IR 05000336/2020002

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Integrated Inspection Report 05000336/2020002 and 05000423/2020002
ML20225A010
Person / Time
Site: Millstone  Dominion icon.png
Issue date: 08/12/2020
From: Daniel Schroeder
Reactor Projects Branch 2
To: Stoddard D
Dominion Energy
Schroeder D
References
IR 2020002
Download: ML20225A010 (25)
v • d • e


Text

August 12, 2020

SUBJECT:

MILLSTONE POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000336/2020002 AND 05000423/2020002

Dear Mr. Stoddard:

On June 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3. On July 23, 2020, 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.

One Severity Level IV violation without an associated finding is documented in this report. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.

No NRC-identified or self-revealing findings were identified during this inspection.

If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:

Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement; and the NRC Resident Inspector at Millstone Power Station, Units 2 and 3. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, X /RA/

Signed by: Daniel L. Schroeder Daniel L. Schroeder, Chief Reactor Projects Branch 2 Division of Reactor Projects Docket Nos. 05000336 and 05000423 License Nos. DPR-65 and NPF-49

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000336 and 05000423 License Numbers: DPR-65 and NPF-49 Report Numbers: 05000336/2020002 and 05000423/2020002 Enterprise Identifier: I-2020-002-0041 Licensee: Dominion Energy Nuclear Connecticut, Inc.

Facility: Millstone Power Station, Units 2 and 3 Location: Waterford, CT 06385 Inspection Dates: April 1, 2020 to June 30, 2020 Inspectors: J. Fuller, Senior Resident Inspector C. Highley, Resident Inspector E. Allen, Resident Inspector L. Dumont, Reactor Inspector N. Floyd, Senior Resident Inspector M. Orr, Reactor Inspector B. Pinson, Reactor Inspector S. Wilson, Senior Health Physicist Approved By: Daniel L. Schroeder, Chief Reactor Projects Branch 2 Division of Reactor Projects Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Millstone Power Station, Units 2 and 3, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.

List of Findings and Violations

Failure to Submit a Licensee Event Report for a Condition Prohibited by Technical Specification Cornerstone Significance Cross-Cutting Report Aspect Section Not Applicable NCV 05000336/2020002-01 Not Applicable 71153 Open/Closed An NRC-identified Severity Level IV non-cited violation (NCV) of 10 CFR 50.73(a)(2)(i)(B) was identified when the licensee failed to submit a licensee event report (LER) within 60 days from discovery of an existing, but previously unrecognized, condition prohibited by the plants technical specifications (TSs). Specifically, the licensee failed to recognize that two main steam safety relief valves that failed as-found set pressure testing on April 22, 2020, represented a condition that existed for a time longer than permitted by the TS, and was reportable under 10 CFR Part 50.73. The licensee entered this issue into the corrective action program as Condition Report (CR) 1151029, and submitted LER 05000336/2020-001-00 on August 11, 2020.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000423/2019-001-00 LER 2019-001-00 for 71153 Closed Millstone Power Station Unit 3, Regarding Plant Shutdown Required by Technical Specifications,

Emergency Diesel Generator Exceeded Allowed Outage Time.

LER 05000336/2019-001-00 LER 2019-001-00 for 71153 Closed Millstone Power Station Unit 2, Manual Reactor Trip due to Loss of the 'A' Steam Generator Feed Pump LER 05000423/2020-001-00 LER 2020-001-00 for 71153 Closed Millstone Power Station Unit 3, Technical Specification Allowed Outage Time Exceeded by Accident Monitoring Instrument

PLANT STATUS

Unit 2 began the inspection period at 100 percent rated thermal power (RTP). Unit 2 commenced a planned shutdown for a refueling and maintenance outage (2R26) on April 23, 2020. Unit 2 returned to 100 percent RTP on June 9, 2020. Unit 2 operated at or near RTP for the remainder of the inspection period.

On April 1, 2020, Unit 3 was in Mode 1 at 100 percent RTP, when an automatic reactor trip occurred as a result of a main generator/turbine trip. The main generator trip was initiated by a main generator protection system actuation from a ground fault. On April 13, 2020, Unit 3 was in Mode 1 at 82 percent RTP, when an automatic reactor trip occurred following a turbine trip due to low condenser vacuum caused by the trip of multiple circulating water pumps. The unit was returned to 100 percent RTP on April 16, 2020. Unit 3 operated at or near RTP for the remainder of the 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/readingrm/doc-collections/insp-manual/inspection-procedure/index.html.

Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), resident inspectors were directed to begin teleworking and to remotely access licensee information using available technology. During this time the resident inspectors performed periodic site visits each week and conducted plant status activities as described in IMC 2515, Appendix D; observed risk significant activities; and completed on site portions of IPs. In addition, resident and regional baseline inspections were evaluated to determine if all or portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP.

