IR 05000321/2024003
| ML24296B164 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 10/30/2024 |
| From: | Alan Blamey NRC/RGN-II/DORS/PB3 |
| To: | Coleman J Southern Nuclear Operating Co |
| References | |
| IR 2024003 | |
| Download: ML24296B164 (1) | |
Text
SUBJECT:
EDWIN I. HATCH - INTEGRATED INSPECTION REPORT 05000321/2024003 AND 05000366/2024003
Dear Jamie Coleman:
On September 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Edwin I. Hatch. On October 18, 2024, the NRC inspectors discussed the results of this inspection with Matthew Busch, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Two findings of very low safety significance (Green) are documented in this report. Two of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:
Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region II; the Director, Office of Enforcement; and the NRC Resident Inspector at Edwin I. Hatch.
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 II; and the NRC Resident Inspector at Edwin I. Hatch.
October 30, 2024 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, Alan J. Blamey, Chief Reactor Projects Branch 3 Division of Operating Reactor Safety Docket Nos. 05000321 and 05000366 License Nos. DPR-57 and NPF-5
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000321 and 05000366 License Numbers:
DPR-57 and NPF-5 Report Numbers:
05000321/2024003 and 05000366/2024003 Enterprise Identifier:
I-2024-003-0017 Licensee:
Southern Nuclear Operating Company, Inc.
Facility:
Edwin I. Hatch Location:
Baxley, GA Inspection Dates:
July 01, 2024 to September 30, 2024 Inspectors:
R. Easter, Resident Inspector P. Niebaum, Senior Resident Inspector Approved By:
Alan J. Blamey, Chief Reactor Projects Branch 3 Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Edwin I. Hatch, 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
Inadequate Preventive Maintenance on Residual Heat Removal Service Water Pump Check Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000321,05000366/2024003-01 Open/Closed None (NPP)71152A A Green self-revealing non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion V,
Instructions, Procedures and Drawings, was identified when the licensee failed to develop an adequate inspection procedure for the residual heat removal service water (RHRSW)pump discharge check valves. As a result, internal valve degradation was not identified which contributed to a failure of the Unit 2 A RHRSW pump discharge check valve in April 2024.
Inoperable Reactor Core Isolation Cooling System Due to Mispositioned Link Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000366/2024003-02 Open/Closed
[H.12] - Avoid Complacency 71153 A Green self-revealed non-cited violation (NCV) of Unit 1 Technical Specification (TS) 3.5.3,
RCIC System was identified because the reactor core isolation cooling (RCIC) system was inoperable for greater than the TS allowed outage time. Specifically, on May 8, 2024, the RCIC high reactor water level trip function was identified to have been inoperable since March 8, 2024, due to an associated electrical link not being restored in accordance with operating permit instructions. RCIC was inoperable for approximately 62 days.
Additional Tracking Items
Type Issue Number Title Report Section Status LER 05000366/
2024-001-00 LER 2024-001-00 for Edwin I. Hatch Nuclear Plant, Unit 2, High Pressure Coolant Injection (HPCI) System Inoperable 71153 Closed LER 05000321/
2024-003-00 LER 2024-003-00 for Edwin I. Hatch Nuclear Plant, Unit 1, Reactor Core Isolation Cooling (RCIC) System Inoperable Due to Mispositioned Link 71153 Closed
PLANT STATUS
Unit 1 began the inspection period at or near rated thermal power (RTP). On July 23, 2024, power was reduced to approximately 20 percent RTP to take the main turbine offline for repairs to the exciter control system. On July 25, 2024, the main turbine was placed back online, and operators began raising power. On July 26, 2024, the unit reached RTP. On September 25, 2024, the operators lowered power to approximately 85 percent RTP due to isolation of feedwater heaters 5A, 7A, and 8A. On September 27, 2024, power was further reduced to approximately 54 percent RTP due to grid instabilities and was manually scrammed due to degrading main condenser vacuum associated with Hurricane Helene and cooled down to mode
4. The unit remained in mode 4 for the remainder of the inspection period.
Unit 2 began the inspection at or near RTP. On September 27, 2024, the unit began lowering power due to grid instabilities experienced from Hurricane Helene. While lowering power, the unit experienced a recirculating system runback (flow reduction) and continued to lower power to approximately 35 percent. On September 28, 2024, the operators began raising power. On September 30, 2024, the unit reached approximately 98 percent RTP.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Impending Severe Weather Sample (IP Section 03.02) (2 Samples)
- (1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather (i.e., Hurricane Debby) in the local area on August 5, 2024.
