IR 05000317/2025003
| ML25343A067 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/09/2025 |
| From: | Matt Young Division of Operating Reactors |
| To: | Mudrick C Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2025003 | |
| Download: ML25343A067 (0) | |
Text
December 9, 2025
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 -
INTEGRATED INSPECTION REPORT 05000317/2025003 AND 05000318/2025003
Dear Christopher Mudrick:
On September 30, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Calvert Cliffs Nuclear Power Plant, Units 1 and 2. On December 1, 2025, the NRC inspectors discussed the results of this inspection with Peter Moodie, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Due to the temporary cessation of government operations, which commenced on October 1, 2025, the NRC began operating under its Office of Management and Budget-approved plan for operations during a lapse in appropriations. Consistent with that plan, the NRC operated at reduced staffing levels throughout the duration of the shutdown. However, the NRC continued to perform critical health and safety functions and make progress on other high-priority activities associated with the ADVANCE Act and Executive Order 14300. On November 13, 2025, following the passage of a continuing resolution, the NRC resumed normal operations. However, due to the 43-day lapse in normal operations, the Office of Nuclear Reactor Regulation granted the Regional Offices an extension on the issuance of the calendar year 2025, third quarter integrated inspection reports normally issued by November 15, 2025, to December 31, 2025. The NRC will resume the routine cycle of issuing inspection reports on a quarterly basis beginning with the calendar year 2025, fourth quarter integrated inspection reports, which will be issued 45 days after the fourth quarter ends on December 31, 2025.
Two findings of very low safety significance (Green) are documented in this report. Two of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations 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, Matt R. Young, Chief Projects Branch 2 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:
Report Numbers:
05000317/2025003 and 05000318/2025003
Enterprise Identifier: I-2025-003-0035
Licensee:
Constellation Energy Generation, LLC
Facility:
Calvert Cliffs Nuclear Power Plant, Units 1 and 2
Location:
Lusby, MD
Inspection Dates:
July 01, 2025 to September 30, 2025
Inspectors:
G. Dipaolo, Senior Resident Inspector
A. Tran, Senior Resident Inspector
C. Borman, Health Physicist
L. Dumont, Senior Reactor Inspector
S. Mercurio, Emergency Preparedness Inspector
J. Patel, Senior Resident Inspector
Approved By:
Matt R. Young, Chief
Projects Branch 2
Division of Operating Reactor Safety
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 Adequately Test Fire Safe Shutdown Equipment Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000317,05000318/2025003-01 Open/Closed
[P.2] -
Evaluation 71111.12 The inspectors identified a Green finding and associated non-cited violation (NCV) of the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License,
Condition 2.E, for failure to implement and maintain in effect all provisions of the approved fire protection program. Specifically, Constellation failed to ensure that equipment and components required to perform manual actions needed for fire safe shutdown were checked periodically to verify they were available to meet the manual action steps as required by Section 4.13.3 of CC-AA-211, Fire Protection Program, Revision 10.
Failure to Adequately Implement Fire Protection Program by Removing Requirements from Technical Requirements Manual Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000317,05000318/2025003-02 Open/Closed
[H.13] -
Consistent Process 71111.12 The inspectors identified a Green finding and associated non-cited violation (NCV) of the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License,
Condition 2E, for making an inappropriate change to Technical Requirements Manual (TRM),
Section 15.3.5, Fire Detection Instrumentation. Specifically, requirements to maintain the function of control room ventilation duct detection were deleted in a revision on February 5, 2019, even though the detector was required by the approved fire protection program.
Additional Tracking Items
None.
PLANT STATUS
Unit 1 began the inspection period at rated thermal power and operated at or near rated thermal power for the remainder of the inspection period.
Unit 2 began the inspection period at rated thermal power and operated at near or full power until July 14, 2025, when operators down powered to 93 percent to maintain condenser vacuum as directed by abnormal operating procedure (AOP) for loss of circulating water pump.
Following repairs, operators commenced power ascension and returned the unit to 100 percent power on July 15, 2025. 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.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather due to the approach of Hurricane Erin on August 21, 2025.
