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Integrated Inspection Report 05000336/2020003 and 05000423/2020003 and Independent Spent Fuel Storage Installation Inspection Report 07200047/2020001
	ML20307A080
Person / Time
Site:	Millstone
Issue date:	11/02/2020
From:	Daniel Schroeder; Reactor Projects Branch 2
To:	Stoddard D; Dominion Energy
	Schroeder D
References
	IR 2020001, IR 2020003
	Download: ML20307A080 (14)
	v • d • e

ber 2, 2020

SUBJECT:

MILLSTONE POWER STATION, UNITS 2 AND 3 - INTEGRATED INSPECTION REPORT 05000336/2020003 AND 05000423/2020003 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07200047/2020001

Dear Mr. Stoddard:

On September 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Millstone Power Station, Units 2 and 3. On October 14, 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.

No findings or violations of more than minor significance were identified during this inspection.

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, 05000423, and 07200047 License Nos. DPR-65 and NPF-49

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000336, 05000423, and 07200047 License Numbers: DPR-65 and NPF-49 Report Numbers: 05000336/2020003, 05000423/2020003, and 07200047/2020001 Enterprise Identifier: I-2020-003-0039 Licensee: Dominion Energy Nuclear Connecticut, Inc.

Facility: Millstone Power Station, Units 2 and 3 Location: Waterford, CT 06385 Inspection Dates: July 1, 2020 to September 30, 2020 Inspectors: J. Fuller, Senior Resident Inspector E. Allen, Resident Inspector C. Highley, Senior Resident Inspector S. Wilson, Senior Health Physicist J. Nicholson, 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 No findings or violations of more than minor significance were identified.

Additional Tracking Items None.

PLANT STATUS

Units 2 and 3 began the inspection period at rated thermal power. On August 4, 2020, both units down powered in response to degraded intake conditions during Tropical Storm Isaias.

Unit 2 reduced power to approximately 76 percent rated thermal power to reduce the differential pressure across both service water pump discharge strainers. Unit 2 returned to full rated thermal power on August 5, 2020, and remained at or near rated thermal power for the remainder of the inspection period. On August 4, 2020, Unit 3 reduced power to 43 percent rated thermal power due to increased fouling of the circulating water system during the tropical storm. Unit 3 returned to full rated thermal power on August 10, 2020, and remained at or near rated thermal power 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/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards. Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), resident and regional inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time the resident inspectors performed periodic site visits each week, increasing the amount of time on site as local COVID-19 conditions permitted. As part of their onsite activities, resident inspectors 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)

Main article: IP 71111.01

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather associated with Tropical Storm Isaias on August 4, 2020.

External Flooding Sample (IP Section 03.03) (1 Sample)

(1) The inspectors evaluated that flood protection barriers, mitigation plans, procedures, and equipment are consistent with the licensees design requirements and risk analysis assumptions for coping with external flooding for Tropical Storm Fay on July 10, 2020.

71111.04 - Equipment Alignment Partial Walkdown Sample (IP Section 03.01)

Main article: IP 71111.04

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

(1) Unit 2 'A' and 'C' reactor building component cooling water pumps and heat exchangers on August 13, 2020

(2) Unit 2 auxiliary feed water on September 3, 2020.

(3) Unit 3 boric acid train 'B' portions of the chemical and volume control system on July 8, 2020

(4) Unit 3 refueling water storage tank (quench spray system) supply to safety significant systems on July 10, 2020

71111.05 - Fire Protection Fire Area Walkdown and Inspection Sample (IP Section 03.01)

Main article: IP 71111.05

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 reactor building component cooling water pumps and heat exchanger area (Fire Area A-1B) on August 13, 2020

(2) Unit 2 waste tank pump and tank rooms (Fire Zones A-1C and A-1D) and auxiliary building general area (-45 foot elevation) (Fire Zone A-1A) on August 19, 2020

(3) Unit 2 maintenance storage crib (Fire Area A-9) on September 1, 2020

(4) Unit 3 auxiliary building east floor area on the 18 foot through 43 foot elevation, and the auxiliary building 43 foot elevation floor area (Fire Areas AB-1 zone C, and AB-1 zone E) on July 8, 2020.

