IR 05000317/2023004

Integrated Inspection Report 05000317/2023004 and 05000318/2023004

ML24032A041
Person / Time
Site:	Calvert Cliffs
Issue date:	02/01/2024
From:	Brice Bickett NRC/RGN-I/DORS
To:	Rhoades D Constellation Energy Generation, Constellation Nuclear
References
IR 2023004
Download: ML24032A041 (1)

Text

February 1, 2024

SUBJECT:

CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 -

INTEGRATED INSPECTION REPORT 05000317/2023004 AND 05000318/2023004

Dear David Rhoades:

On December 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Calvert Cliffs Nuclear Power Plant, Units 1 and 2. On January 22, 2024, 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.

Two findings of very low safety significance (Green) are documented in this report. One of these findings 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 or a finding not associated with a regulatory requirement 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 (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding.

Sincerely, Digitally signed by Brice Brice A. A. Bickett Date: 2024.02.01 Bickett 09:17:46 -05'00'

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: 05000317/2023004 and 05000318/2023004 Enterprise Identifier: I-2023-004-0027 Licensee: Constellation Energy Generation, LLC Facility: Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Location: Lusby, MD Inspection Dates: October 01, 2023 to December 31, 2023 Inspectors: G. Dipaolo, Senior Resident Inspector A. Tran, Resident Inspector C. Borman, Health Physicist E. Chen, Reactor Inspector L. Dumont, Senior Reactor Inspector B. Dyke, Operations Engineer N. Eckhoff, Health Physicist B. Fuller, Senior Operations Engineer D. Kern, Senior Reactor Inspector J. Patel, Senior 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 Control Transient Combustible Material Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.2] - Field 71111.05 Systems NCV 05000317/2023004-01 Presence Open/Closed A Green NRC-identified finding and associated non-cited violation (NCV) of the Unit 1,

Renewed Facility Operation License, Condition 2.E, was identified for failure to adhere to the requirements of a transient combustible exclusion zone (TCEZ). Specifically, on October 17, 2023 and October 19, 2023, Constellation failed to ensure transient combustibles were properly controlled as required by OP-AA-201-009, Control of Transient Combustible Material.

Failure to Implement Required Diverse and Flexible Coping Strategies (FLEX) Preventive Maintenance (PM)

Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.1] - 71111.24 Systems FIN 05000317,05000318/2023004-02 Resources Open/Closed A Green NRC-identified finding was identified for Constellation's failure to implement the required PM activities for FLEX equipment as specified in CC-CA-118, Diverse and Flexible Coping Strategies (FLEX), Spent Fuel Pool Instrumentation (SPFI), and Hardened Containment Vent System (HCVS) Program Document, Revision 5. Specifically, performance of loaded runs of the FLEX diesel generators and FLEX pumps were shorter than required, the performed frequency of some PMs were longer than specified, and several required PM tasks on other FLEX equipment did not have associated existing PMs to complete the tasks.

Additional Tracking Items

Type Issue Number Title Report Section Status LER 05000318/2023-001-00 LER 2023-001-00 for Calvert 71153 Closed Cliffs Nuclear Power Plant,

Unit 2, Condition Prohibited by Technical Specifications due to Inoperable Nuclear Instrumentation at Very Low Power

LER 05000318/2023-001-01 LER 2023-001-01 for Calvert 71153 Closed Cliffs Nuclear Power Plant,

Unit 2, Condition Prohibited by Technical Specifications due to Inoperable Nuclear Instrumentation at Very Low Power

PLANT STATUS

Unit 1 began the inspection period at 70 percent rated thermal power resulting from the unit being down powered to facilitate containment entry to address increased unidentified reactor coolant system leakage. On October 1, 2023, the unit returned to 100 percent rated thermal power. The unit remained at or near rated thermal power for the remainder of the inspection period.

Unit 2 began the inspection period at rated thermal power. On November 7, 2023, the unit experienced an automatic reactor trip due to the loss of the U-4000-22 service transformer.

Operators commenced a unit startup on November 9, 2023, and returned the unit to 100 percent rated thermal power on November 10, 2023. The unit experienced a second automatic reactor trip on November 16, 2023, resulting from the loss of the U-4000-22 service transformer.

