IR 05000352/2023002
| ML24248A212 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 09/04/2024 |
| From: | Jon Greives Division of Operating Reactors |
| To: | Rhoades D Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2023002 | |
| Download: ML24248A212 (1) | |
Text
September 4, 2024
SUBJECT:
LIMERICK GENERATING STATION, UNITS 1 AND 2 - REISSUED INTEGRATED INSPECTION REPORT 05000352/2023002 AND 05000353/2023002
Dear David Rhoades:
The U.S. Nuclear Regulatory Commission (NRC) identified an administrative error in NRC Integrated Inspection Report 05000352/2023002 and 05000353/2023002, dated August 14, 2023 (ADAMS Accession No. ML23226A103). In the inspection results section, Non-Cited Violation (NCV) 05000352,05000353/2023002-01 did not properly annotate the significance screening process. The paragraph in the NCV has been edited for accuracy. As a result, the NRC has reissued the report in its entirety to correct the error.
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, Jonathan E. Greives, Chief Projects Branch 4 Division of Operating Reactor Safety
Docket Nos. 05000352 and 05000353 License Nos. NPF-39 and NPF-85
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000352 and 05000353
License Numbers:
Report Numbers:
05000352/2023002 and 05000353/2023002
Enterprise Identifier: I-2023-002-0039
Licensee:
Constellation Energy Generation, LLC
Facility:
Limerick Generating Station, Units 1 and 2
Location:
Sanatoga, PA 19464
Inspection Dates:
April 1, 2023 to June 30, 2023
Inspectors:
A. Ziedonis, Senior Resident Inspector
L. Grimes, Resident Inspector
E. Eve, Senior Project Engineer
C. Hargest, Health Physicist
M. Henrion, Senior Health Physicist
Approved By:
Jonathan E. Greives, Chief
Projects Branch 4
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees
performance by conducting an integrated inspection at Limerick Generating 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 Follow Maintenance Procedure Results in Emergency Diesel Generator Jacket
Water Leak
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000352,05000353/2023002-01
Open/Closed
[H.12] - Avoid
Complacency
The inspectors determined there was a self-revealing Green finding and associated non-cited
violation (NCV) of Technical Specification (TS) 6.8, Procedures and Programs, when
Constellation did not properly perform procedure M-020-002, Fairbanks Morse Opposed
Piston Diesel Generator Major Examination and General Maintenance, Revision 17, during
the performance of planned maintenance activities on the D21 emergency diesel generator
(EDG). As a result, an instrument root valve threaded fitting was not adequately tightened
during jacket water (JW) piping header restoration, which resulted in JW leakage that
exceeded the administrative operability limit, and subsequent unavailability to perform
corrective maintenance.
Additional Tracking Items
Type
Issue Number
Title
Report Section
Status
05000352,05000353/
2022004-04
Reportability Review
Associated with (EDG)
Jacket Water (JW) Leak
Closed
LER 2022-001-00 for
Limerick Generating Station,
Unit 1 Regarding High-
Pressure Coolant Injection
(HPCI) Inoperable Due to
Inadvertent Isolation Signal
Closed
PLANT STATUS
Unit 1 began the inspection period at rated thermal power (RTP). On April 22, 2023, operators
lowered thermal power to approximately 35 percent to perform repairs on the 'A' recirculation
pump adjustable speed drive cooling system. The unit was restored to RTP on April 23, 2023,
and remained at or near RTP for the remainder of the inspection period.
