuel injection subsystem on October 26 C reactor building closed cooling water heat exchanger (M2X18C) on December 12 Unit 3 A EDG October maintenance outage on October 14 LPSI on October 24 Rod control system on November 21

b. Findings

No findings were identified.

1R13 Maintenance Risk Assessments and Emergent Work Control

a. Inspection Scope

The inspectors reviewed station evaluation and management of plant risk for the maintenance and emergent work activities listed below to verify that Dominion performed the appropriate risk assessments prior to removing equipment for work. The inspectors selected these activities based on potential risk significance relative to the reactor safety cornerstones. As applicable for each activity, the inspectors verified that Dominion personnel performed risk assessments as required by 10 CFR 50.65(a)(4) and that the assessments were accurate and complete. When Dominion performed emergent work, the inspectors verified that operations personnel promptly assessed and managed plant risk. The inspectors reviewed the scope of maintenance work and discussed the results of the assessment with the stations probabilistic risk analyst to verify plant conditions were consistent with the risk assessment. The inspectors also reviewed the TS requirements and inspected portions of redundant safety systems, when applicable, to verify risk analysis assumptions were valid and applicable requirements were met.

Unit 2 Elevated unit risk due to south bus outage and Unit 3 RSST unavailable on October 24 High winds and rain resulting in water intrusion into upper switchgear room and under protected 'B' EDG output breakers while Unit 3 RSST unavailable on October 30 Operation with both A and B power operated relief valve (PORV) block valves closed on November 26 Unit 3 Establishing conditions for reactor head de-tensioning and vessel disassembly on October 17 LPSI on October 24 B EDG risk associated with the outage of the RSST on October 25 Planned surveillance test on fire transfer switch panel PORV (3RCS*PCV455A)during solid plant operations in mode 5 on November 8

b. Findings

No findings were identified.

1R15 Operability Determinations and Functionality Assessments

a. Inspection Scope

The inspectors reviewed operability determinations for the following degraded or non-conforming conditions based on the risk significance of the associated components and systems:

Unit 2

'B' HPSI train, 'D' RCS loop injection valve motor operator loss of power on October 5 Through wall leakage in service water piping to 'C' turbine building closed cooling water heat exchanger on October 16 High winds and rain resulting in water intrusion into upper switchgear room and under 'B' EDG output breakers on October 30 Gas voiding in ECCS/LPSI injection line on October 31 Reactor protection system (RPS) matrix logic test failure on November 2 Failure of 480 VAC bus 22B on November 28 The inspectors selected these issues based on the risk significance of the associated components and systems. The inspectors evaluated the technical adequacy of the operability determinations to assess whether TS operability was properly justified and the subject component or system remained available such that no unrecognized increase in risk occurred. The inspectors compared the operability and design criteria in the appropriate sections of the TS and UFSAR to Dominions evaluations to determine whether the components or systems were operable. The inspectors confirmed, where appropriate, compliance with bounding limitations associated with the evaluations.

Where compensatory measures were required to maintain operability, the inspectors determined whether the measures in place would function as intended and were properly controlled by Dominion.

b. Findings

No findings were identified.

1R18 Plant Modifications

.1 Temporary Modification

a. Inspection Scope

The inspectors reviewed the temporary modification listed below to determine whether the modification affected the safety functions of systems that are important to safety.

The inspectors reviewed 10 CFR 50.59 documentation and post-modification testing results, and conducted field walkdowns of the modification to verify that the temporary modification did not degrade the design bases, licensing bases, and performance capability of the affected systems.

Unit 2 Reconfiguration of RPS trip status mimic on November 2

b. Findings

No findings were identified.

.2 Permanent Modifications

a. Inspection Scope

The inspectors evaluated the modifications listed below to determine whether the modifications affected the safety functions of systems that are important to safety. The inspectors verified that the design bases, licensing bases, and performance capability of the affected systems were not degraded by the modification. In addition, the inspectors reviewed modification documents associated with the upgrade and design change, and interviewed engineering and operations personnel to ensure the procedure could be reasonably performed.

Unit 2 Change in feedwater pump low suction pressure trip and plant full power condensate configuration from three pump operation to two pump operation on November 1 Unit 3 A EDG governor and slow speed start modification on October 14 Design change for the safety injection accumulator fill skid on November 4

b. Findings

No findings were identified.

1R19 Post-Maintenance Testing

a. Inspection Scope

The inspectors reviewed the post-maintenance tests for the maintenance activities listed below to verify that procedures and test activities adequately tested the safety functions that may have been affected by the maintenance activity, that the acceptance criteria in the procedure were consistent with the information in the applicable licensing basis and/or design basis documents, and that the test results were properly reviewed and accepted and problems were appropriately documented. The inspectors also walked down the affected job site, observed the pre-job brief and post-job critique where possible, confirmed work site cleanliness was maintained, and witnessed the test or reviewed test data to verify quality control hold point were performed and checked, and that results adequately demonstrated restoration of the affected safety functions.

