IR 05000220/2023002

Integrated Inspection Report 05000220/2023002 and 05000410/2023002

ML23212B063
Person / Time
Site:	Nine Mile Point
Issue date:	08/01/2023
From:	Erin Carfang NRC/RGN-I/DORS
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
References
IR 2023002
Download: ML23212B063 (1)

Text

August 1, 2023

SUBJECT:

NINE MILE POINT NUCLEAR STATION, UNITS 1 AND 2 - INTEGRATED INSPECTION REPORT 05000220/2023002 AND 05000410/2023002

Dear David Rhoades:

On June 30, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Nine Mile Point Nuclear Station. On July 13, 2023, the NRC inspectors discussed the results of this inspection with Peter Orphanos, 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, Digitally signed by Erin E.

Erin E. Carfang Date: 2023.08.01 Carfang 09:19:16 -04'00'

Erin E. Carfang, Chief Projects Branch 1 Division of Operating Reactor Safety Docket Nos. 05000220 and 05000410 License Nos. DPR-63 and NPF-69

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000220 and 05000410 License Numbers: DPR-63 and NPF-69 Report Numbers: 05000220/2023002 and 05000410/2023002 Enterprise Identifier: I-2023-002-0040 Licensee: Constellation Energy Generation, LLC Facility: Nine Mile Point Nuclear Station Location: Oswego, NY Inspection Dates: April 1, 2023 to June 30, 2023 Inspectors: G. Stock, Senior Resident Inspector C. Kline, Resident Inspector J. Lilliendahl, Senior Emergency Response Coordinator B. Sienel, Resident Inspector Approved By: Erin E. Carfang, Chief Projects Branch 1 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 Nine Mile Point Nuclear Station, 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

Unit 1 began the inspection period shut down for refueling. On April 18, 2023, the unit commenced startup. Shortly after achieving criticality, Unit 1 was shut down to repair a steam leak in the feed heater system. On April 19, 2023, repairs were complete and Unit 1 commenced startup and power ascension and achieved rated thermal power on April 23, 2023. The unit was downpowered to 85 percent on April 23, 2023 and April 25, 2023, for rod pattern adjustments and was returned to rated thermal power on April 24, 2023 and April 25, 2023, respectively. The unit remained at or near rated thermal power for the remainder of the inspection period.

Unit 2 commenced the quarter at rated thermal power. On May 19, 2023, the unit was downpowered to 62 percent for feed pump swap and rod pattern adjustment and was returned to rated thermal power on May 20, 2023. The unit 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 performed activities described in IMC 2515, Appendix D, Plant Status, 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) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal hot temperatures for the Unit 1 and Unit 2 125 volts direct current batteries.

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 2 Division I standby gas treatment system on May 3, 2023

(2) Unit 1 high pressure coolant injection function of feedwater system 12 on May 4, 2023

(3) Unit 2 reactor core isolation cooling system following maintenance on June 13, 2023

Complete Walkdown (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 2 service water system on June 26, 2023.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection (IP Section 03.01) (3 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 reactor core isolation cooling pump room, fire area 2, on June 7, 2023

(2) Unit 2 reactor building south auxiliary bay 175', fire area 3, on June 7, 2023

(3) Unit 2 high pressure core spray pump room, fire area 4, on June 7, 2023

71111.06 - Flood Protection Measures

Flooding (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated external flooding mitigation protections of the 10,000-year berm and revetment ditch on June 22, 2023

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of the:

(1) Unit 1 emergency condenser 111 heat exchanger, HTX-60-42

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 Unit 1 operations personnel during the reactor startup from refueling outage N1R27 on April 18, 2023.

(2) The inspectors observed Unit 2 operations personnel during a power reduction to approximately 62 percent for a control rod sequence exchange and feedwater pump swap on May 19 and 20, 2023.

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

(1) The inspectors observed a Unit 1 simulator evaluation that included the trip of a control rod drive pump, a reactor pressure regulator failure, a low power anticipated transient with a failure to scram, and an unisolable emergency cooling steam leak on May 5, 2023.