Unit 2 began the inspection period at approximately 90 percent RTP in end of cycle coastdown
status. On May 1, 2023, the unit was shut down for a planned refueling and maintenance
outage. The unit was returned to RTP on May 21, 2023, and remained at or near RTP for the
remainder of the inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in
effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with
their attached revision histories are located on the public website at http://www.nrc.gov/reading-
rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared
complete when the IP requirements most appropriate to the inspection activity were met
consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection
Program - Operations Phase. The inspectors performed activities described in IMC 2515,
Appendix DProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 2515,</br></br>Appendix D" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., Plant Status, observed risk significant activities, and completed on-site portions of
IPs. The inspectors reviewed selected procedures and records, observed activities, and
interviewed personnel to assess licensee performance and compliance with Commission rules
and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated readiness for seasonal extreme weather conditions prior to
the onset of seasonal extreme hot weather conditions during the week of
June 5, 2023
71111.04 - Equipment Alignment
Partial Walkdown (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following
systems/trains:
(1)
Unit 2 'C' residual heat removal (RHR) system on April 5, 2023
(2)
Unit 1 D11, D13, and D14 EDGs during D12 EDG planned system outage window the
week of June 9, 2023
(3)
Unit 1 HPCI system on June 20 and 21, 2023
71111.05 - Fire Protection
Fire Area Walkdown and Inspection (IP Section 03.01) (5 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a
walkdown and performing a review to verify program compliance, equipment functionality,
material condition, and operational readiness of the following fire areas:
(1)
Unit 1 fire area 22, Unit 1 cable spreading room on April 17, 2023
(2)
Unit 1 fire area 9, Unit 1 class 1E battery room on May 26, 2023
(3)
Unit 2 fire area 84, D23 EDG and fuel oil-lube oil tank room on May 30, 2023
(4)
Unit 1 fire area 109, HPCI pump room on June 20, 2023
(5)
Unit common fire area 7, corridor 437 on June 27, 2023
71111.06 - Flood Protection Measures
Flooding (IP Section 03.01) (1 Sample)
The inspectors evaluated internal flooding mitigation protections in the:
(1)
Unit 2 reactor building safeguard system access areas and safeguard system
isolation valve area room on May 15 and May 17, 2023
71111.08G - Inservice Inspection Activities (BWR)
BWR Inservice Inspection Activities - Nondestructive Examination and Welding Activities
(IP Section 03.01) (1 Sample)
(1)
The inspectors verified that the following nondestructive examination activities at
Unit 2 were performed appropriately from May 8 through 11, 2023:
- Manual ultrasonic testing examination of 12" elbow to pipe weld on
recirculation nozzle N2K, VRR-2RD-2A-16 SWB (Summary No. LIM-2-
625800)
Automated ultrasonic testing examination of reactor vessel vertical seam weld
BD (Summary No. LIM-2-701900)
Manual ultrasonic testing examination of recirculation nozzle N1B to vessel
weld (Summary No. LIM-2-704200)
Manual ultrasonic testing examination of recirculation nozzle N1B inside
radius (Summary No. LIM-2-704300)
Visual examination of containment surfaces in the suppression pool vapor
space (Summary No. LIM-2-900586)
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
(1)
The inspectors observed and evaluated licensed operator performance in the control
room during the Unit 2 reactor startup on May 18, 2023
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
(1)
The inspectors observed and evaluated licensed operator requalification training on
June 26, 2023
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following
structures, systems, and components (SSCs) remain capable of performing their intended
function:
(1)
Unit 1 D11 EDG functional failure from February 27, 2023 (IR 4557807)
(2)
Unit 2 HPCI minor maintenance overhaul on May 9, 12, and 15, 2023
(3)
Unit 2 D24 EDG functional failures during the week of June 5, 2023 (Issue Report
(IR) 4212649)
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to
ensure the following SSC remains capable of performing its intended function:
(1)
Unit 1 D12 EDG compression ring replacement during planned system maintenance
on June 9 and 15, 2023