- (2) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather (i.e., Hurricane Helene) in the local area on September 26 and 27, 2024.
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Unit 1 'B' standby gas treatment (SBGT) system on August 8, 2024
- (2) Unit 1 'A' standby liquid control (SLC) system on August 13, 2024
- (3) Unit 1 'A' core spray (CS) system on August 14, 2024
- (4) Unit 1 'B' residual heat removal (RHR) system on September 23, 2024
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 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) Service water valve pits on July 11, 2024
- (2) Fire protection pumphouse on July 11, 2024
- (3) Unit 1 reactor building southwest and northwest diagonals on July 17, 2024
- (4) Unit 1 condenser bay 130-foot elevation on July 25, 2024
- (5) Units 1 and 2 fire extinguishers and fire hose stations test date logs reviewed on August 15, 2024
- (6) Units 1 and 2 control building 112-foot elevation on August 22, 2024
Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the onsite fire brigade training and performance during an unannounced fire drill on August 15, 2024.
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated internal flooding mitigation protections on the main control room (MCR) roof due to an inadequately installed temporary plant service water modification on the MCR air conditioning (MCRAC) systems on August 29, 2025.
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) Unit 2 'A' train residual heat removal (RHR)/core spray (CS) pump room cooler, 2T41B002A, in the southeast diagonal on August 21, 2024
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 MCR during the following activities:
- Unit 1 down power and single-loop operation for forced outage on July 22, 2024
- Unit 1 power ascension and startup of the second reactor feed pump on July 26, 2024
- Unit 2 during abnormal procedure entry for circulating water system failure and main condenser low vacuum on August 6, 2024
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated a crew in the simulator performing scenario H-LT-AF-00102-4.0, "High Pressure Coolant Injection Start, Recirc Vibration, Reactor Feed Pump Trip, Loss Feed, Drywell Pressure Rise, Reactor Core Isolation Cooling Manual Control" on July 15, 2024
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (1 Sample)
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 2 off-gas system, N62-01, evaluation for maintenance rule (10 CFR 50.65) (a)(1)status due to exceeding performance criteria within the past 3 years, reviewed on August 29, 2024
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) MCRAC train 1A condensing unit, 1Z41-B008A, reviewed on August 5, 2024
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (6 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
- (1) Unit 1 risk informed completion time (RICT) evaluation for inoperable pressure switch on turbine control valve (TCV) no. 1 on July 22, 2024
- (2) Unit 1 elevated risk due to swapping of the 1C 4160-volt (V) bus from alternate to normal supply on August 22, 2024
- (3) Unit 2 elevated risk due to repairs of 'A' train of RHR/CS pump room cooler in the southeast diagonal on August 21, 2024
- (4) Unit 1 risk assessment following trip of the 1A and 1B MCRAC subsystems during surveillance 42SV-Z41-005-1, Control Room Unit Capacity Verification, on September 3, 2024
- (5) Unit 1 elevated risk due to 1D startup aux transformer being out-of-service during replacement of disconnect switches on September 3, 2024, and while on single-feed on September 4 through September 5, 2024
- (6) Unit 1 RICT evaluation for inoperable fast-acting solenoid valve on TCV no. 4 on September 7, 2024
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (7 Samples)
The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:
- (1) Condition report (CR) 11095799, low oil level cognitive trend on MCRAC train 1A compressor
- (2) CR 11046193, Unit 2 A emergency diesel generator (EDG) fuel oil storage tank has approximately 3-5 gals of fuel oil on top of the tank
- (4) Technical Evaluation (TE) 1159670, past operability review of inoperable Unit 2 A RHRSW pump discharge check valve
- (5) TE 1160665, past operability review of MCRAC train 1A compressor with oil leak
- (6) CR 11106813, intermittent grounding fault signal for Unit 1 station service batteries
- (7) CR 11104261, EDG voltage and frequency instrument uncertainty
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (1 Sample)
The inspectors evaluated the following temporary or permanent modifications:
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) (6 Samples)