Unit 2 RPS matrix logic circuit after reconfiguration on November 2 Unit 3 A EDG October maintenance outage on October 14 A EDG breaker panel board (3EGS*PNL1A) breaker replacement and equivalent evaluation on October 20 B auxiliary feedwater flange (3FWA*FLS1B) leak repair on October 30 PORV actuator maintenance - inadequate voltage on November 4 Boric acid leak from bellows of 3CHS*RV8119 on November 7 Auxiliary feedwater train A and B valve stroke time test after instrument calibration on November 8 Feedwater isolation valve (M33FWS*SOV41C) solenoid replacement on November 8 Replacement of isolation valve 3MSS*V78 for instrument MSS-F512A on November 14

b. Findings

No findings were identified.

1R20 Refueling and Other Outage Activities

a. Inspection Scope

The inspectors reviewed the stations work schedule and outage risk plan for the Unit 3 maintenance and refueling outage (3R18), conducted October 12 through November 14.

The inspectors reviewed Dominions development and implementation of outage plans and schedules to verify that risk, industry experience, previous site-specific problems, and defense-in-depth were considered. During the outage, the inspectors observed portions of the shutdown and cooldown processes and monitored controls associated with the following outage activities:

Configuration management, including maintenance of defense-in-depth, commensurate with the outage plan for the key safety functions and compliance with the applicable TSs when taking equipment out of service Implementation of clearance activities and confirmation that tags were properly hung and that equipment was appropriately configured to safely support the associated work or testing Installation and configuration of reactor coolant pressure, level, and temperature instruments to provide accurate indication and instrument error accounting Status and configuration of electrical systems and switchyard activities to ensure that TSs were met Monitoring of decay heat removal operations Impact of outage work on the ability of the operators to operate the spent fuel pool cooling system Reactor water inventory controls, including flow paths, configurations, alternative means for inventory additions, and controls to prevent inventory loss Activities that could affect reactivity Maintenance of secondary containment as required by TSs Refueling activities, including fuel handling and fuel receipt inspections Fatigue management Tracking of startup prerequisites, walkdown of containment to verify that debris had not been left which could block the ECCS suction strainers, and startup and ascension to full power operation Identification and resolution of problems related to refueling outage activities

b. Findings

Introduction.

A self-revealed NCV of very low safety significance (Green) of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, was identified when during solid-plant cooldown, Dominion failed to maintain RCS pressure in accordance with the limits established by Millstone Power Station General Operating Procedure OP 3208, Plant Cooldown, Revision 028.

Description.

At 2120 on October 13, with Unit 3 in Mode 5 during solid plant cooldown, a portion of the instrument air system was isolated in support of the A component cooling water heat exchanger replacement project. When instrument air was isolated to charging flow control panel 3CHS-PNL01, charging flow control valve 3CHS*FCV121 failed full-open, which maximized charging flow into the RCS. With the plant in solid RCS conditions (i.e., the pressurizer is 100 percent full of water), the increased charging flow resulted in a rapid rise in RCS pressure and the subsequent lifting of the residual heat removal system suction relief valves, as designed. Over the course of approximately 18 seconds, the RCS pressure increased from 350 psia to approximately 472 psia. At the time of the transient, the RCS temperature was approximately 169°F.

Dominion operations staff recognized the increased charging flow and restored instrument air in accordance with contingency actions that were in place for this work activity.

Step 4.4.3.g of OP 3208 required operators to maintain RCS pressure within the limits established by Attachment 1, RCS Cooldown Curves, which incorporated the pressure/temperature limits of TS 3.4.9.1. The maximum allowable RCS pressure at the time of the event was 435 psia. Therefore, Dominion failed to maintain RCS pressure in accordance with approved plant procedures and TS limits.

Figures 3.4-2 and 3.4-3 of TS 3.4.9.1 established operating limits on RCS pressure and temperature that included uncertainty margins to ensure that the limits of 10 CFR Part 50, Appendix G, Fracture Toughness Requirements, and ASME BPV Code, Section XI, Appendix G, 1995 edition were not exceeded during normal operation.

In the event that RCS pressure was not maintained within these limits, ACTION b.2 of TS 3.4.9.1 required an evaluation to determine the effect on the structural integrity of the reactor coolant pressure boundary components. Dominion entered ACTION b.2 and completed an engineering evaluation, prior to entering Mode 4, and concluded that the RCS was acceptable for continued operation. The engineering evaluation verified that the limits of 10 CFR Part 50, Appendix G and ASME Section XI, Appendix G were not exceeded. Moreover, Dominion also entered TS 3.4.9.3, Action f, which required that Dominion submit a special report to the NRC within 30 days. This report was submitted on November 7 (ML17319A089).

In preparation of the component cooling water heat exchanger replacement project, licensee staff were required to implement OP-AA-200, Equipment Clearance, which established the responsibilities, authorities, and methodologies to implement the clearance process. Section 3.4.1.i of this procedure provided specific caution when instrument air supplies were to be isolated. A tagout was developed and authorized that did not correctly identify the impact of isolating air to 3CHS-PNL01. Moreover, the licensee failed to properly evaluate the risk of performing this work while the RCS was in a solid condition. Dominion entered this issue into the CAP as CR 1080842 and completed a root cause evaluation of the event. Dominions corrective actions included revision to operations procedures to enhance administrative controls for maintaining RCS pressure and temperature during solid plant operations. Moreover, Dominion took action to provide lessons learned and operating experience with station personnel to ensure staff have a heightened sensitivity to solid plant operations, including the scheduling of outage and configuration control activities that may impact RCS pressure or temperature while the system is solid.

