IR 05000336/2022004

Integrated Inspection Report 05000336/2022004 and 05000423/2022004

ML23044A029
Person / Time
Site:	Millstone
Issue date:	02/13/2023
From:	Matt Young NRC/RGN-I/DORS
To:	Stoddard D Dominion Energy
References
IR 2022004
Download: ML23044A029 (1)

Text

February 13, 2023

SUBJECT:

MILLSTONE POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000336/2022004 AND 05000423/2022004

Dear Daniel Stoddard:

On December 31, 2022, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3. On February 2, 2023, the NRC inspectors discussed the results of this inspection with Michael OConnor, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.

One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.

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

Document Control Desk, Washington, DC 20555- 0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement; and the NRC Resident Inspector at Millstone Power Station, Units 2 and 3.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555 -0001; with copies to the Regional Administrator, Region I; 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, Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety

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: 05000336/2022004 and 05000423/2022004

Enterprise Identifier: I-2022-004- 0037

Licensee: Dominion Energy Nuclear Connecticut, Inc.

Facility: Millstone Power Station, Units 2 and 3

Location: P.O. Box 128 Waterford, CT 06385

Inspection Dates: October 1, 2022, to December 31, 2022

Inspectors: J. Fuller, Senior Resident Inspector E. Allen, Resident Inspector E. Bousquet, Resident Inspector J. DeBoer, Senior Project Engineer B. Dyke, Operations Engineer N. Eckhoff, Health Physicist B. Fuller, Senior Operations Engineer P. Ott, Operations Engineer S. Wilson, Senior Health Physicist

Approved By: Matt R. Young, Chief Projects Branch 2 Division of Operating Reactor Safety

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 Identify Corrosion of Safety-Related Service Water Piping Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.11 ] - 71111. 06 Systems NCV 05000423/2022004 - 01 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations ( 10 CFR) Part 50, Appendix B, Criterion XVI, Corrective Action," when the licensee failed to assure that conditions adverse to quality were promptly identified and corrected. Specifically, the licensee did not effectively implement its corrective action program procedure, PI-AA-200, Corrective Action, when it failed to investigate the impact of a known service water leak from the flange of 'A' train engineered safety features (ESF) building air conditioning unit supply check valve, 3SWP*V705, and did not correct the leakage in a timely manner. This leakage caused external corrosion of the safety-related service water piping to the point that the size of the slip -on flange fillet weld w as less than the American Society of Mechanical Engineers (ASME) Code requirements.

Additional Tracking Items

None.

PLANT STATUS

Both Units 2 and 3 operated at or near rated thermal power for the entire inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, conducted routine reviews using IP 71152, Problem Identification and Resolution, observed risk -significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

71111.01 - Adverse Weather Protection

Seasonal Extreme Weather (IP Section 03.01) (2 Samples)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the Unit 3 primary makeup water external to the auxiliary building and main feedwater in the main steam valve building on November 30, 2022.

(2) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the Unit 2 fire water storage tanks and diesel fuel oil storage tank (T-148) on December 19, 2022.

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

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe winter weather (high winds, possible local intense precipitation event, and freezing temperatures) on December 22, 2022

71111.04 - Equipment Alignment

Partial Walkdown (IP Section 03.01) (3 Samples)

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

(1) Unit 3 fire protection low pressure carbon dioxide system on October 18, 2022

(2) Unit 2 turbine driven auxiliary feedwater pump steam supply on October 26, 2022

(3) Unit 2 service water to vital alternating current (AC) switchgear cooling coil and AC chillers on November 7, 2022

71111.05 - Fire Protection

Fire Area Walkdown and Inspection (IP Section 03.01) (8 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 3 hydrogen recombiner building, including recombiner cubicles on the 24'-6" elevation, sampling room on the 24'-6" elevation, and heating/ventilation/air conditioning room on the 37'-6" elevation (fire area HR-1) on October 12, 2022

(2) Unit 2 health physics access/control area on the 14'-6" elevation (fire area A-19A) on October 14, 2022

(3) Unit 3 east switchgear area on the 4'-6" elevation (fire area CB-2) due to failed smoke detector on October 14, 2022

(4) Unit 2 boric acid evaporator and tanks on the 5'-6" elevation (fire area A-1I) on October 19, 2022