REACTOR SAFETY

71111.01 - Adverse Weather Protection

Impending Severe Weather Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk- significant systems from impending severe weather on April 13, 2020.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (4 Samples)

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

(1) Unit 2 low pressure safety injection on April 13, 2020
(2) Unit 2 fuel transfer tube containment isolation valves and blank flange on May 17, 2020
(3) Unit 3 auxiliary feedwater 'B' train on April 25, 2020
(4) Unit 3 main steam supply to turbine driven auxiliary feedwater pump on June 23, 2020

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) Unit 2 reactor coolant system loop 2 on May 17, 2020

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Unit 2 containment (Fire Area C-1) on May 1, 2020
(2) Unit 2 letdown heat exchanger (Fire Area A-1H) on May 9, 2020
(3) Unit 2 top of fuel pool and fuel handling area (Fire Area A-14C) on May 10, 2020
(4) Unit 3 north containment recirculation cooler cubicle (Fire Area ESF-2) on April 20, 2020
(5) Unit 3 normal switch gear room, east switch gear area, and west switch gear area (Fire Areas CB-1 through CB-7, and SB-1) on June 3, 2020
(6) Unit 3 control building's computer room, instrument rack room, chiller room, and mechanical equipment room (Fire Areas CB-10A/B, CB-11A/B, CB-13, and CB-14) on June 10, 2020

71111.08P - Inservice Inspection Activities (PWR) PWR Inservice Inspection Activities Sample (IP Section 03.01)

Main article: IP 71111.08
(1) The inspectors verified that the reactor coolant system boundary, steam generator tubes, reactor vessel internals, risk-significant piping system boundaries, and containment boundary are appropriately monitored for degradation and that repairs and replacements were appropriately fabricated, examined and accepted by reviewing the following activities from April 27 to May 12, 2020:

03.01.a - Nondestructive Examination and Welding Activities

  • Manual ultrasonic testing of the pressurizer pipe to tee weld, BPY-C-5015-A (NDE Report M2-UT-20-007)
  • Manual ultrasonic testing of the pressurizer pipe to elbow weld, BPR-C-5100 (NDE Report M2-UT-20-011)
  • Visual examinations of the eight core shroud assembly tie-rods (NDE Report BOP-VT-20-028)

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01)

(2 Samples)

(1) The inspectors observed and evaluated licensed operator performance in the Unit 2 control room during decreased inventory on April 27, 2020; May 26, 2020; and reduced inventory on May 15, 2020.
(2) The inspectors evaluated licensed operator performance in the Unit 3 control room during the Mode 5 to 4 change on April 9, 2020. The inspectors observed electrical breaker operation, normal station transformer energization, reactor coolant system plant heat-up, charging and let down system operation, and testing of the reactor coolant system pressure isolation.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (2 Samples)

(1) The inspectors observed and evaluated operator performance in the Unit 2 simulator during Just in Time Training (JITT) in preparation for the upcoming refueling outage that included reactor coolant drain down (OP 2301E) mid-loop operation, loss of shutdown cooling (AOP 2572), and leak of reactor coolant in Mode 4, 5, 6, and defueled (AOP 2568A) on April 19, 2020.
(2) The inspectors observed and evaluated operator performance in the Unit 3 simulator for critical tasks and emergency classification associated with automatic reactor trip failure, barrier failure, and reactor coolant system leak inside containment on June 9, 2020.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (3 Samples)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Unit 2 maintenance rule functional failure evaluation for the coupling failure of the 'A' steam generator feedwater pump that occurred on December 27, 2019 and was documented in CA7812254
(2) Unit 2 maintenance rule evaluation for 2-FW-51B (steam generator feed flow regulating valve) did not pass main steam isolation (MSI) push button test (CA

===7913165) on April 24, 2020

(3) Unit 3 service water system for potential common cause failures and reliability issues due to dealloying of C95200 aluminum bronze valves (CA7846579) that occurred on February 5, 2020 Quality Control (IP Section 03.02) ===
Main article: IP 79131

The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:

(1) Unit 2 commercial grade dedication of service water system seals on May 5, 2020
(2) Unit 2 reuse of previously installed Grayloc seal rings on May 31, 2020

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (10 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Unit 2 elevated risk during freeze seal on shutdown cooling line to safety injection test header pipe to facilitate leak rate testing of valve 2-SI-460 (low pressure safety injection test header stop valve) on April 15, 2020 (WO 53102831262)
(2) Unit 2 shutdown risk plan for refueling outage (2R26) on April 16, 2020
(3) Unit 2 elevated risk during planned decreased inventory conditions from April 27 to April 28, 2020
(4) Unit 2 elevated risk during as-found stroke testing of low pressure safety injection valves 2-SI-635 and 2-SI 645 while the shutdown cooling system was not in service in Mode 0 on May 3, 2020
(5) Unit 2 elevated risk associated with freeze seal on the emergency core cooling system relief valve while in Mode 5 and decreased inventory on May 15, 2020
(6) Unit 3 walkdown of protected equipment after the reactor trip and loss of the normal station service transformer on April 2, 2020
(7) Unit 3 yellow shutdown risk associated with decay removal and power availability on April 8, 2020
(8) Unit 3 elevated risk during 'B' train auxiliary feedwater testing with predicted severe weather and one off-site 345 kV line out of service on May 11, 2020
(9) Unit 3 elevated risk during procedurally controlled high-risk solid-state protection system testing, and an abnormal auxiliary feedwater system alignment associated with in-process trouble shooting of demineralized water storage tank in-leakage on June 11, 2020
(10) Unit 3 elevated risk associated with removing spent fuel pool cooling to repair the B fuel pool cooling pump discharge valve (3SFC*979) on June 22, 2020

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (8 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) Unit 2 low pressure safety injection header injection isolation valve motor operated valve (2-SI-625) exceeded open limit thrust limit for under-voltage conditions on April 21, 2020 (CR 1145202)
(2) Unit 2 two main steam safety valves failed as-found set pressure test on April 22, 2020 (CR 1145274)
(3) Unit 2 steam generator snubbers SG1-SS2 and SG1-SS3 did not pass functional testing on May 11, 2020 (CR 1147005 / WO 53203269640)
(4) Unit 2 shutdown cooling flow exceeded procedure limits on May 12, 2020 (CR

