IR 05000317/2023002

Integrated Inspection Report 05000317/2023002

ML23215A191
Person / Time
Site:	Calvert Cliffs
Issue date:	08/03/2023
From:	Brice Bickett NRC/RGN-I/DORS
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
References
IR 2023002
Download: ML23215A191 (1)

Text

August 3, 2023

SUBJECT:

CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 -

INTEGRATED INSPECTION REPORT 05000317/2023002 AND 05000318/2023002

Dear David Rhoades:

On June 30, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Calvert Cliffs Nuclear Power Plant, Units 1 and 2. On July 24, 2023, the NRC inspectors discussed the results of this inspection with Patrick Navin, 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 Calvert Cliffs Nuclear Power Plant, Units 1 and 2.

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 Calvert Cliffs Nuclear Power Plant, Units 1 and 2. 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 Brice Brice A. A. Bickett Date: 2023.08.03 Bickett 15:07:48 -04'00'

Brice A. Bickett, Chief Projects Branch 3 Division of Operating Reactor Safety Docket Nos. 05000317 and 05000318 License Nos. DPR-53 and DPR-69

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000317 and 05000318 License Numbers: DPR-53 and DPR-69 Report Numbers: 05000317/2023002 and 05000318/2023002 Enterprise Identifier: I-2023-002-0028 Licensee: Constellation Energy Generation, LLC Facility: Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Location: Lusby, MD Inspection Dates: April 1, 2023 to June 30, 2023 Inspectors: E. Dipaolo, Senior Resident Inspector B. Dyke, Operations Engineer A. Tran, Resident Inspector Approved By: Brice A. Bickett, Chief Projects Branch 3 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 Calvert Cliffs Nuclear Power Plant, Units and 2, 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 Meet Technical Specification Limiting Conditions for Operation (LCOs) Due to Wide Range Logarithmic Neutron Flux Monitor/Instrument (WRNI) Channel D Being Inoperable Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.13] - 71152A Systems NCV 05000318/2023002-01 Consistent Open/Closed Process An NRC identified Green finding and non-cited violation of Unit 2 Technical Specification LCOs 3.3.1, 3.3.2, and 3.0.4 was identified because operators declared the D channel of WRNI operable on March 11, 2023, without satisfying the technical specification required surveillance requirements for channel checks with the other channels of WRNI. Specifically, during startup activities following the spring 2023 refueling outage, the D channel of WRNI was reading off scale low and did not meet channel check acceptance criteria. However, operators inappropriately declared the instrument operable based on past performance of the channel under similar conditions.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 operated at or near rated thermal power for the entire inspection period.

Unit 2 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, 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 Units 1 and 2 27' and 45' switchgear rooms and the intake structure on June 22, 2023.

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, 2A emergency diesel generator when Unit 1, 1A emergency diesel generator was inoperable due to failure, April 27, 2023

(2) Unit 2, 22 and 23 auxiliary feedwater pumps when 21 auxiliary feedwater pump was inoperable due to degradation of the flow element balance seal, May 3, 2023

(3) Unit common, 0C emergency diesel generator when the Unit 1, 1A emergency diesel generator was inoperable due to major engine repairs, May 31, 2023

71111.05 - Fire Protection

Fire Area Walkdown and Inspection (IP Section 03.01) (5 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 common, 0C emergency diesel generator building, fire area DGB2, June 2, 2023

(2) Units 1 and 2, component cooling water pump rooms and 5' fan rooms, fire areas 12, 13, 14, and 15, June 20, 2023

(3) Unit 2, cable spreading room and battery rooms, fire areas 17, 17A, and 17B, June 22, 2023

(4) Unit 1, cable spreading room and battery rooms, fire areas 16, 16A, and 16B, June 23, 2023

(5) Unit 2, 27' switchgear room, purge air room, and 45' switchgear room, fire areas 18, 18A, and 25, June 27, 2023

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

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

(1 Sample)

(1) The inspectors observed and evaluated licensed operator performance in the control room during elevated risk activity due to main turbine trip testing, specifically emergency trip device and overspeed circuit online test, on June 16, 2023.