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) Unit 1, compressed air system, August 7, 2025
- (2) Unit 2, 21 auxiliary feedwater pump while 22 auxiliary feedwater pump was out of service for maintenance, August 27, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 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, 0C diesel generator, fire area 22, July 1, 2025
- (2) Units 1 and 2, 1B, 2A, and 2B diesel generator buildings, fire areas 28, 30, and 31, July 16, 2025
- (3) Unit 1, auxiliary building, 45' east and west electrical penetration rooms, fire areas 32 and 33, September 18, 2025
- (4) Unit 2, cable spreading room, 2C cable chase, and battery rooms, fire areas 17 and 17A, September 18, 2025
Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated and observed the onsite fire brigade training and performance during an unannounced fire drill on the 45 north service building on September 16, 2025.
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 component cooling pump rooms on July 23, 2025.
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 main control room when operators on Units 1 and 2 entered AOP-7L, "Circulating Water/Intake Malfunctions," due to high differential pressure on intake traveling screens caused by jellyfish intrusion on September 17, 2025.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 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, chemical and volume control letdown process radiation monitors, 1/2RY202-1/2, availability, reliability, and equipment corrective actions, August 5, 2025
- (2) Units 1 and 2, maintenance effectiveness review of infrequently operated equipment necessary to support safe shutdown due to a fire in the control room and cable spreading room, August 25, 2025
- (3) Units 1 and 2, Action Request (AR) 4887524, control room air conditioning supply damper, 0-HVAC-5342, went closed, September 23, 2025
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (3 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 13 high pressure safety injection pump planned maintenance, July 15, 2025
- (2) Units 1 and 2, elevated risk condition due to 11 and 23 auxiliary feedwater planned valve maintenance, September 3, 2025
- (3) Units 1 and 2, elevated risk condition and compensatory measures associated with 21 station service transformer unavailability, September 24, 2025
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) Units 1 and 2, AR 4887524, control room air condition supply damper went closed, August 6, 2025
- (2) Unit 1, AR 4889940, multiple unexpected alarms received on 1C18B for the 1B emergency diesel generator (EDG), August 22, 2025
- (3) Units 1 and 2, Temporary Configuration Change (TCC) 0-TCC-25-0017, operability of control room emergency ventilation and functionality of fire detection system with automatic function of supply duct smoke detector, 0AE5347, bypassed, September 12, 2025
- (4) Units 1 and 2, AR 4890827, 0C EDG did not start, September 19, 2025
- (5) Unit 1, AR 4890938, 17-11 4 kilovolt bus tie breaker, 1BKR152-1701, did not close in local control, September 26, 2025
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) (4 Samples)
- (1) Unit 2, Work Orders (WOs) 69391458 and 62517887, 21 emergency core cooling system pump room air cooler post-maintenance test following maintenance, September 22, 2025
- (2) Unit 1, WO 62601473, 11 125VDC station battery post-maintenance testing following modified discharge test, September 26, 2025
- (3) Unit 2, WO 62511163, 22 auxiliary feedwater post-maintenance testing following current-to-pressure instrument calibration, September 29, 2025
- (4) Unit 2, WO 62646172, 21 penetration room exhaust filter train post-maintenance testing following charcoal tray realignment maintenance, September 30, 2025
Surveillance Testing (IP Section 03.01) (3 Samples)
- (1) Unit 2, STP-O-5A12-1, "12 Auxiliary Feedwater Pump Quarterly Surveillance Test,"
Revision 14, July 15, 2025
- (3) Unit 1, O-008AFSSD-1, "1A Diesel Generator Fire Safe Shutdown Test," Revision 0, August 19, 2025
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
- (1) Unit 2, STP-O-73KB-2, "B-Train Containment Spray Pump and Check Valve Quarterly Operability Test," Revision 2, July 22, 2025
71114.02 - Alert and Notification System Testing
Inspection Review (IP Section 02.01-02.04) (1 Sample)
- (1) The inspectors evaluated the licensee's maintenance and testing of the station alert and notification system on September 8 through September 11, 2025, for the period of September 2023 through August 2025.
71114.03 - Emergency Response Organization Staffing and Augmentation System
Inspection Review (IP Section 02.01-02.02) (1 Sample)
- (1) The inspectors evaluated the readiness of the licensee's Emergency Preparedness Organization on September 8 through September 11, 2025.