(5) Unit 3 auxiliary building floor area on the 66 foot elevation, and the two supplementary leak collection filter banks (Fire Areas AB-1 zone F, AB-11, and AB-12) on July 9, 2020.

(6) Unit 3 auxiliary feed pump cubical south east floor area (Fire Area ESF-5) on September 17, 2020.

(7) Unit 3 north normal transformer and south normal transformer (Fire Areas XR-1 and XR-2) on September 22, 2020.

(8) Unit 2 and 3 fire pump houses on August 28, 2020 (FP-1 and 2)

71111.06 - Flood Protection Measures Inspection Activities - Internal Flooding (IP Section 03.01)

Main article: IP 71111.06

The inspectors evaluated internal flooding mitigation protections in the:

(1) Unit 3 southeast floor area/auxiliary feed pump cubicle (elevation 4 foot 6 inch and 24 foot 6 inch) on September 17, 2020

Cable Degradation (IP Section 03.02) (1 Sample)

The inspectors evaluated cable submergence protection in:

(1) Unit 2 manhole on September 9, 2020 (work order [WO] 53203264223), which is in-scope for maintenance rule and license renewal

71111.07A - Heat Sink Performance Annual Review (IP Section 03.01)

Main article: IP 71111.07A

The inspectors evaluated readiness and performance of:

(1) Unit 2 'B' reactor building closed cooling water heat exchanger (WO 53203259843)

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01)

Main article: IP 71111.11Q

(1) The inspectors observed and evaluated licensed operator performance in the Unit 2 control room during Tropical Storm Isaias on August 4, 2020. The inspectors observed operators respond to fouling of the service water strainers and a subsequent down power to approximately 76 percent rated thermal power.

(2) The inspectors observed and evaluated licensed operator performance in the Unit 3 control room in response to increased fouling of the main condenser during Tropical Storm Isaias on August 4, 2020. The inspectors observed control room operators perform several rapid power reductions and remove a main feedwater pump from service.

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

(1) The inspectors observed and evaluated operator performance in the Unit 2 simulator. They observed loss of a control element drive fan, single partially dropped rod, second dropped rod, rapid down power, reactor trip response, emergency diesel generator failure to start, failure to emergency borate due to loss of all charging pumps, recovery actions for reactivity, and emergency action level classification loss of fuel barrier on August 4, 2020.

(2) The inspectors observed and evaluated operator performance in the Unit 3 simulator. They observed failure of reactor coolant system temperature instrument, failure of a main steam system pressure transmitter, and loss of off-site power requiring emergency action level classification on September 22, 2020.

71111.12 - Maintenance Effectiveness Aging Management (IP Section 03.03)

Main article: IP 71111.12

The inspectors evaluated the effectiveness of the aging management program for the following structures, systems and components that did not meet their inspection or test acceptance criteria:

(1) On September 9, 2020, the inspectors reviewed Unit 2 Tan Delta testing results for 'C' phase of station blackout diesel to 4.16 kV normal switchgear (WO 53102821945 and condition report [CR] 572555), which was performed on May 8, 2020, and was a follow-up to the 2015 test that resulted in the "further study advised" criteria of the testing procedure.

71111.13 - Maintenance Risk Assessments and Emergent Work Control Risk Assessment and Management Sample (IP Section 03.01)

Main article: IP 71111.13

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 control element assembly (CEA) 46 normal power supply replacement at power high risk evolution for placing CEA 46 on the hold bus on July 9, 2020 (WO

===53203289747)

(2) Unit 2 emergent elevated risk during troubleshooting associated with the inadvertent opening of the atmospheric dump valve 2-MS-190B on July 17, 2020

(3) Unit 3 refueling outage risk plan on September 25, 2020

71111.15 - Operability Determinations and Functionality Assessments Operability Determination or Functionality Assessment (IP Section 03.01)

