IR 05000263/2025010
| ML26026A332 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 01/28/2026 |
| From: | Jasmine Gilliam NRC/RGN-III/DORS/EB1 |
| To: | Hafen S Northern States Power Company, Minnesota |
| References | |
| IR 2025010 | |
| Download: ML26026A332 (0) | |
Text
SUBJECT:
MONTICELLO NUCLEAR GENERATING PLANT - COMPREHENSIVE ENGINEERING TEAM INSPECTION REPORT 05000263/2025010
Dear Shawn Hafen:
On December 18, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Monticello Nuclear Generating Plant and discussed the results of this inspection with Michelle Neal and other members of your staff. The results of this inspection are documented in the enclosed report.
Five findings of very low safety significance (Green) are documented in this report. Five 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 III; the Director, Office of Enforcement; and the NRC Resident Inspector at Monticello Nuclear Generating Plant.
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 III; and the NRC Resident Inspector at Monticello Nuclear Generating Plant.
January 28, 2026 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, Jasmine A. Gilliam, Chief Engineering Branch 2 Division of Operating Reactor Safety Docket No. 05000263 License No. DPR-22
Enclosure:
As stated
Inspection Report
Docket Number:
05000263
License Number:
Report Number:
Enterprise Identifier:
I-2025-010-0044
Licensee:
Northern States Power Company, Minnesota
Facility:
Monticello Nuclear Generating Plant
Location:
Monticello, MN
Inspection Dates:
August 25, 2025 to December 18, 2025
Inspectors:
C. Baron, Contractor
T. Briley, Senior Reactor Inspector
J. Corujo-Sandin, Senior Reactor Inspector
M. Gangewere, Senior Reactor Inspector
S. Kobylarz, Contractor
G. Nicely, Contractor
M. Siddiqui, Reactor Inspector
M. Yeminy, Contractor
Approved By:
Jasmine A. Gilliam, Chief
Engineering Branch 2
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a Comprehensive Engineering Team Inspection at Monticello Nuclear Generating Plant, 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
Maintaining Applicability of EPRI MOV PPM Predictions Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-01 Open/Closed
[P.5] -
Operating Experience 71111.21M The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50.55a(b)(3)(ii) when the licensee failed to establish a program to ensure that motor operated valves (MOVs) continued to be capable of performing their design basis safety functions. Specifically, the licensee failed to account for and adhere to all the precautions, limitations, and conditions when using the Electric Power Research Institute (EPRI) MOV Performance Prediction Methodology (PPM) model. This was contrary to the sites Motor Operated Valve Program (procedure FP-PE-MOV-07) and 10 CFR 50.55a(b)(3)(ii).
Failure to Translate the Correct Motor Control Center Voltage and Safety-Related Direct Current Motor Operated Valve Vendor Motor Performance Data Curves into Motor Operated Valve Voltage, Torque, and Thrust Calculations Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-02 Open/Closed None (NPP)71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the licensees failure to assure that applicable regulatory requirements and the design basis for safety-related direct current (DC)motor operated valves (MOVs) were correctly translated into specifications, drawings, procedures, and instructions. Specifically, electrical and mechanical calculations performed under engineering change 25729 to incorporate updated Limitorque motor performance data curves to ensure that each safety-related DC MOV would be capable of performing its design basis safety function contained technical errors which, in many cases, reduced MOV operational margins. Errors included: (1) non-conservative motor control center (MCC)voltages; and (2) the electrical (DC load flow) and corresponding mechanical (motor operated valve intelligent diagnostic and analysis system (MIDAS)) calculations each utilized different motor performance data curves for the same MOV.
Failure to Correct MOV Testing Frequency Following Replacement Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-03 Open/Closed
[H.10] - Bases for Decisions 71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to correct a condition adverse to quality. Specifically, the licensee failed to correct the inadequate periodic verification testing (PVT) frequency on safety-related (SR) valve, MO-2036, when Corrective Action Program (CAP) document 50100076098 was closed with insufficient justification to defer PVT testing beyond the required testing interval, following valve replacement in 2019.
Failure to Follow ASME OM Testing Requirements After Failing Acceptance Criteria Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-04 Open/Closed
[H.3] - Change Management 71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50.55a(f)(4)(ii) for the licensees failure to perform the required inservice testing (IST) to verify the operational readiness of main steam isolation valve (MSIV) AO-2-80A, a valve whose function was required for safety.
Specifically, the licensee failed to retest or declare inoperable AO-2-80A following an as-found failure to meet stroke time acceptance criteria under Work Order (WO) 700113220.
Failure to Account Instrument Bias in Acceptance Criteria for the 11 Emergency Diesel Generator Technical Specification Surveillance Tests Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-05 Open/Closed
[P.2] -
Evaluation 71111.21M The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when the licensees procedures 0187-01B, 0187-01, and OSP-ECC-0566-01 failed to include appropriate quantitative or qualitative acceptance criteria for determining the important activities affecting quality were satisfactorily accomplished. Specifically, the licensee decided to continue to utilize frequency meter (F/DG1/C-08) with a known bias and failed to account for the bias in the respective procedures acceptance criteria.
Additional Tracking Items
None.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.21M - Comprehensive Engineering Team Inspection For each component sample, the inspectors reviewed the licensing and design bases including:
- (1) the Updated Final Safety Analysis Report (UFSAR);
- (2) the Technical Specifications (TS);and
- (3) the Technical Requirements Manual (TRM). The inspectors reviewed a sample of operating procedures (including normal, abnormal and emergency procedures), overall system/component health (including condition reports and operability evaluations, if any) and associated maintenance effectiveness (e.g., Maintenance Rule, procedures). The inspectors performed visual inspections of the accessible components to identify potential hazards and/or signs of degradation. Additional component specific design attributes reviewed by the inspectors are listed below.
Structures, Systems, and Components (SSCs) (IP section 03.01) (5 Samples)
- (1) BUS 15 4.16KV Switchgear (BUS 15)
1. Translation of vendor specifications
2. Electrical design calculations and considerations:
a.
Loading calculations b.
Short circuit calculations c.
Voltage regulation d.
BUS capacity e.
Degraded voltage protection f.
Overcurrent protection g.
Loss of voltage (2)11 Emergency Diesel Generator (EDG) (G-3A)
1. Translation of vendor specifications
2. Environmental qualification
3. Protection against external events:
a.
Seismic b.
Fire
4. Mechanical design calculations and considerations:
a.
Engine sizing b.
Engine lubrication c.
Room heat up calculations d.
Jacket water cooler e.
Fuel oil volume consumption f.
Fuel oil available volume/level and vortexing g.
Fuel oil transfer design:
i.
Number of pumps ii.
flow capacity iii.
net positive suction head (NPSH)iv.
adequacy of design v.
pump swap vi.
operator actions.
h.
Combustion air supply design i.
Exhaust system design j.
Starting air design:
i.
system capacity ii.
compressors iii.
setpoints and alarms iv.
Station Blackout (SBO) recovery capability
5. Test/inspection procedures, acceptance criteria, and recent results:
a.
Engine b.
TS surveillances c.
Lube oil cooler d.
Jacket water cooler e.
Fuel oil volume f.
Starting air
6. Electrical design calculations and considerations:
a.
Starting circuit Direct Current (DC) power for LOCA/LOOP and SBO recovery b.
DC Field flashing and starting air solenoid capability c.
Output breaker control logic d.
Diesel combustion air temperature
7. Fuel Oil Transfer Pump (FOTP) potential issues:
a.
FOTP NPSH under low level conditions b.
Foot valve parameters c.
Potential voiding in the FOTP suction line
8. EDG Room Cooling Fan/Blower
a.
Fans / Blowers room cooling capacity b.
Minimum Fan(s) flow rate capacity requirements under the most limiting design conditions c.
Dampers adequacy, quality rating, maintenance, replacement parts, and modes of failure.
9. Incoming Breaker 125VDC control circuits
- (3) HPCI Turbine Steam Supply (MO-2036)
1. Protection against external events:
a.
Seismic
2. Use of Electric Power Research Institute (EPRI) Performance Prediction
Methodology (PPM)
3. Mechanical design
a.
Weak link analysis b.