The unit was returned to 100 percent power on November 17, 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 Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the fire pump house, 11 fuel oil storage tank, and 12 condensate storage tank on December 19, 2023.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (2 Samples)

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

(1) Units 1 and 2, 13 kV and 4 kV electrical distribution system alignment when service transformer U-4000-22 was out of service due to maintenance, November 22, 2023

(2) Unit 2, auxiliary feedwater system alignment following steam release in 5' east penetration room, November 28, 2023

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

(1) The inspectors evaluated system configurations during a complete walkdown of the Unit 1 low pressure safety injection system on December 20, 2023.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (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) Units 1 and 2, cable chases 1A, 1B, 2A, and 2B, fire areas 20-23, October 2, 2023

(2) Units 1 and 2, 69' electrical rooms and horizontal chases, fire areas 35-38, October 5, 2023

(3) Unit 1, service water pump room, fire area 39, October 6, 2023

(4) Unit 2, 45' west and east electrical penetration rooms, fire areas 26-27, October 19, 2023

(5) Unit 2, 21 and 22 emergency core cooling system pump rooms, fire areas 1-2, November 6, 2023

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the Units 1 and 2 service water pump rooms on October 13, 2023.

71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance

Requalification Examination Results (IP Section 03.03) (1 Sample)

(1) The inspectors reviewed and evaluated the licensed operator examination results for the requalification annual operating exam administered between November 1-30, 2023, and the biennial written examinations completed on December 1, 2023.

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 examinations administered on December 1, 2023.

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 main control room simulator in modeling the actual plant, and for meeting the requirements contained in 10 CFR 55.46.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

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

(1) The inspectors observed and evaluated the conduct of a licensed operator simulator training scenario involving an instrument air leak, loss of reactor protection system power, steam generator tube rupture, reactor trip, and a failure of the emergency core cooling system equipment resulting in the declaration of an Alert on October 17, 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) Units 1 and 2, AR 4705896, FLEX preventive maintenance extent of condition, November 28, 2023

(2) Unit 1, AR 722673, 12 inverter frequency found pegged high, December 14, 2023

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)

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

(1) Unit 2, risk-informed completion time implementation due to auxiliary feedwater actuation system channel ZE bistable trip being inoperable, October 3, 2023

(2) Unit 2, risk-informed completion time implementation due to auxiliary feedwater actuary system channel ZE bistable trip being inoperable, November 1, 2023

(3) Unit 2, Technical Specification Limiting Condition for Operation 3.0.4.b, risk assessment for transition from Mode 3 to Modes 2 and 1 for one inoperable offsite power source (U-4000-22 service transformer) during startup from forced outage 2F2301, November 9, 2023

(4) Unit 2, Technical Specification Limiting Condition for Operation 3.0.4b, risk assessment for transition from Mode 3 to Modes 2 and 1 for one inoperable offsite power source, U-4000-22 service transformer, during startup from forced outage 2F2302, November 21, 2023

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 1, AR 4706077, boric acid corrosion inside 11A reactor coolant pump midlevel case studs, fasteners, and flange, October 5, 2023

(2) Units 1 and 2, AR 4544011, review Operating Instruction 29 minimum saltwater flow bases, October 25, 2023

(3) Unit 1, AR 4722673, 12 inverter frequency found pegged high, December 13, 2023

(4) Unit 2, AR 4723185, abnormal indication on abnormal condition monitoring plan for U-4000-22 4kV service transformer trip circuits, December 20, 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 2, word order (WO) C93944602, 22B charging line stop valve, 2-CVC-518-CV, post-maintenance testing following repairs due to stroking slow, October 6, 2023

(2) Unit 1, WO C93765859, 12 service water post-maintenance testing following pump bearing replacements, October 12, 2023

(3) Unit 1, WO C93909197, 12 component cooling water post-maintenance testing following relief valve and positioner replacements, October 24, 2023

(4) Unit 1, WO C93910509 and C93869802, 12 control room heating, ventilation, and air condition post-maintenance testing following work window, November 3, 2023

(5) Unit 2, WO C93911168, auxiliary feedwater actuation system post-maintenance testing following channel ZE instrument circuitry replacement, November 14, 2023

(6) Unit 2, WO C93949021, U-4000-22 4kV service transformer post-maintenance testing following troubleshooting and replacement of associated instrumentation, November 30, 2023

(7) Unit 2, WO C93448732, 22 service water system post-maintenance testing following strainer flushing actuator maintenance, December 15, 2023

Surveillance Testing (IP Section 03.01) (2 Samples)

(1) Unit 1, STP-O-B2YR-1, "Biennial Test of 2B Emergency Diesel Generator," Revision 3, October 13, 2023