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management (IP Section 03.01) (5 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the
following planned and emergent work activities to ensure configuration changes and
appropriate work controls were addressed:
(1)
Unit 2 emergent risk informed completion time TS action statement entry in response
to an electrical fault in the Division 1 safeguard battery system during the weeks of
April 3 and 10, 2023
(2)
Unit 1 emergent risk assessment in response to D13 EDG unavailability on
May 2, 2023
(3)
Unit 2 elevated shutdown safety risk during reactor cavity drain-down to below the
reactor vessel flange on May 14, 2023
(4)
Unit 1 HPCI Nuclear Steam Supply Shutoff System relay failure on
May 25 and 26, 2023
(5)
Unit 2 reactor core isolation coolant full flow test valve hand switch failure on
May 31, 2023
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (5 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the
following operability determinations and functionality assessments:
(1)
Unit 2 D24 EDG voltage above the allowable procedure band during planned testing
on May 8 and 9, 2023
(2)
Unit 2 HPCI testing at 200-psig during startup on May 18, 2023
(3)
Unit 2 safety relief valves (SRVs) E, F, L, N, and S lift pressure testing on
May 22, 2023
(4)
Unit 1 outboard main steam relief valves following room temperature exceeding max
safe operating temperature during reactor enclosure heating ventilation and air
conditioning system trip on May 26, 2023
(5)
Unit 2 SRVs A and M elevated tail pipe temperatures on June 30, 2023
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)
The inspectors evaluated the following temporary or permanent modifications:
(1)
Unit common emergency service water dissimilar metal weld elimination on
May 22 and June 21, 2023
(2)
Unit common EDG lube oil instrument tap modification on June 9, 20, and 21, 2023
71111.20 - Refueling and Other Outage Activities
Refueling/Other Outage Sample (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated Unit 2 refueling and maintenance outage (2R17) activities
from May 1, 2023 through May 21, 2023
71111.24 - Testing and Maintenance of Equipment Important to Risk
The inspectors evaluated the following testing and maintenance activities to verify system
operability and/or functionality:
Post-Maintenance Testing (PMT) (IP Section 03.01) (5 Samples)
(1)
Unit 2 RT-6-051-206-2, 'C' RHR shutdown cooling crosstie valve test following
maintenance to replace valve gear box and associated linkage on April 4, 2023
(2)
Unit 2 primary containment isolation valves HV-049-2F080, HV-049-2F019, and
HV-051-225A, following restoration of control power during the week of April 11, 2023
(3)
Unit 2 main steam isolation valve stroke timing following refueling outage (RFO)
maintenance on May 1 and 17, 2023
(4)
Unit 2 RHR shutdown cooling return valve 15A, following RFO maintenance on
May 16, 2023
(5)
Unit common 'A' RHR service water comprehensive test following pump lift
adjustment on June 2, 2023
Surveillance Testing (IP Section 03.01) (4 Samples)
(1)
ST-6-055-230-2, Unit 2 HPCI pump, valve and flow test following planned
maintenance on April 14 and 15, 2023
(2)
ST-6-052-231-1, Unit 1 'A' loop core spray pump, valve, and flow test on
April 19, 2023
(3)
ST-6-043-321-1, Unit 1 daily jet pump operability verification for single loop operation
on April 23, 24, and 25, 2023
(4)
ST-6-051-232-2, Unit 2 'B' RHR pump, valve and flow test following planned
maintenance on June 22, 2023
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
(1)
ST-6-055-231-2, Unit 2 HPCI comprehensive inservice test on June 28, 2023
Containment Isolation Valve Testing (IP Section 03.01) (1 Sample)
(1)
ST-4-LLR-031/041/051/061-2, Unit 2 main steam line A/B/C/D on May 17, 2023
71114.06 - Drill Evaluation
Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)
The inspectors evaluated:
(1)
Drill / Training Evolution Observation on June 26, 2023
RADIATION SAFETY
71124.01 - Radiological Hazard Assessment and Exposure Controls
Radiological Hazard Assessment (IP Section 03.01) (1 Sample)
(1)
The inspectors evaluated how the licensee identifies the magnitude and extent of
radiation levels and the concentrations and quantities of radioactive materials and
how the licensee assesses radiological hazards.
Instructions to Workers (IP Section 03.02) (1 Sample)
(1)
The inspectors evaluated how the licensee instructs workers on plant-related
radiological hazards and the radiation protection requirements intended to protect
workers from those hazards.