(1)34SV-C71-005-1, TCV fast-closure instrument functional test after replacement of the pressure switch for TCV no. 1 on July 25, 2024
- (2) SNC1906569, MCRAC train 1A after replacement of seal, compressor, and motor, reviewed on August 5, 2024 (3)34SV-E51-002-1, Unit 1 RCIC operability test after repairs to valve position indicator on August 9, 2024 (4)34SV-C41-002-1, Unit 1 SLC B pump operability test after preventive maintenance on August 13, 2024 (5)34SO-R22-00101, Alternating-current (AC) power distribution system (4160-volt) test following repairs to 1C 4160-volt normal supply breaker reviewed on August 22, 2024
- (6) SNC1178533, Voltage testing of Unit 2 A EDG battery cell after replacement on August 29, 2024
Surveillance Testing (IP Section 03.01) (3 Samples)
(1)34SV-R43-011-2, Unit 2 'A' EDG 24-hour surveillance on July 8, 2024 (2)34SV-T46-001-1, Division 1 SBGT system operability on July 29, 2024 (3)34SV-E51-002-2, Unit 2 RCIC pump operability test on August 29, 2024
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
(1)34SV-E11-001-2, Unit 2 A and C RHR pump IST and electromagnetic interference (EMI) testing on July 11, 2024
Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)
- (1) SNC1719855, FLEX support air compressor functional test reviewed on July 18, 2024
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
- (1) Training drill involving emergency action level classifications/notifications due to an operating basis earthquake, an anticipated transient without scram, and a RCIC steam line break with a radiological release on September 24,
OTHER ACTIVITIES - BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS06: Emergency AC Power Systems (IP Section 02.05)===
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
MS07: High Pressure Injection Systems (IP Section 02.06) (2 Samples)
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
MS08: Heat Removal Systems (IP Section 02.07) (2 Samples)
- (1) Unit 1 (July 1, 2023 through June 30, 2024)
- (2) Unit 2 (July 1, 2023 through June 30, 2024)
71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) Corrective action report (CAR) 666270, Unit 2 A RHR service water pump discharge check valve, 2E11-F005A, failure
71153 - Follow Up of Events and Notices of Enforcement Discretion Event Follow up (IP Section 03.01)
The inspectors evaluated the following events and/or degraded conditions for plant status and mitigating actions; and provided input to NRC management to determine whether an incident investigation, augmented inspection, or special inspection team (IIT, AIT, or SIT)was warranted:
- (1) The inspectors evaluated the licensee response to a Unit 1 manual scram due to degraded condenser vacuum condition associated with Hurricane Helene and subsequent containment isolation valve actuation on September 27, 2024 (NRC Event Notification 57343). The inspectors evaluated this event in accordance with NRC Management Directive (MD) 8.3 and determined that no follow-up inspection was necessary.
Event Report (IP Section 03.02) (2 Samples)
The inspectors evaluated the following licensee event reports (LERs) to verify the accuracy and completeness of the information provided and the appropriateness of the corrective actions:
- (1) LER 05000366/2024-001-00, "Unit 2 High Pressure Coolant Injection (HPCI) System Inoperable, dated February 14, 2024 (ADAMS Accession No. ML24045A152). The inspectors determined that the cause of the condition described in the LER was not reasonably within the licensee's ability to foresee and correct, and therefore was not reasonably preventable. No performance deficiency nor violation of NRC requirements was identified. This LER is Closed.
- (2) LER 05000321/2024-003-00, Unit 1 Reactor Core Isolation Cooling (RCIC) System Inoperable Due to Mispositioned Link dated July 3, 2024 (ADAMS Accession No.
ML24185A269). The inspection conclusions associated with this LER are documented in this report under Inspection Results section (NCV 05000321/2024003-02). This LER is Closed.
INSPECTION RESULTS
Inadequate Preventive Maintenance on Residual Heat Removal Service Water Pump Check Valves Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000321,05000366/2024003-01 Open/Closed None (NPP)71152A A Green self-revealing non-cited violation (NCV) of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures and Drawings, was identified when the licensee failed to develop an adequate inspection procedure for the residual heat removal service water (RHRSW)pump discharge check valves. As a result, internal valve degradation was not identified which contributed to a failure of the Unit 2 A RHRSW pump discharge check valve in April 2024.