Analysis.

The inspectors determined that the failure to maintain RCS pressure during solid plant cooldown in accordance with operating procedure OP 3208 was a performance deficiency that was reasonably within Dominions ability to foresee, correct, and prevent. This performance deficiency was determined to be more than minor because it adversely affected the configuration control attribute of the Barrier Integrity cornerstone objective to provide reasonable assurance that physical design barriers (RCS) protect the public from radionuclide releases caused by accidents or events.

Specifically, during solid plant cooldown, Dominion failed to maintain RCS pressure within the limits established by Attachment 1 of OP 3208 and TS 3.4.9.1. The exceedance of these limits required an engineering evaluation to determine the effects of the out of limit condition on the structural integrity of the RCS.

The inspectors determined the finding could be evaluated using IMC 0609, Attachment 0609.04, Initial Characterization of Findings. Because the finding pertains to an event while the plant was shut down, the inspectors screened the finding through IMC 0609, Appendix G, Attachment 1, Shutdown Operations Significance Determination Process Phase 1 Initial Screening and Characterization of Findings, using Exhibit 4, Barrier Integrity Screening Questions. The finding screened to be of very low safety significance (Green) because it was determined that the RCS pressure did not exceed the pressure limits of 10 CFR Part 50, Appendix G or ASME Section XI, Appendix G and all of the questions in Exhibit 4 of IMC 0609, Appendix G, Attachment 1 were answered No.

The inspectors concluded that this finding had a cross-cutting aspect in the area of Human Performance related to Work Management because the licensee did not implement an adequate process of planning, controlling, and executing work activities such that nuclear safety was the overriding priority. Specifically, Dominion failed to recognize the increased risk of isolating instrument air during solid plant operations.

[H.5]

Enforcement.

10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, states in part that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Step 4.4.3.g of Section 4.4, Solid Plant Cooldown, of Millstone Power Station General Operating Procedure OP 3208, Plant Cooldown, Revision 028, states, MAINTAIN RCS pressure in the recommended operating region as specified in Attachment 1 (RCS Cooldown Curves)

Contrary to the above, on October 13, Dominion failed to accomplish an activity affecting quality, plant cooldown, in accordance with approved procedures. Specifically, during solid plant cooldown, over the course of 18 seconds, RCS pressure increased from 350 psia to 472 psia, which exceeded the limit of 435 psia established by Attachment 1, RCS Cooldown Curves, of OP 3208, Plant Cooldown.

Dominion operations staff took prompt actions to restore RCS pressure to within limits and completed an engineering evaluation to determine the effects of the out of limit condition on the structural integrity of the RCS. Dominion entered this issue into the CAP as CR 1080842 and completed a root cause evaluation of the event. Because this violation was of very low safety significance (Green) and was entered into Dominions CAP, this violation is being treated as an NCV consistent with Section 2.3.2.a of the NRC Enforcement Policy (NCV 05000423/2017004-01, Failure to Maintain RCS Pressure during Solid Plant Cooldown)

1R22 Surveillance Testing

a. Inspection Scope

The inspectors observed performance of surveillance tests and/or reviewed test data of selected risk-significant SSCs to assess whether test results satisfied TS, the UFSAR, and Dominion procedure requirements. The inspectors verified that test acceptance criteria were clear, tests demonstrated operational readiness and were consistent with design documentation, test instrumentation had current calibrations and the range and accuracy for the application, tests were performed as written, and applicable test prerequisites were satisfied. Upon test completion, the inspectors considered whether the test results supported that equipment was capable of performing the required safety functions. The inspectors reviewed the following surveillance tests:

Unit 2 Gas Accumulation Verification, Facility 1 and Common Header, on October 31 RPS channel B high power trip test on November 7 Unit 3 Electrical penetration of containment for reactor coolant pumps on October 8 (CIV)

Main steam relief valve testing on October 11 A EDG October maintenance outage on October 14 Supplementary leak collection and recovery system (SLCRS) drawdown test in mode 5 from the Unit 3 control room on October 15 Loss of offsite power/loss of coolant accident train A test on October 15 Train A engineered safety features with loss of power test infrequently conducted or complex evolution on October 16 Type C local leak rate testing - Penetration No. 26(i) [3CHS*V58] on October 26 (CIV)

A residual heat removal pump comprehensive operational test and check valves 3RHS*V1 and 3SIL*V3 flow test on November 2 (IST)

A & B safety injection pump comprehensive operational test on November 5 (IST)

A, B, C charging pump comprehensive operational test on November 5 (IST)

Fire transfer switch panel operational testing 3RCS*PCV455A (PORV) on November 8 A & B motor driven auxiliary feedwater pump comprehensive operational test on November 8 (IST)

b. Findings

No findings were identified.

1EP4 Emergency Action Level and Emergency Plan Changes

a. Inspection Scope

Dominion implemented various changes to the Millstone Emergency Action Levels (EALs), Emergency Plan, and Implementing Procedures. Dominion had determined that, in accordance with 10 CFR 50.54(q)(3), any change made to the EALs, Emergency Plan, and its lower-tier implementing procedures, had not resulted in any reduction in effectiveness of the Plan, and that the revised Plan continued to meet the standards in 50.47(b) and the requirements of 10 CFR Part 50, Appendix E.