(2) Unit 1, STP-O-8A2YR-1, "Biennial Test of 1A Emergency Diesel Generator," Revision 5, October 26, 2023

71114.06 - Drill Evaluation

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

(1) The inspectors evaluated the conduct of a licensed operator simulator training scenario involving an operating basis earthquake, main turbine control valve failure, reactor trip, and a loss of cooling accident resulting in an Alert declaration on October 17,

71124.05 - Radiation Monitoring Instrumentation

Walkdowns and Observations (IP Section 03.01) (8 Samples)

The inspectors evaluated the following radiation detection instrumentation during plant walkdowns:

(1) Eberline R020 #0012245, radiation protection instrument locker at radiological controlled area (RCA) entrance

(2) Ludlum Model 26 #002708, radiation protection instrument locker at RCA entrance

(3) Radeye PX #0025311, radiation protection instrument locker at RCA entrance

(4) Wide Range Gas Monitor #HVRE-5416B, Unit1 fan room

(5) Main Vent Particulate and Tritium Monitor #1RE5320B, Unit 1 fan room

(6) Fuel Pool Area Radiation Indicator #O-R1-5420A, spent fuel pool area

(7) Eberline AMS4 #0025413, spent fuel pool area

(8) Ludlum Model 3030P #0027977, chemistry laboratory

Calibration and Testing Program (IP Section 03.02) (13 Samples)

(1) ARGOS-5 #0912-157

(2) ARGOS-5 #0912-158

(3) ARGOS-5 #0912-159

(4) Eberline RO-20AA #01283

(5) Eberline AMS-4 #1441/1844

(6) Ludlum 177 #339048

(7) Ludlum 177 #346596

(8) Ludlum Model 26 #PF013341

(9) Ludlum Model 26 #PF009855

(10) Ludlum Model 79 #25013676

(11) MGP TELEPOLE #6608-081

(12) SAM-12 #12038

(13) SAM-12 #12039 Effluent Monitoring Calibration and Testing Program Sample (IP Section 03.03) (2 Samples)

The inspectors evaluated the calibration and maintenance of the following radioactive effluent monitoring and measurement instrumentation:

(1) Unit 1, Wide Range Effluent Radiation Monitor Element - Low Range #1-RE-5416A

(2) Liquid Waste Discharge Radiation Monitor #0-RE-2201

OTHER ACTIVITIES - BASELINE

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

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

=

(1) Unit 1, October 1, 2022 through September 30, 2023

(2) Unit 2, October 1, 2022 through September 30, 2023

MS09: Residual Heat Removal Systems (IP Section 02.08) (2 Samples)

(1) Unit 1, October 1, 2022 through September 30, 2023

(2) Unit 2, October 1, 2022 through September 30, 2023

MS10: Cooling Water Support Systems (IP Section 02.09) (2 Samples)

(1) Unit 1, October 1, 2022 through September 30, 2023

(2) Unit 2, October 1, 2022 through September 30, 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) Actions to address NRC Finding, 05000318,05000317/2023001-02, Failure to Follow Instrument Performance Trending Process

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 Report (IP Section 03.02)

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

(1) LER 05000318/2023-001-00, 01, "Condition Prohibited by Technical Specifications due to Inoperable Nuclear Instrumentation at Very Low Power" (ADAMS Accession No. ML23272A104). The inspectors reviewed the LER submittal during the Calvert Cliffs Nuclear Power Plant, Units 1 and 2 - Biennial Problem Identification and Resolution Inspection completed on November 2, 2023. The inspection conclusions associated with this LER are documented in Calvert Cliffs Nuclear Power Plant -

Integrated Inspection Report 05000318/2023002 (ADAMS Accession No.

ML23215A191) under the Inspection Results section, NCV 05000318/2023002-01.

===This LER is closed.

Personnel Performance (IP Section 03.03) (4 Samples)===

(1) The inspectors evaluated AR 4712455, Unit 2, blowdown heat exchanger relief valve causing steam plume in 5' east penetration, requiring entry into OP-CA-108-3.0, 26, "Large Steam Leak," Revision 9, on October 25, 2023.

(2) The inspectors evaluated AR 4716036, Unit 2, automatic reactor trip and loss of main feedwater due to loss of U-4000-22 service transformer on November 7, 2023.