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.01-02.03) (1 Sample)
- (1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes:
- 23-33, EP-AA-1011, Addendum 3, "Calvert Cliffs Nuclear Power Plant Emergency Action Levels," Revision 9
- 24-49, EP-AA-1000, "Standardized Radiological Emergency Plan,"
Revision 34
- 24-46, ECP-14-000209, "Replace Containment Area Radiation Monitor System"
- 25-22, EP-AA-122-100, "Drill and Exercise Planning and Scheduling,"
Revision 14
This evaluation does not constitute NRC approval.
71114.05 - Maintenance of Emergency Preparedness
Inspection Review (IP Section 02.01 - 02.11) (1 Sample)
- (1) The inspectors evaluated the maintenance of the emergency preparedness program on September 8 through September 11, 2025, for the period of September 2023 through August 2025.
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (2 Samples)
The inspectors evaluated:
- (1) A licensee operator simulator training scenario involving failures that resulted in the declaration of a General Emergency on August 5, 2025.
- (2) The conduct of an emergency preparedness drill in the main control room simulator, operations support center, and technical support center involving failures that resulted in the declaration of a General Emergency on September 16,
RADIATION SAFETY
71124.08 - Radioactive Solid Waste Processing & Radioactive Material Handling, Storage, &
Transportation
Radioactive Material Storage (IP Section 03.01)
The inspectors evaluated the licensees performance in controlling, labeling and securing the following radioactive materials:
- (1) Lake Davies radioactive waste storage area
Radioactive Waste System Walkdown (IP Section 03.02) (1 Sample)
The inspectors walked down the following accessible portions of the solid radioactive waste systems and evaluated system configuration and functionality:
- (1) Miscellaneous waste receiver tank and pumps
Waste Characterization and Classification (IP Section 03.03) (2 Samples)
The inspectors evaluated the following characterization and classification of radioactive waste:
- (1) Waste characterization of LSA-1, shipment number W25-008 (2)2024 Part 61 dry active waste stream characterization and analysis
Shipment Preparation (IP Section 03.04) (1 Sample)
- (1) The inspectors observed the preparation of radioactive shipment #W25-011 of dry active waste on September 24,2025.
Shipping Records (IP Section 03.05) (3 Samples)
The inspectors evaluated the following non-excepted radioactive material shipments through a record review:
- (1) UN3321 Radioactive material, low specific activity (LSA-11), Shipment number W24-009
- (2) UN3321 Radioactive material, low specific activity (LSA-11) Shipment Number W25-001
- (3) UN3321 Radioactive material, low specific activity (LSA-11) Shipment Number W25-006
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
IE01: Unplanned Scrams per 7000 Critical Hours Sample (IP Section 02.01)===
- (1) Unit 1, July 1, 2024 through June 30, 2025
- (2) Unit 2, July 1, 2024 through June 30, 2025
IE04: Unplanned Scrams with Complications (USwC) Sample (IP Section 02.03) (2 Samples)
- (1) Unit 1, July 1, 2024 through June 30, 2025
- (2) Unit 2, July 1, 2024 through June 30, 2025
MS07: High Pressure Injection Systems (IP Section 02.06) (2 Samples)
- (1) Unit 1, July 1, 2024 through June 30, 2025
- (2) Unit 2, July 1, 2024 through June 30, 2025
EP01: Drill/Exercise Performance (DEP) Sample (IP Section 02.12) (1 Sample)
- (1) July 1, 2024 through June 30, 2025
EP02: Emergency Response Organization (ERO) Drill Participation (IP Section 02.13) (1 Sample)
- (1) July 1, 2024 through June 30, 2025
EP04: Emergency Response Facility and Equipment Readiness (ERFER) (IP Section 02.14) (1 Sample)
This is a new NRC performance indicator, introduced in Nuclear Energy Institute (NEI) 99-02, Revision 8 (ML24331A114). Licensees began collecting data for this performance indicator on January 1, 2025.
- (1) January 1, 2025 through June 30, 2025
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, loss of shutdown cooling due to operations' de-energization of 21 4kV bus (AR 4841661), August 14, 2025
- (2) Units 1 and 2, saltwater pump degradation identified from 2024 NRC Age Related Degradation Inspection (ARs 4780069 and 4765586), August 25, 2025
- (3) Units 1 and 2, deficiencies in testing fire safe shutdown equipment associated with required manual actions (ARs 4801524 and 4842240), September 16, 2025
71153 - Follow-up of Events and Notices of Enforcement Discretion Personnel Performance (IP Section 03.03)
- (1) The inspectors reviewed and evaluated AR 4878330, trip of U-40000-12 feeder breaker and entry into AOP-7I, "Loss of 4KV, 480 Volt or 208/120 Volt Instrument Bus Power," on July 2, 2025.