Main article: IP 71111.15

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

(1) Unit 2 inadvertent opening of the #2 atmospheric dump valve 2-MS-190B on July 13, 2020 (condition report [CR] 1151406)

(2) Unit 2 feedwater heater temperature instruments out of calibration and associated impact on calorimetric power on July 28, 2020 (CR 1152264)

(3) Unit 2 extent of condition and common mode failure evaluation of reactor protection system (RPS) channels A/C/D after failure of 'B' power range monitor power supply on July 30, 2020 (CRs 1152542, 1153180, 1153712)

(4) Unit 2 pressurizer girth and head to shell weld on August 18, 2020 (CR1131816 and CR1140019)

(5) Units 2 and 3 evaluation of degraded hydraulic fluid (batch SF1154) on operability of installed snubbers (CR 1148035 - 10 CFR Part 21 Lake engineering)

(6) Unit 3 service water pump 'C' (3SWP*P1C) with increase gland seal leakage on July 9, 2020 (CR1151216)

(7) Unit 3 operational decision-making checklist and evaluation of degraded 'A' reactor coolant pump seals (CR 1151659)

(8) Unit 3 functionality assessment and reasonable assurance of safety for the station blackout diesel upon identification of starting air system leak on August 30, 2020 (CR 1154399)

(9) Unit 3 technical specification missed inservice testing surveillance of residual heat removal and main steam system valves (3RHS*MV8701B, 3RHS*MV8702B &

(3MSS*MOV74A/B/C/D) on September 21, 2020 (CR 1150783)

71111.18 - Plant Modifications Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)

Main article: IP 71111.18

The inspectors evaluated the following temporary or permanent modifications:

(1) Unit 2 temporary modification on February 7, 2020 to 2CHW-14 for vital chill water review on September 14, 2020

71111.19 - Post-Maintenance Testing Post-Maintenance Test Sample (IP Section 03.01)

Main article: IP 71111.19

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

(1) Unit 2 control rod number 46 after replacement of normal power supply on July 9, 2020 (WO 53203289747)

(2) Unit 2 after replacement of the power supply (M2X-APPR-1) for fire shutdown panel (C09), which failed and caused the inadvertent opening of the #2 steam generator atmospheric dump valve on July 13, 2020 (WO 53203290067)

(3) Unit 2 SW 3.2A ('A' train service water inlet to 'A' turbine building component cooling water heat exchanger) replacement on August 24, 2020 (WO 53203270038)

(4) Unit 2 replacement of low and high voltage power supplies for the reactor protection system 'A' power range monitor drawer on September 9, 2020 (WO 53203292043)

(5) Unit 3 service water system operation after 'C' strainer (3SWP*STR1C) disassembly to correct rotational movement on July 13, 2020 (WO 53203289973)

==71111.20 - Refueling and Other Outage Activities Refueling/Other Outage Sample (IP Section 03.01) (1 Partial)

(1) (Partial)

The inspectors evaluated Unit 3 refueling outage (3R20) preparations during this quarter.

71111.22 - Surveillance Testing The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)==

Main article: IP 71111.20

(1) Unit 3 testing of the alternating current vital bus (34C) under voltage on July 9, 2020

(2) Unit 3 SP 3646A.5, Offsite Power Transfer Operability Test; review of the licensee's justification to credit the fast transfer from normal service station transformer to reserve station service transformer during the April 1, 2020 reactor trip for completion of this six year surveillance (WO 53102967284)

Inservice Testing (IP Section 03.01) ===

Main article: IP 53203

(1) Unit 3 boric acid transfer pump (3CHS*P2A) train 'A' on July 8, 2020

71114.06 - Drill Evaluation Drill/Training Evolution Observation (IP Section 03.02)

Main article: IP 71114.06

The inspectors evaluated:

(1) The inspectors observed the emergency action level determination during the Unit 2 simulator exam on August 4,

OTHER ACTIVITIES - BASELINE

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

MS05: Safety System Functional Failures (SSFFs) Sample (IP Section 02.04) ===

Main article: IP 71151