===1145439)

(5) Unit 2 'B' containment spray pump failed to meet differential pressure requirement during pump periodic verification test on May 20, 2020 (CR 1147900)
(6) Unit 3 operability determination and engineering technical evaluation for a pinhole leak on the 'A' train service water blowdown line on March 31, 2020 (CR 1144004)
(7) Unit 3 'A' emergency diesel generator (EDG) issues with the lube oil temperature control and failed annunciator power supply May 18, 2020 (CR 1147459, CR 1147633, CR 1147721, CR 1147711)
(8) Unit 3 operability determination for service water pipe leak identified on 'A' train of service water blowdown line (3-SWP-003-274-3) on June 9, 2020 (CR 1149479 and CA 7891388)

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)

=

Main article: IP 11454

The inspectors evaluated the following temporary or permanent modifications:

(1) Unit 2 re-gearing of low pressure safety injection inlet valves (MOVs 2-SI-615, -625, -

635, -645) on May 20, 2020

(2) Unit 3 permanent change to the slave relay test of the train 'B' auxiliary feedwater pump start procedure (SP 3646A.9) incorporating the test position and restoration position of an additional valve on May 21, 2020

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (9 Samples)

The inspectors evaluated the following post maintenance test activities to verify system operability and functionality:

(1) Unit 2 steam generator feedwater regulating valve 2-FW-51B after maintenance to resolve failed in-service testing on April 24, 2020
(2) Unit 2 steam generator snubber (SG1-SS2) after repairs on May 12, 2020 (WO

===53203269640)

(3) Unit 2 low pressure safety injection header injection isolation motor operated valves 2-SI-615 and 2-SI-635 after implementation of re-gearing design change on May 20, 2020 (WO 53203268396 and WO 53203268397)
(4) Unit 2 Grayloc seal replacement on June 1, 2020
(5) Unit 2 replacement of containment isolation valve 2-CH-986 (regenerative heat exchanger thermal relief valve) on June 3, 2020 (WO 53203287722)
(6) Unit 3 energization of the 4160 and 6900 volt busses from the normal station transformers following maintenance. on April 9, 2020.
(7) Unit 3 'B' control building chiller heat exchanger (3HVK*CHL1B) following cleaning and inspection on June 10, 2020 (WO 53203250159)
(8) Unit 3 replacement, in service testing, and inspection of 'B' train service water thermal relief valve (3SWP*RV89B) on June 10, 2020 (WO 53103104296)
(9) Unit 3 replacement of 'B' EDG jacket water coolant piping on June 19, 2020 (WO 53103113783)

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage Sample (IP Section 03.01) ===

Main article: IP 53203
(1) The inspectors evaluated Unit 3 forced outage activities from April 1 to April 11, 2020.
(2) The inspectors evaluated Unit 3 forced outage activities from April 13 to April 15, 2020.
(3) The inspectors evaluated Unit 2 refueling outage 2R26 activities from April 23 to June 9, 2020.

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

Main article: IP 71111.22
(1) Unit 2 refueling water storage tank valve back leakage test of 2-SI-460 (low pressure safety injection test header stop valve) on April 16, 2020
(2) Unit 2 main steam safety valve as-found simmer testing on April 22, 2020
(3) Unit 2 integrated system test of facility 2 components (loss of normal power) on April 25, 2020
(4) Unit 3 test of the 'B' solid state protection system on June 18, 2020

Inservice Testing (IP Section 03.01) (1 Sample)

(1) Unit 3 in-service testing of 3CCI*P1A, safety injection pump 'A' cooling pump and check valve 3CCI*V1 on June 3, 2020

Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)

(1) Unit 2 containment leak test, type 'C' for the primary drain and quench tank vent header isolation valve (2GR-11.1) penetration 51 on May 13, 2020

71114.06 - Drill Evaluation

Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) The inspectors evaluated the conduct of a routine emergency planning drill and post drill critique in the Unit 3 simulator for the identification and classification of a barrier and reactor trip failure on June 9,

RADIATION SAFETY

71124.01 - Radiological Hazard Assessment and Exposure Controls

Radiological Hazard Assessment (IP Section 03.01) (1 Partial)

The inspectors verified that the licensee was identifying the magnitude and extent of radiation levels; concentrations, and quantities of radioactive materials.

(1) (Partial)

  • The inspectors verified that the licensee's survey protocol considers the current and historical isotopic mix and isotopic percent abundance, including current and historical presence of hard-to-detect radionuclides and potential alpha hazards.
  • The inspectors evaluated changes to plant operations that may result in a significant new radiological hazard for onsite personnel.
  • The inspectors reviewed the thoroughness and timing of radiological surveys.
  • The inspectors verified that workers are instructed in plant-related radiological hazards and the radiation protection requirements intended to protect workers from those hazards.

Instructions to Workers (IP Section 03.02) (1 Partial)

The inspectors verified licensee controls radiological hazards during radiological work.