- (2) The inspectors reviewed and evaluated AR 4881303, loss of 24 circulating water pump and entry into AOP-7L, "Circulating Water/Intake Malfunctions," on July 14, 2025.
- (3) The inspectors reviewed and evaluated AR 4900024, 21 battery discharge test abort due to failure of cell 54, on September 23,
INSPECTION RESULTS
Failure to Adequately Test Fire Safe Shutdown Equipment Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000317,05000318/2025003-01 Open/Closed
[P.2] -
Evaluation 71111.12 The inspectors identified a Green finding and associated non-cited violation (NCV) of the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License, Condition 2.E, for failure to implement and maintain in effect all provisions of the approved fire protection program. Specifically, Constellation failed to ensure that equipment and components required to perform manual actions needed for fire safe shutdown were checked periodically to verify they were available to meet the manual action steps as required by Section 4.13.3 of CC-AA-211, Fire Protection Program, Revision 10.
Description:
On September 13, 2024, AR 4801524 was written by operations to identify that equipment used in manual action steps to local start the 0C diesel generator and 1A EDG in AOP-09A-1(2), Control Room Evacuation and Safe Shutdown due to a Severe Control Room Fire, may require periodic or functional testing in accordance with CC-AA-211, Fire Protection Program, Revision 10. CC-AA-211, Step 4.13.3, required equipment and components required to perform various manual actions, such as local start of the 0C diesel generator or 1A EDG, needed for fire safe shutdown are checked periodically to verify they are available to meet the manual action steps. A provision is given that if a component must be operated at least once per operating cycle during normal plant operation, then the function is demonstrated and a formal test procedure is not required.
AR 4801524 created Assignment 02 to determine if additional test requirements were required for fire safe shutdown equipment by reviewing the action report, AOP-9A, and AR 1517272-15 by October 8, 2024. AR 1517272-15 was completed in 2014 and had actions to review test requirements for fire safe shutdown equipment.
Following the multiple deferrals of AR 4801524, Assignment 02, with the new due date of May 2, 2025, the inspectors performed a partial review of fire safe shutdown procedures to determine if equipment and components required to perform manual actions were periodically functionally checked or operated during normal plant operation. The inspectors performed partial reviews of AOP-9B-1, Safe Shutdown due to a Severe Cable Spreading Room Fire, Revision 24, and AOP-9X-2, Safe Shutdown due to a Severe Fire, Revision 1.
The inspectors partial review identified nine pieces of equipment necessary for fire safe shutdown that were neither periodically tested per the preventive maintenance program nor periodically manipulated during normal plant operations. This included equipment necessary to fulfill risk-significant actions such as local/remote bus feeder breaker switches, manual emergency start push buttons, the 1A EDG synchronizing jack, local circuit breaker controls, etc. Based on the inspectors review, Constellation concluded that there were no periodic tests for the 1A EDG and 0C diesel generator local start and synchronizing necessary for safety shutdown manual actions. Constellation entered the issue into the corrective action program on March 3, 2025, as AR 4842240.
Corrective Actions: Constellation entered the issue into the corrective action program, initiated an extent-of-condition review, and performed testing on the 1A EDG and 0C diesel generator.
Corrective Action References: ARs 4842240, 4869369, 4871225, and 4801524
Performance Assessment:
Performance Deficiency: The inspectors determined that the failure to perform periodic functional testing on active equipment and components associated with manual actions for fire safe shutdown on Units 1 and 2 was a performance deficiency. Specifically, Constellation did not perform periodic functional testing as required by the fire protection program, CC-AA-211, to ensure manual actions required for safe shutdown were available in the event of a significant fire.
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, required periodic checks or testing of all equipment and components required to perform manual actions needed for fire safe shutdown were not performed as required by the fire protection program, CC-AA-211.
Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The finding was associated with the Post-fire Safe Shutdown category and was not assigned a low degradation rating in Step 1.3.1, because it did not constitute a minor procedure deficiency.