Description:
On April 13, 2024, during flushing of Unit 2 RHRSW dead-leg piping in accordance with licensee procedure 34GO-OPS-024-2, Equipment Rotation and Flushing of Plant Service Water (PSW) and RHRSW Piping Deadlegs, an operator in the field observed that the A RHRSW pump appeared to be running. Since the operators only started the B RHRSW pump, it was quickly identified by licensee staff that the A RHRSW pump was rotating backwards. Condition report (CR) 11067437 documented the suspected failure of the 2A RHRSW pump discharge check valve 2E11-F005A. The dead-leg flush procedure opened the RHRSW discharge crosstie valves that connects division 1 (A and C RHRSW pumps) to division 2 (B and D RHRSW pumps). Subsequently plant operators declared the 2C RHRSW pump inoperable due to the likelihood of a reduction in RHRSW flow available to supply and cool plant equipment. This is because of the backflow through the degraded 2A RHRSW check valve, the 2A RHRSW pump, and back to the intake structure pump suction bay when the 2A RHRSW pump was not running. The 2A RHRSW pump was inoperable and unavailable when it was tagged out and isolated for corrective maintenance on the degraded check valve. At this time, the operability of the C RHRSW pump was restored. The as-found condition of the check valve was documented in CR 11068256, and noted, Extreme wear and degradation in valve body hinge pin contact area. Excessive wear on disk to hanger contact area. Excessive wear on disk anti-rotation fingers.
The inspectors discussed the issue with licensee plant staff and noted corrective action report (CAR) 260708 that evaluated a similar check valve failure (i.e., internal operating experience)of a PSW pump in October 2015. The licensees extent of condition review initially considered including the RHRSW pump discharge check valves, but subsequently excluded them from the corrective actions because the licensee judged that, despite being susceptible to the same environmental service conditions, they were a sufficiently lower risk. As a result, in January 2016, the procedure change that added detailed inspection criteria for the PSW pump check valves to 51GM-MNT-048-0, Bolted Bonnet Swing Check Valves, Ver. 6.0, did not include the same criteria for the RHRSW check valves. Also, in September 2019, the licensee again revised maintenance procedure 51GM-MNT-048-0 (Version 6.3). This time, the licensee added a detailed internal inspection of the RHRSW pump check valves for wear and degradation. This was as a corrective action following a similar failure of the redundant 2B RHRSW pump discharge check valve in May of 2019. However, the inspection requirement was later removed in 2020 via CR 10749369 without an adequate justification.
Lastly, the inspectors noted that the licensee did not generate an action to reinspect the 2A RHRSW pump discharge check valve, following the 2B RHRSW check valve failure, even though it was inspected satisfactory in February 2019 using the less intrusive inspection criteria.
According to the plant logs, the 2A RHRSW was manually started and ran on April 2, 6, and 12, 2024, with no observed indications of a degraded 2A RHRSW pump discharge check valve. The 2C RHRSW pump was manually started and ran on April 6 and 12, 2024 with no observed indications of a degraded 2A RHRSW pump discharge check valve.
Corrective Actions: The licensee repaired the 2A RHRSW pump discharge check valve, revised procedure 51-GM-MNT-048-0 to ensure an adequate inspection of valve components susceptible to corrosion, and is evaluating replacing all the RHRSW check valve bodies with stainless steel.
Corrective Action References: CRs 11067437, 11092115 and CARs 276390 and 666270
Performance Assessment:
Performance Deficiency: Failure to develop an adequate inspection procedure for the RHRSW pump discharge check valves was a performance deficiency. Specifically, licensee procedure 51-GM-MNT-048 contained less than adequate inspection guidance that prevented a degraded condition from being identified during its preventive maintenance inspection.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Procedure Quality 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 led to the actual failure of the 2A RHRSW check valve and adversely affected the capability of the 2C RHRSW pump in providing adequate cooling flow to the Unit 2 A RHR heat exchanger and resulted in the unavailability of the 2A RHRSW pump for check valve repairs.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.
Because all questions under the Mitigating SSC and PRA Functionality (except Reactivity Control Systems) header were answered no, the finding screened to Green, very low safety significance. Although the failure mechanism of the check valve was long-term corrosion, there were no previous definitive instances indicative of a check valve failure to the extent that allowed sufficient backflow to reverse rotate the A RHRSW pump and render it inoperable.