(5) Unit 3 liquid waste floor area (Penthouse) on the 68'-0" elevation (fire area WDB-1A)and solid waste disposal - truck bay/waste transportation area on the 24'-6" elevation (fire area WDB-1B) on November 17, 2022

(6) Unit 2 storage area (former snubber repair shop) on the 14'-6" elevation (fire area A-18) on November 30, 2022

(7) Unit 3 turbine building basement floor area/condenser pit on the 14'-6" elevation (fire area TB-2A) on December 16, 2022

(8) Unit 2 hallway storage area hot tool crib area on the 38'-6" elevation (fire area A-19B)on December 20, 2022

71111.06 - Flood Protection Measures

Inspection Activities - Internal Flooding (IP Section 03.01) (1 Sample)

The inspectors evaluated internal flooding mitigation protections in the:

(1) Unit 3 ESF building on the 4'-6" elevation (area ESF-5X) on November 17, 2022

71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance

Requalification Examination Results (IP Section 03.03) (2 Samples)

(1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered in November and December 2022.

(2) The inspectors reviewed and evaluated the Unit 3 licensed operator requalification exam results for the annual operating exam and biennial written exam on December 19, 2022.

71111.11B - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Requalification Program (IP Section 03.04) (1 Sample)

(1) Biennial Requalification Written Examinations

The inspectors evaluated the quality of the licensed operator biennial requalification written examination administered in November 2022.

Annual Requalification Operating Tests

The inspectors evaluated the adequacy of the facility licensees annual requalification operating test.

Administration of an Annual Requalification Operating Test

The inspectors evaluated the effectiveness of the facility licensee in administering requalification operating tests required by 10 CFR 55.59(a)(2) and that the facility licensee is effectively evaluating their licensed operators for mastery of training objectives.

Requalification Examination Security

The inspectors evaluated the ability of the facility licensee to safeguard examination material, such that the examination is not compromised.

Remedial Training and Re-examinations

The inspectors evaluated the effectiveness of remedial training conducted by the licensee, and reviewed the adequacy of re-examinations for licensed operators who did not pass a required requalification examination.

Operator License Conditions

The inspectors evaluated the licensees program for ensuring that licensed operators meet the conditions of their licenses.

Control Room Simulator

The inspectors evaluated the adequacy of the facility licensees control room simulator in modeling the actual plant and for meeting the requirements contained in 10 CFR 55.46.

Problem Identification and Resolution

The inspectors evaluated the licensees ability to identify and resolve problems associated with licensed operator performance.

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 3 control room during the 'D' feed regulator valve positioner replacement following reactor down power on October 26, 2022.

(2) The inspectors observed and evaluated licensed operator performance in the Unit 2 control room during surveillance testing, shift rounds, and shift turnover on December 21 and 30, 2022

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

(1) The inspectors observed and evaluated operator performance in the Unit 2 simulator involving emergency operating procedures and an emergency declaration on October 4, 2022.

(2) The inspectors observed and evaluated operator performance of job performance measures in Unit 3 as part of in-plant exam on November 15, 2022.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (2 Samples)

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

(1) Unit 3 containment recirculation cubicle level alarm switch failures on May 24, 2021 (CR1173666), and June 8, 2021 (CR1174770), and associated maintenance rule action plan

(2) Unit 3 ESF self-contained air conditioning unit (3HVQ*ACUS1A) failure on August 31, 2022 (CR1206829 and CR1206901)

Aging Management (IP Section 03.03) (1 Sample)

The inspectors evaluated the effectiveness of the aging management program for the following SSCs that did not meet their inspection or test acceptance criteria:

(1) Unit 2 seismic category I concrete intake structure priority 2 tier 3 concrete degradation identification and repair on November 28, 2022 (CR1143683)

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management (IP Section 03.01) (7 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 3 risk mitigating actions after 3C circulating water pump motor failure and spurious trip of the 3A screen wash pump on October 2, 2022

(2) Units 2 and 3 risk mitigating actions after the 'A' and 'B' fire water storage tanks were declared non-functional on October 3, 2022

(3) Unit 2 risk assessment and mitigating actions for inverter 5, which was not operable due to out of sync conditions on October 26, 2022

(4) Units 2 and 3 elevated risk during emergent switchyard work on November 9, 2022

(5) Unit 2 yellow risk associated with 'A' and 'B' service water pump configuration that prevented facility Z1 to automatically sequence following a loss of normal power, while 'A' auxiliary feedwater pump and 'A' circulating water bay were out of service for planned maintenance on November 30, 2022