Question 1.4.7-C was answered Yes because the finding could adversely affect the ability to reach and maintain safe and stable conditions using the credited safe shutdown success path. Calvert Cliffs Nuclear Power Plant has a fire probabilistic risk assessment (PRA) model, therefore, Step 1.5, Screen Based on Licensee Fire PRA Result, applies. Constellation completed a PRA-based risk evaluation of this issue and concluded the bounding change in core damage frequency (delta CDF) and large early release frequency (delta LERF) was less than 1E-6 and less than 1E-7, respectively. A regional senior reactor analyst reviewed Constellations risk assessment. Based on satisfactory testing of the risk-significant circuits as well as the risk results provided by Constellation, the senior reactor analyst determined the risk associated with the performance deficiency was of very low safety significance (Green).
Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, actions in AR 4801524 to review fire safe shutdown procedures to determine if additional test requirements were needed were deferred multiple times over an eight-month period.
Enforcement:
Violation: Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License, Condition 2.E, required, 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, as supplemented, and approved by NRC safety evaluation dated August 30, 2016.
NRC safety evaluation dated August 30, 2016, states, in part, to implement and maintain the 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 Plant, 2001 Edition. NFPA 805, Section 3.2, Fire Protection Plan, required a site-wide fire protection plan shall be established. CC-AA-211, Fire Protection Program, Revision 10, established the fire protection plan for Calvert Cliffs Nuclear Power Plant.
CC-AA-211, Section 4.13.3. Equipment and Components Required to Perform Manual Actions or Repairs, required equipment and components required to perform various manual actions needed for fire safe shutdown are checked periodically to verify they are available to meet the manual action steps.
Contrary to the above, as of December 1, 2025, Constellation did not implement and maintain in effect all provisions of the approved fire protection program, in that, Constellation failed to ensure that equipment and components required to perform various manual actions needed for fire safe shutdown, such as local start of the 0C diesel generator or 1A EDG, were checked periodically to verify they were available to meet the manual action steps.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Adequately Implement Fire Protection Program by Removing Requirements from Technical Requirements Manual Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000317,05000318/2025003-02 Open/Closed
[H.13] -
Consistent Process 71111.12 The inspectors identified a Green finding and associated non-cited violation (NCV) of the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License, Condition 2E, for making an inappropriate change to Technical Requirements Manual (TRM),
Section 15.3.5, Fire Detection Instrumentation. Specifically, requirements to maintain the function of control room ventilation duct detection were deleted in a revision on February 5, 2019, even though the detector was required by the approved fire protection program.
Description:
On July 31, 2025, at 1744, control room operators noted that 0-PO-5342, control room air conditioning supply damper, had closed and reopened. While the damper was closed, control room ventilation was out of service requiring entry into Technical Specification Limiting Condition for Operation (LCO) 3.0.3, LCO 3.7.8, Control Room Emergency Ventilation System, and LCO 3.7.9, Control Room Emergency Temperature System.
Closure of 0-PO-5342 was due to inadvertent actuation of smoke detector 0AE5347, control room (Room 405) ventilation duct smoke detector, located in the control room ventilation return duct header. Operators exited the associated Technical Specification LCOs when the damper reopened.
Operators failed open 0-PO-5342 to prevent inadvertent damper closure. Failing 0-PO-5342 open, rendered the auto closure function provided by smoke detector 0AE5347 non-functional. Operators entered TRM 15.3.5, Fire Detection Instrumentation, on August 1, 2025, at the time considering the requirements of the TRM applied to smoke detector 0AE5347.
Following engineering and operations review of the history of TRM 15.3.5, operations exited TRM 15.3.5 for control room ventilation duct smoke detector 0AE5347 on August 27, 2025.
This was based on a revision (Revision 00200) to the TRM made in 2019 to reflect changes in fire protection licensing basis from Appendix R to NFPA 805. The revision removed smoke detector 0AE5347 from the requirements of TRM 15.3.5.
The inspectors reviewed the Calvert Cliffs Nuclear Power Plant licensing basis for NFPA 805.