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.
Enforcement:
Violation: 10 CFR 50 Appendix B, Criterion V, Instruction Procedures and Drawings required in part, that activities affecting quality shall be prescribed by documented instructions, procedures or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Contrary to these requirements, since January 2016, licensee procedure 51GM-MNT-048-0, Bolted Bonnet Swing Check Valves, Version 6.0 was not appropriate to the circumstances because it was not adequate to detect degradation of RHRSW check valves during preventive maintenance inspections (an activity affecting quality).
Enforcement Action: This violation is being treated as a NCV, consistent with Section 2.3.2 of the Enforcement Policy.
Inoperable Reactor Core Isolation Cooling System Due to Mispositioned Link Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000366/2024003-02 Open/Closed
[H.12] - Avoid Complacency 71153 A Green self-revealed non-cited violation (NCV) of Unit 1 Technical Specification (TS) 3.5.3, RCIC System was identified because the reactor core isolation cooling (RCIC) system was inoperable for greater than the TS allowed outage time. Specifically, on May 8, 2024, the RCIC high reactor water level trip function was identified to have been inoperable since March 8, 2024, due to an associated electrical link not being restored in accordance with operating permit instructions. RCIC was inoperable for approximately 62 days.
Description:
On May 8, 2024, with Unit 1 at rated thermal power, licensee maintenance staff identified, while conducting a surveillance, an open electrical link (JJ-60) that should have been closed in main control room panel 1H11-P925. With the link open, RCIC would not automatically shut down on a high reactor vessel water level actuation and was inoperable.
The licensee determined that this link should have been closed during restoration of operating permit 1-OP-24-1E51-23350 on March 8, 2024. The licensee closed the link on May 8, 2024, restoring RCIC to operable status. The link was left open for a period of 62 days (i.e., March 8 to May 8, 2024). During this time, Unit 1 entered the mode of applicability on March 10, 2024, and exited the mode of applicability on March 11, 2024, when the unit was cooled down to Mode 4 following a reactor scram (NRC Event 57021). The unit again entered the mode of applicability on March 17, 2024, at 1928 EDT. TS 3.5.3 Condition A.1 required the licensee to verify that the high-pressure coolant injection (HPCI) system was operable within 1-hour. The licensee determined that the HPCI system was operable during the time RCIC was inoperable except from March 10, at 2331 EDT until March 11, at 0027 EDT for the performance of a surveillance test. The TS 3.5.3 allowed outage time for Condition A of 14 days plus Condition B of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> was exceeded on April 1, 2024, at 0728 EDT.
On July 3, 2024, the licensee reported this as a condition prohibited by TS in licensee event report (LER) 2024-003, Unit 1 Reactor Core Isolation Cooling (RCIC) System Inoperable Due to Mispositioned Link. (ADAMS Accession No. ML24185A269)
Corrective Actions: The licensee closed the electrical link to restore RCIC operability on May 8, 2024.
Corrective Action References: Condition report (CR) 11075088 and corrective action report (CAR) 684766
Performance Assessment:
Performance Deficiency: The failure to restore electrical link JJ-60 to its closed position in main control room panel 1H11-P925 as required by operating permit 1-OP-24-1E51-23350 was a performance deficiency and was contrary to licensee procedure NMP-AD-003, Equipment Clearance and Tagging, Section 4.6.5.4.d.(5). This section required, in part, equipment to be placed in the position specified on the clearance checklist.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Human 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, Unit 1 RCIC, would not automatically shut down on a high reactor vessel water level actuation. This could overfill the reactor vessel, lead to moisture carry over in the main steam lines, and result in unreliable operation due to excessive water in the RCIC and HPCI turbine steam supply lines.
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 this finding using Exhibit 2, Mitigating Systems Screening Questions of IMC 0609, Appendix A. The finding could not be screen to Green and required a detailed risk evaluation (DRE) because the degraded condition represented a loss of the PRA function of a single train TS for greater than its TS allowed outage time. RCIC was inoperable for longer than its TS allowed outage time.
A regional senior reactor analyst (SRA) performed a DRE using the guidance in IMC 0609 Appendix A, The Significance Determination Process for Findings At-Power, and the Risk Assessment of Operational Events Handbook (RASP Manual) Volume 1 - Internal Events.