(6) Unit 3 performance of SP 3623.1, Turbine Generator Testing, with a degraded #2 auxiliary speed signal on December 19, 2022

(7) Unit 3 risk assessment and associated mitigating actions associated with protection set cabinet III operational test and verification of 'B' train protected equipment on December 29, 2022

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)

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

(1) Unit 2 functionality assessment of both the 'A' and 'B' fire water storage tanks on October 4, 2022 (CR1208954 and CR12093330)

(2) Unit 3 'A' train of emergency core cooling system operability determination after gas voids were identified along the horizontal run of residual heat removal piping on October 6, 2022 (CR1210351, CR1210313, and CR1209700)

(3) Unit 2 operability determination of the reactor building closed cooling water system increased leakage during maintenance on the 'A' reactor building closed cooling water pump on October 18, 2022 (CR1210235)

(4) Unit 3 structural integrity evaluation for 'A' train of service water header piping and slip-on flange fillet weld on December 7, 2022 (CR1214610)

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)

The inspectors evaluated the following temporary or permanent modifications:

(1) Unit 2 permanent procedural modifications associated with the Flood Hazard Focused Evaluation and Integrated Assessment on December 19, 2022 (MP-DC-000-MP2-21-01025)

(2) Permanent change to the Unit 3 Technical Requirement Manual 3.3.3.8 for the loose-part detection system (MPS3-EVAL-2018-0005)

71111.19 - Post-Maintenance Testing

Post-Maintenance Test (IP Section 03.01) (4 Samples)

The inspectors evaluated the following post-maintenance testing activities to verify system operability and/or functionality:

(1) Unit 3 cycling the breaker and observing start of auxiliary building exhaust fan 6B on the auxiliary building ventilation system following the replacement of a control relay on October 26, 2022 (WO53102792904)

(2) Unit 3 'D' steam generator feedwater regulating valve cycle following the replacement of valve positioner on October 26, 2022 (WO53203358337 and WO53203359897)

(3) Unit 2 'A' reactor building closed cooling water pump test following the replacement of the pump oil seal on October 27, 2022 (WO53203365145)

(4) Unit 2 'A' emergency diesel generator operability test (Fast Start, Loaded Run)following the replacement of the flexible coupling on November 3, 2022 (WO53203357809)

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance testing activities to verify system operability and/or functionality:

Surveillance Tests (other) (IP Section 03.01) (3 Samples)

(1) Unit 2 'A' emergency diesel generator fast start operability test on October 5, 2022

(2) Unit 3 'B' emergency diesel generator operability test on October 25, 2022

(3) Unit 3 weekly turbine generator testing on December 19, 2022

Inservice Testing (IP Section 03.01) (1 Sample)

(1) Unit 2 turbine driven auxiliary feedwater pump operational readiness and quarterly inservice test on October 26, 2022 (WO53203346364)

71124.04 - Occupational Dose Assessment

Internal Dosimetry (IP Section 03.03) (1 Sample)

The inspectors evaluated the following internal dose assessments:

(1) Individual (committed effective dose equivalent) assessment; procedure number RP-AA-151; assessment number RP-22-09, dated June 3,

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification

The inspectors verified licensee performance indicators submittals listed below:

OR01: Occupational Exposure Control Effectiveness (IP Section 02.15) (1 Sample)

(1) October 1, 2021, through September 30, 2022

PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences Radiological Effluent Occurrences (IP Section 02.16)

=

(1) October 1, 2021, through September 30, 2022

71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends in emergency diesel equipment performance and reliability that might be indicative of a more significant safety concern.

(2) The inspectors reviewed the licensees corrective action program for potential adverse trends in the implementation of the licensees radiation protection program that might be indicative of a more significant safety issue.

INSPECTION RESULTS

Failure to Identify Corrosion of Safety-Related Service Water Piping Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.11 ] - 71111.

Systems NCV 05000423/2022004 - 01 Challenge the Open/Closed Unknown The inspectors identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action," when the licensee failed to assure that conditions adverse to quality were promptly identified and corrected.

Specifically, the licensee did not effectively implement its corrective action program procedure, PI-AA-200, Corrective Action, when it failed to investigate the impact of a known service water leak from the flange of ' A' train ESF building air conditioning unit supply check valve, 3SWP*V705, and did not correct the leakage in a timely manner. This leakage caused external corrosion of the safety - related service water piping to the point that the size of the slip - on flange fillet weld was less than the ASME Code requirements.