(3) The inspectors evaluated AR 716258, 22 steam generator feed pump trip, causing entry into Abnormal Operating Procedure (AOP)-3G-2, "Malfunction of Main Feed Water System," on November 8, 2023.

(4) The inspectors evaluated AR 4718086, Unit 2, automatic reactor trip and loss of main feedwater due to loss of U-4000-22 service transformer on November 16,

INSPECTION RESULTS

Failure to Control Transient Combustible Material Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.2] - Field 71111.05 Systems NCV 05000317/2023004-01 Presence Open/Closed A Green NRC-identified finding and associated non-cited violation (NCV) of the Unit 1, Renewed Facility Operation License, Condition 2.E, was identified for failure to adhere to the requirements of a transient combustible exclusion zone (TCEZ). Specifically, on October 17, 2023 and October 19, 2023, Constellation failed to ensure transient combustibles were properly controlled as required by OP-AA-201-009, Control of Transient Combustible Material.

Description:

On October 17, 2023, inspectors performed a walkdown of the Unit 1, service water pump room, fire area 39, and identified an area beneath a room stairway marked no combustible permanent storage area with transient combustibles stored in the area.

Constellation issued AR 4710362 to capture the issue and removed the combustible materials.

The inspectors reviewed OP-AA-201-009, Control of Transient Combustible Material, Revision 29, step 4.4.1.5, and noted it documents do not STAGE or STORE Transient Combustible Material that is inside or beneath stairways, unless the area underneath the stairway is protected by an operable automatic sprinkler system.

The inspectors reviewed calculation CA02243, Combustible Loading Analysis Revision, Revision 4, for fire area 39 and noted it had 360,661 British Thermal Units (BTU) of margin.

The transient combustibles found in the room had a loading of 972,500 BTU.

On October 19, 2023, NRC inspectors performed a walkdown of the Unit 1, cable spreading room, fire area 16, which is designated as a TCEZ. During the walkdown, unattended transient combustibles were found without a corresponding transient combustible permit.

These transient combustibles were brought into the room on October 19, 2023, for a conduit installation. Constellation generated AR 4711095 documenting the unattended transient combustibles in the TCEZ and removed the transient combustibles.

The inspectors reviewed OP-AA-201-009 and noted that a TCEZ is defined as an area in the plant in which transient combustible materials are prohibited when not constantly attended, depending on plant operations. Additionally, OP-AA-201-009, step 4.4.3.1, stated that in combustible control zones, all transient combustible materials MUST be either: Constantly ATTENDED, CONTAINED in closed metal containers with closed metals lids/openings, or have a Transient Combustibles Permit (TCP). Combustible control zones are defined as a combustible free zone, TCEZ, transient combustible free zone, and transient free zone.

The inspectors reviewed calculation CA02243, "Combustible Loading Analysis Revision,"

Revision 4, for fire area 16, and noted it had no allowable margin. The transient combustible found in the room had a loading of 823,850 BTU.

Corrective Actions: Constellation removed the associated transient combustibles from the areas when identified on October 17, 2023 and October 19, 2023. Constellations corrective action for the October 19 transient combustibles included performing a human performance review board. Additionally, on October 19, 2023, Standing Order 23-13, was issued requiring restricted access to TCEZs, the logging of all transient combustibles into TCEZs, and a supervisor to perform an independent walkdown of the area following the removal of transient combustibles.

Corrective Action References: AR 4711095, AR 4710362

Performance Assessment:

Performance Deficiency: The inspectors determined that Constellations failure to implement OP-AA-201-009 for the control of transient combustibles was a performance deficiency.

Specifically, on October 17, 2023 and October 19, 2023, Constellation failed to properly control the transient combustibles in a no combustible storage area and a TCEZ.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Protection Against External Factors 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 transient combustible additional fire loading was not within the fire hazard analysis limit. This issue is similar to IMC 0612, Appendix E, Examples of Minor Issue, Example 4.j, because the fire loading was not within the fire hazard analysis limits.

Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The finding screened to very low safety significance (Green) based on association with Fire Prevention and Administrative Controls and assignment of a Low degradation rating in accordance with 2 because the actual transient combustibles were not low flashpoint liquids or self-igniting combustibles.

Cross-Cutting Aspect: H.2 - Field Presence: Leaders are commonly seen in the work areas of the plant observing, coaching, and reinforcing standards and expectations. Deviations from standards and expectations are corrected promptly. Senior managers ensure supervisory and management oversight of work activities, including contractors and supplemental personnel.