License amendment request Attachment C, Attachment C - NEI 04-02 Table B-3 - Fire Area Transition, as supplemented by a letter dated February 24, 2016, required ionization smoke detection in control room ventilation ductwork because of Existing Engineering Equivalency Evaluation (EEEE) 91-0205-02. EEEE 91-0205-02, Room 512 to CR-Fire Damper 0FD512F1 and 0FD512F2, Revision 000, accepted the non-conforming arrangement of the associated fire dampers based on several factors including fire detection in the control room ventilation ductwork (including automatic shut-off of ventilation to the control room upon in-duct detection of smoke). The changes to the Calvert Cliffs Nuclear Power Plant fire protection licensing basis to reflect the requirements of NFPA 805 were approved by NRC safety evaluation (ML16175A359) dated August 30, 2016. The inspectors concluded that the changes made to remove smoke detector 0AE5347, control room (Room 405) duct smoke detector, from the requirements of TRM 15.3.5 in Revision 00200, were inappropriate.
Corrective Actions: Operations declared smoke detector 0AE5347 non-functional, and contingency measures of TRM 15.3.5, Fire Detection Instrumentation, were entered.
Corrective Action References: ARs 4887524, 4893548, 4895583, and 4895878
Performance Assessment:
Performance Deficiency: The inspector determined that the inappropriate removal of control room duct smoke detector (0AE5347) from the TRM in Revision 00200, was a performance deficiency. Specifically, Constellations submittal of the license amendment to implement the requirements of NFPA 805 required the smoke detector to be functional because it was relied upon as justification for EEEE 91-0205-02 (Room 512 to Control Room - Fire Dampers 0FD512F1 and 0FD512F2).
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, inappropriate removal of control room ventilation duct smoke detector from the requirement of TRM 15.3.5, Fire Detection Instrumentation, affected the availability, reliability, and capability of the control room emergency ventilation system from responding to a fire by removing the required automatic function of the smoke detector without taking appropriate compensatory measures.
Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix F, Fire Protection and Post - Fire Safe Shutdown SDP. The inspectors determined the finding was of very low safety significance (Green) because it was associated with Fire Confinement category and was assigned a low degradation rating in Step 1.3.1. This was because the damper controlled by the control room ventilation duct smoke detector (0AE5347) was still capable of closing completely by remote switch operation from the control room.
Cross-Cutting Aspect: H.13 - Consistent Process: Individuals use a consistent, systematic approach to make decisions. Risk insights are incorporated as appropriate. Specifically, the current fire protection licensing bases (e.g., implementing the requirement of NFPA 805) was not reviewed using a consistent process when exiting TRM 15.3.5 for control room ventilation duct smoke detector (0AE5347) on August 27, 2025.
Enforcement:
Violation: Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License Condition 2.E required, 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, as supplemented by letter dated February 24, 2016, and approved by NRC safety evaluation dated August 30, 2016.
The license amendment request Attachment C, as supplemented by letter dated February 24, 2016, and as approved by NRC safety evaluation dated August 30, 2016, required control room (Room 405) duct smoke detection because it supported EEEE 91-0205-02 (Room 512 to Control Room - Fire Dampers 0FD512F1 and 0FD512F2).
Contrary to the above, Constellation failed to maintain all provisions of the approved fire protection program when requirements for control room duct smoke detection were removed from the TRM, Section 15.3.5, Fire Detection Instrumentation, on February 5, 2019.
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 Review of Fire Safe Shutdown Equipment Testing 71152A The inspectors reviewed Constellations actions in response to AR 4801524. AR 4801524 was written to identify that equipment used in manual action steps to locally start the 0C diesel generator and 1A EDG in AOP-09A-1(2), Control Room Evacuation and Safe Shutdown due to a Severe Control Room Fire, may require periodic or functional testing.
During the review, the inspectors identified NCV 05000517,05000518/2025003-01, of the Calvert Cliffs Nuclear Power Plant, Units 1 and 2, Renewed Facility Operating License, Condition 2.E, for failure to implement and maintain in effect all provisions of the approved fire protection program which is documented in the results section of this report.
The inspectors' technical review of AR 4801524 identified several pieces of equipment necessary to fire safe shutdown that were neither tested per the preventive maintenance program nor periodically manipulated during normal plant operations, contrary to CC-AA-211, Fire Protection Program. The deficiency was entered into the corrective action program as AR 4842240, Fire Protection Equipment Testing. AR 4842240 documented that no periodic test or operation during normal plant operation existed for the local start or synchronizing switches associated with the 0C diesel generator and 1A EDG, required to be manually operated during certain fire safe shutdown scenarios, contrary to the CC-AA-211, Fire Protection Program, requirements. AR 4842240 was given a significance level of 4, with planned actions to create a preventive maintenance periodic functional test of the switches and to perform an extent-of-condition review. Because AR 4842240 was assigned a significance level of 4, no investigation was planned.