Description:

On November 17, 2022, during a walkdown of the ESF building, the inspectors observed that a known service water leak from the flange of 'A' t rain ESF building air conditioning unit supply check valve, 3SWP*V705, was dripping onto the 26-inch 'A' train service water supply piping (3 - SWP- 026 - 66-3). The leak from 3SWP*V705 was previously documented in the corrective action program as CR1205520, which was initiated on August 12, 2022. This condition report was closed to the work management process (WO53203361476) to replace the check valve during a future refueling outage. The service water for Unit 3 is from Long Island Sound, which can be corrosive to susceptible carbon steel piping.

The inspectors reviewed CR1205520 and noted that the licensee states that the ESF air conditioning unit check valve was leaking onto the service water pipe below; however, the condition report incorrectly stated that the condition did not impact the 'A' train of service water. Based on this condition, the inspectors performed a walkdown and observed that the insulation surrounding pipe 3-SWP-026-66-3 had trapped the leakage from 3SWP*V705, and the condition of this pipe spool was not apparent with the insulation installed. In response to the NRC questions, the licensee removed the insulation and noted excessive corrosion of the piping and adjacent fillet weld between the pipe spool and the slip-on flange. The licensee took prompt action to clean the pipe and slip-on flange weld, perform ultrasonic thickness measurements of the pipe spool base metal, and conduct a visual inspection of the fillet weld.

Through performance of these inspections, the licensee determined that the pipe wall had been reduced in several locations to approximately 75 percent of the nominal wall thickness but remained above the code minimum wall thickness. However, the fillet weld between the slip-on flange and the pipe spool had corroded to a point, that in several locations, the weld did not meet the ASME C ode requirements.

The service water system provides cooling water for heat removal from the reactor plant auxiliary systems during all modes of operation and from the turbine plant auxiliary systems during normal operation. This portion of the service water system is safety-related and seismic category I. This portion of the service water system operates in support of ESF systems acting to mitigate the consequences of accidents and are designed in accordance with ASME Section III, 1971 edition, up to and including the summer 1973 addenda.

Because the weld was noncompliant with the Code, the licensee entered Technical Requirement 3.4.10, Structural Integrity - ASME Code Class 1, 2, 3 Components, on December 6, 2022. On December 7, 2022, the licensee completed a structural integrity evaluation that was documented in engineering technical evaluation ETE-MP-2022-1097.

Therefore, the licensee determined that structural integrity was maintained, and the 'A' train of service water was OPERABLE. The inspectors reviewed this engineering technical evaluation and associated operability determination and did not identify any concerns with the licensees methodology.

Step 3.1.7 of PI-AA-200, Corrective Action, states PROVIDE sufficient information to ensure that the deviating condition can be understood by subsequent reviewers. See Attachment 3.

The inspectors noted that Attachment 3, Guidelines for Condition Report Submittal, states that the condition report needs to contain the consequence, potential consequence, and risk associated with the deviating condition in a plant impact statement

The inspectors determined that the licensee did not implement Step 3.1.7 of PI-AA-200 when it incorrectly stated in the plant impact statement that the leak from check valve 3SWP*V705 did not adversely impact the 'A' train of service water. The impact from the leakage was not known at the time CR1205520 was written. Moreover, the condition report was closed to a work order to repair the leaking check valve. No corrective action was created to investigate the impact of the leak onto the service water piping below.

Corrective Actions: The licensee entered this issue in its corrective action program as CR1214610 and CR1213254 and created corrective action assignments to restore the fillet weld profile to code required minimum at the next available opportunity when the pipe is out of service (i.e., 'A' train service water scheduled refueling outage). In the interim, the licensee will coat the service water pipe to protect it from further corrosion.

Corrective Action References: CR1214610; CR1213254

Performance Assessment:

Performance Deficiency: The licensee did not implement step 3.1.7 of procedure PI-AA-200, Corrective Action, when the plant impact statement in CR1205520 incorrectly stated that the leak from check valve 3SWP*V705 did not adversely impact the 'A' train of service water. As a result, the impact on the service water piping from the leakage from 3SWP*V705, a condition adverse to quality, was not identified and corrected in a timely manner.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the as-found condition of the weld did not meet the current licensing basis (ASME Code), which resulted in reasonable doubt about the equipments seismic qualifications, which reduced assurance in the equipments availability and reliability. As described by Example 3.e in IMC 0612, Appendix E, regardless of the conclusion of the operability determination, there was reasonable doubt about the seismic qualification because the licensee used a different calculation to determine minimum fillet weld size because the original approach resulted in a nonconforming weld and the licensees design process would not have accepted a weld to be noncompliant with the ASME C ode.

Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process for Findings At-Power. The finding is a deficiency affecting the qualification of a mitigating SSC, but the SSC maintained its operability and probabilisti c risk assessment functionality; therefore, it screens to Green.

Cross-Cutting Aspect: H.11 - Challenge the Unknown: Individuals stop when faced with uncertain conditions. Risks are evaluated and managed before proceeding. Specifically, CR1205520 clearly stated that valve 3SWP*V705 was leaking onto the service water piping below; however, the licensee did not investigate the impact of this leakage.

Enforcement:

Violation: 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected.

Contrary to the above, from August 12 to November 17, 2022, the licensee did not assure that a condition adverse to quality was promptly identified and corrected. Specifically, the licensee did not identify corrosion on the Unit 3 service water supply piping to the ESF building, which resulted in the outside diameter slip-on flange fillet weld legs and throat size to be less than the ASME C ode requirements.

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

Observation: Emergency Diesel Equipment Performance and Reliability 71152S Semiannual Trend Review The inspectors reviewed the licensees corrective action program for trends that might be indicative of more significant safety issues with regards to emergency diesel equipment performance and reliability. The inspectors reviewed condition reports, evaluations, system health reports, performed system walkdowns, and interviewed responsible system engineers.

In particular, the inspectors evaluated the condition reports generated over approximately the past 2 years to identify any negative trends in equipment and human performance, as well as problem identification and resolution. The inspectors determined that the issues were evaluated by the licensee at a low threshold and resolved within the scope of the corrective action program.

The inspectors noted two trends while reviewing condition reports during this period. The first is an adverse trend associated with the Unit 2 'A' and 'B' emergency diesel generators lube oil consumption. The inspectors challenged the licensee regarding the high number of condition reports that documented low lube oil levels and the need to add oil to the engines with short frequencies between oil additions. The inspectors questioned why this was not being trended or evaluated outside of the corrective action process when it is being recommended by the vendor technical manual. The second is an adverse trend associated with emergency diesel engine trips within the past year. The inspectors noted that the Unit 3 'A' and 'B' emergency diesel generators, the Unit 2 'A' emergency diesel generator, and the station blackout generator have all tripped within the past year. All of the trips dealt with an overspeed trip mechanism with the exception of the station blackout trip which was due to an electrical fault.

The inspectors determined that the licensee had appropriately entered the trips into the corrective action program and evaluated the identified conditions for significance and resolution. The inspectors had previously reviewed each of these instances of diesel generator trips and determined that each trip was not the result of a performance deficiency or the performance deficiency was not more than minor in accordance with IMC 0612.

However, the inspectors observed that the license had not evaluated these trips as a collective or as part of a larger trend review.

No findings of significance were identified as a result of this inspection.

Observation: Radiation Protection Program Implementation Semiannual Trend 71152S Review The inspectors reviewed the licensees response to occupational radiation protection program implementation performance deficiencies that occurred between January 1, 2020, and November 1, 2022. The inspection involved a review of the licensee s corrective action program reports, causal evaluations, radiation work permits, as-low-as-reasonably-achievable plans, extent of condition reviews, self-assessments, and corrective actions.

The inspectors observed that multiple issues were identified and documented by the licensee in its corrective action program within the inspection timeframe. Examples of the issues reviewed by the licensee included: workers not following radiation work permit or radiological briefing instructions, unanticipated skin contamination received by workers, unplanned minor internal contamination (committed effective dose equivalent) received by workers, unanticipated dose rate alarms on personal dosimeters, failure to properly survey, procedural errors, and a sample of contaminated water removed from the site without proper authorization. The inspectors reviewed these issues separately during the conduct of routine inspections using NRCs Enforcement Policy and, where appropriate, were documented in Millstone Power Station, Units 2 and 3 - Integrated Inspection Report 05000336/2021003 and 05000423/2021003, Agencywide Documents Access and Management System Accession No. ML21316A028.