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated a licensed operator simulator examination involving instrument failures, a condenser tube leak, a steam generator tube leak requiring a reactor trip, and a steam generator tube rupture resulting in a declaration of an Alert on April 11, 2023.

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 (SSCs) remain capable of performing their intended function:

(1) Unit 1, AR 4673763, 1A emergency diesel generator piston inspection review, June 5, 2023

(2) Unit 2, AR 4675097, 21 auxiliary feedwater pump binding and associated overhaul,

June 26, 2023 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) Unit 1, AR 4674016, 1A emergency diesel generator failure and associated repairs, June 22, 2023

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management (IP Section 03.01) (5 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 condition due to 12B service water heat exchanger cleaning, April 13, 2023

(2) Units 1 and 2, elevated risk condition due to 1A emergency diesel generator failure, April 26, 2023

(3) Unit 2, elevated risk condition and fire risk management actions due to 21 auxiliary feedwater pump emergent work, May 4, 2023

(4) Unit 1, risk informed completion time implementation due to 1A emergency diesel generator inoperability, June 1, 2023

(5) Unit 1, elevated risk conditions and fire risk management actions due to 12 saltwater pump replacement, June 21, 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 2, AR 4558594 and AR 4558596, 2-LT-1114B and 2-LT-1114D, 21 steam generator wide range level instruments as-found calibration data out-of-tolerance, April 6, 2023

(2) Unit 1, Operability Evaluation 23-002, Revision 0, associated with AR 4669157, 11 component cooling heat exchanger pressure indicator line sheared off, April 4, 2023

(3) Unit 1, CAL-1-2023-0117, operability and operation decision-making process of the 1A emergency diesel generator prior to return-to-service following emergent repairs, May 1, 2023

(4) Units 1 and 2, AR 4679091, 0C emergency diesel generator engine piston cracks did not meet new vendor criteria, May 22, 2023

(5) Unit 1, "Operability Evaluation 23-003," Revision 1, associated with 1A emergency diesel generator operability following maintenance window to address several degraded and nonconforming conditions, June 9, 2023

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 1, ECP-23-000174, "Remove 1PI5205 from Service to Allow Leak Repair of Broken Threaded Coupling," Revision1, May 10, 2023

(2) Unit 2, ECP-23-000089, "2BUS2Y09 and 2BUS2Y10 Focused Load Single Point Vulnerability Reduction," Revision 1, June 26, 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) Unit 1, C93897543, remove, inspect, clean, and repair 11 saltwater pump due to low developed differential pressure and testing, April 17, 2023

(2) Unit 1, C93909267, remove, inspect, and repair 12 saltwater pump due to testing in the required action range, April 28, 2023

(3) Unit 1, C93909573, 1A emergency diesel generator (1A2 engine) emergent repairs following failure during monthly testing, May 4, 2023

(4) Unit 2, C93910008, inspect and overhaul 21 auxiliary feedwater pump, May 10, 2023

(5) Unit 1, C93910625 and C93910612, 1A emergency diesel generator borescope inspections post new pistons 12-hour break-in run, June 5, 2023

(6) Unit 1, C93910810, 1A emergency diesel generator emergent repairs following engine trip on lo-lo lubricating oil pressure during 12-hour run, June 7, 2023

Surveillance Testing (IP Section 03.01) (3 Samples)

(1) Unit 2, I-525C-2, "Auxiliary Feedwater Actuation System Pipe Rupture LOOP Calibration Steam Generator 21 Channel ZE S/G Motor Train," Revision 7, April 11, 2023

(2) Unit 2, STP-O-8A-2 "Test of 2A DG and 4kV Bus 21 UV," Revision 35; and CA-STI-034, "Evaluation of One-Time Surveillance Interval Extension for Diesel Generator 2A and Fuel Oil System SRs," Revision 0, May 7, 2023

(3) Unit 1, STP-M-510EL-1, "RPS Pressurizer Pressure and Thermal Marginal/Low Pressure Loop Calibration," Revision 00700, June 26, 2023

Inservice Testing (IST) (IP Section 03.01) (1 Sample)