Required thrust (torque) MIDAS and PPM Calculations c.
Pressure locking and/or thermal binding d.
Maximum differential pressure
4. Test/inspection procedures, acceptance criteria, and recent results:
a.
Inservice Testing (IST)b.
Thermal overload testing c.
TS Required Surveillance d.
Leak Rate Testing
5. Motor power requirements:
a.
Voltage drop b.
Control logic c.
Control voltage drop d.
Load flow e.
Thermal overload f.
Required minimum voltage g.
Motor thermal overload protection h.
Protective devices (4)11 ESW Pump (P-111A)
1. Translation of vendor specifications
2. Protection against external events:
a.
Seismic
3. Mechanical design calculations and considerations:
a.
Flow capacity & balance b.
Minimum flow c.
Sump/pool level setpoints and instrument uncertainty
4. Test/inspection procedures, acceptance criteria, and recent results:
a.
Pump comprehensive IST surveillances b.
Flow balance/capacity tests
5. Electrical design calculations and considerations:
a.
Overcurrent relay setpoint b.
Control voltage c.
Starting and running voltage at offsite degraded voltage d.
Brake horsepower/motor service factor (5)13 Outboard Main Steam Isolation Valve (MSIV) (AO-2-86C)
1. Translation of vendor specifications
2. Protection against external events:
a.
3. Mechanical design calculations and considerations:
a.
Required thrust (torque)b.
Maximum allowed leakage c.
Upstream filter capability to remove crud d.
Maximum differential pressure
5. Closure/Opening Time
6. Test/inspection procedures, acceptance criteria, and recent results:
a.
Leakage b.
IST c.
TS Required Surveillance d.
Leak Rate Testing
Modifications (IP section 03.02) (2 Samples)
- (1) Engineering Change (EC) 26182, Klockner Moeller 480VAC Upgrade For Degraded Voltage OBN On-Line Modifications to MCC 34 and 44 480VAC Cubicles
- (2) EC 601000000010, EDG 11 Oil Change from MOBILGARD 450 to MOBILGARD 410 10 CFR 50.59 Evaluations/Screening (IP section 03.03) (7 Samples)
- (1) SCR-22-0072, QF0501 - Change to Intercell Acceptance Criteria for D8 Battery
- (3) SCR-22-0043, QF0501 - 601000003663 - Revise 01-074
- (4) SCR-23-0040, QF0501 - Isolate One Main Steam Line Via MSIV During Power Operation
- (5) SCR-23-0163, QF0501 - Calculation 04-133 - Major Revision
- (6) SCR-23-0047, QF0501 - TRM 3.8.1 and 3.8.2 Surveillance Requirement
- (7) SCR-20-0050, 11 EDG Droop Modification
Operating Experience Samples (IP section 03.04) (1 Sample)
- (1) Information Notice (IN) 2021-01, Lessons Learned from US NRC Inspections of Design-Basis Capability of POVs
INSPECTION RESULTS
Maintaining Applicability of EPRI MOV PPM Predictions Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-01 Open/Closed
[P.5] -
Operating Experience 71111.21M The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50.55a(b)(3)(ii) when the licensee failed to establish a program to ensure that motor operated valves (MOVs) continued to be capable of performing their design basis safety functions. Specifically, the licensee failed to account for and adhere to all the precautions, limitations, and conditions when using the Electric Power Research Institute (EPRI) MOV Performance Prediction Methodology (PPM) model. This was contrary to the sites Motor Operated Valve Program (procedure FP-PE-MOV-07) and 10 CFR 50.55a(b)(3)(ii).
Description:
The EPRI MOV PPM, described in Topical Report TR-103237, EPRI MOV Performance Prediction Program, was developed to provide an analytical approach for determining the design basis thrust and torque requirements of safety-related MOV applications, in lieu of design basis testing. The NRC performed a safety evaluation (SE) (ADAMS Accession ML15142A761) and considered the EPRI MOV PPM as an acceptable methodology, with conditions and limitations, to predict the thrust or torque required to operate gate, globe, and butterfly valves within the scope of the program, and to bound the effects of load sensitive behavior on motor-actuator thrust output.
During the 2025 CETI inspection, the inspectors reviewed the safety-related high pressure coolant injection (HPCI) turbine steam supply valve, MO-2036, which used the EPRI MOV PPM to determine the design basis required thrust. On or about August 28, 2025, the inspectors noted during a review of the licensees MOV program procedures that Monticello had not implemented an adequate internal valve preventive maintenance program for the valves using the EPRI PPM methodology. That same day, inspectors informed the licensee the NRCs SE for the EPRI MOV PPM methodology stated PPM model users would need to ensure an adequate internal valve preventive maintenance program was established for the thrust or torque requirements predicted by the model to remain valid.
NRC regulations in 10 CFR 50.55a(b)(3)(ii), in part, required licensees to establish a program to ensure MOVs continue to be capable of performing their design basis safety functions. To comply with this requirement, the licensee implemented multiple procedures including procedure FP-PE-MOV-07, Motor Operated Valve Program. In this procedure, the licensee established the use of the EPRI MOV PPM for evaluating valves required to be in the MOV program (i.e., Generic Letter 89-10 and 96-05 programs). Section 5.5.3.2.a.2)b) of FP-PE-MOV-07 established that when using the EPRI PPM to determine valve thrust margin, the following conditions would be met:
- The guidance in the EPRI documentation and the NRC Safety Evaluation are met;
- Appropriate maintenance activities are performed to keep the MOV in good working order.
Further, Step 5.5.3.2.a.2)c), stated, the NRC had conditionally approved the EPRI PPM as documented in the NRC Safety Evaluation.
The NRC SE (page 10) relied on EPRI statements that the user is responsible for accounting for any potential changes to the MOV which may occur and which may affect the disk-to-seat friction, and that the default friction coefficients within the computer model will bound the disk-to-seat friction at any time, provided the MOV is properly maintained. The NRC SE (page 13) indicated that EPRI has stated that the use of the computer model assumes that the valve is in good condition. The NRC SE also noted that model users will need to ensure that an adequate internal valve preventive maintenance program is established for the thrust or torque requirements predicted by the model to remain valid. On page 23, it acknowledges the butterfly model assumes that the seat material of the butterfly valve is in good condition. It also notes EPRI recognizes that seating material of butterfly valves may degrade (lose flexibility) and cause higher seating or unseating torque than the torque calculated by the model. Also, on page 23, the SE establishes the NRC staff considers that the information from the EPRI program emphasizes the need for a butterfly-valve preventive maintenance program that addresses potential seat material degradation.
The inspectors questioned the licensee on whether they had established an internal valve preventive maintenance program in accordance with the guidelines in the NRC SE. The licensee provided written responses to the inspectors and also generated a White Paper (PPM Method for MNGP). In these, the licensee indicated they had not established an internal valve preventative maintenance program as EPRI did not require (nor had EPRI ever required) periodic internal inspections/disassembly or periodic differential pressure testing be performed for the implementation of a PPM evaluation or to maintain the ongoing validity of a PPM evaluation.
The licensee further indicated that static diagnostic testing required by the MOV program provided the site with reasonable assurance that the condition of the valve was within the restrictions put in place of PPM, and was in alignment with current industry practices, in that it employed the use of Static Diagnostic Testing techniques to validate acceptable ongoing valve performance. The inspectors disagreed with that assertion because the seat to disk friction factor cannot be determined with a static test. EPRI PPM provides a conservative calculation based on a tested friction value. This friction value remains valid provided the valve internals remain in good or as new condition. The EPRI PPM or static testing does not address the long term friction value change due to age, wear and tear. Hence why the SE expects model users to monitor and/or address long term degradation.
The inspectors concluded the information provided by the licensee did not describe sufficient activities to confirm the thrust and torque predictions provided by the EPRI PPM, for MOVs at Monticello, would be sufficient to provide reasonable assurance the MOVs would continue to perform their design basis safety functions over their service life. The activities referenced by the licensee, such as static diagnostic testing, periodic external MOV walkdowns, and the corrective action process provided insights into evaluating certain aspects of the valves external and internal condition. However, these activities would not confirm the valves internal condition support the continued applicability of the thrust or torque predictions by the EPRI MOV PPM for the design-basis operating requirements over the service life of the valve.