The exposure period was 2 months when the link for the high reactor vessel water level trip was open. In this case, RCIC would have started and injected as designed however the pump would not be able to cycle between reactor vessel water level 2 and level 8 automatically to maintain level control. The SRA assumed the pump would start and run until it reached level 8 at which point operators would trip RCIC manually and remove it from service. Therefore, RCIC would not restart for events where it is credited for reactor vessel water level control.
The SRA used SAPHRIE 8 Version 8.2.10 and the Hatch Units 1 and 2 Standardized Plant Analysis Risk (SPAR) model revision 8.83, dated September 7, 2023. The SRA modeled these failures by setting the term RCI-TDP-RS-FRST (RCIC Turbine-Driven Pump Restart Failure per Event) to True. The dominant accident sequence was a switchyard-centered loss of offsite power, with a HPCI failure to run, operators failing to manually depressurize, and control rod drive (CRD) pump being unavailable. The resulting change in core damage frequency (CDF) was approximately 1.87 E-7.
Internal fire, flooding, and seismic sequences were considered because the risk from internal events was greater than 1 E-7. The SRA ran the SPAR model for fire sequences, flooding sequences, tornado hurricane, high wind sequences, and seismic sequences separately. The dominant fire sequence was a fire in the intake structure resulting in a switchyard-centered loss of offsite power, with a loss of power conversion systems and late injection. The change in CDF was determined to be approximately 2.47 E-7, relatively minimal.
The risk from internal events and internal fire/flooding/seismic were added and determined to be less than 1 E-6 event per year and therefore, is characterized as very low safety significance (Green).
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. The operators involved in removing the operating permit and restoring the link failed to use sufficient error reduction measures. As a result, the performer, peer check, and independent verifier all failed to recognize the link was left open contrary to the tagout restoration requirement.
Enforcement:
Violation: Hatch Unit 1 TS 3.5.3, RCIC System, requires that the RCIC system shall be operable while the unit is in Modes 1, 2 and 3 with reactor steam dome pressure greater than 150 psig. The TS Action statement Condition A requires that with the RCIC system inoperable, verify that the HPCI system is operable within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and to restore RCIC to operable status within 14 days. Condition B requires the licensee to place the plant in hot shutdown (Mode 3) in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> if the required actions and completion times of Condition A are not met.
Contrary to this requirement, between March 17 and May 8, 2024, with Unit 1 in the modes of applicability, RCIC was inoperable due to its inability to automatically shut down on a high reactor vessel water level actuation, and action was not taken to verify HPCI was operable within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and RCIC restored within 14 days, or the unit placed in Mode 3 in the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The completion time of the required actions was exceeded on April 1, 2024, at 0728 EDT.
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 October 18, 2024, the inspectors presented the integrated inspection results to Matthew Busch, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
Resulting from
Inspection
CR 11113788
Potential missile hazards
09/25/2024
Naturally Occurring Phenomena
20.5
Procedures
NMP-OS-017
Severe Weather Preparation Checklist Operations
08/02/24
H-16061
Unit 1 Standby Liquid Control System P&ID
Drawings
H-16331
Core Spray System PI&D
39.0
21.7
Standby Liquid Control System
13.1
Residual Heat Removal System
46.8
Procedures
Core Spray System
24.11
CR 11096313
Corrective Action
Documents
CR 11102464
Crew Learning - Team "C" 3rd Qtr 2024 Unannounced Fire
Drill
08/16/2024
Condition Reports
(CR)
11101885, 11101888, 11101957, 11103201, 11103340,
11104351
Corrective Action
Documents
Resulting from
Inspection
CR 11089274
Cables routed next to safety-related cable tray
RER SNC1900268 Evaluate Communication Cables Routed Next to ESS-I
Cable Tray
07/25/2024
Engineering
Evaluations
RER SNC642935
Free Air Voice/Data/Video Cable Installation
03/23/2015
NMP-ES-035-
019-GL02-F01
Control Building 112'
1.0
NMP-ES-035-
019-GL02-F09
U1 Turbine Building El. 130
1.0
NMP-ES-035-
019-GL02-F12
U1 Reactor Building El. Below 130
1.0
NMP-ES-035-
019-GL02-F200
Legend text
1.0
Fire Plans
NMP-ES-035-
019-GL02-F70
Fire protection pumphouse
2.0
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NMP-ES-035-
019-GL02-F84
Service water valve pits
1.0
Fire Extinguisher Surveillance-Annual
3.25
Fire Hose Hydrostatic Testing
1.1
Procedures
NMP-TR-425-F14
Fire Drill Package
08/15/2024
Engineering
Evaluations
TE1145391
Past operability review (POR) flooding evaluation
03/28/2024
Corrective Action
Documents
Condition Reports
(CR)
11103397, 1104606
Work Orders
Work Order Nos.