Contamination and Radioactive Material Control (IP Section 03.03) (3 Samples)
The inspectors observed/evaluated the following licensee processes for monitoring and
controlling contamination and radioactive material:
(1)
Licensee surveys of potentially contaminated material leaving the Unit 2 drywell
during 2R17
(2)
Observed worker protective clothing practices for Unit 2 drywell, suppression pool,
and refueling floor entry and exit during 2R17
(3)
Observed surveying of potentially contaminated material leaving the radiological
controlled area through small article monitors and frisking by hand
Radiological Hazards Control and Work Coverage (IP Section 03.04) (4 Samples)
The inspectors evaluated the licensee's control of radiological hazards for the following
radiological work:
(1)
Radiation Work Permit LG-0-23-00506
(2)
Radiation Work Permit LG-0-23-00901
(3)
Radiation Work Permit LG-0-23-00903
(4)
Radiation Work Permit LG-0-23-00906
High Radiation Area and Very High Radiation Area Controls (IP Section 03.05) (3 Samples)
The inspectors evaluated licensee controls of the following High Radiation Areas and Very
(1)
Unit 2 drywell
(2)
Unit 2 control rod drive mechanism hatch
(3)
Unit 2 suppression pool leakage tank room
Radiation Worker Performance and Radiation Protection Technician Proficiency (IP Section
03.06) (1 Sample)
(1)
The inspectors evaluated radiation worker and radiation protection technician
performance as it pertains to radiation protection requirements.
OTHER ACTIVITIES - BASELINE
71151 - Performance Indicator Verification
The inspectors verified licensee performance indicators submittals listed below:
MS05: Safety System Functional Failures (IP Section 02.04) (2 Samples)
(1)
Unit 1 for the period of April 1, 2022 through March 31, 2023
(2)
Unit 2 for the period of April 1, 2022 through March 31, 2023
MS06: Emergency AC Power Systems (IP Section 02.05) (2 Samples)
(1)
Unit 1 for the period of April 1, 2022 through March 31, 2023
(2)
Unit 2 for the period of April 1, 2022 through March 31, 2023
71152A - Annual Follow-up Problem Identification and Resolution
Annual Follow-up of Selected Issues (Section 03.03) (2 Samples)
The inspectors reviewed the licensees implementation of its corrective action program
related to the following issues:
(1)
Review of reportability associated with D21 EDG jacket water leak (IR 4514473) and
closure of unresolved item (URI) 2022004-04
(2)
Unit 1 HPCI outboard isolation, corrective action program (CAP) evaluation and
corrective actions review (IR 4529359)
71152S - Semiannual Trend Problem Identification and Resolution
Semiannual Trend Review (Section 03.02) (1 Sample)
(1)
The inspectors reviewed the licensees CAP for potential adverse trends in that might
be indicative of a more significant safety issue
71153 - Follow-Up of Events and Notices of Enforcement Discretion
Event Report (IP Section 03.02) (1 Sample)
The inspectors evaluated the following licensee event report (LER):
(1)
LER 05000352/2022-001-00, Unit 1 HPCI Inoperable Due to Inadvertent Isolation
Signal (ADAMS Accession No. ML22347A286). The inspectors determined that it was
not reasonable to foresee or correct the cause discussed in the LER; therefore, no
performance deficiency was identified. The inspectors did not identify a violation of
NRC requirements. This LER is closed.
INSPECTION RESULTS
Failure to Follow Maintenance Procedure Results in EDG JW Leak
Cornerstone
Significance
Cross-Cutting
Aspect
Report
Section
Mitigating
Systems
Green
NCV 05000352,05000353/2023002-01
Open/Closed
[H.12] - Avoid
Complacency
The inspectors determined there was a self-revealing Green finding and associated NCV of
TS 6.8, Procedures and Programs, when Constellation did not properly perform procedure
M-020-002, Fairbanks Morse Opposed Piston Diesel Generator Major Examination and
General Maintenance, Revision 17, during the performance of planned maintenance
activities on the D21 EDG. As a result, an instrument root valve threaded fitting was not
adequately tightened during JW piping header restoration, which resulted in JW leakage that
exceeded the administrative operability limit and subsequent unavailability to perform
corrective maintenance.
Description: On August 2, 2022, during a monthly surveillance test of D21 EDG at full load,
equipment operators discovered a JW leak from a threaded fitting connection on a 0.25-inch
diameter tubing instrument root valve connection to the five-inch JW piping header. At
approximately 30 minutes into the loaded run, operators measured leakage at 0.37 ounces
per minute. Just prior to completion of the two-hour loaded run, operators measured leakage
at 0.78 ounces per minute. Operators subsequently declared D21 EDG inoperable, because
leakage was measure above the pre-determined operability limit of 0.5 ounces per minute, as
calculated in Technical Evaluation (TE) 202873-01. The inspectors noted the 0.5 ounce per
minute limit supported successful operation of the EDG over the seven-day mission time
required for TS operability, without credit for inventory make-up to the closed-loop JW sub-
system. The inspectors further noted that Updated Final Safety Analysis Report, Section
9.5.5.2.1 stated that normal maintenance of system components will ensure that leakage
rates will be kept below the amount requiring tank makeup within a seven-day period.