(1) (Partial)

The inspectors:

  • Reviewed radiological work permits (RWP) and other documentation the licensee uses to control access to radiological hazards and evaluate instructions and controls. Unit 2 Outage RWP numbers:

o 2200302 o 2200305 o 2200377 o 2200401 o 2200427

  • Reviewed routine radiological survey maps
  • Observed radiological protection-related instructions to plant workers
  • Verified that electronic alarming dosimeters dose and dose rate alarm set points were based on current radiological survey data and plant procedures
  • Attended a pre-job briefing for the Unit 2 pressurizer heater removal to observe instructions to workers Contamination and Radioactive Material Control (IP Section 03.03) (1 Partial)

The inspectors evaluated licensee processes for monitoring and controlling contamination and radioactive material.

(1) (Partial)

  • The inspectors reviewed the licensees criteria for the survey and release of personal items (e.g., using small article monitors (SAMs)).
  • The inspectors evaluated the licensees physical and programmatic controls for highly activated or contaminated materials (non-fuel) stored within spent fuel pool and other storage pools.

Radiological Hazards Control and Work Coverage (IP Section 03.04) (1 Partial)

The inspectors verified that the licensee controls radiological hazards during radiological work.

(1) (Partial)

  • The inspectors verified electronic alarming dosimeter dose and dose rate alarm set points were based on current radiological survey data and plant procedures.
  • The inspectors evaluated the work controls and dosimetry used for activities where dose rate gradients could be severe.

High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (1 Partial)

The inspectors evaluated licensee controls of the following High Radiation Areas and Very High Radiation Areas:

(1) (Partial)

The inspectors reviewed:

  • The circumstances of Technical Specification High Radiation Area Occurrences, as defined by Nuclear Energy Institute guidance document number 99-02
  • Procedural changes since the last inspection to determine the adequacy of access controls for high radiation and very high radiation areas

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01) ===

Main article: IP 71151
(1) Unit 2 (April 1, 2019 - March 31, 2020)
(2) Unit 3 (April 1, 2019 - March 31, 2020)

IE03: Unplanned Power Changes per 7000 Critical Hours Sample (IP Section 02.02) (2 Samples)

(1) Unit 2 (April 1, 2019 - March 31, 2020)
(2) Unit 3 (April 1, 2019 - March 31, 2020)

IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)

(1) Unit 2 (April 1, 2019 - March 31, 2020)
(2) Unit 3 (April 1, 2019 - March 31, 2020)

71152 - Problem Identification and Resolution

Semiannual Trend Review (IP Section 02.02) (1 Sample)

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends in the area of foreign material exclusion (FME) that might be indicative of a more significant safety issue.

Annual Follow-up of Selected Issues (IP Section 02.03) (4 Samples)

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

(1) Unit 2 engineered safety features actuation system (ESFAS) circuitry following an identified high resistance connection on actuation cabinet 6
(2) Units 2 and 3 EDG excellence program and associated corrective actions to improve EDG reliability and unavailability
(3) Unit 3 'A' direct current (DC) battery locked-in ground issues (CR 1138383)
(4) Review of causal analysis, corrective actions, and LER associated with the Unit 3 'A' EDG that failed post-maintenance testing following planned modifications to the exhaust system. The limiting condition for operation (LCO) expiration required a plant shutdown on December 17, 2019

71153 - Followup of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)

Main article: IP 71153

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000336/2019-001-00, Unit 2 Manual Reactor Trip Due to Loss of the 'A' Steam Generator Feedwater Pump, (ADAMS Accession No. ML20050D676). The inspectors determined that it was not reasonable to foresee or correct the cause discussed in the LER therefore no performance deficiency nor violation of NRC requirements was identified.
(2) LER 05000423/2020-001-00, Unit 3 Technical Specification Allowed Outage Time Exceeded by Accident Monitoring Instrument (ADAMS Accession No.

ML20070H650). The inspectors determined that it was not reasonable to foresee or correct the cause discussed in the LER therefore no performance deficiency was identified. However a minor violation of TS 3.3.3.6, Accident Monitoring Instrumentation, was identified when the licensee determined during routine surveillance testing that one of two auxiliary feedwater flow indications to the 'B' steam generator was inoperable for longer than the seven day allowed outage time.

(3) LER 05000423/2019-001-00, Plant Shutdown Required by Technical Specifications, Emergency Diesel Generator Exceeded Allowable Outage Time (ADAMS Accession No. ML20055D320). The inspectors determined that the cause of the condition described in the LER was not reasonably within the licensees ability to foresee and correct and therefore was not reasonably preventable. No performance deficiency nor violation of NRC requirements was identified.

Personnel Performance (IP Section 03.03) (2 Samples)

The inspectors evaluated the plant and operator response during the following non-routine evolutions or transients:

(1) Unit 3 automatic reactor trip following a main generator trip due to a circuit fault between the main generator output breaker and the normal station service transformers on April 1, 2020
(2) Unit 3 automatic reactor trip following a turbine trip due to low condenser vacuum caused by the trip of multiple circulating water pumps on April 13, 2020

Reporting (IP Section 03.05) (3 Samples)

(1) The inspectors reviewed the circumstances surrounding a potential report issue involving the potential inoperability of the containment particulate radiation monitor (3CMS*RE22B) during plant heat up on April 10, 2020.
(2) The inspectors reviewed the circumstances surrounding a potential report issue involving the inservice testing failure of steam generator snubbers SG1-SS2 and SG1-SS3 during the Unit 2 outage (CR 1147005 and CR 1147024).
(3) The inspectors reviewed the circumstances surrounding a potential report issue involving the failure of two Unit 2 main steam safety valves (2-MS-242 and 2-MS-245 ) to meet the "as-found" set pressure requirement of TS Surveillance 4.7.1.1 on April 22,

INSPECTION RESULTS

Observation: Condition Report 1138383, Unit 3 'A' 125 Volt DC Battery Locked- 71152 in Ground Issues The inspectors reviewed corrective actions, work orders, and other documentation associated with the Unit 3 A 125 volts DC battery locked-in ground issue, including equipment surveillances, Operational Decision Making (ODM) checklist, and vendor manuals, to ensure that that licensees corrective action program and NRC regulatory requirements were followed as required.

