IR 05000220/2024010
ML24235A520 | |
Person / Time | |
---|---|
Site: | Nine Mile Point ![]() |
Issue date: | 08/22/2024 |
From: | Mel Gray NRC/RGN-I/DORS |
To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
References | |
IR 2024010 | |
Download: ML24235A520 (1) | |
Text
August 22, 2024
SUBJECT:
NINE MILE POINT NUCLEAR STATION, UNITS 1 AND 2 - AGE-RELATED DEGRADATION INSPECTION REPORT 05000220/2024010 AND 05000410/2024010
Dear David Rhoades:
On July 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Nine Mile Point Nuclear Station, Units 1 and 2 and discussed the results of this inspection with Nick Tryt, Operations Director and other members of your staff. The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement; and the NRC Resident Inspector at Nine Mile Point Nuclear Station, 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 Nine Mile Point Nuclear Station, 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, Mel Gray, Chief Engineering Branch 1 Division of Operating Reactor Safety
Docket Nos. 05000220 and 05000410 License Nos. DPR-63 and NPF-69
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000220 and 05000410
License Numbers:
Report Numbers:
05000220/2024010 and 05000410/2024010
Enterprise Identifier: I-2024-010-0026
Licensee:
Constellation Energy Generation, LLC
Facility:
Nine Mile Point Nuclear Station, Units 1 and 2
Location:
Oswego, NY
Inspection Dates:
June 10, 2024 to July 31, 2024
Inspectors:
D. McHugh, Reactor Inspector
N. Mentzer, Reactor Inspector
B. Pinson, Senior Reactor Inspector
Approved By:
Mel Gray, Chief
Engineering Branch 1
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an age-related degradation inspection at Nine Mile Point Nuclear Station, Units 1 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 implement a preventive maintenance schedule on some safety-related circuit breakers Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000220,05000410/2024010-01 Open/Closed
[H.3] - Change Management 71111.21N.
The inspectors identified a finding of very low safety significance (Green) associated with a non-cited violation (NCV) of Technical Specification 5.4.1.a, Procedures, for the failure to implement a preventive maintenance schedule to inspect and lubricate safety-related 600 VAC and 125 VDC circuit breakers. Specifically, the licensee inadvertently retired all preventive maintenance activities on 10 safety-related breakers.
Additional Tracking Items
None.
INSPECTION SCOPE
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
71111.21N.04 - Age-Related Degradation Age-Related Degradation
- (1) Unit 1, Emergency Diesel Generator EG-EDG-102 Raw Water Cooling Pump PMP-79-53
- (2) Unit 1, 112 Emergency Condenser Cooling Valves CK-3904 and AOV-3906
- (3) Unit 1, Emergency Condenser EC-121
- (4) Unit 2, Instrument Air Compressor 21AS-C3B
- (5) Unit 2, High Pressure Core Spray Motor 2CSH*M1 Cabling
- (6) Unit 2, Containment Vent Valves 2CPS*AOV109, 2CPS*AOV110, and 2CPS*AOV111
- (7) Unit 2, Reactor Core Isolation Cooling Lube Oil Cooling Subsystem
- (8) Unit 2, Residual Heat Removal Pump 2RHS*P1B
- (9) Unit 2, Service Water Piping, Motor Operated Valves, and Strainers
- (10) Unit 2, Emergency Diesel Generator 2EGS*EG2 Fuel Supply Subsystem
- (11) Unit 2, 125VDC Bus 2BYS*SWGG002A
- (12) Unit 2, 600V Emergency Switchgear 2EJS*US1
INSPECTION RESULTS
Failure to implement a preventive maintenance schedule on some safety-related circuit breakers Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000220,05000410/2024010-01 Open/Closed
[H.3] - Change Management 71111.21N.
The inspectors identified a finding of very low safety significance (Green) associated with an NCV of Technical Specification 5.4.1.a, Procedures, for the failure to implement a preventive maintenance schedule to inspect and lubricate safety-related 600 VAC and 125 VDC circuit breakers. Specifically, the licensee inadvertently retired all preventive maintenance activities on 10 safety-related breakers.
Description:
The inspectors requested and reviewed copies of the current preventive maintenance strategy associated with 600 VAC safety-related breakers at Nine Mile Point Unit 2. During response to inspectors questions, the licensee discovered that some safety-related breakers did not have any active preventive maintenance activities associated with them. The initial scope of affected breakers included two 600 VAC circuit breakers associated with vital bus 2EJS*US1, and one 125 VDC circuit breaker associated with switchgear 2BYS*SWG002A. Based on the inspectors questions, the licensee initiated a condition report to evaluate and re-establish the preventive maintenance activities, and to perform an extent of condition to identify any other safety-related circuit breakers that had the preventive maintenance activities removed. The extent of condition identified the following (totaling 10 safety-related breakers at Nine Mile Point Unit 2) circuit breakers that had no active preventive maintenance activities:
- 2BYS*SWG002A1B (Battery 2BYS*BAT2A breaker)
- 2BYS*SWG002A-2D (Protection and control for 4160V bus 2ENS*SWG101)
- 2BYS*SWG002A-3A (125 VDC distribution panel 2BYS*PNL201A)
- 2BYS*SWG002A-3B (125 VDC breaker to 2BYS*PNL204A bus)
- 2BYS*SWG002A-3C (125 VDC breaker to 2VBA*UPS2A bus)
- 2BYS*SWG002A-3D (125 VDC breaker to 2DMS*MCCA1 bus; RCIC DC breakers power supply)
- 2BYS*SWG002A-4C (125 VDC supply to 2EJS*US1)
- 2BYS*SWG002A-4D (125 VDC breaker to 2BYS*PNL202A bus)
- 2EJS*US1-6D (Supply breaker to 2EJS*PNL100A)
- 2EJS*US1-7C (Supply breaker to 2LAC*PNL100A)
The preventive maintenance program at Nine Mile Point Unit 2 is performed in accordance with procedure ER-AA-200, Preventive Maintenance Program. Preventive Maintenance Modification Requests (PMMRs) are utilized in the program to evaluate a preventive maintenance activity for frequency or scope changes, deferrals, and adjustments. In 2017, PMMR 17-001694 was initiated and resulted in the retirement of the breaker inspect and test activity, and adjusted the frequency of the overhaul activity to four refueling outages (eight years) for breakers 2EJS*US1-6D and 2EJS*US1-7C. In 2020, PMMR 20-126002 was initiated with the intent to retire the overhaul activity and re-establish the inspect and test activities. Due to an administrative error, all the preventive maintenance activities for the circuit breakers were inadvertently retired without reinstatement of the inspect and test activity.