Corrective Actions: The licensee entered the inspectors concern into the CAP and planned to perform a Condition Evaluation to better understand the nonconformance. The licensee documented, in part, An enhancement exists in our implementation of our programmatic motor and air operated valves that are analyzed utilizing EPRI's Performance Prediction Model (PPM) to determine thrust or torque requirements to perform their design basis functions. The NRC performed a safety evaluation on the PPM in 1996 and one of the requirements of implementing PPM is Model users will need to ensure that an adequate internal valve preventive maintenance program is established for the thrust or torque requirements predicted by the model to remain valid. The user is also cautioned that aging conditions can influence valve performance. A sample of PPM valves has been reviewed, and any validation requirements of critical measurements strictly relies on the skill of the valve program owners to ensure the required PPM actions are adhered to.
In addition, the licensee planned to introduce a new fleet procedure to ensure all requirements of the PPM methodology and safety evaluation were adhered.
Corrective Action References: CAP 501000102459, PPM Implementation Requirements
Performance Assessment:
Performance Deficiency: The licensee failed to establish a program to ensure MOVs continue to be capable of performing their design basis safety functions. Specifically, the licensee failed to account for and adhere to all the precautions, limitations and conditions when using the EPRI MOV PPM model. This was contrary to the sites MOV Program (FP-PE-MOV-07)and 10 CFR 50.55a(b)(3)(ii).
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, failure to ensure the valves internal critical measurements remain consistent with the assumption/inputs of the EPRI MOV PPM model can lead to required thrust and torque values which exceed the models predictions. This could eventually lead to component deterioration and result in failures of MOV valves to perform their safety-related functions. This is consistent with more than minor example 13.a.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.
Specifically, the inspectors determined this finding was of very low safety significance (Green)because although the finding was a design or qualification issue of mitigating systems and components it did not result in a loss operability or PRA functionality.
Cross-Cutting Aspect: P.5 - Operating Experience: The organization systematically and effectively collects, evaluates, and implements relevant internal and external operating experience in a timely manner. Specifically, the NRC had provided guidance on use of the EPRI PPM and the SE in Information Notice (IN) 2021-01, Lessons Learned from US NRC Inspections of Design-Basis Capability of Power Operated Valves. The licensee reviewed IN-2021-01 under CAP 610000001303 and closed out the CAP on August 31, 2022, without implementing the full provisions of the EPRI PPM and NRC SE.
Enforcement:
Violation: Title 10 CFR 50.55a(b)(3)(ii) states, in part, the licensee must establish a program to ensure that MOVs continue to be capable of performing their design basis safety functions.
The licensee established Procedure FP-PE-MOV-07, Motor Operated Valve Program, Revision 11, as one of the implementing procedures to ensure MOVs continue to be capable of performing their design basis safety function. Regarding the use of the EPRI PPM, section 5.5.3.2.a.2)b) stated, in part, [W]hen determining thrust margin, any positive margin is considered high margin provided the following conditions are met:
- Appropriate maintenance activities are performed to keep the MOV in good working order.
FP-PE-MOV-07, Step 5.5.3.2.a.2)c), acknowledged the NRC had conditionally approved the EPRI PPM as documented in the NRC Safety Evaluations.
EPRI Topical Report TR-103237, EPRI MOV Performance Prediction Program, page 3-4 stated the use of the PPM requires specific information about the system and valve. Further, page 5-17 of TR-103237 stated the model is applicable to only valves which are properly fabricated and maintained.
EPRI Technical Report TR-103244-R1, EPRI MOV Performance Prediction Program Implementation Guide Revision 1, Section 4, Applicability Evaluation, stated in page 4-1 that In addition to meeting the specific applicability criteria described below, users must ensure that an adequate valve maintenance program is followed in order that the thrust/torque predictions made by the model remain valid over time.
EPRI Topical Report TR-106563, Application Guide for Motor-Operated Valves in Nuclear Power Plants, Volume 1, Revision 1: Gate and Globe Valves, stated in Section 5.1 when discussing the NRC acceptance of the EPRI MOV PPM that the long-term reliability of the PPM predictions depends on implementation of an appropriate preventive maintenance program for valves.
NRC SE dated March 15, 1996, determined the EPRI Topical Report TR-103237 (i.e., EPRI PPM), with the conditions and limitations described in the Safety Evaluation, was considered as an acceptable methodology to predict the thrust or torque required to operate gate, globe and butterfly valves.
NRC SE Section B, Specific Comments on EPRI Computer Model, specifically Section B.2.a, Gate Valve Model - Model Description, on page 10 establishes EPRI stated that the user is responsible for accounting for any potential changes to the MOV which may occur and which may affect the disk-to-seat friction. EPRI believes that the default friction coefficients within the computer model will bound the disk-to-seat friction at any time, provided the MOV is properly maintained.
NRC SE Section B.2.b, Gate Valve Model - Model Evaluation, on page 13 established that EPRI has stated that the use of the computer model assumes that the valve is in good condition. Model users will need to ensure that an adequate internal valve preventive maintenance program is established for the thrust or torque requirements predicted by the model to remain valid. The user is also cautioned that aging conditions can influence valve performance.
NRC SE Section B.3.b, Globe Valve Model - Model Evaluation, on page 20, states in part EPRI believes the thrust requirements for globe valves are not strongly influenced by friction forces between the seat and disk. Therefore, EPRI did not conduct preconditioning tests of its globe valves. The staff does not object to this practice by EPRI but notes that computer model users will need to establish appropriate preventive maintenance programs to address other aspects of valve aging.
Section B.4.b, Butterfly Valve Model - Model Evaluation, on page 23, states, in part, the butterfly valve model assumes the seat material of the butterfly valve is in good condition.
EPRI recognizes seating material of butterfly valves may degrade (lose flexibility) and cause higher seating or unseating torque than the torque calculated by the model. [...] The staff considers the information from the EPRI program emphasizes the need for a butterfly-valve preventive maintenance program that addresses potential seat material degradation.
Contrary to the above, as of September 11, 2025, the licensee failed to establish a program to ensure that MOVs continue to be capable of performing their design basis safety functions. Specifically, the licensee failed to account for and adhere to all the precautions, limitations, and conditions for the use of the EPRI PPM as required by FP-PE-MOV-07 Section 5.5.3.2.a.2)b). This was noted by the following examples:
1. Licensee failed to ensure an adequate internal valve preventive maintenance was
established for the thrust or torque requirements predicted by the PPM model to remain valid as discussed in SE sections B.2.a; B.2.b; B.3.b; and B.4.b.
2. FP-PE-MOV-07, Section 5.5.3.2.a.2)b) assumed appropriate maintenance activities
are performed to keep the MOV in good working order to ensure the thrust or torque requirements predicted by the PPM model remain valid. However, the licensee failed to justify this assumption.
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Translate the Correct Motor Control Center Voltage and Safety-Related Direct Current Motor Operated Valve Vendor Motor Performance Data Curves into Motor Operated Valve Voltage, Torque, and Thrust Calculations Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-02 Open/Closed None (NPP)71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, Design Control, for the licensees failure to assure that applicable regulatory requirements and the design basis for safety-related direct current (DC)motor operated valves (MOVs) were correctly translated into specifications, drawings, procedures, and instructions. Specifically, electrical and mechanical calculations performed under engineering change 25729 to incorporate updated Limitorque motor performance data curves to ensure that each safety-related DC MOV would be capable of performing its design basis safety function contained technical errors which, in many cases, reduced MOV operational margins. Errors included:
- (1) non-conservative motor control center (MCC)voltages; and
- (2) the electrical (DC load flow) and corresponding mechanical (motor operated valve intelligent diagnostic and analysis system (MIDAS)) calculations each utilized different motor performance data curves for the same MOV.