(2) The inspectors observed a Unit 2 simulator evaluation that included a seismic event, an inadvertent start of reactor core isolation cooling, a fuel failure requiring containment isolation, and an anticipated transient without scram on May 19, 2023.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

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

(1) Unit 2 Division I control room chiller

Quality Control (IP Section 03.02) (1 Sample)

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

(1) Commercial grade dedication of check valves and filters installed in the Unit 2 reference leg backfill system

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management (IP Section 03.01) (8 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 1 elevated risk during emergent work on offsite Line 3 for breaker repairs on April 25, 2023

(2) Unit 1 elevated risk during emergent work on emergency diesel generator 102 circulating oil pump on April 26, 2023

(3) Unit 1 elevated risk during scheduled high pressure coolant injection system feedwater pump 12 surveillances on May 1, 2023

(4) Unit 2 elevated risk during scheduled maintenance on Division II residual heat removal air conditioning unit on May 2, 2023

(5) Unit 1 elevated risk during scheduled liquid poison pump 12 breaker maintenance on May 10, 2023

(6) Unit 2 elevated risk during scheduled reactor core isolation cooling system maintenance on May 10, 2023

(7) Unit 2 elevated risk due to unexpected half main steam isolation signal during planned surveillance testing on May 30, 2023

(8) Unit 1 elevated risk during atmosphere to containment vacuum relief valve IV-68-06 actuator replacement on June 6, 2023

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)

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

(1) Unit 1 control rod drive flow controller due to failure of automatic control function on April 14, 2023

(2) Unit 1 IV-68-05 atmosphere to containment vacuum relief valve following failed stroke time testing on June 9, 2023

(3) Unit 2 reactor core isolation cooling system due to a leak on the keep fill line on June 21, 2023

(4) Unit 2 service water to residual heat removal crosstie, 2RHS*MOV116, packing leak affecting material condition on June 21, 2023

(5) Unit 2 Division II diesel generator due to a leak on the motor driven lube oil circulating pump on June 24, 2023

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (3 Samples)

The inspectors evaluated the following temporary or permanent modifications:

(1) Permanent Modification: ECP-20-000468, Installation of a Hydrogen Generation Unit

(2) Permanent Modification: ECP-21-000014, Unit 1 Modify Mounting Location and Power Supply for Feedwater Channel 12 Pressure Signal Isolator

(3) Permanent Modification: ECP-21-000057, Unit 1 Emergency Condenser Isolation Trip Filtering

71111.20 - Refueling and Other Outage Activities

Refueling/Other Outage (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated Unit 1 refueling outage 27 (N1R27) activities from April 1, 2023 to April 21, 2023.

71111.24 - Testing and Maintenance of Equipment Important to Risk

The inspectors evaluated the following testing and maintenance activities to verify system

operability and/or functionality: Post-Maintenance Testing (PMT) (IP Section 03.01)

(1) N1-ST-Q13, Emergency Service Water Pump and Check Valve Operability Test, following pump 11 replacement, on April 6, 2023

(2) N1-ST-R30, Reactor Pressure Vessel and American Society of Mechanical Engineers (ASME) Class 1 System Leakage Test, following refueling outage N1R27, on June 16, 2023

(3) N1-TSP-201-001, Integrated Leak Rate Test of Primary Containment Type A Test, following refueling outage N1R27, on June 22, 2023

Surveillance Testing (IP Section 03.01) (7 Samples)

(1) N1-ST-R12, Initiation of Emergency Condensers from the Remote Shutdown Panel, on April 14, 2023

(2) N1-ESP-001-130, Main Steam Isolation Valve 7 percent and 10 percent Limit Switch Test, on April 20, 2023

(3) N1-ST-R2A, loss of offsite power (LOOP) and emergency diesel generator (EDG) 102 Simulated Auto Initiation Test, on May 1, 2023

(4) N1-ST-R5, Primary Coolant Manual Isolation Signal Test, on May 9, 2023

(5) N1-ISP-066-003, Auto Depressurization System Operability Test, on May 25, 2023

(6) N1-ISP-036-004, Low-Low Reactor Level Instrument Trip Channel Test/Calibration, on May 31, 2023

(7) N2-OSP-EGS-R002, Operating Cycle Diesel Generator 24 Hour Run Division II, on

June 8, 2023 Inservice Testing (IST) (IP Section 03.01) (1 Sample)

(1) N1-ST-Q13, Emergency Service Water Pump and Check Valve Operability Test, on May 4, 2023

71114.06 - Drill Evaluation

Select Emergency Preparedness Drills and/or Training for Observation (IP Section 03.01)

(1 Sample)

The inspectors evaluated:

(1) Unit 1 simulator evaluation which included an unisolable steam leak requiring a reactor pressure vessel blowdown and the declaration of a Site Area Emergency on

May 5, 2023 Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) Unit 2 simulator evaluation that included a containment isolation and an anticipated transient without scram requiring an Alert declaration on May 19,

OTHER ACTIVITIES - BASELINE

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

BI01: Reactor Coolant System (RCS) Specific Activity (IP Section 02.10) ===

(1) Unit 1 (April 1, 2022 through March 31, 2023)

(2) Unit 2 (April 1, 2022 through March 31, 2023)

BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)

(1) Unit 1 (April 1, 2022 through March 31, 2023)

(2) Unit 2 (April 1, 2022 through March 31, 2023)

71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)

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

(1) IR 04506482 - Review of Corrective Actions to Address Marathon C+ Control Rod Blade Cracking Operating Experience

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

(1) The inspectors reviewed Constellation's corrective action program for potential adverse trends that might be indicative of a more significant safety issue.