The inspectors performed an in-office review of all EAL and Emergency Plan changes submitted by Dominion as required by 10 CFR 50.54(q)(5), including the changes to lower-tier emergency plan implementing procedures, to evaluate for any potential reductions in effectiveness of the Emergency Plan. This review by the inspectors was not documented in an NRC Safety Evaluation Report and does not constitute formal NRC approval of the changes. Therefore, these changes remain subject to future NRC inspection in their entirety. The requirements in 10 CFR 50.54(q) were used as reference criteria.

b. Findings

No findings were identified.

2RS1 Radiological Hazard Assessment and Exposure Controls

a. Inspection Scope

The inspectors reviewed Dominions performance in assessing and controlling radiological hazards in the workplace. The inspectors used the requirements contained in 10 CFR Part 20, TSs, Regulatory Guide 8.38, and the procedures required by TSs as criteria for determining compliance.

Inspection Planning

The inspectors reviewed the performance indicators (PIs) for the occupational exposure cornerstone, radiation protection program audits, and reports of operational occurrences in occupational radiation safety since the last inspection.

Radiological Hazards Control and Work Coverage (1 sample)

The inspectors evaluated in-plant radiological conditions and performed independent radiation measurements during facility walk-downs and observation of radiological work activities. The inspectors assessed whether posted surveys; radiation work permits; worker radiological briefings and radiation protection job coverage; the use of continuous air monitoring, air sampling and engineering controls; and dosimetry monitoring were consistent with the present conditions. The inspectors examined the control of highly activated or contaminated materials stored within the spent fuel pools and the posting and physical controls for selected high radiation areas (HRAs), locked HRAs, and very high radiation areas (VHRAs) to verify conformance with the occupational PI.

Risk-Significant HRA and VHRA Controls (1 sample)

The inspectors reviewed the procedures and controls for HRAs, VHRAs, and radiological transient areas in the plant.

Radiation Worker Performance and Radiation Protection Technician Proficiency (1 sample)

The inspectors evaluated radiation worker performance with respect to radiation protection work requirements. The inspectors evaluated radiation protection technicians in performance of radiation surveys and in providing radiological job coverage.

Problem Identification and Resolution (1 sample)

The inspectors evaluated whether problems associated with radiation monitoring and exposure control (including operating experience) were identified at an appropriate threshold and properly addressed in the CAP.

b. Findings

No findings were identified.

4OA1 Performance Indicator Verification

.1 Safety System Functional Failures (2 samples)

a. Inspection Scope

The inspectors sampled Dominions submittals for the Safety System Functional Failures PI for both Unit 2 and Unit 3 for the period of October 1, 2016, through September 30, 2017. To determine the accuracy of the PI data reported during those periods, inspectors used definitions and guidance contained in Nuclear Energy Institute (NEI)

Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 7, and NUREG-1022, Event Reporting Guidelines 10 CFR 50.72 and 10 CFR 50.73."

The inspectors reviewed Dominions operator narrative logs, operability assessments, maintenance rule records, maintenance work orders, CRs, event reports, and NRC integrated inspection reports to validate the accuracy of the submittals.

b. Findings

No findings were identified.

.2 Mitigating Systems Performance Index (10 samples)

a. Inspection Scope

The inspectors reviewed Dominions submittal of the Mitigating Systems Performance Index for the following systems for the period of July 1, 2014, through September 30, 2017:

Unit 2 Emergency AC Power System Unit 3 Emergency AC Power System Unit 2 High Pressure Injection System Unit 3 High Pressure Injection System Unit 2 Heat Removal System Unit 3 Heat Removal System Unit 2 Residual Heat Removal System Unit 3 Residual Heat Removal System Unit 2 Cooling Water System Unit 3 Cooling Water System To determine the accuracy of the PI data reported during those periods, the inspectors used definitions and guidance contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 7. The inspectors also reviewed Dominions operator narrative logs, CRs, mitigating systems performance index derivation reports, event reports, and NRC integrated inspection reports to validate the accuracy of the submittals.

b. Findings

No findings were identified.

.3 Occupational Exposure Control Effectiveness (1 sample)

a. Inspection Scope

The inspectors reviewed Dominions submittals for the occupational radiological occurrences PI for the third quarter 2016 through the third quarter 2017. The inspectors used PI definitions and guidance contained in NEI 99-02, Revision 7, to determine the accuracy of the PI data reported. The inspectors reviewed electronic personal dosimetry accumulated dose alarms, dose reports, and dose assignments for any intakes that occurred during the time period reviewed to determine if there were potentially unrecognized PI occurrences. The inspectors conducted walkdowns of various LHRA and VHRA entrances to determine the adequacy of the controls in place for these areas.

b. Findings

No findings were identified.

Occurrences (1 sample)

a. Inspection Scope

The inspectors reviewed Dominions submittals for the radiological effluent TS/Offsite Dose Calculation Manual radiological effluent occurrences PI for the third quarter 2016 through the third quarter 2017. The inspectors used PI definitions and guidance contained in NEI 99-02, Revision 7, to determine if the PI data was reported properly.