For the remaining eight affected circuit breakers identified in the extent of condition, the preventive maintenance activities specifying inspect and test, and overhaul frequencies were inadvertently retired as a result of PMMR 18-113872 in 2018.
Inspectors reviewed the licensees preventive maintenance template for the breakers, which identified the specific tasks and frequencies recommended for components to minimize consequential failures based on the criticality of the component, how often it was used, and the environment in which it operated. The template recommended overhaul frequency for non-critical metal-clad breakers in a mild environment was 12 years with a 25% grace period (i.e. 15 years total.
The identified breakers were ABB K-line metal-clad breakers, classified as non-critical, normally closed, operated in mild environments, and had safety functions to provide power to their respective loads and to trip (open) on fault conditions prior to initiation of a trip of any upstream protective device. Circuit breakers 2EJS*US1-7C, 2BYS*SWG002A-2D, and 2BYS*SWG002A-3A were last overhauled in 2012, while the other 7 breakers were last overhauled in 2016.
Corrective Actions: The licensee entered the issues into the corrective action program, performed an extent of condition, and initiated PMC-24-150128 to re-establish preventive maintenance activities in accordance with the preventive maintenance program.
Corrective Action References: IRs 04787178, 04780587, and 04783270
Performance Assessment:
Performance Deficiency: The inspectors determined that the failure to implement a preventive maintenance schedule to inspect and lubricate safety-related 600 VAC and 125 VDC circuit breakers was contrary to Technical Specification 5.4.1.a and was a performance deficiency.
Screening: The inspectors determined the performance deficiency was more than minor because if left uncorrected, it would have the potential to lead to a more significant safety concern. Specifically, absent the inspectors questions, the circuit breakers would not have the intended preventive maintenance activities. Absent intended preventive maintenance, the probability that these breakers may spuriously open or fail to open in response to a fault when required would be increased. The inspectors review of licensee information found that operator response to most of these conditions would either require a manual scram or render some mitigating equipment unavailable. Additionally, the inspectors noted that for the breaker 2BYS*SWG002A-3D, a spurious opening would result in a manual scram and render some reactor core isolation cooling automatic actions unavailable. Therefore, the failure to implement preventive maintenance reduces the reliability and capability of the safety-related circuit breakers, and affects the availability, reliability, and capability of the systems that rely on the circuit breakers to respond to initiating events. The issue was similar to example 13.a in IMC 0612, Appendix E, Examples of Minor Issues.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process for Findings At-Power. The inspectors determined this finding was of very low safety significance (Green) because although the finding was a deficiency affecting the design or qualification of a mitigating system, structure, and component (SSC), the SSC maintained its operability and probabilistic risk analysis 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 preventive maintenance activities for the circuit breakers were inadvertently retired, leading to the components having no recurring inspection, testing or overhaul activities.
Enforcement:
Violation: Technical Specification 5.4.1 requires, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978.
NRC Regulatory Guide 1.33, Revision 2, Appendix A, section 9 addresses Procedures for Performing Maintenance and section 9.b states, Preventive maintenance schedules should be developed to specify lubrication schedules, inspections of equipment, replacement of such items as filters and strainers, and inspection or replacement of parts that have a specific lifetime such as wear rings.
Contrary to the above, from 2018 for eight breakers, and from 2020 for two breakers, and ongoing at the time of the exit meeting, the licensee failed to implement a preventative maintenance schedule for the inspection or lubrication of some safety-related 600 VAC and 125 VDC circuit breakers.
Enforcement Action: This violation is being treated as an 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 July 31, 2024, the inspectors presented the design basis assurance inspection (programs) inspection results to Nick Tryt, Operations Director and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
71111.21N.04 Calculations
Environmental Qualification Document Package
Revision 5
Environmental Qualification Document Package
Revision 4
Corrective Action
Documents
04199519
04539945
04703385
Corrective Action
Documents
Resulting from
Inspection
04780067
04780570
04780587
04780753
04783270
04783423
04783494
04783570
Miscellaneous
A3PE
10CFR50.65 (a)(3) Maintenance Rule Periodic
Assessment, October 2021 to September 2023
Procedures
2EQPBD
Environmental Qualification Program Basis Document
Revision 6
Conduct of Equipment Reliability Manual
Revision 30
LR-PBD-ELECT1
License Renewal Aging Management Program Basis
Document
Revision 1
NMPNS-IST-001
Nine Mile Point Unit 1 and Unit 2 Inservice Testing (IST)
Program Plan
Revision 14
Work Orders
C92393017
C93659812
C93664607
C93698747
C93700919
C93750300
C93784786
C93792145
C93793545
C93799566
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
C93805909
C93808152
C93809222
C93816120
C93844381
C93884641
C93899070