SNC855620, SNC1988215
Reactor Recirculation System
07/23/2024
Procedures
H-LT-AF-00101-
4.0
HPCI Start, Recirc Vibration, RFPT Trip, Loss Feed, DW
Press Rise, RCIC Manual Control
07/15/2024
Corrective Action
Documents
Condition Reports
(CR)
11097966, 11072222, 11097783, 11095774, 11089356,
11089352, 10913686, 10907195
Please review NCR
04/25/2024
TE 1153362
Site Design Support needed for NCR Review
05/02/2024
Engineering
Evaluations
Technical
Evaluations (TE)
1158042, 1157958
Miscellaneous
SX16241
Vendor Manual for Control Room Condensing Units
NMP-ES-045
Design Authority
10.0
Procedures
NMP-MA-037
Shaft/Coupling Alignment
1.4
Work Orders
Work Order Nos.
SNC1942404, SNC1906569, SNC1942415
Corrective Action
Documents
CR 11108496
TCV #4 expected annunciators not received during
surveillance testing
09/07/2024
Corrective Action
Documents
Resulting from
Inspection
Condition Report
(CR)
11107727
1-RICT-2024-02
RICT evaluation
07/22/2024
Miscellaneous
1-RICT-2024-03
RICT evaluation
09/08/2024
NMP-DP-001
Operational Risk Awareness (BWR Red Sheet)
08/20/2024
Procedures
NMP-GM-031
On-Line Configuration Risk Management Program
9.4
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NMP-GM-031-
001
Online Maintenance Rule (a)(4) Risk Calculations
8.0
NMP-GM-031-
2
Calculation of RMAT and RICT for the RICT Program
6.2
NMP-OS-010
Protected train/division and protected equipment program
NMP-OS-010-002
Hatch Protected Equipment Logs
2.6
Calculations
SMNH-09-010
Diesel Generator and Fuel Oil Consumption and Storage
Capacity
3.0
Corrective Action
Documents
Condition Reports
(CR)
10941310, 10944314, 10947537, 10967430, 10972170,
10984667, 11003003, 11046193, 11067437, 11093207,
11095799, 11074745, 11093207, 11096545, 11106813,
11107108
H-17148
U1 RCIC System E51 Elem. Diagram, Sheet 2
36.0
H-17149
U1 RCIC System E51 Elem. Diagram, Sheet 3
26.0
Drawings
H-44120
U1 RCIC System E51 Elem. Diagram, Sheet 9
7.0
S77014
Design Report DR-264, Fig. 5344F, 200LB, Swing Check
Valve
1.0
Engineering
Evaluations
TE 1160665
Operability
Evaluations
APC 1-24-084
Annunciator and Plant Component (APC) Sheet
07/15/2024
Procedures
NMP-AD-012
16.1
SNC1465194
Locate source of fuel oil found on top of fuel oil storage and
transfer
04/12/2023
SNC1559529
Repack Valve 2Y52-C101A
2/04/2024
SNC531708
Replace compressor on 1Z41-B008A
03/02/2014
SNC805415
Replace MCR ACU Compressor on 1Z41-B008A
10/16/2023
Work Orders
Work Order Nos.