The inspectors reviewed the public dose assessments for the PI for public radiation safety to determine if related data was accurately calculated and reported.

The inspectors reviewed the CAP database to identify any potential occurrences such as unmonitored, uncontrolled, or improperly calculated effluent releases that may have impacted offsite dose. The inspectors reviewed gaseous and liquid effluent summary data and the results of associated offsite dose calculations to determine if indicator results were accurately reported.

b. Findings

No findings were identified.

4OA2 Problem Identification and Resolution

.1 Routine Review of Problem Identification and Resolution Activities

a. Inspection Scope

As required by Inspection Procedure 71152, Problem Identification and Resolution, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify Dominion entered issues into the CAP at an appropriate threshold, gave adequate attention to timely corrective actions, and identified and addressed adverse trends. In order to assist with the identification of repetitive equipment failures and specific human performance issues for follow-up, the inspectors performed a daily screening of items entered into the CAP and periodically attended CR screening meetings.

b. Findings

No findings were identified

.2 Annual Sample: Chronic Tritium Contamination of the Condensate Drawdown and

Makeup System

a. Inspection Scope

The inspectors reviewed Dominions actions associated with the discovery of radioactive tritium contamination in the condensate drawdown and makeup system (CNS) at Millstone Unit 3.

The event was first documented in CR 1048909 False Positive Tritium Results on Vent Samples, written on September 28, 2016. A second (companion) CR, CR 1052791, Tritium is Periodically Found in MP3 Lab Water, was written on November 3, 2016, to document that Unit 3 demineralized laboratory wash water was found to be contaminated with tritium and that this was the cause of the false positive results on vent samples.

During the various inspection efforts, the inspectors observed an air-operated valve in the condensate demineralizer system, and walked down portions of the CNS piping, the condensate surge tank, the condensate storage tank, their cross-tie valve, the associated check valves, and the isolation valve between the CNS and the condensate demineralizer system with a chemistry supervisor and a system engineer. The inspectors toured the Unit 3 chemistry laboratory, examined piping diagrams for the condensate demineralizer system and the CNS system, performed a table-top review of C OP 200.11, Operation of Cross Contaminated System, with a chemistry manager and a Unit 3 Shift Manager, held meetings with the Manager of Organizational Effectiveness regarding the trending program and the CAP, examined several Radiological Environmental Reviews and Health Physics Memos regarding the potential impacts from the tritium contamination, and reviewed chemistry sample results for tritium in lab water and in the condensate surge tank.

b. Findings and Observations

No findings were identified.

Dominions CAP documents indicate that the source of the tritium contamination of the CNS system was several leaking valves in the condensate demineralizer system (which normally contains low levels of tritium) and a leaking manually-operated isolation valve (which connects the demineralizer recycle header portion of the condensate demineralizer system to the CNS system). The conditions by which the tritium can cross-contaminate the CNS system require a particular system line-up and only occur for short durations. A similar tritium cross-contamination event was documented in 2005, and leaking isolation valves in the condensate demineralizer system have been documented as a chronic problem since 2005.

The inspectors identified two performance deficiencies.

In the first deficiency, the inspectors determined that Millstone staff did not follow procedure C OP 200.11, Operation of a Cross Contaminated System, Revision 004-02 as written during the evaluation of tritium found in the CNS in November 2016. This was verified on July 13, 2017, when the inspectors performed a table-top review of the procedure with a Chemistry Department representative and a Unit 3 Shift Manager who utilized this procedure in response to the tritium contamination of the CNS in late 2016.

Specifically:

Millstone personnel indicated that in Step 4.1.3 of the procedure, they referred to 2 and did find that the affected system was listed as a Site Systems Identified that Meet IE 80-10 Criteria. The system listed was Condensate and Feed System.

Millstone personnel indicated that they determined that the CNS was part of the Condensate and Feed System after consultation with the appropriate system engineer. The rationale was that although they are treated as separate systems, for the purpose of impacts of cross-contamination by tritium, they can be treated the same because of the common water source.

Millstone personnel indicated to the inspectors that they completed procedure Step 4.1.4 (comparison of tritium levels to limits in Attachment 2) and then exited the procedure at Step 4.1.5.c.

The inspectors determined that it was inappropriate to consider the CNS system as part of the Condensate and Feed System as listed on Attachment 2. This is because:

Station specification SP-M3-ME-024, Revision 0, defines a system as an assemblance of components (pipes, valves, pressure vessels, motors, etc.) that perform a function or provide a service and has a unique system identifier associated with it. The CNS, the condensate demineralizer system, the condensate system, and feedwater systems all have unique identifiers as described in the FSAR and as designated on piping diagrams.

The CNS has temperature and pressure ratings that are significantly different than that of the nearby condensate system.

The function and purpose of the CNS is to provide pure makeup water to various secondary plant systems, including the chemistry laboratory and the condensate demineralizer recycle header, whereas the condensate system delivers condensed steam to the feedwater system.

The CNS is not expected to be contaminated with radioactive tritium, the condensate system is expected to be so contaminated.

The water source for the condensate system is the main condenser, the water source for the CNS system is the condensate storage tank. They do not share a common water source.