The remaining issues were determined to be not more than minor performance deficiencies or observations and were not documented in inspection reports. In accordance with IMC 0611, Power Reactor Inspection Reports, minor performance deficiencies are not routinely documented in inspection reports.

Based on the examples above and other observations by the licensee, performance improvement plans were developed and implemented for training program effectiveness, to address lapses in radiation worker performance regarding radiation work permit compliance, worker briefs, requirements to enter radiologically controlled areas, and to increase management oversight and communications with radiation protection staff as well as other radiation workers.

The inspectors reviewed the licensees assessments and found that the licensee identified gaps in training, procedural guidance, and management oversight associated with radiation protection related activities. This was identified as a station-wide and cross-discipline issue, and management has taken comprehensive corrective actions to improve performance in this area. Since the implementation of the licensee s corrective actions, no repeat radiation protection issues have been identified.

Examples of the corrective actions taken and planned included improved communications, benchmarking with other sites, standards and procedure reviews, improvements in leadership mentoring and oversight, innovative knowledge drills between technicians, workers and supervision, operating experience communications to all station employees, and procedure revisions.

Based on the overall results of the semiannual trend review, the inspectors determined that the licensee had identified radiation protection program issues and potential trends before they could become more significant safety problems. The inspectors will continue to monitor the radiation protection effectiveness during future routine inspection activities.

EXIT MEETINGS AND DEBRIEFS

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

• On October 27, 2022, the inspectors presented the semiannual trend review on emergency diesel equipment performance inspection results to Phil Brant, Engineering, and other members of the licensee staff.

• On February 2, 2023, the inspectors presented the integrated inspection results to Michael OConnor, Site Vice President, and other members of the licensee staff.

THIRD PARTY REVIEWS

The inspectors reviewed Institute on Nuclear Power Operations reports that were issued during the inspection period.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action CR1209634

Documents CR1215417

Drawings 2512-26919 Primary Grade Water System, Sheet 1 Revision 34

DWG-1700116-Sheet 5

M-25203-26026-A

L-55 25203-Lighting Panel Schedule Panel Revision 11

35038

Procedures C OP 200.13 Seasonal Weather Operations Revision 20

MPG-17-00116 Fire Water Storage Tank Permanent Electric Heating Revision 4

OP 2268 Cold Weather Operation Revision 8

Work Orders 53203337400

71111.04 Corrective Action CR1165760

Documents CR1176969

CR1203155

CR1205132

CR1206269

CR1209063

CR1189273

CR1201827

Drawings 25203-26002 Main Steam from Generators, Sheet 1 Revision 88

203-26008 PI&D Service Water to Vital AC Switchgear Cooling Coil and Revision 34

AC Chillers, Sheet 3

212-26946 Piping and Instrumentation Diagram Fire Protection Revision 29

Miscellaneous TRM 3.7.12.3 Fire Protection Systems CO2 Systems 01/31/2011

Procedures SP 2610BO-003 Valve Remote Position Indication IST Revision 1

SP 3641C.1 Fire Protection CO2 Revision 5

SP 3641C.2 Functional Check of the CO2 Fire Protection System Revision 23

SP 3670.1-008 Plant Equipment Rounds - Outside Revision 33

71111.05 Calculations EPM Calc. No. Unit 2 Combustible Loading Re-Analysis Calculation Revision 2

186

Corrective Action CR1209234

Documents

Miscellaneous 2509-21-IS Fire Permit

Inspection Type Designation Description or Title Revision or

Procedure Date

203-SP-M2-MP2 Appendix R Compliance Report Revision 01

SU-1046

Procedures C OP 200.1 Fire Watch and Impairment Tracking Revision 4

ENG-U3-24-FFS-Control Building 4'6" Revision 1

BAP01-CB-MAP

ENG-U3-FFS-Unit 3 Fire Fighting Strategy Revision 3

BAP01-CB

MP-PROC-AOP Cooldown and Cold Shutdown, Appendix R Fire Area R-1 Revision 008

2579AA

MP-PROC-ENG-Index of Fire Areas Revision 3

U2-24-FFS-

BAP01-AB-14-38

MP-PROC-ENG-Aux Building Fire Strategy Map Revision 2

U2-24-FFS-

BAP01-AB-MAP

PROC-ENG-U2-Unit 2 Fire Fighting Strategy Revision 3

24-FFS-BAP01-

AB-14-38

SP 3641D.3 Fire Detection and Control System Operability Check Revision 31

SP 3641D.3-009 Fire Detection Zone Panel 4E Detector Operability Checks Revision 6