The inspectors reviewed AR 4842240 against the screening criteria contained in PI-AA-120, Issue Identification and Screening Process, Revision 13. Attachment 2, CAP Issue Report Level and Class Criteria, contained guidance and examples of the different significance levels of issues. The inspectors questioned whether the significance level of AR 4842240 should have been assigned a significance level 3 based on the non-conforming condition of not testing equipment necessary for fire safe shutdown in accordance with the requirements of CC-AA-211. Constellation determined that AR 4842240 met the significance level 3 criteria because the issue constituted the failure to follow a level 2 or 3 procedure that resulted in undesirable consequences.
Constellation entered the issue into the corrective action program as AR 4869369, AR 4842240 not Screened at the Correct Significance Level. AR 4842240 was reclassified with a significance level 3 and a work group evaluation was performed to determine corrective actions to restore compliance. The inspectors determined that the inappropriate significance level assignment was minor because action items, vice corrective actions, were planned to restore compliance with the testing requirements of CC-AA-211.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 1, 2025, the inspectors presented the integrated inspection results to Peter Moodie, Site Vice President, and other members of the licensee staff.
- On September 11, 2025, the inspectors presented the emergency preparedness program inspection results to Angela Dowell, Senior Manager Regulatory and Learning Programs, and other members of the licensee staff.
- On September 26, 2025, the inspectors presented the 71124.08 radioactive solid waste processing and radioactive material handling, storage, and transportation inspection results to Christopher Smith, Plant Manager, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Procedures
OP-AA-108-111-
1001
Severe Weather and Natural Disaster Guidelines
OP-CA-108-111-
1001
Severe Weather Preparation
007
Procedures
FFSM-119
NFPA 805 Fire Area 17A
FFSM-122
NFPA 805 Fire Area 17
FFSM-165
NFPA 805 Fire Area DGB2
FFSM-59
NFPA 805 Fire Area 32
FFSM-63
NFPA 805 Fire Area 44
Corrective Action
Documents
Resulting from
Inspection
1/2 RY202-1/2 Letdown Process Radiation Monitor - Process
Gaps
07/22/2025
Corrective Action
Documents
CR A/C Supply Damper, 0-HVAC-5342, Closed
07/31/2025
Drawings
60723SH0004
Ventilation Systems Control Room and Cable Spreading
Room HVAC
Corrective Action
Documents
Abnormal Noise when Stopping 22 Containment Spray
Pump
07/19/2025
Drawings
18002-
0083SH0019
DGP SACM Elementary Contact Layout of Switches
18002-
0083SH0027
Elementary Diagram Phase Measuring
18002-
0083SH0155
DGP SACM Elementary Diagram Counter Start Number and
Isolation Relay
18002-
0083SH0181
DGP SACM Relay Cross References (Instantaneous Relays
- RF202 Type)
61086SH0084
Schematic Diagram 4KV Unit Bus 17 Diesel Generator 1A
Breaker 152-1703
Procedures
O-008AFSSD-1
1A Diesel generator Fire Safe Shutdown Test
Miscellaneous
Calvert Cliffs Nuclear Power Plant (CCNPP) Alert and
Notification System (ANS) Design Report
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
04886454
Objective 3 - NRC EP Self-Assessment Ops Min Shift
Staffing
07/28/2025
Procedures
Addendum 1
Calvert Cliffs Nuclear Power Plant On-Shift Staffing
Technical Basis
OP-CA-119-1001
Shift Staffing, Overtime and Vacation Guidelines
OP-CA-119-1001
Shift Staffing, Overtime and Vacation Guidelines
Procedures
CFR 50.54(q) Change Evaluation
Miscellaneous
Constellation Standardized Radiological Emergency Plan
Exelon Nuclear Radiological Emergency Plan Annex for
Calvert Cliffs Station
71151
Corrective Action
Documents
Resulting from
Inspection
June 2025 Unplanned Downpower Performance Indicator
Error
07/28/2025
Miscellaneous
F.506944-
C/Calvert Cliffs
Failure Analysis Report GE VB-4.16-250-3 Circuit Breaker
09/10/2025