Furthermore, the inspectors determined that it was inappropriate to exit procedure C OP 200.11, Revision 004-02, at Step 4.1.5.c on or about November of 2016 when the tritium contamination of the CNS was discovered. Specifically:

Step 4.1.5 directs the user to compare contamination levels to limits on Attachment 2 and directs the user to initiate a CR, take corrective actions, consider new or additional sources of contamination, and exit the procedure if the levels are above the Alert Level but below the Fixed Activity Limit. Tritium levels in the CNS system were not above the alert level. Step 4.1.5 should have been passed-over, leading to Step 4.1.6.

Step 4.1.6 provides three criteria by which a system may be considered to be an IE 80-10 system as listed on Attachment 2 of the procedure. All three criteria must be met. Step 4.1.6 is not functional because one of the criteria can never be met, and another criteria refers to guidance in Attachment 1 which does not adequately reflect the IE 80-10 criteria. Since Millstone determined that the CNS was listed on 2, Step 4.1.6 would be skipped, leading to Step 4.1.7.

Step 4.1.7 leads the reader to Section 4.2 and an additional series of actions. This was not done.

Therefore, the inspectors determined that the incorrect classification of the CNS, and inappropriately exiting the procedure at Step 4.1.5.c, led to a failure to perform several actions that are important to the guidance provided in IE 80-10 for the discovery of a contaminated system. These include:

The performance of a 10 CFR 50.59 screening or evaluation for the CNS cross-contamination; An establishment of radiological controls for the system; The development of a system decontamination plan and acceptance criteria; The identification of potential environmental release permitting (NPDES) release paths, and; The evaluation of any inadvertent chemical release issues.

The inspectors reviewed licensee-provided engineering determinations and environmental assessments and determined that the tritium contamination of the CNS had a minimal impact on plant operation, on human health, and on the environment; with potential radiation doses to the general public or plant workers at a very small fraction of established limits.

Using IMC 0612, Appendix B, Issue Screening, the inspectors determined that this performance deficiency was not more than minor in its significance. Specifically, the deficiency could not be reasonably viewed as a precursor to a significant event, did not have the potential to lead to a more significant safety concern, would not have caused a PI to exceed a threshold, and did not adversely affect a cornerstone objective. The inspectors reached this determination based on their determination that underlying cause of the issue being the incorrect classification of the CNS. Dominion wrote CR 1084148 to address the deficiency.

In the second deficiency, contrary to MP-PROC-000-PI-AA-200, Corrective Action, Revision 33, a series of leaking valves in the condensate demineralizer system, for which CRs were written and classified as conditions adverse to quality, were not identified as potential repeat events, or as a potential adverse trend.

Specifically, procedure Step 5.3.35 defines potential repeat as: an identified condition (failure, problem, or deficiency) that has had a previous occurrence documented within the Corrective Action Program. When determining if a significance level 3 event is a potential repeat, review events for the previous three years.

Procedure Step 5.3.1 defines an adverse trend as: A series of events in which the frequency combined with their significance warrant evaluation for corrective action.

This may include:

A significant increase in the number of events in an area or activity when compared to another time period; Multiple occurrences of a specific event; and Multiple occurrences of a general type of event that share a close or common cause.

Procedure Step 3.4.1 directs the Condition Report Team to Perform cognitive trending of CRs as they are reviewed.

Procedure Step 3.4.3.c directs the Condition Report Team to Determine level of evaluation desired for deviating conditions using Attachment 6 by applying the significance level and the type of deviation condition using Attachment 7.

Between August 2016 and December 2016, four CRs were written regarding leaking valves in the condensate demineralizer system, which resulted in unintended pressurization of the condensate demineralizer recycle header to approximately 500 psig (i.e., CR 1045292, CR 1046621, CR 1052162, and CR 1056066).

All four CRs were classified as conditions adverse to quality and screened as a significance level 3. Contrary to procedure MP-PROC-000-PI-AA-200, Step 5.3.35, three of these were not identified as potential repeat conditions. All four events occurred within a one-year period. Contrary to procedure MP-PROC-000-PI-AA-200, Step 5.3.1, the series of leaking valves was not identified as an adverse trend, despite multiple occurrences of a specific event. Contrary to procedure MP-PROC-000-PI-AA-200, Step 3.4.1, cognitive trending of the CRs did not identify the potential adverse trend.

MP-PROC-000-PI-AA-200, Attachment 6, CAQ Screening Matrix, is used to determine the type of evaluation to perform for conditions adverse to quality. Contrary to column 3, row three of Attachment 6, and due to the previously described errors, an apparent cause evaluation was not assigned to the potential repeat condition of leaking valves in the condensate demineralizer system.

The inspectors also noted that a very comprehensive Request for Engineering Assistance regarding the potential for tritium cross-contamination of the CNS system was written by the Chemistry Department in 2010. This attempt at correcting the conditions leading to tritium contamination was cancelled with no action taken. The reason(s) for the cancellation could not be explained to the inspectors by Dominion personnel.