Description:
On August 27, 2025, the inspectors reviewed electrical and mechanical design basis calculations associated with safety-related DC MOV MO-2036, high pressure coolant injection (HPCI) turbine steam supply valve, and noted several discrepancies which were shared with the licensee the same day. The inspectors compared the MCC voltage feeding MOV MO-2036 from the electrical 250 volt DC division II battery sizing and load flow analysis (calculation 04-047) and the corresponding MCC voltage used by the mechanical MIDAS MOV torque and thrust calculation (MOVDS-MT:1:HPC:MO-2036). The inspectors noted that 1) the MIDAS calculation used the steady-state MCC voltage after MOV MO-2036 had started and unseated (versus the minimum or most limiting voltage that would bound the entire stroke of the valve), which would non-conservatively result in a higher terminal voltage and associated MOV torque/thrust values, and 2) the locked-rotor amperage for MOV MO-2036 used in the electrical DC load flow calculation was 51 amperes, whereas 81.5 amperes was used in the mechanical MIDAS calculation which would non-conservatively result in higher MCC voltages.
Non-Conservative MCC Voltages:
The inspectors determined the mechanical MIDAS calculation for MOV MO-2036 used a non-conservative steady-state MCC voltage versus a lower MCC voltage that was bounding for the entire stroke of the valve. One of the safety functions of MOV MO-2036 was to open under various plant conditions and was therefore assumed to have a lower bounding voltage while the valve operated near the full seated position. The MOV program, in part, was based upon NRC generic letter (GL) 89-10, Safety-Related Motor-Operated Valve Testing and Surveillance, issued to all licensees of operating nuclear power plants on June 28, 1989, and its associated supplements. The NRC expected licensees to use the voltage that would be present at the MOV when determining its ability to operate under design bases conditions and the licensee should determine a voltage that would be present at the MOV that is a lower bound for the expected voltage. The bounding requirements apply to all safety-related DC MOVs in the MOV program. Non-conservative usage of steady-state MCC voltages appeared to apply to multiple other safety-related DC MOVs in the MOV program (primarily HPCI-related DC MOVs that were supplied electrical power by MCC 312).
Use of Different Motor Currents for the DC Electrical Load Flow and Mechanical MIDAS Calculations:
The inspectors determined the electrical and mechanical safety-related DC MOV design bases calculations did not utilize the same Limitorque motor performance data curves, and therefore utilized different motor currents, to accurately predict MOV voltage, torque, and thrust values. For example, MOV MO-2036 electrical calculations used the superseded Limitorque K-5050 motor performance data curve and corresponding MOV MO-2036 mechanical calculations used the updated Limitorque K-11842 motor performance data curve.
On May 9, 2013, Limitorque issued a letter (LIMDOC-2013-002) to the Boiling Water Reactor (BWR) Owners Group (BWROG), Notification to BWROG of Peerless DC Motor Curve Updates, that stated updated motor performance curves were developed with the original equipment manufacturer and shall be deemed current standard curves. The letter further stated, in part, that these performance curves were applicable regardless of motor serial number or manufacture date.
On approximately September 23, 2013, the licensee received information regarding the updated Limitorque motor performance curves and generated action request (AR) 01397997 to review and update MOV calculations using the updated motor performance curves. The AR stated the updated curves were deemed current standard curves and replaced/superseded other curves that were previously issued. All DC MOV analyses were based on historical motor curves that have been superseded.
On April 29, 2014, the BWROG issued a letter (ADAMS Accession ML14121A114) to notify the NRC of a revision to the BWROG DC motor (DCM) methodology report. The letter stated that as the DCM methodology was used to evaluate torque capability and design basis stroke time for safety-related DC MOVs, these motor curve updates could potentially affect a large percentage of the DC motor evaluations performed in previous years. The letter also stated the updated DC motor performance curves were determined by Limitorque and Peerless as being most representative of the DC motors currently in service in DC MOV applications and are considered to be the best available as compared to the original motor curves developed in the 1960s and 1970s timeframe.
In response to AR 01397997, the licensee developed and completed on March 3, 2016, engineering change (EC) 25729 to incorporate the updated Limitorque MOV motor performance data curves to existing safety-related DC MOV calculations. The inspectors identified on, or around, August 27, 2025, that the engineering change revised the superseded Limitorque motor performance data curves in the mechanical MIDAS calculations but did not revise the superseded motor performance data curves utilized in the electrical DC load flow calculations. This was attributed, in part, to the electrical group not being included in the engineering change process. The result was two different motor performance data curves (electrical used the superseded performance data curves and mechanical used the updated performance data curves), and therefore two different motor currents, were utilized across coordinated calculations for the same MOV. The licensee generated AR 501000102915 on September 12, 2025, to address that inadequate design controls may have been applied to EC 25729 for safety-related DC MOVs in the MOV program.
Corrective Actions: The licensee performed a prompt operability determination for MOV MO-2036 (and other safety-related DC MOVs) which utilized a bounding MCC voltage, and the same Limitorque motor performance data curves for both the electrical and mechanical MOV design basis calculations. Additionally, other previously assumed scenario parameter values needed to be revised. Based on this work the licensee concluded MOV MO-2036 remained capable of performing its intended safety function. The licensee also performed an extent of condition evaluation, for all safety-related DC MOVs in the MOV program, applying similar assumption modifications, and concluded the remaining MOVs remained capable of performing their intended safety function(s), although some valves had reduced operational margins.
Corrective Action References: CAPs 501000102893 CETI: Locked Rotor Amps Mismatch, 501000102915 CETI: Inadequate Design Controls Applied, 501000102966 "CETI 2025: DC Motor Curves MO-2036, and 501000106075 CETI: Full Load Amp MCC Voltage
Performance Assessment:
Performance Deficiency: The licensees failure to assure that applicable regulatory requirements and the design basis for safety-related DC MOVs were correctly translated into specifications, drawings, procedures, and instructions in accordance with 10 CFR Part 50, Appendix B, Criterion III, Design Control, was a performance deficiency. Specifically, electrical and mechanical calculations performed under engineering change 25729 to incorporate updated Limitorque motor performance data curves to ensure that each safety-related DC MOV would be capable of performing its design basis safety function contained technical errors which, in many cases, reduced MOV operational margins. Errors included:
- (1) non-conservative MCC voltages; and
- (2) the electrical (DC load flow) and corresponding mechanical (MIDAS) calculations each utilized different motor performance data curves for the same MOV.
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, non-conservative MCC voltages and utilization of different vendor motor performance data curves for the same MOV in safety-related DC MOV design basis calculations could potentially result in MOVs not being capable of performing their specified safety function(s). This was similar to Inspection Manual Chapter 0612, Appendix E, Examples of Minor Issues, examples 3.a, 3.h, 3.m, and 13.a, where the licensee re-performed calculations to demonstrate operability or functionality, and revised calculation assumptions in order to obtain favorable results.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.
Specifically, the inspectors determined the finding was of very low safety significance (Green)because the finding was a deficiency affecting the design or qualification of a mitigating structure, system, or component (SSC), and the SSC maintained its operability and probabilistic risk assessment functionality.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance. Specifically, the technical errors introduced in EC 25729 occurred during or before the 2016 timeframe.
Enforcement:
Violation: 10 CFR Part 50, Appendix B, Criterion III, Design Control, requires, in part, that measures be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions.
Updated Safety Analysis Report (USAR) 8.11.1, "Motor Operated Valves," stated, in part, generic letter 89-10, safety-related motor operated valve testing and surveillance, recommended a program be established to ensure that all safety-related MOVs are selected, set, and maintained appropriately.
Multiple licensee MOV program procedures were developed, in part, to establish an MOV program and perform design basis reviews to ensure requirements are correctly translated into specifications, drawings, procedures, and instructions.
Licensee procedure FP-PE-MOV-07, "Motor Operated Valve Program," Revision 0, Section 5.5.1.4, Design Basis Review, in part, stated a design basis review is conducted to establish the operating requirements for each valve in the MOV program (5.5.1.4(a)) and typical documents that are reviewed to determine the valve operating design basis include vendor information (5.5.1.4(b)(16)).
Licensee procedure FP-PE-MOV-03, "Motor Operated Valve Program Design Methodology,"
Revision 3, Section 5.5, degraded actuator capability DC motors, stated, in part, the worst-case DC supplied voltages are based on the DC load evaluations and battery sizing analysis.
The MOV degraded voltage actuator capability and stroke time shall be evaluated using either the BWROG methodology for predicting capability and stroke time, as applicable (5.5.2.1).