The inspectors determined that the licensees actions in identifying and resolving the issue were adequate and timely. The inspectors noted that U3 A 125 volt DC battery charger remained grounded on the negative side of the solenoid of Pressurizer Operating Relief Valve (PORV) 3RCS*PCV455A. The inspectors reviewed the last two surveillances performed on the A PORV (May 11, 2019 and December 21, 2019) to ensure that PORV could perform its safety functions. The A PORV will be replaced during the next refueling outage. In addition, the inspectors verified that the licensee had generated a standing order to minimize the risk when performing operational activities that could cause a ground on the 125V DC bus.

Observation: Review of Corrective Actions Associated with the Unit 2 71152 Engineered Safety Features Actuation System Circuitry Following an Identified High Resistance Connection on Actuation Cabinet 6 The inspectors reviewed Dominions evaluation and corrective actions associated with the Unit 2 ESFAS circuitry following the occurrence of flickering indication lights in 2019.

Specifically, in March 2019, Dominion staff identified that indicating lights associated with ESFAS actuation cabinet 6 remained lit longer than anticipated during the systems periodic automatic test (CR 1117153). Following initial evaluation and monitoring, the condition began occurring more frequently, and Dominion staff took additional troubleshooting steps including voltage checks and component tightness checks. Following the initial component tightness checks, the measured voltages were determined to be within expected ranges. In May 2019, the ESFAS lights on actuation cabinet 6 once again remained lit longer than anticipated during the automatic testing (CR 1122670). In response to the recurrence of the issue, Dominion staff established an ODM checklist and developed a work order to identify and correct the issues. The ODM checklist established daily voltage checks, additional monitoring criteria by the Operations department, and a modified risk profile for online work activities affected by ESFAS. In July 2019, as a part of the voltage checks established by the ODM checklist, Dominion staff identified a high resistance connection caused by a crimped connection installed during original plant construction. A work order was established and scheduled for the Spring 2020 refueling outage. The work order was implemented in April 2020, and, following completion, Dominion staff monitored the ESFAS actuation cabinets to ensure the issue was corrected. No indications of high resistance or flickering lights were noted during the monitoring period.

Inspectors performed an in-depth review of the CRs written for ESFAS actuation cabinet issues beginning in March 2019, as well as the evaluations and work orders performed as part of the issue investigation. Inspectors interviewed Dominion staff from the Operations, Instrumentation and Controls, and Engineering departments in order to understand and evaluate Dominions response to the issues. Inspectors also evaluated the corrective actions associated with the issues and determined that the classification and prioritization were commensurate with the safety significance. Inspectors determined that Dominions identification, evaluation and response to the issues was appropriate.

Observation: Review of Corrective Actions Associated with Recent Unit 2 and 71152 Unit 3 Emergency Diesel Generator Issues The inspectors reviewed the licensee's EDG Excellence Plan and many of the corrective actions performed and planned for improving the health of the EDGs at both units. The inspectors noted the purpose of this Excellence Plan was to ensure the emergency and station blackout diesel generators are brought to and maintained at high levels of reliability and availability, to ensure they perform their safety and backup functions when needed. The inspectors noted that the plan and corrective actions adequately identified specific activities needed to achieve the objective and included system and component improvement activities with appropriate prioritization to improve the overall performance of both units EDGs commensurate with the safety significance of the problem.

The inspectors also reviewed the licensees causal analysis, corrective actions, and LER 2019-001-00 associated with the Unit 3 A EDG that failed post-maintenance testing following planned modifications to the exhaust system, leading to a required plant TS shutdown. The inspectors found the Level of Effort Evaluations identified and contributing causes to be well-supported and appropriately determined. Specifically, the evaluation identified the most probable cause for the EDGs inability to maintain 110% load during the 14-day allowed outage time was low operating margin to the turbocharger surge curve that only became evident after installation of the new, improved-efficiency, spread exhaust system. Further contributing causes included a signal generator failure and vendor support process. The inspectors concluded the evaluation of the deficiencies identified were technically supported and programmatically addressed to support the 3A EDGs return to operation. No performance deficiencies were identified.

Observation: Foreign Material Exclusion Semi-Annual Trend Review 71152 During the recent Unit 2 refueling outage (2R26) the inspectors observed several instances where the licensee lost FME integrity in high risk FME areas. Specifically, on April 28, 2020, a rope was found inside the high risk FME area surrounding the refueling floor, which had not been logged into the FME area as required by procedure. A second loss of FME integrity occurred in the same area on May 10, 2020, when the latch for a wall mounted light fell into the spent fuel pool. On May 6, 2020, while the reactor pressure vessel head (RPVH) was removed from the vessel and on the head stand, away from the reactor pressure vessel, a flashlight being used on top of the RPVH came apart and the plastic bezel fell onto the RPVH. The licensee entered these individual issues into the corrective action program and took action to promptly retrieve the FME and restore the integrity of the FME area.