(1) Unit 1, STP-O-5A12-1, "12 Auxiliary Feedwater Pump Quarterly Surveillance Test," Revision 12, April 18, 2023

71114.06 - Drill Evaluation

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

(1 Sample)

(1) The inspectors observed and evaluated the conduct of an emergency preparedness drill in the control room simulator and Technical Support Center on May 16,

OTHER ACTIVITIES - BASELINE

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

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

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

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

MS06: Emergency AC Power Systems (IP Section 02.05) (2 Samples)

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

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

MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)

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

(2) Unit 2, July 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) Unit 2 startup from refueling outage with the 'D' channel of WRNI inoperable, AR

4559548, June 16, 2023 71152S - Semi-annual Trend Problem Identification and Resolution Semi-annual Trend Review (Section 03.02)

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

71153 - Follow-Up of Events and Notices of Enforcement Discretion Event Follow-up (IP Section 03.01)

(1) The inspectors evaluated AR 4672350, Unit 1, 1A emergency diesel generator failure during monthly surveillance testing on April 24, 2023.

(2) The inspectors evaluated AR 4675097, Unit 2, 21 auxiliary feedwater pump balancing seal was discovered to be seized following quarterly surveillance testing on May 3, 2023.

(3) The inspectors evaluated AR 4678953, Unit 1, 1A emergency diesel generator trip on lo-lo lubricating oil pressure during 12-hour abnormal condition monitoring plan testing on May 18,

INSPECTION RESULTS

Failure to Meet Technical Specification Limiting Conditions for Operation (LCOs) Due to Wide Range Logarithmic Neutron Flux Monitor/Instrument (WRNI) Channel D Being Inoperable Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.13] - 71152A Systems NCV 05000318/2023002-01 Consistent Open/Closed Process An NRC identified Green finding and non-cited violation of Unit 2 Technical Specification LCOs 3.3.1, 3.3.2, and 3.0.4 was identified because operators declared the D channel of WRNI operable on March 11, 2023, without satisfying the technical specification required surveillance requirements for channel checks with the other channels of WRNI. Specifically, during startup activities following the spring 2023 refueling outage, the D channel of WRNI was reading off scale low and did not meet channel check acceptance criteria. However, operators inappropriately declared the instrument operable based on past performance of the channel under similar conditions.

Description:

During the spring 2023 Unit 2 refueling outage, the D channel instrument channel failed off scale low. Operability Evaluation 21-003, Revision 3, documented that although channel checks between the instrument and other channels of WRNI were not satisfied, the performance of the instrument channel was similar to performance during the 2021 refueling outage when the channel indication aligned with the other WRNI channels at approximately 1E-6 percent reactor power. Based on Operability Evaluation 21-003, Revision 3, and maintenance on the instrument channel during the refueling outage to eliminate circuit noise, operators documented that they had reasonable assurance that once power levels increased, the D channel of WRNI indication would return to normal. At 1908, on March 11, 2023, with Unit 2 in Mode 3, operators declared the channel operable. At that time, the D channel of WRNI was reading off scale low and did not meet channel check acceptance criteria of within two decades of the other three channels of WRNI.

During the review of the corrective action program evaluation associated with the issue (AR 4559548), the inspectors identified that the evaluation failed to identify that declaring the D channel of WRNI operable was inappropriate because technical specification surveillance requirements for channel checks with the other WRNIs were not satisfied. See Observation documented in the Inspection Results for additional information.

The inspectors reviewed the technical specifications implications of inappropriately declaring the D channel of WRNI operable. At 2027, on March 11, 2023, operators closed the reactor trip breakers making the control element assemblies capable of being withdrawn thus satisfying the Applicability of LCO 3.3.2, Reactor Protective System (RPS) Instrumentation-Shutdown. With one channel of WRNI inoperable, LCO 3.3.2.A required placing the affected RPS bistable trip units in bypass or trip within one hour. At 0425, on March 12, 2023, the B channel of WRNI was declared inoperable for an unrelated issue. For two channels of WRNI inoperable, LCO 3.3.2.B required that one RPS bistable trip unit be placed in bypass and the other in trip within one hour.