Engineering Change 25729 was developed, in part, to incorporate updated vendor information utilized in the BWROG DC motor methodology into existing safety-related DC MOV electrical and mechanical DC MOV calculations to ensure those MOVs remained capable of performing their design basis safety function(s).
Contrary to the above from March 3, 2016, to as of December 18, 2025, the licensee failed to assure that applicable regulatory requirements and the design basis for safety-related DC MOVs were correctly translated into specifications, drawings, procedures, and instructions.
Specifically, electrical and mechanical calculations, performed under engineering change 25729, to incorporate updated Limitorque motor performance data curves to ensure that each safety-related DC MOV would be capable of performing its design basis safety function contained technical errors which, in many cases, reduced MOV operational margins. Errors included:
- (1) non-conservative MCC voltages; and
- (2) the electrical (DC load flow) and corresponding mechanical (MIDAS) calculations each utilized different motor performance data curves for the same MOV.
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Correct MOV Testing Frequency Following Replacement Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-03 Open/Closed
[H.10] - Bases for Decisions 71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to correct a condition adverse to quality. Specifically, the licensee failed to correct the inadequate periodic verification testing (PVT) frequency on safety-related (SR) valve, MO-2036, when Corrective Action Program (CAP) document 50100076098 was closed with insufficient justification to defer PVT testing beyond the required testing interval, following valve replacement in 2019.
Description:
The licensees American Society of Mechanical Engineers (ASME) Code of Record for Operation and Maintenance (OM) of Nuclear Power Plants was the 2017 Edition. ASME OM Mandatory Appendix III, Paragraph III-3310(b) stated, if insufficient data exist to determine the test interval in accordance with para. III-6400, then MOV [motor operated valve] inservice testing shall be conducted every two refueling cycles or three years (whichever is longer) until sufficient data exist, from an applicable MOV or MOV group, to justify a longer inservice test interval. This type of recurring test is referred to as periodic verification testing (PVT) by the licensee.
The inspectors reviewed CAP document 501000076098, MO-2036 PVT Test Required, originated on August 17, 2023, which stated, MO-2036 PVT is due. Current frequency shows a 5R requirement, however the valve was replaced in 2019 under WO 700033950. In accordance with ASME Mandatory App III, a component without sufficient data to extend an interval shall be tested every
- (2) refueling cycles or 3 years. the valve needs to be tested during the next HPCI window to not violate ASME code. Additionally, the CAP stated, start to prepare paperwork for MO-2036 test to occur the week of 09/17/23. The inspectors noted the CAP status was marked as completed on September 1, 2023. The inspectors requested the current PVT frequency and the last two dates credited for MO-2036 PVT completion.
In response to the inspectors questions, the licensee stated the established PVT frequency for MO-2036 was 4R (every 4th refuel cycle) and the last two credited test dates were during refueling cycle 1R28 (April 2017) and 1R32 (April 2025). The inspectors noted the PVT frequency for MO-2036, following the valve replacement in 2019, was longer than allowed per the ASME OM code unless justification was provided. On September 08, 2025, during conversations with licensee staff, the inspectors requested the basis to justify the longer test interval.
For reference, MO-2036 is a safety-related MOV in the High Pressure Coolant Injection (HPCI) system. Specifically, it is the HPCI Turbine Steam Supply Isolation Valve, which must open in order for HPCI to perform its safety function.
On September 09, 2025, the licensee stated the basis for justifying a longer interval was captured in Corrective Action (CA) 500000325276 (included under CAP 501000076098). The CA 500000325276 stated Action being taken to completion. Though valve was replaced, the replacement was the same as previous valve. Degradation of valve performance can be validated by falling under EPRI PPM [Performance Prediction Methodology] applicable valve and assurance is maintained that the valve will reach next PVT test without issue. The inspectors further questioned the licensees basis for extending the MO-2036 PVT interval, as the EPRI PPM provides a method for determining required torque/thrust under design-basis conditions and does not predict valve degradation over time.
Corrective Actions: On September 11, 2025, the licensee generated a CAP which stated, in part, MO-2036 the PVT should have occurred in 1R31it is understood that valve replacement and certain maintenance activities would meet the ASME Code language of insufficient Data exist regardless of the use of PPM on the valve being applied and using like for like parts during maintenance. The licensee is also considering an extent of condition review to evaluate PVT frequencies on other MOV Program valves which had undergone similar maintenance activities.
Corrective Action References: CAP 501000102849, CETI 2025: MOV PVT Interval MO-2036
Performance Assessment:
Performance Deficiency: The licensees failure to correct a condition adverse to quality was contrary to 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, and was a performance deficiency. Specifically, the licensee closed CAP 50100076098 without correcting the PVT frequency for MO-2036 in accordance with the ASME OM code of record or justifying sufficient data existed for the longer test interval.
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, extending the PVT frequency longer than allowed by the ASME OM, without adequate justification, can result in potential degradation issues not being detected in time to prevent the MOV from failing. This would impact the component and the HPCI systems availability and reliability. As documented in CAP 501000097718, when MO-2036 was subsequently tested in 1R32 (about six years after its replacement) the licensee noted abnormal diagnostic testing results. This caused the licensee to perform a condition evaluation and revaluation of PVT frequency.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the finding was of very low safety significance (Green), because although the finding was a deficiency affecting the design or qualification of a mitigating SSC, the SSC maintained its operability and PRA functionality.
Cross-Cutting Aspect: H.10 - Bases for Decisions: Leaders ensure that the bases for operational and organizational decisions are communicated in a timely manner. Specifically, the licensee incorrectly relied on the EPRI PPM as a basis to extend the test frequency for MO-2036, without adequately evaluating whether this approach satisfied ASME OM Code Section ISTC-3310, in particular as the PPM does not predict degradation over time.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, defective material and equipment, and nonconformances are corrected.
Contrary to the above, since September 1, 2023 and as of September 11, 2025, the licensee failed to correct a condition adverse to quality. Specifically, for safety-related valve MO-2036 the licensee failed to establish a PVT frequency in accordance with ASME OM Mandatory Appendix III, Paragraph III-3310(b), which require a frequency of two refueling cycles or three years (whichever is longer) until sufficient data exist to justify a longer inservice test interval.
Instead, the licensee closed the corrective action program document, CAP 50100076098, which had identified and was tracking the nonconformance, without correcting the PVT frequency or justifying sufficient data existed for the longer test interval.
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Follow ASME OM Testing Requirements After Failing Acceptance Criteria Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-04 Open/Closed
[H.3] - Change Management 71111.21M The inspectors identified a Green finding and associated non-cited violation (NCV) of Title 10 of the Code of Federal Regulations (10 CFR) Part 50.55a(f)(4)(ii) for the licensees failure to perform the required inservice testing (IST) to verify the operational readiness of main steam isolation valve (MSIV) AO-2-80A, a valve whose function was required for safety. Specifically, the licensee failed to retest or declare inoperable AO-2-80A following an as-found failure to meet stroke time acceptance criteria under Work Order (WO) 700113220.
Description:
The licensee established procedure 0255-07-IA-2, Main Steam Isolation Valve (MSIV)
Functional Checks Test, Revision 46, for performing Inservice Testing (IST) exercise testing, fail-safe testing, and position indication testing (PIT). Procedure 0255-07-IA-2, Step 1, performed IST stroke time testing (STT) and PIT of the inboard MSIVs (i.e., AO-2-80A, AO-2-80B, AO-2-80C, AO-2-80D), the testing results were listed under Table 1.
Inservice Testing is required by Title 10 CFR Part 50.55a, Codes and Standards. The applicable Code of Record for the licensee was the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) of Nuclear Power Plants 2017 Edition.
OM Mandatory Appendix IV, Paragraph IV-7200, stated, in part, Valves with measured stroke times that do not meet the acceptance criteria of para. IV-7100 shall be immediately retested or declared inoperable."