During this inspection period, the inspectors independently evaluated the licensee's corrective actions to ensure that each foreign material was thoroughly evaluated and retrieved. The inspectors also performed a review of the Millstone corrective action database to determine whether the recent loss of FME integrity events were isolated or were indicative of an adverse trend. The inspectors also reviewed licensee FME procedures to determine if they were appropriate to prevent the introduction of FME into plant systems. The inspectors determined that the FME events during 2R26 were not indicative of an adverse trend, and licensee procedures were adequate. The inspectors also noted that the licensee created a performance improvement detail report and the operations department is actively tracking a performance improvement item related to FME. The inspectors observed that the licensee is taking appropriate action to improve performance in this area with a focus on the upcoming Unit 3 refueling outage this Fall.

Failure to Submit a Licensee Event Report for a Condition Prohibited by Technical Specification Cornerstone Severity Cross-Cutting Report Aspect Section Not Severity Level IV Not 71153 Applicable NCV 05000336/2020002-01 Applicable Open/Closed An NRC-identified Severity Level IV non-cited violation (NCV) of 10 CFR 50.73(a)(2)(i)(B)was identified when the licensee failed to submit a licensee event report (LER) within 60 days from discovery of an existing, but previously unrecognized, condition prohibited by the plants technical specifications (TSs). Specifically, the licensee failed to recognize that two main steam safety relief valves that failed as-found set pressure testing on April 22, 2020, represented a condition that existed for a time longer than permitted by the TS, and was reportable under 10 CFR Part 50.73. The licensee entered this issue into the corrective action program as Condition Report (CR) 1151029 and submitted LER 05000336/2020-001-00 on August 11, 2020.

Description:

On April 22, 2020, while in Mode 1, prior to scheduled refueling outage 2R26, all sixteen main steam safety valves (MSSVs) were in-situ tested using an auxiliary lift device in accordance with procedure SP 2730B, "Main Steam Safety Valve Testing," to verify set pressure compliance with Unit 2 TS 3.7.1.1. During this testing, valves 2-MS-242 and 2-MS-245 (both associated with the B steam generator) did not meet the required As-Found set pressure test acceptance criteria of +/- 3 percent and were declared inoperable. Upon identification of the testing failure, the licensee promptly entered the issue in its corrective action program as CR 1145274 and entered TS 3.7.1.1.

TS 3.7.1.1 LCO states, All main steam line code safety valves shall be operable with lift settings as specified in Table 4.7-1. With one or more main steam line code safety valves per steam generator inoperable, the TS Condition 3.7.1.1.a Required Action is to reduce thermal power within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to less than or equal to the applicable percent of rather thermal power in Table 3.7-1, and reduce the power level-high trip setpoint in accordance with Table 3.7-1 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Otherwise be in hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and hot shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

The licensee immediately retested both valves. Valve 2-MS-242 was tested two additional times following the As-Found test failure, and without adjustment, the two consecutive tests were within the required "As-Left +/- 1% test acceptance criteria. Valve 2-MS-245 was tested three additional times following the As-Found test failure, and without adjustment, the last two consecutive tests were within the required "As-Left +/- 1 percent test acceptance criteria. Upon successful test results, in accordance with test procedures, the licensee exited TS 3.7.1.1.

Dominion Engineering evaluated the test failures and reviewed previous surveillance test data from 2R25 and 2R24. The licensee did not identify any adverse trends associated with any of the MSSVs. The licensee noted that 2-MS-242 and 2-MS-245 were last replaced in

2R21 (2012) and 2R23 (2015), respectively. At the time of replacement, both valve discs

were replaced with a pre-oxidized X-750 Inconel material. The licensee's evaluation stated that "the cause of higher as-found set pressure is unknown at this time." The engineering evaluation also determined that both valves would have lifted prior to reaching the updated final safety analysis report design limit of 1085.3 psig and thus would have reliably performed their design function of protecting the main steam system. The inspectors noted that engineering evaluation recommended a corrective action assignment to engineering to evaluate which MSSVs should be removed during the next refueling outage to be sent for disassembly and inspection, and overhaul, and replacement of disc material, as needed.

The licensee reviewed these two failures for reportability under 10 CFR 50.73(a)(2)(i)(B) - a 60 day LER for operation or condition which was prohibited by the plant's technical specifications. The licensee's evaluation, documented in CR1145274, stated, in part, "Based on the lack of failures of these specific valves since installation with the improved valve discs and seats, and lack of failure of our safety valves with upgraded discs and seats in general, there is no firm evidence that a failure mechanism exists that would have rendered the valves inoperable during the operating cycle. Therefore, this condition is NOT REPORTABLE and no 60-day LER is required pursuant to 10 CFR 50.73(a)(2)(i)(B) as any operation or condition which was prohibited by the plant's TSs."

The inspectors reviewed the licensees reportability evaluation and determined that the conclusion was inadequate. While an exact duration could not be determined, the failure of multiple valves is an indication that the discrepancies may have arisen over a period of time. Therefore, the inspectors concluded that the condition existed during plant operation, a time longer than permitted by the TS, even though the condition was not discovered until after the allowable time had elapsed and the condition was rectified upon discovery.

Based on this, the inspectors determined that the subject condition existed longer than the TS Completion Times for the associated Required Action. Therefore, this event was reportable in accordance with 10 CFR 50.73(a)(2)(i)(B).

Corrective Actions: The licensee entered the violation in its corrective action program as CR 1151029 and submitted LER 05000336/2020-001-00. The licensee also re-performed its engineering evaluation of the test failures to provide assurance that the valves will remain operable throughout the next operating cycle.