SNC805415, SNC1908649, SNC1784874, SNC1906569
Corrective Action
Documents
Condition Reports
(CR)
11009250, 11068248, 11101153
NMP-ES-050-F01
SNC Response to GEH DIR DBR-0073836, Rev. 1 (HPCI
System Evaluation)
09/19/2023
TE 1137647
Operability Support Basis - HPCI and RCIC Turbine Control
System Setpoint Increase
Engineering
Evaluations
TE 1152319
OPS Training Impact Review
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
TE 1152320
I&C Training Impact Review
SNC1512291
Hatch SRV Opening Setpoint Increase
07/12/2023
Work Orders
SNC1580461
HPCI and RCIC Turbine Control System Setpoint Increase
09/26/2023
CR 10933595
Job plan for FLEX Equipment not available via D2
2/22/2022
CR 11083916
Battery tender needed
06/11/2024
CR 11096315
CR 11097731
Failure of valve position indicator 1E51-R008
07/31/2024
CR 11106481,
11106502
RCIC IST, and Unit 2 RCIC Pump Inboard Bearing Oil Level
Corrective Action
Documents
CR11095002
Engineering
Evaluations
TE 1118292
Job plan for FLEX Equipment not available via D2
06/30/2023
4160 VAC System
08/22/2024
Residual heat removal pump operability
07/11/2024
RCIC pump operability
08/09/2024
RCIC Pump Operability
08/29/2024
Diesel Generator 2A 24 Month Operability Test
07/08/2024
Standby Gas Treatment System Operability
07/29/2024
NMP-AD-002-F04
Troubleshooting Log
08/15/2024
NMP-AD-002-F04
Troubleshooting Log
08/22/2024
NMP-MA-009-
F01
FME Checklist
7.1
Procedures
NMP-MA-054
General Plant Housekeeping
3.2
SNC1059447
FLEX Support PM: Support air compressor functional test
2/20/2022
SNC1178533
Crack in battery cell
08/29/2024
SNC1576822
SNC1719855
FLEX Support PM: FLEX support air compressor functional
testing
06/10/2024
SNC1906569
1Z41-B008A Control Room Cond Unit 1A Oil Leak
7/31/2024
SNC1929990
Investigate/Repair issue Unit 1 4160V Bus C Normal Supply
Failed to Close
08/22/2024
SNC1942375
Failure of valve position indicator 1E51-R008
Work Orders
SNC581522
Turbine Control Valve Fast Closure Pressure Switch
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Miscellaneous
24EX02
Training Drill Scenario
09/24/2024
NMP-EP-141
Event Classification
4.0
Procedures
NMP-EP-141-002
Hatch Emergency Action Levels and Basis
5.0
71151
Miscellaneous
PI information
report
PI information report July 1, 2023, through June 30, 2024
1.0
Residual Heat Removal Service Water Pump Discharge
08/07/2019
Corrective Action
Documents
Condition Reports
(CR)
11068256, 11070876
Corrective Action
Documents
Resulting from
Inspection
Condition Report
(CR)
11092115
Engineering
Evaluations
Technical
Evaluation (TE)
1159670
RHR Service Water Pump Operability
19.5
Procedures
Bolted Bonnet Swing Check Valve Maintenance
6.4
71152A
Work Orders
SNC586631,
SNC1413918
2A RHRSW Check Valve Internal Inspection
Human Performance Checklist for CR 11075088
06/06/2024
CR 10256426
NRC Unresolved Item (URI) - Protection System Design
Basis [ATTS]
08/03/2016
CR 10412623
Failed ATTS card 2E51-N664B
09/25/2017
CR 10666695
Unit 1 alarms due to ATTS instrument 1B21N623B
11/22/2019
CR 10671686
Half Scram on Unit 2 ATTS
2/16/2019
CR 11032350
Unit 2 HPCI 2E41-F003 Auto Isolation
2/18/2023
Corrective Action
Documents
CR 11075088
Link JJ-60 in 1H11-P925 found open
05/08/2024
Drawings
H-17148
Unit 1 Reactor Core Isolation Cooling Sys. E51 - Elem.
Diagram, Sheet 2 of 9
36.0
TE 1153796
MSPI evaluation for CR 11075088
Engineering
Evaluations
TE 1153797
Maintenance Rule Evaluation for CR 11075088
Miscellaneous
1-OP-24-1E51-
23350
Operating Permit 1-OP-R31
03/08/2024
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR 11114439
Event Recovery Report - Unit 1 Manual Scram - Hurricane
Helene
09/30/2024
RC RPV Control For Hot Conditions
13.1
Scram Procedure
13.6
Procedures
NMP-AD-003
Equipment Clearance and Tagging
33.1
Work Orders
Work Order No.
SNC 1474126