The inspectors reviewed the 2025 refueling outage WO 700120481 (dated May 14, 2025)credited for completion of procedure 0255-07-IA-2. The inspectors noted three inboard MSIVs (AO-2-80A, AO-2-80B, AO-2-80C) had STT results outside the procedural acceptance criteria listed in Table 1. On August 25, 2025, the inspectors questioned if the licensee had retested the valves in accordance with the requirements of OM Mandatory Appendix IV-7200. On August 27, 2025, in response to the inspectors questions, the licensee stated WO 700120481 performed as-left testing, following refueling outage maintenance activities. The MSIV stroke times were adjusted to within procedural acceptance criteria, prior to declaring the valves operable. Therefore, valve retesting was not required under WO 700120481.
However, on August 28, 2025, while further reviewing the inspectors questions, the licensee identified they had failed to perform required IST testing of MSIV AO-2-80A. Specifically, under WO 700113220 (dated April 19, 2025), while performing as-found testing in preparation for the upcoming refueling outage, the closing stroke time for AO-2-80A was found outside the acceptance band (i.e., the acceptance criteria). The licensee had failed to retest the valve or declared it inoperable as required by the ASME OM Code, Appendix IV, Paragraph IV-7200. The established close time acceptance criteria for AO-2-80A was 5.6 to 7.6 seconds. The as-found results showed an actual close time of 5.37 seconds.
Corrective Actions: The licensee entered this issue into their corrective action program, and planned to revise the MSIV testing procedure, 0255-07-IA-2, to align with the requirements of OM Mandatory Appendix IV.
Corrective Action References: CAP 501000102437, MT CETI: 501000097424 Inadequate Actions
Performance Assessment:
Performance Deficiency: The licensees failure to perform inservice testing to verify the operational readiness of MSIV AO-2-80A, a valve whose function was required for safety, was a performance deficiency and contrary to 10 CFR 50.55a(f)(4)(ii). Specifically, when performing WO 700113220 the licensee failed to immediately retest or declare inoperable MSIV AO-2-80A following the as-found testing which showed a closing time outside the acceptance criteria.
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, failure to comply with the requirements of the ASME OM following a testing failure can result in component degradation issues not being detected and/or addressed in time to prevent the MSIV from performing its intended safety function.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the finding was of very low safety significance (Green), because although the finding was a deficiency affecting the design or qualification of a mitigating SSC, the SSC maintained its operability and PRA functionality.
Cross-Cutting Aspect: H.3 - Change Management: Leaders use a systematic process for evaluating and implementing change so that nuclear safety remains the overriding priority.
Specifically, the licensee failed to incorporate the new requirements of the 2017 Edition of the ASME OM Code, Mandatory Appendix IV, into their IST program and testing procedures.
Enforcement:
Violation: Title 10 CFR, Part 50.55a(f)(4)(ii) requires, in part, Inservice tests to verify operational readiness of pumps and valves, whose function is required for safety, conducted during successive code of record intervals must comply with the requirements in the latest edition and addenda of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv)of this section.
The 2017 edition of the ASME OM was the code of reference applicable to the licensee for Inservice Testing.
The 2017 ASME OM, Mandatory Appendix IV, Paragraph IV-7200, states, in part, Valves with measured stroke times that do not meet the acceptance criteria of para. IV-7100 shall be immediately retested or declared inoperable.
WO 700113220, implemented procedure 0255-07-IA-2, MSIV Functional Check Test, Revision 46. Step 1 of the procedure established the IST close time acceptance criteria for MSIV AO-2-80A as 5.6 to 7.6 seconds.
Contrary to the above, on April 19, 2025, the licensee failed to perform inservice testing to verify the operational readiness of MSIV AO-2-80A, a valve whose function is required for safety, at successive code of record intervals which complied with the latest edition and addenda of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) of 10 CFR Part 50.55a. Specifically, the licensee failed to immediately retest or declare inoperable MSIV AO-2-80A following as-found testing showing a close time of 5.37 seconds, which was outside the acceptance criteria.
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Failure to Account Instrument Bias in Acceptance Criteria for the 11 Emergency Diesel Generator Technical Specification Surveillance Tests Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000263/2025010-05 Open/Closed
[P.2] -
Evaluation 71111.21M The inspectors identified a Green finding and associated Non-cited Violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when the licensees procedures 0187-01B, 0187-01, and OSP-ECC-0566-01 failed to include appropriate quantitative or qualitative acceptance criteria for determining the important activities affecting quality were satisfactorily accomplished. Specifically, the licensee decided to continue to utilize frequency meter (F/DG1/C-08) with a known bias and failed to account for the bias in the respective procedures acceptance criteria.
Description:
Emergency Diesel Generators (EDG) are relied upon to provide standby power to the station during Loss-of-Offsite Power (LOOP) conditions, including a postulated Loss-of-Coolant Accident (LOCA) and LOOP. Periodic surveillance tests, performed in accordance with Technical Specifications (TS), demonstrate the capability to provide the required power.
On April 16, 2020, the station submitted Corrective Action Program (CAP) 501000039721, 11 EDG Frequency Out of Band, which identified during the 11 EDG surveillance test, the generator frequency meter read 60.3 Hz for conditions when the system frequency was 60 Hz (when the diesel generator was load tested on the grid). The issue was considered a calibration issue and within the TS required value with margin. The meter calibration was planned for the 8 yr preventative maintenance scheduled for 2021.
On April 11, 2022, the station performed meter calibration work order 700063314 and provided completion comments that the frequency meter for 11 EDG on MCR panel C-08 should be replaced as the meter is not calibratable and slightly off, but within acceptable accuracy. The station determined the meter had a frequency bias of +0.3 Hz.
On September 2, 2025, the inspectors reviewed several completed surveillance tests for 11 EDG and found the acceptance limits for adjusting diesel generator speed (between 60.4 and 60.6 Hz) could not be accomplished when the identified frequency meter bias of +0.3 Hz was considered. In all cases, the inspectors found the corresponding step in the test procedure was signed as completed. However, there was no note or comment the condition of meter bias would not allow for generator frequency adjustment within the required range.
The inspectors determined the impacts of using an uncalibrated frequency meter with a known bias, were not fully recognized and accounted in the quantitative acceptance criteria used in surveillance procedures. As an example, the inspectors noted the following WOs were completed without adjusting the acceptance criteria to account for the known instrument bias (note, this is not an all inclusive list of procedures with EDG frequency acceptance criteria):
- WO 700133848-0010: Implemented procedure 0187-01B 11 Emergency Diesel Generator / 11 ESW Monthly Pump & Valve Tests, Revision 48 o
Step 77.a 9) established the Acceptance Criteria as 60.4 - 60.6 Hz
- WO 700149454-0010: Implemented procedure 0187-01 11 Emergency Diesel Generator / 11 ESW Quarterly Pump and Valve Tests, Revision 115 o
Step 103.a 9) established the Acceptance Criteria as 60.4 - 60.6 Hz
- WO 700114257: Implemented procedure OSP-ECC-0566-01 Low Pressure ECCS Automatic Initiation and Loss of Auxiliary Power Test - DIV I Outage, Revision 5 o
Step 113.e established the Acceptance Criteria as 60.4 - 60.6 Hz
Additionally, the inspectors noted the sites Quality Assurance Topical Report (QATR)
NSPM-1, Part B, Performance/Verification, item B.9, Measuring and Test Equipment Control, stated in part:
Measuring and test equipment found out of calibration is tagged or segregated and not used until it is successfully re-calibrated."
Corrective Actions: The licensee initiated a CAP evaluation on September 11, 2025, to address the inspectors findings. In the CAP the licensee recognized that when the frequency meter was identified out of calibration, (in accordance with the QATR) the instrument should have been removed out of service similar to if a portable instrument was found out of calibration; or assuming the meter was still usable with a fixed bias, other controls should have been put in place to allow continued use of this meter with the bias incorporated.
However, prior to September 11, 2025, the licensee took neither action.
The licensees subsequent evaluation determined this issue did not impact the operability of 11 EDG or equipment powered by 11 EDG. The evaluation concluded that when taking into account the current meter bias, the 11 EDG would remain within TS surveillance requirement limits.
Corrective Action References: CAP 501000102885, MT CETI: 11 EDG Freq Meter
Performance Assessment:
Performance Deficiency: The licensee failed to use a calibrated frequency meter for the 11 EDG TS Surveillance tests or establish controls which allowed the continued use of the meter with the bias incorporated. This was contrary to the licensees QATR NSPM-1, Part B.9, Measuring and Test Equipment Control; 10 CFR Appendix B, Criterion V, Instructions, Procedures, and Drawings; and a performance deficiency.