INSPECTION RESULTS

Observation: Review of Corrective Actions to Address Marathon C+ Control Rod 71152A Blade Cracking Operating Experience The inspectors reviewed Constellations evaluation and corrective actions associated with operating experience related to Marathon C+ control blade cracking. In April 2022, Susquehanna Steam Electric Station observed control rod blades (CRBs) with absorber tube cracking. The CRB manufacturer, General Electric Hitachi (GEH), determined the physical mechanism for the CRB cracking was irradiation-assisted stress-corrosion cracking. Boron capsules inside the CRB swell over the lifetime of a blade due to high neutron radiation. Over time, the capsules can swell enough to come in contact with the absorber tube and can eventually lead to cracking. The safety concern with absorber tube cracking is the potential leaching and loss of boron carbide neutron absorber and a reduction in nuclear reactivity worth of the affected control rods, which can then lead to an overall reduction in the core shutdown margin, which is a Technical Specification (TS) required core operating parameter related to the ability to safely shutdown the reactor.

GEH issued a Safety Communication, SC 22-03, which reduced the lifetime limit for Marathon C+ style CRBs. By reducing the CRB lifetime, the boron capsule swelling is reduced, and cracking can be avoided. GEH incorporated these new limits in NEDE-30931P, "GEH BWR Control Rod Lifetime," Revision 20. Constellation revised NF-AB-135-1410, "BWR Control Blade Lifetime Management," Revision 17, to ensure Marathon C+ CRBs are replaced prior to exceeding the new lifetime limits.

At the time of the initial discovery, GEH determined that Marathon C+ CRBs were installed at Nine Mile Point Unit 2. GEH confirmed that adequate shutdown margin, as calculated, met and exceeded the requirement in TS for the current cycle. Furthermore, there was no impact on the cycle thermal and operating limits presented in the Supplemental Reload Licensing Report as a result of the reduced lifetime limit for Marathon C+ control rods. Future actions require applying the revised lifetime limits and continuing to monitor reactor water chemistry for signs of CRB cracking. Constellation captured this issue in issue reports 04506441 and 04506482.

The inspectors reviewed technical evaluations for CRB replacement for Nine Mile Point Unit 2 for the current cycle (ECP-21-248, Revision 0) and the upcoming cycle (ECP-23-182, Revision 0). The inspectors verified that the technical evaluation for the upcoming cycle applied the revised lifetimes in accordance with NF-AB-135-1410 and CRBs approaching end of life are properly referred to Reactor Engineering for shutdown margin calculations. The inspectors reviewed CY-AB-120-100, "Reactor Water Chemistry," Revision 21 and reactor water chemistry results to confirm that Constellation is adequately monitoring for indications of CRB cracking in accordance with GEH recommendations. Although operational experience and mechanical engineering assessments demonstrate that the ability to insert the control rods is not compromised, the inspectors reviewed scram time testing data for a sample of Marathon C+ CRBs.

Observation: Semi-Annual Trend 71152S The inspectors evaluated a sample of issues and events that occurred from January 2023 through June 2023 to determine whether issues were appropriately considered as emerging or adverse trends. The inspectors verified issues were appropriately evaluated by Constellation staff for potential trends and addressed within the scope of the corrective action program or through department review.

The inspectors did not identify any new trends that could indicate a more significant safety issue. Constellation identified a trend in maintenance rework during refueling outage N1R27.

Constellation initiated a Performance Improvement Action Plan using Constellation procedure AP-2023-1483 to remediate the trend identified. Additionally, Constellation identified a self-assessment performance gap for failure to correct problems in a timely manner. Specifically, seven issue reports which were more than 3 years old had open action items. Constellation developed a reprioritized list of actions to close out outstanding actions.