Specifically, Constellation identified that leaders did not adequately enforce the standards.

Enforcement:

Violation: Unit 1, Renewed Facility Operating License for Calvert Cliffs Nuclear Power Plant, Condition 2.E., requires, in part, that Constellation implement and maintain in effect all provisions of the approved fire protection program that comply with 10 CFR 50.48(a) and 10 CFR 50.48(c), as specified in the License Amendment Request, dated September 24, 2013, and as approved in the NRC Safety Evaluation, dated August 30, 2016.

NRC Safety Evaluation, dated August 30, 2016, stated, in part, to implement and maintain fire protection program in accordance with 10 CFR 50.48(c), National Fire Protection Association (NFPA)-805, "Performance-Based Standard Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition. NFPA 805, Section 3.3.1.2, "Control of Combustible Materials," required procedures for the control of general housekeeping practices and the control of transient combustibles shall be developed and implemented. OP-AA-201-009, Control of Transient Combustible Material, Revision 29, contained the procedure requirements for the control of transient combustible materials.

Contrary to the above, on October 17, 2023 and October 19, 2023, Constellation failed to control transient combustible materials by OP-AA-201-009.

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

Failure to Implement Required Diverse and Flexible Coping Strategies (FLEX) Preventive Maintenance (PM)

Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.1] - 71111.24 Systems FIN 05000317,05000318/2023004-02 Resources Open/Closed A Green NRC-identified finding was identified for Constellation's failure to implement the required PM activities for FLEX equipment as specified in CC-CA-118, Diverse and Flexible Coping Strategies (FLEX), Spent Fuel Pool Instrumentation (SPFI), and Hardened Containment Vent System (HCVS) Program Document, Revision 5. Specifically, performance of loaded runs of the FLEX diesel generators and FLEX pumps were shorter than required, the performed frequency of some PMs were longer than specified, and several required PM tasks on other FLEX equipment did not have associated existing PMs to complete the tasks.

Description:

On September 14, 2023, the inspectors observed annual PM of equipment used for FLEX. The inspectors reviewed equipment run time requirements, testing parameters, and the PM that was performed.

The inspectors identified that the FLEX diesel generators were operated for approximately 30 minutes and the associated work order loaded run time requirement was two hours.

Constellation initiated AR 4702601 to capture the difference in run time requirements and reran the FLEX diesel generators for two hours.

The inspectors reviewed CC-CA-118, "Calvert Cliff Implementation of Diverse and Flexible Coping Strategies (FLEX) and Spent Fuel Pool Instrumentation Program," Revision 9, and noted that it states, in part, "2. FLEX equipment is maintained under the site's PM program 4.

PM requirements for FLEX Direct Equipment, FLEX Support Equipment, and FLEX Equipment storage buildings and associated support systems are defined in CC-AA-118, 3."

The inspectors reviewed CC-AA-118, Diverse and Flexible Coping Strategies (FLEX), Spent Fuel Pool Instrumentation (SPFI), and Hardened Containment Vent System (HCVS) Program Document, Attachment 3, and noted it contained a list of required PMs for FLEX equipment.

This included a requirement to perform loaded runs of the FLEX diesel generators for two hours at a minimum.

The inspectors also noted that the annual PM requirement for the diesel-driven FLEX main pumps (e.g., auxiliary feedwater pump, reactor coolant system make-up pump) was to perform a full flow test for two hours at a minimum. The work orders for FLEX pumps stated that the pumps were to start and run the diesel at minimum of 30 minutes full flow. The inspectors observed a FLEX auxiliary feedwater pump run of approximately an hour and identified that there were no criteria to determine if full flow was met.

Constellation initiated AR 4704844, to capture that not all requirements of CC-AA-118, Revision 5, were implemented.

As a result, Constellation performed an extent of condition on FLEX PMs as documented in AR 4705896, and determined that multiple PM items specified in CC-AA-118, Attachment 3, were found to be missing, inadequate, or had the wrong specified periodicity.

Corrective Actions: Constellations planned corrective actions include aligning the FLEX PM templates to the CC-AA-118 requirements, performing a self-assessment on the FLEX program, and to create a site-specific PM user aid.