E & W Switchgear

Work Orders 53203365414

71111.11Q Corrective Action CR1211400

Documents

Miscellaneous MP2 LORP Evaluated Simulator Exam#: ES22501

Procedures OP-AA-100 Conduct of Operations Revision 45

OP-M3-MOP-SG Feedwater Control Valve Online Positioner Replacement Revision 2

FWS-001

Work Orders 53203358337

203359897

71111.12 Work Orders 53102841573

203264964

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.13 Corrective Action CR1211236

Documents

Miscellaneous Calculated Risk Assessment 11/30/2022

Procedures MA-AA-103 Trouble Shooting Sheet, Attachment 2 10/26/2022

Work Orders 53203366247

203366776

203368097

71111.15 Calculations MP-CALC-ENG-MP2 Reactor Building Cooling Water System Surge Tank

17-ENG-Sizing

04478M2

Corrective Action CR11471235

Documents

Miscellaneous MP-DC-000-MP2-Correction of RBCCW Surge Tank High Alarm Setpoint

14-01141

Procedures ETE-CME-2012-Determination of Allowable ECCS Gas Accumulation in Revision 1

1018 Support of Surveillance 4.5.2.b.1

ETE-MP-2022-Evaluation of the 'B' Fire Water Storage Tank for Continued Revision 0

1087 Functionality

ETE-MP-2022-Evaluation of the 'A' Fire Water Storage Tank for Continued Revision 0

1088 Functionality

OP-AA-102 Attachment 5 Operability Determination 10/13/2022

71111.18 Miscellaneous Licensing Basis Document Change Request Number 11/17/2010

07-MP3-018

MP 3704A-722A Watertight and Airtight Door Inspections

Procedures AOP 2560 Storms, High Winds, and Tides Revision 19-

AOP 3569 Severe Weather Conditions Revision 22

C-OP-200.6 Storms and Other Hazardous Phenomena (8, 10, 11) Revision 8

ETE-MP-2018-Millstone Power Station Unit 2 Local Probable Maximum Revision 0

1006 Precipitation Trigg

SP 3665.2 Intake Structure Condition Determination Revision 12

71111.19 Corrective Action CR1202655

Documents CR1203207

CR1209428

CR565006

Inspection Type Designation Description or Title Revision or

Procedure Date

Miscellaneous CBM 104 Vibration Data Acquisition and Overall Vibration Analysis Revision 4

Procedures MP 2703B5 Reactor Building Closed Cooling Water Pump Overhaul Revision 16

OP 2330A RBCCW System Revision 30

OP 2330A.12 'A' RBCCW Pump Maintenance Revision 3

OP-M3-MOP-SG Feedwater Control Valve Online Positioner Replacement Revision 2

FWS-001

SP 2611A 'A' RBCCW Pump Tests Revision 17

SP 2613A-001 Periodic DG Operability Test, Facility 1 (Fast Start, Loaded Revision 023

Run)

SP 3614A.1 Auxiliary Building Filter System Operability Test Revision 016

SP 3670.4 Routine PMs Revision 52

Work Orders 53102792904

203357809

203365626

71111.22 Corrective Action CR1185353

Documents CR1209586

CR1211400

Corrective Action CR1211221

Documents

Resulting from

Inspection

Drawings 25203-26002 Steam from Steam Generators, Sheet 1 Revision 90

203-26005 Condensate Storage and Auxiliary Feed, Sheet 3 Revision 60

Miscellaneous ODM 2-MS-4B Check Valve Chatter Revision 1

Procedures SP 2610BO TDAFP Tests, Operating Revision 011

SP 2613A Diesel Generator Operability Tests, Facility 1 Revision 28

SP 3623.1 Turbine Generator Testing (ICCE) Revision 34

SP 3646A.2 Emergency Diesel Generator B Operability Test Revision 033

Work Orders 53203346250

71152S Corrective Action CR1188862

Documents CR1198508

CR1203517

CR1203990

Inspection Type Designation Description or Title Revision or

Procedure Date

Corrective Action Notification RP Performance Deficiencies 2020; 2021

Documents Numbers

1146805 and

1137726

Corrective Action CR1211442

Documents CR1211444

Resulting from

Inspection

Self-Assessments RP Program MP-HPO-22027 09/30/2022

Annual Review

Report

18