Operators determined that D21 EDG remained available, because leakage was not expected
to exceed the 24-hour probabilistic risk assessment mission time limit of 3.5 ounces per
minute, based on no visible cracks observed in the fitting connection and no evidence that
there was a risk of complete fitting failure. In addition, the downstream (JW outlet) side of the
instrument root valve was noted to consist of a second, leak-tight, threaded connection to a
pressure switch and small diameter hard pipe tubing, such that complete unthreading of the
upstream (JW inlet) threaded connection to the JW header was very unlikely.
On August 3, 2022, Constellation performed corrective maintenance repairs that consisted of
tagging out D21 EDG, draining the JW system, disassembling the two fittings on either side of
the instrument root valve, replacing a reducer coupling at the threaded connection between
the instrument root valve and JW header, re-installing the threaded fittings on either side of
the instrument root valve, and performing an unloaded EDG run with no JW leakage
observed from the re-assembled threaded connections.
Following corrective maintenance, Constellation performed work group evaluation (WGE)
4514473-12, to determine the cause of the leaking fitting that resulted in D21 EDG
inoperability. Constellation determined that the cause was attributed to inadequately
tightening the instrument root valve fitting connection to the JW header during D21 EDG
planned maintenance that was completed on June 18, 2022. As part of the WGE,
Constellation sent the reducer coupling, which was removed during the August 3, 2022
corrective maintenance, off-site for a failure analysis. No presence of cracks, galling, or
cross-threading were noted in the reducer coupling. The inspectors reviewed the reportability
aspects associated with this issue under the closure of URI 2022004-04, as discussed in this
report.
The inspectors reviewed the WGE and discussed the D21 EDG JW leak with maintenance
technicians, operators, and engineers. The inspectors reviewed Constellation procedure
M-020-002, Fairbanks Morse Opposed Piston Diesel Generator Major Examination and
General Maintenance, Revision 17, and noted that step 5.3.58, requires re-installation of the
instrument root valve and its associated pipe fitting in the jacket water pump discharge
header piping, following planned maintenance and testing that required root valve
removal. Therefore, the inspectors determined that step 5.3.58 was not adequately
performed.
Corrective Actions: Constellation documented the JW leakage on August 2, 2022
(IR 4514473), completed corrective maintenance on August 3, 2022 (work order (WO)
5281072), performed a WGE to determine the cause of the leakage (4514473-12), and
assigned corrective action 4514473-18 to enhance maintenance procedure instructions.
Corrective Action References: IRs 4514473 and 4508586, and WOs 5281072 and 5219425
Performance Assessment:
Performance Deficiency: The inspectors determined that not properly pre-planning and
performing preventive maintenance in accordance with station procedures was reasonably
within Constellations ability to foresee and correct, should have been prevented, and was
therefore determined to be 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 performance deficiency resulted in JW leakage
that rendered the D21 EDG inoperable and resulted in unavailability of the EDG during repair
activities.
Significance: The inspectors assessed the significance of the finding using IMC 0609
Appendix AProperty "Inspection Manual Chapter" (as page type) with input value "NRC Inspection Manual 0609</br></br>Appendix A" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process., The Significance Determination Process (SDP) for Findings At-Power. The
inspectors utilized Exhibit 2, Mitigating System Screening Questions, to determine this
finding was of very low safety significance (Green) because it did not represent the loss of the
probabilistic risk assessment function of a TS system (EDG). Specifically, the inspectors
determined that the D21 EDG JW leak would not have exceeded the 24-hour PRA mission
time leakage limit.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the
possibility of mistakes, latent issues, and inherent risk, even while expecting successful
outcomes. Individuals implement appropriate error reduction tools. Specifically, Constellation
did not recognize and plan for the possibility of a mistake, nor plan for the inherent risk,
during reinstallation of a D21 EDG JW header root valve that consisted of two separate
threaded fitting connections at both the valve inlet and outlet, which resulted in a loose
connection at the valve inlet that rendered the EDG inoperable due to JW leakage.