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, the licensees decision to use the uncalibrated equipment, without identifying additional evaluations and the controls or procedural steps to account for the fixed basis, could result in test results failures being masked and/or driving operators to take inappropriate actions based on incorrect/inaccurate meter readings.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors screened the finding to Green (very low safety significance) because the inspectors were able to answer NO to all the questions of Exhibit 2 - Mitigating Systems Screening Questions. Specifically, the licensee determined the 11 EDG remained operable because it passed the most recent surveillance tests when the meter bias was considered. In addition, the PRA functionality remained unaffected.
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, the licensee failed to evaluate the use of the uncalibrated frequency instrument during 11 EDG surveillance tests and resolve whether continued use of the instrument in the affected procedures was appropriate.
Enforcement:
Violation: Title 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.
The licensee established the following implementing procedures, in part, to perform TS Surveillances on the safety-related EDGs. These are activities affecting quality.
- Procedure 0187-01B, 11 Emergency Diesel Generator/ 11 ESW Monthly Pump &
Valve Tests, Revision 48 o
Step 77.a 9) established the Acceptance Criteria as 60.4 - 60.6 Hz
- Procedure 0187-01, 11 Emergency Diesel Generator / 11 ESW Quarterly Pump and Valve Tests, Revision 115 o
Step 103.a 9) established the Acceptance Criteria as 60.4 - 60.6 Hz
- Procedure OSP-ECC-0566-01, Low Pressure ECCS Automatic Initiation and Loss of Auxiliary Power Test - DIV I Outage, Revision 5 o
Step 113.e established the Acceptance Criteria as 60.4 - 60.6 Hz The 11 EDG Frequency Meter (F/DG1/C-08), is used to satisfy the above procedures acceptance criteria. The meter included an uncalibrated bias of +0.3 Hz.
Contrary to the above, since April 11, 2022, the licensees procedures 0187-01B, 0187-01, and OSP-ECC-0566-01, failed to include appropriate quantitative or qualitative acceptance criteria for determining the important activities affecting quality were satisfactorily accomplished. Specifically, since the licensee decided to continue to utilize frequency meter (F/DG1/C-08), with a known bias, the inspectors found the licensee failed to account for said bias in the respective procedures acceptance criteria. As a result, certain instructions to adjust generator frequency could not be accomplished within the limits prescribed in the Technical Specification surveillance procedures. Additionally, failing to account for the bias could mask an actual failure to meet the acceptance criteria.
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On December 18, 2025, the inspectors presented the Comprehensive Engineering Team Inspection results to Michelle Neal and other members of the licensee staff.
- On September 11, 2025, the inspectors presented the Initial Technical Debrief inspection results to Michelle Neal, Plant Manager and other members of the licensee staff.
- On December 18, 2025, the inspectors presented the Final Technical Debrief inspection results to Michelle Neal, Plant Manager and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2-079
MNGP 125 Volt Div. I Battery Calculation
2-179
25DC Div. 1 Battery Calculation
04-166
EOG ESW Heat Exchanger Performance - Baseline
11-140
1R & 2R Load Tap Changer Setpoint Calculation
14-020
AC Auxiliary Power Systems Analysis14-073
EDG Diesel Oil Hydraulic Model
15-063
AC Power Analysis 120V Control Circuit
16-073
4KV Coordination Study
18-007
SD-1 Storm Drain Capacity
90-023
Minimum Allowable Fuel Oil Storage Tank Level
2-220
4.16kV Degraded Voltage Instrument Setpoint
96-020
HPCI Room Transient Temperature
5C
MOVDS-MT 1
HPC MO-2036
MO-2036 Component Data (MIDAS)
R1
Calculations
MWI-3-M-2.06
Fuse/Breaker Coordination Study and Electrical
Coordination
1398965
2013 INPO - Medium Voltage Breakers
2/04/2014
500001426730
Replacement Damper Actuator Not Available
04/14/2014
501000038858
Incorrect Acceptance Criteria D312-08
03/17/2020
501000039721
EDG Frequency Out of Band
04/16/2020
501000070650
EDG Hz Meter Out of Cal
2/12/2023
501000076098
MO-2036 PVT Test Required
08/17/2023
501000093236
Check Emergency Service Water Pumps
2/13/2024
501000097424
"A" Inboard MSIV Closure Time too Fast
04/19/2025
Corrective Action
Documents
501000102481
MT CETI: HPCI Slope Conflicting Info
08/28/2025
501000100865
Bird Nest at X02 YV&XV LTC
07/14/2025
501000100909
Records Duplicated in DRMS
07/15/2025
501000101146
MT CETI: Training Update Log Missing Sig
07/22/2025
501000101211
MOV Component Calc Not Set to History
07/23/2025
501000101259
MT CETI: Pri 0 Procedure Set at Pri 1
07/25/2025
Corrective Action
Documents
Resulting from
Inspection
501000101349
Obs. Calcs for 2R Found at ACTIVE Status
07/29/2025
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
501000101418
Calc 16-073 Typo Error
07/30/2025
501000101425
MT CETI SSA: ECR Incomplete Record
07/31/2025
501000101506
MT CETI: Records - Work Order Lost Records
08/01/2025
501000101642
MT CETI: Input to Calculation 99007
08/05/2025
501000101653
MT CETI: Improper Signature on Calculation
08/06/2025
501000101661
No Documents Found for '18 HELB TCOA Val
08/05/2025
501000101683
MT CETI: Minor Discrepancy in Calculation
08/06/2025
501000101781
Delay Initiating POR CAP Action
08/07/2025
501000102331
CETI: 2023 AL LLRT 0137-07A Record Issue
08/25/2025
501000102367
MT CETI: Equip in Intake Building Not Secured
08/27/2025
501000102373
MT CETI: NRC Response Longer than 24 Hours
08/26/2025
501000102424
MT CETI: NRC Response Longer than 24 Hours
08/27/2025
501000102437
MT CETI: 501000097424 Inadequate Actions
08/28/2025
501000102459
CETI: PPM Implementation Requirements
08/29/2025
501000102462
MT CETI: NRC Response Longer than 24 Hours
08/28/2025
501000102465
MT CETI Discrepant Damper Safety Ratings
08/29/2025
501000102467
MT CETI Error in Response to NRC
08/29/2025
501000102481
MT CETI: HPCI Slope Conflicting Info
08/28/2025
501000102501
BWORG JOG Classification
08/28/2025
501000102564
MT CETI Confidential-Restricted in ADAMs
09/02/2025
501000102600
MT '25 CETI: C.4-B.09.02.B Diesel Oil
09/02/2025
501000102616
MT CETI B.08.11-05 FO Pump Swap
09/03/2025
501000102642
MT CETI: NRC Response Longer than 24 Hours
09/03/2025
501000102684
MT CETI: NRC Response Longer than 24 Hours
09/04/2025
501000102704
MT CETI: Available MCC 312 Voltage
09/05/2025
501000102774
MT CETI: Questions on 94-084
09/08/2025
501000102776
MT CETI: Cable Length Discrepancy
09/08/2025
501000102782
MT CETI 2025: NE-36394-18 Editorial Error
09/08/2025
501000102783
MT CETI: Incorrect Criteria 7004 Proc
09/08/2025
501000102819
MT CETI: NRC Observation, APPJ Evals
09/10/2025