EXIT MEETINGS AND DEBRIEFS

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

• On July 13, 2023, the inspectors presented the integrated inspection results to Peter Orphanos, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Corrective Action 04547878

Documents 04548356

04676982

04684803

Procedures WC-AA-107 Seasonal Readiness 026

71111.04 Corrective Action 04366311

Documents

Drawings PID-035-A Piping & Instrumentation Diagram, Reactor Core Isolation 17.01

Cooling

PID-035-B Piping & Instrumentation Diagram, Reactor Core Isolation 15.02

Cooling

PID-61-B Piping & Instrumentation Diagram, Primary Containment 23

Purge & Standby Gas Treatment

Procedures N1-OP-16 Feedwater System Booster Pump to Reactor 071

N2-OP-11- Service Water System - Lineups 00600

LINEUPS

N2-OP-35 Reactor Core Isolation Cooling 019

N2-OP-35- Reactor Core Isolation Cooling - Lineups 00200

LINEUPS

N2-OP-61B Standby Gas Treatment System 01700

N2-OP-61B- Standby Gas Treatment System - Lineups 00100

LINEUPS

71111.05 Fire Plans N2-FPI-PFP-0201 Unit 2 Pre-Fire Plans 07

71111.07A Procedures GAP-HSC-02 System Aging Inspection and Cleanliness Controls 02100

Work Orders C93805616

71111.11Q Miscellaneous NM1C26-SU Reactivity Maneuver Plan 0

NM2C19-09 Reactivity Maneuver Plan 0

Procedures N1-OP-43A Plant Startup 054

N2-OP-3 Condensate and Feedwater System 06100

71111.12 Corrective Action 04541257

Documents 04554062

Inspection Type Designation Description or Title Revision or

Procedure Date

04676982

Miscellaneous 0409 and 4201 PREF (procurement requirements evaluation form)

110257 and Quality Receipt Inspection Package

111241

Work Orders C93760991

C93775403

71111.13 Corrective Action 04681332

Documents

Procedures N1-OP-47A 125 VDC Power System 03200

OP-AA-108-117 Protected Equipment Program 007

WC-AA-101-1006 On-line Risk Management and Assessment 004

71111.15 Corrective Action 04413846

Documents 04670131

04677157

04683194

04685520

04686646

Procedures ER-AA-2030 Conduct of Equipment Reliability Manual 29

N1-ST-Q5 Primary Containment Isolation Valves Operability Test 038

N2-OP-100A Standby Diesel Generators 03300

N2-OP-35 Reactor Core Isolation Cooling 019

71111.18 Corrective Action 04547899

Documents 04552666

Corrective Action 04666818

Documents

Resulting from

Inspection

Engineering ECP-20-000468 Installation of a Hydrogen Generation Unit 0

Changes ECP-21-000014 Modify Mounting Location and Power Supply for Feedwater 1

Channel 12 Pressure Signal Isolator

ECP-21-000057 U1 NMP Emergency Condenser Isolation Trip Filtering 0

Procedures N1-ISP-036-106 Emergency Cooling System - High Steam Flow Instrument 01100

Trip Channel Test/Calibration

Inspection Type Designation Description or Title Revision or

Procedure Date

Work Orders C93748939

C93776606

C93791233

C93793629

C93906976

71111.20 Corrective Action 04562620

Documents

71111.24 Corrective Action 04565581

Documents 04666351

04667415

04667415

04670572

04670814

Procedures N1-ESP-001-130 Main Steam Isolation Valve 7% and 10% Limit Switch Test 00500

N1-ISP-036-004 Low-Low Reactor Level Instrument Trip Channel 01500

Test/Calibration

N1-ISP-066-003 Auto Depressurization System Operability Test 00400

N1-PM-V2 Pump Curve Validation Test 01100

N1-ST-Q13 Emergency Service Water Pump and Check Valve 02500

Operability Test

N1-ST-R12 Initiation of Emergency Condensers from the Remote 01000

Shutdown Panel

N1-ST-R2A LOOP and EDG 102 Simulated Auto Initiation Test 002

N1-ST-R30 Reactor Pressure Vessel and ASME Class 1 System 01800

Leakage Test

N1-ST-R5 Primary Coolant Manual Isolation Signal Test 016

N1-TSP-201-001 Integrated Leak Rate Test of Primary Containment Type A 008

Test

N2-OSP-EGS- Operating Cycle Diesel Generator 24 Hour Run Division 1 01100

R002 and 2

Work Orders C93791359

C93793695

C93793699

Inspection Type Designation Description or Title Revision or

Procedure Date

C93805722

C93808264

C93808270

C93844132

71114.06 Miscellaneous FAQ 20-04 Crediting Automated Notifications in the DEP Performance 08/26/2020

Indicator - Final Approved

71151 Miscellaneous NEI 99-02 Regulatory Assessment Performance Indicator Guideline 7

71152S Corrective Action 04324166

Documents 04413822

04428655

04442254

04448532

04675818

04677633

04687040

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