Enforcement:
Violation: Limerick Generating Station, Unit 1, TS 6.8, Procedures and Programs, Section
6.8.1a, requires written procedures shall be established, implemented, and maintained
covering the activities in Regulatory Guide (RG) 1.33, Quality Assurance Program
Requirements, Revision 2. RG 1.33, Section 9.a, Procedures for Performing Maintenance,
requires maintenance that can affect the performance of safety-related equipment be properly
pre-planned and performed in accordance with written procedures. Constellation
procedure M-020-002, Fairbanks Morse Opposed Piston Diesel Generator Major
Examination and General Maintenance, Revision 17, step 5.3.58, requires re-installation of
the instrument root valve and its associated pipe fitting in the JW pump discharge header
piping.
Contrary to the above, from June 18, 2022 until August 3, 2022, Constellation did not properly
perform installation of the root valve pipe fitting in the D21 EDG JW pump discharge header
piping. Specifically, the pipe fitting was not properly tightened in the JW header piping during
planned maintenance that completed on June 18, 2022. Consequently, JW coolant leakage
was identified on August 2, 2022, which resulted in D21 EDG being declared inoperable, and
subsequently resulted in unavailability for corrective maintenance.
Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2
of the Enforcement Policy.
URI (Closed)
Reportability Review Associated with (EDG) JW Leak
URI 05000352,05000353/2022004-04
Description: The inspectors reviewed URI 2022004-04, and Constellations engineering
technical evaluations (TEs) performed under TE 202873-01 and engineering change (EC) 638279, to determine whether the D21 EDG was inoperable for greater than the allowed
outage time under TS limiting condition for operation (LCO) 3.8.1, after D21 was declared
inoperable on August 2, 2023, due to a loose JW fitting that was determined to not be
adequately tightened on June 18, 2023. This URI was originally described and documented in
Inspection Report 05000352,353/2022004 (ML23041A388).
The inspectors reviewed focused on whether there was firm evidence that D21 would have
exceeded the allowable JW leakage during the time between June 18 and August 2, 2023,
given the limited amount of actual run time during that period. The inspectors noted from
interviews with maintenance technicians and engineering staff that thread sealant was
applied to the fitting during maintenance reassembly on June 18, 2022, but without the
appropriate amount of cure time prior to post-maintenance test (PMT) runs. Additionally, the
inspectors noted that no leakage was identified during PMT runs on June 17 and 18,
2023. While weepage was subsequently identified on June 30, 2022, during equipment
operator rounds with D21 EDG in a standby condition (IR 4508586), no leakage was
observed during the July 5, 2022, monthly surveillance test. During the monthly surveillance
test on August 2, 2023, operators identified JW leakage that was above the administrative
limit for operability and declared the EDG inoperable until repairs were completed. Based on
the overall timeline of circumstances and uncertainty, as well as the unknown conditions of
the semi-cured thread sealant that could have experienced viscosity changes with ambient
temperature fluctuations between June 18 and August 2, 2022, with the EDG in standby, the
inspectors determined there was no firm evidence that D21 was inoperable for a period of
time greater than the TS-allowed outage time of 30 days.
The inspectors documented the maintenance performance aspects of this issue under
NCV 2023002-01. This URI is closed.
Corrective Action Reference(s): IRs 4514473 and 4508586, and TE 202873
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On May 11, 2023, the inspectors presented the Inservice Inspection Activities inspection
results to Shannon Rafferty-Czincila, Engineering Director, and other members of the
licensee staff.
On May 11, 2023, the inspectors presented the Radiological Hazard Assessment and
Exposure Controls inspection results to Shannon Rafferty-Czincila, Engineering Director,
and other members of the licensee staff.
On August 3, 2023, the inspectors presented the integrated inspection results to
Matthew Bonanno, Plant Manager, and other members of the licensee staff.