At 0811, on March 12, 2023, Unit 2 entered Mode 2 thus satisfying the Applicability of LCO 3.3.1, RPS Instrumentation-Operating. With two channels of WRNI inoperable, LCO 3.3.1.B required that one RPS bistable trip unit be placed in bypass and the other in trip within one hour. Also, LCO 3.0.4 specified requirements when an LCO is not met when entering a Mode or other specified condition of an LCO applicability. At the time, operators satisfied the requirements of LCO 3.0.4 for the B channel of WRNI but not for the D channel.

When power was raised to 1E-6 percent, the D channel of WRNI did not align with the other channels of WRNI as expected. At 1040, on March 12, 2023, operators declared the channel inoperable. This required the submittal of Licensee Event Report 05000318/2023-001, dated May 11, 2023, due to Unit 2 being in conditions prohibited by technical specifications during startup with the D channel of WRNI being inoperable.

Corrective Actions: Operators declared the D channel of WRNI inoperable when the channel did not align with the other channels of WRNI as expected by Operability Evaluation 21-003 when raising power to 1E-6 percent.

Corrective Action References: ARs 4559548 and 4685166

Performance Assessment:

Performance Deficiency: Declaring the D channel of WRNI operable on March 11, 2023, without satisfying the technical specification required surveillance requirements for channel checks with the other WRNIs, was a performance deficiency that was reasonably within Constellations ability to foresee and correct and should have been prevented. Per Surveillance Requirement 3.0.1, Failure to Meet a Surveillance, whether such failure is experienced during the performance of the surveillance or between performances of the surveillance, shall be failure to meet the LCO. Specifically, during startup activities following the spring 2023 refueling outage, the D channel of WRNI was reading off scale low and did not meet channel check acceptance criteria. However, operators inappropriately declared the instrument operable based on past performance of the channel under similar conditions.

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, failing to factor into account all requirements into the operability declaration of the D channel of WRNI affected the capability of the instrument to mitigate initiating events because the required actions of the associated LCOs were not implemented within the required completion times. Additionally, this issue is similar to IMC 0612, Appendix E, Example 2.b, in that the D channel of WRNI was later determined to be inoperable.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. Using Exhibit 2, Section C, the finding screened as Green because it only affected a single reactor protection system trip signal to initiate a reactor scram (i.e., if technical specification required actions were taken to place the channel in trip) and the function of other redundant trips or diverse methods of reactor shutdown were not affected.

Cross-Cutting Aspect: H.13 - Consistent Process: Individuals use a consistent, systematic approach to make decisions. Risk insights are incorporated as appropriate. Specifically, the D channel of WRNI was declared operable by operators based on an operability evaluation despite failing to meet technical specification surveillance requirements for channel checks with the other channels of WRNIs.

Enforcement:

Violation: Unit 2, Technical Specification Surveillance Requirements 3.3.1.1 and 3.3.2.1, required channel checks of the WRNIs. Surveillance Requirement 3.0.1 required that surveillance requirements shall be met during the Modes or other specified conditions in applicability for individual LCOs. Failure to meet a surveillance, whether such failure is experienced during the performance of the surveillance or between performances of the surveillance, shall be failure to meet the LCO. LCO 3.3.1 and 3.3.2 contained required actions to be taken for an inoperable channel of WRNI. LCO 3.0.4 specified requirements when an LCO is not met when entering a Mode or other specified condition of an LCO applicability.

Contrary to the above, between 2027 on March 11, 2023, and 0811 on March 12, 2023, the Unit 2 D channel of WRNI failed to meet the channel checks of Surveillance Requirement 3.3.2.1 while in Mode 3 with reactor trip circuit breakers closed and any control element assembly capable of being withdrawn and the required actions of LCO 3.3.2, Reactor Protective System Instrumentation - Shutdown, were not taken within the required completion time. Between 0811 and 1040 on March 12, 2023, the channel failed to meet the channel checks of Surveillance Requirement 3.3.1.1 while in Mode 2 and the required actions of LCO 3.3.1, Reactor Protection System Instrumentation - Operating, were not taken within the required completion time. Also, on March 12, 2023, at 0811, Unit 2 entered Mode 2 from Mode 3 and the requirements of LCO 3.0.4 were not satisfied.