501000102827
MT CETI: Untimely Response to NRC Q124
09/10/2025
501000102849
CETI 2025: MOV PVT Interval MO-2036
09/11/2025
501000102885
MT CETI: 11 EDG Frequency Meter
09/11/2025
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
501000102893
CETI: Locked Rotor Amps Mismatch
09/10/2025
501000102900
CETI: NRC Response Not Timely
09/10/2025
501000102915
CETI: Inadequate Design Controls Applied
09/12/2025
501000102924
25 CETI - Calc 04-047 Thermal Overload
09/12/2025
501000102935
MT CETI 2025: NRC Observations
09/12/2025
501000102936
CETI 2025: MO-3502 Datasheet
09/12/2025
501000102943
MT CETI: MCC Voltage in MIDAS Datasheets
09/12/2025
501000102966
CETI 2025: DC Motor Curves MO-2036
09/13/2025
501000103273
MT CETI: Part 21 Eval Needed
09/23/2025
501000103413
MO-2036 Datasheet Issues
09/26/2025
501000103455
25 CETI: MOV Risk Ranking
09/29/2025
501000103482
25 CETI: App III vs CC OMN-1
09/29/2025
501000103705
CETI: TTS-MIDAS Software Classification
10/06/2025
501000104045
MO-2036 MCC Voltage
10/15/2025
501000104353
Need to Reopen CE for CAP 501000102774
10/21/2025
501000104465
MT CETI: Supplemental info needed
10/24/2025
501000104687
MO-2035 DC Motor Values
10/29/2025
501000104703
25 CETI - MOV Cable R in Att. U
10/29/2025
501000104927
MO-2106&MO-2107 DC Motors
11/05/2025
501000105708
MO-2078 DC Motor Values
2/02/2025
501000105742
MO-2398 Datasheet Issues
2/02/2025
501000105875
MO-2107 DCMM MCC Voltage
2/08/2025
501000105933
MO-2076 Alternate Thrust
2/09/2025
501000106075
Full Load Amp MCC Voltage
2/12/2025
NE-36347-15
134-480V MCC B34
NE-36394-18
Emergency Service Water Pumps
NE-36403-2
Standby Diesel Generator ACB 152-502 Control
NE-36640-5
250V DC MCC Schedule D311, D312, D313
NF-36175
Single Line Diagram Station Connections
NF-36177
4160V System Buses 13, 14, 15, 16 Diagram
NF-36249
NF-36298-2
DC Electrical Load Distribution One Line Drawing
Drawings
NH-36241
Nuclear Boiler System-Steam Supply P&ID
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NH-36665
P&ID Service Water System and Makeup Intake Structure
114
NX-236744-10-1
2R Transformer Nameplate Drawing
NX-8292-12-5
Elementary Diagram HPCI System (MO-2036)
NX-9235-58
MO-2036 Limitorque Valve Control
23982
Tornado Missile Barriers on EDG Building
266
As Built ECN for EC23085 EDG Fuel Oil Train Separation
25613
Regain T-44 Operating Margin from EC23085 PRE-OP Test
Data
601000000010
EDG 11 OIL CHANGE FROM MOBILGARD 450 TO
MOBILGARD 410
Engineering
Changes
Klockner Moeller 480VAC Upgrade for Degraded Voltage
OBN Online Modifications to MCC34 and 44 480V Cubicles
SCR-16-0328
Klockner Moeller 480VAC MCC 34 and 44 Cubicle
Upgrades
SCR-22-0043
50.59 Screening 601000003663 - Revise 01-074
SCR-22-0072
Change to Intercell Acceptance Criteria for DB Battery
SCR-23-0040
50.59 Screening Isolate One Main Steam Line via MSIV
During Power Operation
Engineering
Evaluations
SCR-23-0047
Change to Technical Requirements Manual 3.8.1 and 3.8.2
Rev 24
System Health Report for 4KV Safety Buses
06/23/2025
2000027884
Operations Memo: TS SR 3.6.1.3.6 Potentially Non-
Conservative
09/09/2025
610000001303
OEER: NRC IN 2021-01
09/01/2022
610000002004
OEER: NRC IN 2021-01, Supplement 1
2/14/2025
ASME-OM-2017
Operation and Maintenance of NPP
05/31/2017
Letter From BWROG to NRC - Addressing LTU 13-02
04/29/2014
FCR-00642-01
Replace TOLs MCC311 and MCC312
MPS-0009
Specification for Process and Service Piping and
Instrumentation
07/17/1969
N/A
Letter from Flowserve-Limitorque Re: MO-2036 Motor
curves
09/08/2025
Miscellaneous
NX-16932-1
Vendor Manual Motor Operated Valve - Limitorque
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NX-17350
ESW Pump Curves
11/03/1992
NX-236809
2R Transformer Vendor Manual
NX-9216-7
Operating Manual, 999 System, Generating Plant, Model
999-20
Oct-1969
SCR-20-050
EDG Droop Modification
SCR-23-0163
QF0501-Calculation 04-133 Major Revision
SEG# MT-OPS-
CETI-ELAP
Simulator Exercise Guide Extended Loss of AC Power
TR-103237
03/15/1996
0187-01
Emergency Diesel Generator /11 ESW Quarterly Pump
and Valve Tests
115
0187-014
Emergency Diesel Generator /11 ESW Comprehensive
Pump and Valve Tests
0187-01A
Emergency Diesel Generator /11 ESW Comprehensive
Pump and Valve Tests
0187-02
Emergency Diesel Generator /12 ESW Quarterly Pump
and Valve Tests
114
255-11-IIC-3-1
EDG-ESW System Leakage Test Loop A Accessible
Pressure Boundary Components
255-11-IIC-4-1
EDG-ESW System Leakage Test Loop B Accessible
Pressure Boundary Components
1404-01
EDG ESW Heat Exchanger Performance Test
1478
External Flood Monthly and Annual Surveillance
4858-PM
4KV GE AMH Air Circuit Breaker maintenance
8-B-19
8-B-30
NO. 11 DIESEL ENG. TROUBLE
8300-02
External Flooding Protection Implementation to Support A.6
Acts of Nature
A.6
Acts of Nature
B.02.04-05
B.08.01.02-01
EDG Emergency Service Water
B.08.07-05
Heating And Ventilating
Procedures
B.09-08-05
Emergency Diesel Generators System Operation
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
C.4-B.09.02.A
Station Blackout
C.5-1100
RPV Control (Mode 1, 2, 3)
FP-E-RTC-02
Functional Location Classification
FP-PE-AOV-01
Air Operated Valve Program
FP-PE-MOV-07
Motor Operated Valve Program
FP-PE-MOV-4
MOV Margin Analysis and Periodic Verification
IST-BASIS
Pump and Valve In-Service Testing Program Basis
608000000472
MNGP AOV Program Scoping and Categorization
NSPM-1
Quality Assurance Topical Report
Self-Assessments 60602242
Comprehensive Engineering Team Inspection
01/27/2015
441564
TD-4KV Bus 15 Perform PM 4858-15
04/13/2013
501025
EC23982 - Ready to Install
2/26/2018
700001938-30
Weld Piping, Seal Penetrations
700017960-0010
WDW, Storm Drain Inspection and Evaluation
700039703-00
2R Transformer and Associated Bus PM
09/10/2020
700063314-0010
Calibrate Meters on C-08 and C-91
04/11/2022
700068501
4858-PM for EDG Feeder Breaker on Bus 15
06/06/2022
700086525-0010
Low Pressure ECCS Automatic Initiation and Loss of
Auxiliary Power Test - Div I Outage
05/09/2021
700093418-0010
VSF-10 Dampers Functional Check, Inspection PM
10/12/2023
700114257-0010
Low Pressure ECCS Automatic Initiation and Loss of
Auxiliary Power Test - Div I Outage
05/12/2025
700114394-0010
Emergency Diesel Generator/11 ESW Comprehensive
Pump and Valve Tests
01/13/2025
700122577
4858-15 PM for Bus 15 Maintenance
05/02/2025
700125707
1404-01 EDG-ESW Heat Exchanger Performance Test
07/15/2024
700130898-0010
Emergency Diesel Generator - Consolidated Testing
05/07/2025
700133848-0010
Emergency Diesel Generator/11 ESW Monthly Pump and
Valve Tests
05/11/2024
700146236-0010
Emergency Diesel Generator/11 ESW Monthly Pump and
Valve Tests
2/09/2025
Work Orders
700147567-0010
Emergency Diesel Generator/11 ESW Monthly Pump and 03/10/2025
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Valve Tests
700149454-0010
Emergency Diesel Generator/11 ESW Quarterly Pump
and Valve Tests
04/13/2025
700154516-0010
Emergency Diesel Generator, 11 ESW Monthly Pump
and Valve Test
08/10/2025