The inspectors previously determined that the tritium contamination of the CNS had a minimal impact on plant operation, on human health, and on the environment. The failure to identify the potential repeat and/or potential adverse trend in leaking valves in the condensate demineralizer system (leading to unwanted pressurization of the recycle header) may have caused a delay in taking appropriate corrective action. Prompt corrective action might have prevented the false positive indication of tritium in the chemistry vent samples.

Using IMC 0612, Appendix B, Issue Screening, the inspectors determined that this performance deficiency was not more than minor in its significance. Specifically, the deficiency could not be reasonably viewed as a precursor to a significant event, did not have the potential to lead to a more significant safety concern, would not have caused a PI to exceed a threshold, and did not adversely affect a cornerstone objective. Dominion wrote CR 1084150 to address the deficiency.

.3 Annual Sample: Failure of Supplemental Leak Collection Release System Door A-24-4

a. Inspection Scope

The inspectors performed an in-depth review of Dominions apparent cause evaluation and corrective actions associated with CR 1058241, Unit 3 TRM fire and SLCRS door A-24-4 stuck open. This CR was associated with Licensee Event Report (LER)05000423/2017-001-00: Loss of Safety Function - Secondary Containment, dated March 20, 2017, and Event Number 52501, dated January 20. This door, A-24-4, is part of the secondary containment boundary which must be intact for the SLCRS to perform its safety function. As a result, the failure of this door to close rendered the secondary containment inoperable from 8:35 am to 12:56 pm on January 20.

The inspectors assessed Dominions problem identification threshold, cause analyses, extent of condition reviews, compensatory actions, and the prioritization and timeliness of corrective actions to determine whether Dominion was appropriately identifying, characterizing, and correcting problems associated with this issue and whether the planned or completed corrective actions were appropriate. The inspectors compared the actions taken to the requirements of Dominions CAP and 10 CFR Part 50, Appendix B.

b. Findings and Observations

No findings were identified.

Dominion determined the direct cause of the door becoming stuck open was the failure of the hydraulic door closer due to high usage. A new door closer was promptly installed and new preventative maintenance tasks were created to replace the door closer devices on a 4-year frequency. During the extent of condition review, door A-24-10 was identified as another high traffic door that contained the same door closer device. The A-24-10 door closer was replaced per work order 53103065851 on April 26.

The inspectors performed an independent review of corrective action records related to door failures and did not identify any relevant occurrences that Dominion had not already considered in their apparent cause evaluation. However, the inspectors did note that CR 1083716, dated November 12, described a subsequent failure of door A-24-4. The inspectors reviewed the CR to determine whether previous corrective actions taken to address CR 1058241 were effective. The inspectors noted that the subsequent failure of this door was not related to the closer and that the stuck open door did not constitute a loss of safety function because the door was not stuck open wide enough to challenge the supplemental leak collection release system.

The inspectors determined Dominions overall response to the issue was commensurate with the safety significance, was timely, and included appropriate compensatory actions.

.4 Annual Sample: Effectiveness of Corrective Actions for Motor Operated Valves

Deficiencies

a. Inspection Scope

The inspectors reviewed 37 CRs involving motor operated valve (MOV) problems identified and entered into the CAP by Dominion staff over the past four years. These problems were identified through testing and inspections of safety-related MOVs in systems from Millstone Units 2 and 3. The problems involved instances where torque or thrust test acceptance criteria were not met, observations involving degraded grease, calculation errors, and in one instance, a motor stall condition identified during testing after maintenance was performed. Additionally, the inspectors performed a review of the Millstone high pressure to low pressure system isolation valves program to verify that the MOVs design limits properly included the maximum expected differential pressure that would result from a postulated back-leakage thru the isolation valves. The inspectors reviewed Dominions corrective actions reports, a sample of diagnostic and stroke time test data, and interviewed plant personnel to evaluate the adequacy of Dominions corrective actions. Finally, the inspectors visually inspected 21 MOVs and reviewed MOV program procedures, drawings, and system health reports to evaluate the quality and effectiveness of the Dominion MOV program as implemented at Millstone Power Station.

The inspectors assessed Dominions problem identification threshold, assessment and operability determinations for each of the identified issues, extent of condition reviews, and the prioritization and timeliness of corrective actions to determine whether Dominion staff was appropriately identifying, characterizing, and correcting problems associated with MOVs and whether the corrective actions were appropriate. The inspectors compared the actions taken to the standards in Dominions CAP and regulatory requirements in 10 CFR Part 50, Appendix B.

b. Findings and Observations

No findings were identified.

The inspectors determined the deficiencies had been properly entered in the Millstone CAP for evaluation, extent of condition review, and corrective actions. The inspectors verified that for the identified problems Dominion staff properly evaluated the issues and determined sufficient margin remained and the valve design limits had not been exceeded. Additionally, for thrust related problems the inspectors determined Dominions evaluations determined the structural capability of the valves was maintained such that the identified deficiencies did not impact operability of the valves.