Corrective Action References: CR 1145274, CR 1151029

Performance Assessment:

The inspectors determined this violation was associated with a minor performance deficiency.

Enforcement:

The ROPs significance determination process does not specifically consider the regulatory process impact in its assessment of licensee performance. Therefore, it is necessary to address this violation which impedes the NRCs ability to regulate using traditional enforcement to adequately deter non-compliance.

Severity: The failure to make reports to the NRC as required by 10 CFR 50.73(a)(2)(i)(B)impacted the regulatory process and was a violation of NRC requirements. The violation was processed using traditional enforcement and determined to be a Severity Level IV violation consistent with NRC's Enforcement Policy section 6.9.d.9, Inaccurate and Incomplete Information or Failure to Make a Required Report.

Violation: 10 CFR 50.73(a)(2)(i)(B) requires in part that the holder of an operating license shall submit an LER within 60 days of discovery of the event, which includes any operation or condition which was prohibited by TSs.

Millstone Unit 2 TS 3.7.1.1 LCO requires, All main steam line code safety valves shall be operable with lift settings as specified in Table 4.7-1. With one or more main steam line code safety valves per steam generator inoperable, the TS Condition 3.7.1.1.a Required Action is to reduce thermal power within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to less than or equal to the applicable percent of rated thermal power listed in Table 3.7-1, and reduce the power level-high trip setpoint in accordance with Table 3.7-1 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Otherwise be in hot standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and hot shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

Contrary to the above, the licensee failed to submit an LER within 60 days from discovery of an existing but previously unrecognized condition prohibited by the plants TSs. Specifically, the licensee failed to recognize that two main steam safety relief valves that failed as-found set pressure testing on April 22, 2020, represented a condition that existed for a time longer than permitted by the TS, and was reportable under 10 CFR Part 50.73.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Minor Violation 71153 Minor Violation: On January 15, 2020, with Millstone Unit 3 operating in Mode 1 at 100 percent power, while performing TS surveillance SP 3673.6-001, Accident Monitoring Instrumentation, auxiliary feedwater flow indication to the 'B' steam generator on computer point 3FWA-F51 B3 indicated 118 gpm while all other channels indicated approximately 12 gpm with no auxiliary feedwater pumps operating. The licensee entered TS 3.3.3.6 Action a.

at 8:00 p.m. on January 15, 2020, for an inoperable accident monitoring instrumentation channel.

Millstone Unit 3 TS 3.3.3.6, Accident Monitoring Instrumentation, requires that while the plant is in Modes 1, 2, or 3, the accident monitoring instrumentation channels shown in Table 3.3-10 shall be OPERABLE. The TS ACTION Statement 'a' requires that, "With the number of OPERABLE accident monitoring instrumentation channels except the containment area high range radiation monitor, and reactor vessel water level, less than the Total Number of Channels shown in Table 3.3-10, restore the inoperable channel(s) to OPERABLE status within 7 days, or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in at least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />." Table 3.3-10 instrument number 11, auxiliary feedwater flow rate, specifies 2 as the total number of channels per generator.

Investigation of the flow transmitter, 3FWA*FT51 B, showed the "As Found" calibration to be outside of its allowable range. After the successful calibration of 3FWA*FT51B, the flow indication was returned to operable status and operations exited TS Action 3.3.3.6 a. at 8:40 p.m. on January 16, 2020. The licensee determined that the transmitter experienced a zero shift in its calibration. The redundant channel of auxiliary feedwater flow indication to the

'B' steam generator remained operable. The inspectors verified that the flow transmitter was previously calibrated on April 16, 2019, and licensee procedures require that it's calibration be verified once every 18 months.

The licensee performed a historical operability determination review, and determined by trending 3FWA-F51 B3 that the elevated indicated flow began on January 4, 2020, at 8:23 p.m. Therefore, the channel was inoperable for approximately 11 days, which is longer than the 7 days allowed by TS 3.3.3.6. The licensee noted that the increased indication occurred during venting the auxiliary feedwater containment header to the 'B' steam generator to seat a check valve.

The inspectors reviewed previous surveillance test results and noted that this instrument passed its surveillance test on December 11, 2019. The surveillance test frequency is monthly.

The inspectors determined that the out of calibration condition was not the result of the licensees failure to meet a requirement or standard. Moreover, the inspectors determined that this out of calibration condition was not reasonably within the licensees ability to foresee and correct. Therefore, the inspectors determined that the issue was not a performance deficiency.

Screening: The NRC Enforcement Policy, Section 2.2.1 states, in part, that, whenever possible, the NRC uses risk information in assessing the safety significance of violations. The inspectors determined that this violation is of minor significance because 1) it could not reasonably be viewed as a precursor to a significant event, 2) if left uncorrected, it would not have the potential to lead to a more significant safety concern, 3) was not associated with one of the cornerstone attributes and did not adversely affect the mitigating systems cornerstone objective, and 4) was not similar to one of the examples in Section 6.1, Violation Examples for Reactor Operations, of the NRC Enforcement Policy (i.e., it was less significant that a severity level IV violation).

Enforcement:

This failure to comply with TS 3.3.3.6 constitutes a minor violation that is not subject to enforcement action in accordance with the NRCs Enforcement Policy.