Corrective Action References: ARs 4702601, 4704844, and 4705896

Performance Assessment:

Performance Deficiency: The inspectors determined that Constellations failure to implement the required PM activities for FLEX equipment as specified in CC-AA-118, was a performance deficiency. Specifically, performance of loaded runs of the FLEX diesel generators and FLEX pumps were shorter than required by CC-AA-118, the performed frequency of PMs were longer than specified in CC-AA-118 (e.g., functional testing of fuel tank pumps and FLEX equipment nozzles and valves), and several required CC-AA-118 PM tasks on other FLEX equipment (e.g., FLEX equipment starting batteries, tracker loaders, etc.) did not have associated existing PMs to complete the tasks.

Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, absent NRCs intervention, the licensees failure to establish and perform appropriate PMs could lead to deterioration and resultant failures of FLEX equipment to perform their function. This issue was also similar to IMC 0612, Appendix E, Example of Minor Issues, Example 13.a. This finding was associated with the Mitigating System cornerstone.

Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, Exhibit 2, Section E, "Flexible Coping Strategies (FLEX)." The finding screened to very low safety significance (Green) because both screening questions were answered as "No."

Cross-Cutting Aspect: H.1 - Resources: Leaders ensure that personnel, equipment, procedures, and other resources are available and adequate to support nuclear safety.

Specifically, PM task procedures were not adequately established for FLEX equipment.

Enforcement:

Inspectors did not identify a violation of regulatory requirements associated with this finding.

Minor Performance Deficiency 71152A ER-AA-520, Instrument Performance Trending Minor Performance Deficiency Minor Performance Deficiency: The inspectors selected NRC Finding 05000318,05000317/2023001-02, Failure to Follow Instrument Performance Trending Process, as an annual Problem Identification and Resolution sample because the central cause of the performance deficiency had the potential to adversely affect safety-related equipment reliability and operability. The finding was associated with not identifying and correcting adverse instrument performance trends as required by ER-AA-520, "Instrument Performance Trending," and past-operability assessments of degraded instruments were not performed. Inspection scope included review of issue documentation and prioritization, causal evaluation, corrective actions for the four instruments documented in the NRC Finding, and detailed evaluation of 12 additional safety-related instruments to assess whether licensee actions had properly addressed the extent of condition for the NRC Finding.

The principle corrective actions were

(1) implementation of an instrument out-of-tolerance action template, and

(2) focused training for engineering and operations staff on common-mode failure evaluations and past-operability assessments respectively. Notwithstanding these corrective actions, the inspectors identified continued knowledge deficiencies associated with implementing ER-AA-520. Corrective action to identify/document individual instrument adverse trends (IR 4565186-05) was inadvertently closed without being performed. The inspectors also identified several safety-related instruments with adverse performance trends, which the licensee had not evaluated. The licensee initiated issue report 4720886 to address ER-AA-520 knowledge deficiencies, identification and performance of instrument adverse trend evaluations, and to evaluate several instrument-specific calibration trends.

Screening: The inspectors determined the performance deficiency was minor. The inspectors determined failure to implement corrective actions to identify and correct adverse instrument performance trends as required by ER-AA-520 was a minor performance deficiency because there were not significant changes to operating margin and the instruments remained operable.

No findings of more than minor significance were identified.

Observation: Semi-Annual Trend Review 71152S The inspector 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 identification and control of transient combustibles. Inspector-identified examples included:

• Transient combustibles were identified in the 45 switchgear room which resulted in a violation, NCV 05000317/2023001-01, Failure to Adhere to the Requirements of a Transient Combustible Exclusion Zone, documented in inspection report 05000317, 05000318/2023001 (AR 4546736 and 4676524)

• Pooling of flammable diesel fuel oil in the fuel injector area of the Unit 2 B emergency diesel generator due to a notable fuel injector leak was identified near the end of a 24-hour surveillance test (AR 4691428)

• Transient combustibles (gloves) were identified on a scaffold pan in the Unit 1 A cable chase, a TCEZ (AR 4706539)

• Transient combustibles (foreign material exclusion covers and duct tape) were identified in the Unit 2 west electrical penetration room instead of being stored inside the designated metal toolbox in the room (AR 4711017)

• Permitted transient combustibles were identified in an improper plant storage area in the Unit 2 service water pump room labeled as a no combustible permanent plant storage area (AR 4717950)