For example, CR 1035455 documented the safety injection accumulator tank #3 outlet isolation valve (3SIL*MV8808C) exceeded as-left testing close total thrust test limit due to a decrease in stem to stem nut coefficient of friction. The evaluation concluded the structural limit of the valve was not exceeded and the valve remained capable of performing its design safety function. Corrective actions included adjustments of the torque switch and satisfactory as-left testing. Additionally, CR 1066417 evaluated degraded grease identified on the valve stem for a SG main steam isolation bypass valve (2-MS-65A). This valve has a safety function to close and is located in a high ambient temperature area. The inspectors verified valve operability was properly demonstrated via a satisfactory as-found MOV static test and adequate corrective actions were completed including sampling, cleaning, and removal of the old grease; lubrication of the valve stem; and a satisfactory as-left diagnostic test. For a problem involving a locked rotor and motor stall (CR 564011 related to valve 3CHS*MV8109B),the inspectors determined the condition was introduced during valve packing maintenance and corrected prior to placing the valve in service.

For the MOV issues reviewed, the inspectors concluded that Dominion staff completed timely and appropriate actions to address the applicable deficiencies and that associated corrective actions including preventive maintenance reviews and implementation frequency adjustments, are being properly tracked, appropriately documented, and completed as scheduled. In addition, the inspectors concluded that applicable MOVs for both Units 2 and 3 had been properly sized and designed for the maximum expected pressure that would result from back leakage from a high pressure system into a low pressure system.

4OA3 Follow-Up of Events and Notices of Enforcement Discretion

.1 Plant Events

a. Inspection Scope

For the plant events listed below, the inspectors reviewed and/or observed plant parameters, reviewed personnel performance, and evaluated performance of mitigating systems. The inspectors communicated the plant events to appropriate regional personnel, and compared the event details with criteria contained in IMC 0309, Reactive Inspection Decision Basis for Reactors, for consideration of potential reactive inspection activities. As applicable, the inspectors verified that Dominion made appropriate emergency classification assessments and properly reported the event in accordance with 10 CFR 50.72 and 50.73. The inspectors reviewed Dominions follow-up actions related to the events to assure that Dominion implemented appropriate corrective actions commensurate with their safety significance.

Notice of Unusual Event for explosive gas in the Unit 3 turbine building on October 9

b. Findings

No findings were identified.

.2 (Closed) LER 05000423/2017-001-00: Loss of Safety Function - Secondary

Containment On January 20, 2017 while operating in mode 1 at 100 percent power, Dominion discovered that a door (A-24-4) in the auxiliary building failed to fully close. This door is part of the secondary containment boundary, which must be intact for the SLCRS to perform its safety function. As a result, the failure of this door to close rendered the secondary containment inoperable from 8:35 am to 12:56 pm on January 20, 2017. The inspectors did not identify any new issues during the review of the LER. The inspection of this issue is documented in section 4OA2.3. This LER is closed.

4OA6 Meetings, Including Exit

On January 17, 2018, the inspectors presented the inspection results to Mr. John Daugherty, Site Vice President, and other members of the Millstone staff. The inspectors verified that no proprietary information was retained by the inspectors or documented in this report.

ATTACHMENT:

SUPPLEMENTARY INFORMATION

KEY POINTS OF CONTACT

Licensee Personnel

J. Daugherty, Site Vice President

C. Olsen, Plant Manager

L. Armstrong, Director, Performance Recovery

J. Birch, Supervisor Nuclear Training

D. Blakeney, Assistant Plant Manager

R. Borchart, Senior Reactor Engineer

S. Brabec, Assistant Manager Outage and Planning

M. Bradley, Manager, Radiation Protection & Chemistry

C. Chatman, Unit 3 Shift Manager

F. Cietek, Consulting Engineer (PRA)

M. Cote, Supervisor Nuclear Training

D. Dodson, Supervisor - ISI/NDE Engineering

R. Garver, Director Engineering

M. Garza, Unit 2 Senior Nuclear Shift Operator

J. Go, Supervisor Nuclear Training

M. Goolsby, Unit 2 Operations Manager

J. Grogan, Operations Manager Unit 3

K. Hacker, Dominion Corporate Level III

M. Hall, Dominion Corporate Welding Engineer

R. Hanson, Manager Protection Services

J. Langan, Licensing Manager

D. Lawrence, Director, Nuclear Safety and Licensing

P. Malzahn, Nuclear Simulator Operations Coordinator

B. McDonald, Senior Instructor Nuclear Operations

H. McKenney, Corrective Action Supervisor

F. Newton, Superintendent Protection Services

M. OConnor Manager Nuclear Operations

D. Rowe, Superintendent Nuclear Shift Operations Unit 3

R. Royce, Senior Instructor Nuclear Operations

S. Smith, Manager Outage and Planning

D. Smith, Site Emergency Preparedness Manager

J. Stafford, Manager Training

D. Stoddard, Supervisor Component Engineering

M. Sweet, Superintendent Health Physics Operations

E. Treptow, Manager Systems and Component Engineering

K. Underwood, Senior Instructor Nuclear Operations

R. Van-Steenbergen, MOV Program Engineer

C. Walsh, Manager Operations Training

B. Willkens, Manager Nuclear Organizational Effectiveness

M. Wynn, Superintendent Health Physics Operations

N. Yonker, Supervisor Nuclear Engineering Primary Systems

LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED

Opened and Closed

05000423/2017-004-01 NCV Failure to Maintain RCS Pressure during Solid Plant Cooldown (Section 1R20)

Closed

05000423/2017-001-00 LER Loss of Safety Function - Secondary Containment (Section 4OA3)