EXIT MEETINGS AND DEBRIEFS

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

  • On May 7, 2020, the inspectors presented the RP Inspection Debrief - Rad Hazard Assess Exposure Controls inspection results to John Daugherty, Site Vice President and other members of the licensee staff.
  • On May 12, 2020, the inspectors presented the remote ISI inspection results to John Daugherty, Site Vice President, and other members of the licensee staff.
  • On June 4, 2020, the inspectors presented the Unit 3 'A' 125 volt DC Battery Locked in Ground Issues inspection results to Daniel C Beachy, Millstone Station Licensing and other members of the licensee staff.
  • On June 11, 2020, the inspectors presented the Unit 2 Engineered Safety Features Actuation System circuitry following an identified high resistance connection on Actuation Cabinet 6 inspection results to Daniel Beachy and other members of the licensee staff.
  • On July 23, 2020, the inspectors presented the integrated inspection results to John Daugherty, Site Vice President and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.04 Drawings 12179-EM-112C Low Pressure Safety Injection / Containment Re-circulation.

203-26014, SH Reactor Coolant System Revision 41

203-26023, SH Spent Fuel Cooling and Cleanup Revision 18

71111.05 Procedures MP-PROC-ENG- Containment C-1 Fire Zone Maps Revision 1

U2-24-FFS-

BAP01-CONT-

MAP

71111.08P Corrective Action 1146198

Documents

71111.12 Engineering AWA-DOM-2020- Advanced Work Authorization for Design Change MP2-20- 05/02/2020

Changes 0046 10192

PTE Commercial Grade Item Evaluation 05/02/2020

10000056651

Engineering MP-ETE-000- Reuse of previously installed MP2 ICI Grayloc seal rings Revision 0

Evaluations ETE-MP-2020-

1053

71111.13 Miscellaneous Shutdown Risk Contingency Plan Replacement of 2-SW-97B 03/09/2020

Shutdown Risk Contingency Plan Actuator work on 2-RB-211D 03/07/2020

and 2-RB-251B

Procedures MP-PROC-000- Operational Risk Assessment

WM-AA-301

71111.15 Corrective Action 1144101

Documents

Corrective Action CR 1151746

Documents

Resulting from

Inspection

Engineering ETE-MP-2020- Engineering Technical Evaluation for Unit 3 'A' Service Water Revision 0

Evaluations 1030 Blowdown Line

ETE-MP-2020- ETE To Address CR1147900 P43B. "B" Containment Spray Revision 0

Inspection Type Designation Description or Title Revision or

Procedure Date

1047 Pump PPV Surveillance Test

71111.18 Corrective Action 1145202

Documents

Engineering MP2-20-01087 MOVs 2-SI-615, 2-SI-625, 2-SI-635, &. 2-SI-645 Need to be Revision 0

Changes Re-Geared to Increase Margin

71111.19 Procedures MP-20-WP- Pre and Post Maintenance Testing Revision 014

GDL40

71111.22 Miscellaneous SP 2605P 2-SI-460 Leak Rate IST 03/16/2016

Procedures MP-PROC-OPS- Containment Leak Test, Type C Revision 022

SP 2605D

MP-PROC-OPS- Integrated System Test of Facility 2 Components Revision 021

SP 2613H

71124.01 Corrective Action 1107907 10/17/2018

Documents 1142898 03/10/2020

71152 Corrective Action 1115549

Documents 1117153

1117646

21588

22576

24010

26112

26460

29712

1132554

1132845

1138325

1138358

1138383

1140539

1141646

22670

27012

CA7693354

CA7693355

Inspection Type Designation Description or Title Revision or

Procedure Date

CA7807222

CA7831977

CA7831980

CR1126559

CR1139297

CR1139303

CR1146486

CR1146928

CR1146984

DSEM

PIR1150875

Engineering PI-AA-300-3007 - Level of Effort Evaluation - EDG Outage Duration Exceeds 12/18/2019

Evaluations Attachment 1 Planned AOT

Miscellaneous Millstone Power Station Emergency Diesel Generators Revision 02

Excellence Plan

Train A Pressurizer Steam Space Vent Path and PORV Stroke 05/11/2019

Time Operability.

Train A Pressurizer Steam Space Vent Path and PORV Stroke 12/21/2019

Time Operability.

1138383 Operation Decision Making 02/03/2020

MP-VTM-000- Installation, Operation and maintenance of 200 Amp Battery Revision 3

212-260-002 Chargers

SO-20-001 Operations Standing Oder for the Battery 1 Ground on 01/03/2020

3RCS*PCV455A (A PZR PORV).

Procedures AOP3551 Abnormal Operating Procedure, DC Bus Ground Revision 005

MA-AA-102 Foreign Material Exclusion Revision 23

MA-AA-103 Conduct of Troubleshooting Revision 16

OP-AAA-102 Operability Determination Revision 15

PI-AA-200 Corrective Action Revision 35

Work Orders 53203246458

203248397

203250689

203250391

203256049

Inspection Type Designation Description or Title Revision or

Procedure Date

203256050

203256051

203256052

203259993

203257432

203243138

203262235

203262236

203251249

71153 Corrective Action 1012549

Documents 1144097

1144320

1144638 04/10/2020

1148174 05/23/2020

7812229

7899468 Post Trip Report for April 1, 2020 Unit 3 Reactor Trip 04/09/2020

7899473 Prompt Issue Review Team Report for Millstone Power Station 04/09/2020

Unit 3 Automatic Reactor Trip Due to 15G3U Generator

Ground Fault

8088550

Miscellaneous OP-AP-105 Post Millstone Power Station Unit 3 Trip 06/06/2020

Trip Review

Report

2

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