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

Observation: Corrective Action Program Review of Unit 2 Startup from Refueling 71152A Outage With the 'D' Channel of WRNI Inoperable Inspectors reviewed the corrective action program evaluation (CAPE 4559548) and corrective actions associated with the Unit 2 D channel WRNI erratic or failed low indications during recent refueling outages. The annual follow-up sample was selected to assess Constellations evaluation and corrective action plan to resolve the long-standing equipment issue as well as the evaluation of the cause of the reportable condition. See NCV 05000318/2023002-01, Failure to Meet Technical Specification Limiting Conditions for Operation (LCOs), due to WRNI Channel D being inoperable and documented in Inspection Results for additional background information.

The CAPE included an equipment evaluation and organizational effectiveness evaluation per PI-AA-125-1006, Investigation Techniques Manual. The inspectors observed that the evaluation of the equipment issues appeared to be thorough. The cause of the D channel of WRNI reading off scale low at low power levels was due to discriminator voltage needing to be adjusted for system alignment. Corrective actions were completed or planned to address the equipment issues.

The evaluation of organizational effectiveness identified issues with determining significance level of issues entered into the corrective action program, failure to transition to focused/complex troubleshooting, and delays in implementing online troubleshooting.

Although weaknesses in recognizing the risk associated with revising operability evaluations was identified, the CAPE failed to identify that declaring the D channel of WRNI operable was inappropriate because technical specification surveillance requirements for channel checks with the other WRNIs were not satisfied. Constellation wrote AR 4685166 and placed the issue into the corrective action program for evaluation and additional corrective actions. NRC identified NRC 05000318/2023002-01 is documented in Inspection Results.

Observation: Semi-Annual Trend Review 71152S The inspectors performed a semi-annual review to identify trends that might indicate the existence of a more significant safety issue, including issues that may have been documented outside the normal corrective action program.

Inspectors identified an adverse trend associated with degraded equipment and transient combustible control problems not being identified by equipment operators during equipment operations and on routine rounds. Inspector-identified examples included:

• A rolling work platform was observed to be in contact with the saltwater system piping associated with the 11 emergency core cooling system pump room air cooler piping with no associated permit or evaluation. The rolling work platform was considered a work tool and should have been removed when the associated work was completed several weeks prior to being identified by the inspectors (AR 4548223).

• Protected equipment boundaries around the Unit 2 auxiliary feedwater cross-connect valve did not ensure that all approaches to the valve were encompassed as required by the protected equipment procedure. The boundary deficiency was identified several days after being put in place (AR 4674974).

• A rubber bellows seal for a governor arm on the 1A emergency diesel generator was identified as degraded (as indicated by escaping crankcase exhaust gases) during a post-maintenance test. This was identified after a 12-hour break-in operating run following major maintenance on the emergency diesel generator (AR 4674583).

• A jacket cooling water leak from a mechanical joint on the 2A emergency diesel generator was identified. This was identified after initial equipment operator rounds were completed following starting the engine for operational surveillance testing (AR 4676247).

• An electrical instrument connection was identified as detached on the 1A emergency diesel generator. This was identified during a planned 12-hour confidence run of the generator (AR 4678935).

• Transient combustible exclusion zone signs were identified missing on entrance doors to the Units 1 and 2, 27 switchgear rooms (AR 4673485). Besides being transient combustible exclusion zones, the rooms were categorized as high-risk fire areas.

• A Green NRC identified finding and non-cited violation (NCV 05000317/2023001-01)was issued for the failure to adhere to the requirements of a transient combustible exclusion zone in accordance with the transient combustible control procedure (AR 4546736).

Constellation acknowledged the adverse trend, identified additional similar examples, and wrote AR 4683803. Constellation planned to evaluate the adverse trend to determine the cause and implement corrective actions. Inspectors independently evaluated the deficiencies noted above for significance in accordance with Inspection Manual Chapter 0612, Appendix B and Appendix E guidance. Except for NCV 05000317/2023001-01, which was previously dispositioned, the inspectors did not identify any findings or violations of more than minor significance.