• Transient combustible items were identified in a plant storage area labeled as a no combustible permanent plant storage area in the Unit 1 service water pump room (AR 4710362) and in a TCEZ in the Unit 1 cable spreading room (AR 4711095). A Green NRC-identified finding and non-cited violation (NCV 05000317/2023004-01)was identified. See Inspection Results of this inspection report for additional details regarding these examples Constellation evaluated prior identified gaps in housekeeping and transient combustion controls in AR 4683803 and determined that operations had not prioritized ensuring engaged and rigorous rounds and took actions to increase supervisor field observations of equipment operator rounds. In addition, Constellation placed NCV 05000317/2023004-01 in the corrective action program as AR 4710362 and 4711095. Inspectors independently evaluated the deficiencies noted above for significance in accordance with IMC 0612, Appendix B and Appendix E guidance. Except for NCV 05000317/2023001-01, which was previously dispositioned, and NCV 05000317/2023004-01, 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 January 22, 2024, the inspectors presented the integrated inspection results to Patrick Navin, Site Vice President, and other members of the licensee staff.

• On November 16, 2023, the inspectors presented the radiation monitoring instrumentation inspection results to Heath Crockett, Director of Organizational Performance and Regulatory, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

71111.04 Corrective Action AR 4717950 NRC ID: Transient Combustibles in the U-2 SRW PP Room 11/15/2023

Documents

Resulting from

Inspection

Procedures STP-O-90-2 AC Sources and On-Site Power Distribution Systems 7 Day 28

Operability Verification

71111.05 Corrective Action AR 4707335 Fire Door 551 Potential Noncompliance of Gap at Bottom of 10/05/2023

Documents Door

Resulting from AR 4711017 NRC-Identified Housekeeping / Transient Combustible Issue 10/19/2023

Inspection

Engineering ECP-13-000304 Generic Letter 86-10 Evaluation of Fire Doors for Various 5

Evaluations Non-Compliant Conditions

71111.06 Calculations M-94-01 Service Water Pump Room Flooding from a Passive Failure 01/05/1994

of the Saltwater Common Piping

Corrective Action AR 4707095 Possible Seal Degradation on Door 204 10/04/2023

Documents AR 4707099 Possible Seal Degradation on Door 213 10/04/2023

Resulting from

Inspection

Engineering ECP-20-000451 Structures, Systems, and Components Functional 0

Evaluations Classification for K-Line Doors

Miscellaneous NRC Safety Evaluation Report-Methodology for Postulating 02/24/1995

Passive Failure Pipe Break

ES-001 Flooding 5

71111.12 Corrective Action AR 04719988 NRC ID: Update CC-CA-FIP

Documents

Resulting from

Inspection

71111.13 Corrective Action AR 04711095 NRC-Identified Transient Combustibles in TCEZ Unattended 10/19/2023

Documents

Resulting from

Inspection

Miscellaneous CA-MODE-008 Calvert Cliffs Unit 2 TS 3.0.4.b Risk Assessment for 0

Inspection Type Designation Description or Title Revision or

Procedure Date

Inoperable U04999022 Transformer During Transition from

Mode 3 to Mode 2 and Mode 1 During Startup from 2F2301

Procedures ER-AA-600-1052 Risk Management Support of RICT 1

71111.15 Calculations SR-1796 Evaluation of Corrosion Limits for Reactor Coolant Pump 0

Driver Mount Flange and Hex Nuts - Cover to Case

Corrective Action AR 04722673 12 Inverter Frequency Pegged High 12/11/2023

Documents

Engineering ECP-23-000028 Calculation of Saltwater Flow for Single Service Water Heat 0

Changes Exchanger Operations

Engineering ECP-23-00028 Minimum Salt Water Flow for Service Water Plate Heat 0

Evaluations Exchangers

71111.24 Engineering CA-2022-02 Surveillance Frequency Control Program Evaluation for SR 0

Changes 3.8.1.11

Procedures STP-O-65A1-2 A Train Chemical and Volume Control System Valve 4

Quarterly Operability Test

Work Orders C93765859 Swap Bearings on 12 SRW Pump 10/14/2023

C9382712 Biennial Test of 1A DG 10/25/2023

C93855264 Biennial Test of 1B DG

C93911168 AFAS Equipment Response Testing 10/30/2023

71151 Miscellaneous MS09 PI Data MS09 PI Data 4Q2022-3Q2023 10/20/2023

4Q2022-3Q2023

MS10 PI Data MS10 PI Data 4Q2022-3Q2023 10/20/2023

4Q2022-3Q2023

71152A Corrective Action 04543297

Documents 04565186

Corrective Action 04720886

Documents

Resulting from

Inspection

Procedures ER-AA-520 Instrument Performance Trending 5

18