EXIT MEETINGS AND DEBRIEFS

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

• On July 24, 2023, the inspectors presented the integrated inspection results to Patrick Navin, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.01 Procedures PE-0-102-65-O-A Warm Weather Checks

71111.04 Procedures OI-21A 2A Diesel Generator 03100

OI-32A Auxiliary Feedwater System 3800

71111.05 Corrective Action AR 4685826 NRC Identified: 2-SW-421 Small Packing Leak on Valve 06/20/2023

Documents AR 4686937 NRC Identified: Door 402 Not Latching Sometimes 06/26/2023

Resulting from

Inspection

71111.11Q Procedures OI-43C Unit 1 Main Turbine Performance Evaluation Checks 04300

71111.12 Miscellaneous DGP-PM-95-0158 Memorandum on NSR Spare Parts 10/25/1993

DLTC02155 DGP Spare Parts for Engine and Auxiliaries 03/17/1994

71111.13 Corrective Action AR 4673485 NRC Identified: Issue With Missing Transient Combustible 04/27/2023

Documents Exclusion Zone Sign

Resulting from AR 4674974 NRC Identified: PEB FOR 2CV4550 Not Encompassing 05/02/2023

Inspection Enough

Procedures ER-CA-600-2001 Calvert Cliffs RICT System Guidelines 2

OP-AA-108-118 Risk Informed Completion Time 3

OP-CA-201-012- On-Line Fire Risk Management 004

1001

71111.15 Drawings 65664SH0001 Instrument Installation Detail for 1-PI-5205 2

FSL-MP- 2" and Under Branch Connections for LJ-1 Pipe 16

4498SJ0001

Engineering ECP-23-000231 Evaluation of 1A Emergency Diesel Generator Fuel Rack 000

Evaluations and Fuel Injection Pump Settings

ECP-23-000232 Evaluation of 1A Emergency Diesel Generator Fuel Injector 000

Pump Stroke Lengths

71111.18 Drawings 65664SH0001 Instrument Installation Detail for 1-PI-5205 2

FSK-MP- 2" and Under Branch Connections for LJ-1 Pipe 16

4498SH0001

71111.24 Corrective Action AR 4674583 1A1 Emergency Diesel Generator Governor Arm Rubber 05/01/2023

Documents Bellows is Degraded

Resulting from AR 4676247 NRC Identified - 1drop/10sec Leak From Joint on 2A EDG 05/07/2023

Inspection

Inspection Type Designation Description or Title Revision or

Procedure Date

Engineering CA-2023-01 Perform a One-Time Interval Extension of the Technical 000

Changes Specification Surveillance Requirement for the 2A

Emergency Diesel Generator Monthly Tests From 31 Days

to 62 Days

Miscellaneous AR 4672350 Adverse Condition Monitoring Plan 1A2 Melted Piston 2023 2

STP-O-5A21-2 21 Auxiliary Feedwater Pump Quarterly Surveillance Test 05/07/2023

STP-O-73H-2 Auxiliary Feedwater Pump Large Flow Test 05/07/2023

Procedures OI-21A 1A Emergency Diesel Generator 02700

STP-O-8A-1 Test of 1A Diesel Generator and 11 4 kV Bus Undervoltage 35

71114.06 Corrective Action AR 4678778 TSC Lessons Learned From Calvert Cliffs ERO Drill

Documents AR 4679092 Operations Lessons Learned From Calvert Cliffs ERO Drill

AR 4679098 ERO Facility and Equipment Issues

71151 Corrective Action AR 4687942 NRC ID: EAC MSPI Data Inaccuracy From August 2022 6/30/2023

Documents

Resulting from

Inspection

Miscellaneous MS05 PI Data MS05 PI Data 2Q2022-1Q2023 06/09/2023

2Q2022-1Q2023

MS06 PI Data MS06 PI Data 3Q2022-1Q2023 06/09/2023

3Q2022-1Q2023

MS08 PI Data MS08 PI Data 3Q2022-1Q2023 06/09/2023

3Q2022-1Q2023

13