IR 05000324/2024003

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Integrated Inspection Report 05000324/2024003 and 05000325/2024003
ML24317A146
Person / Time
Site: Brunswick  Duke Energy icon.png
Issue date: 11/13/2024
From: Matthew Fannon
NRC/RGN-II/DORS
To: Krakuszeski J
Duke Energy Progress
References
IR 2024003
Download: ML24317A146 (1)


Text

SUBJECT:

BRUNSWICK STEAM ELECTRIC PLANT - INTEGRATED INSPECTION REPORT 05000324/2024003 AND 05000325/2024003

Dear John A. Krakuszeski:

On September 30, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Brunswick Steam Electric Plant. On October 29, 2024, the NRC inspectors discussed the results of this inspection with Jay Ratliff 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. One of these findings 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 II; the Director, Office of Enforcement; and the NRC Resident Inspector at Brunswick Steam Electric Plant.

If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement 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 Brunswick Steam Electric Plant.

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.

November 13, 2024

Sincerely, Matthew S. Fannon, Chief Projects Branch 2 Division of Reactor Oversight Docket Nos. 05000324 and 05000325 License Nos. DPR-62 and DPR-71

Enclosure:

As stated

Inspection Report

Docket Numbers:

05000324 and 05000325

License Numbers:

DPR-62 and DPR-71

Report Numbers:

05000324/2024003 and 05000325/2024003

Enterprise Identifier:

I-2024-003-0020

Licensee:

Duke Energy Progress, LLC

Facility:

Brunswick Steam Electric Plant

Location:

Southport, NC

Inspection Dates:

July 01, 2024 to September 30, 2024

Inspectors:

C. Curran, Resident Inspector

P. Gresh, Operations Engineer

J. Hickman, Senior Resident Inspector

D. Johnson, Senior Emergency Preparedness Specialist

B. Kellner, Senior Health Physicist

G. Smith, Senior Resident Inspector

J. Walker, Senior Emergency Preparedness Inspector

Approved By:

Matthew S. Fannon, Chief

Projects Branch 2

Division of Reactor Oversight

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Brunswick Steam Electric 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

Failure to Install Approved AC Cable in the Unit 1 Station Auxiliary Transformer Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green FIN 05000325/2024003-01 Open/Closed

[H.12] - Avoid Complacency 71111.12 A self-revealed Green finding was identified for the licensees failure to design and select an appropriately rated 4.16 kilovolt (kV) cable used in the station auxiliary transformer (SAT). Specifically, on May 8, 2024, an electrical power cable failed and resulted in a ground and damage to a fuse and potential transformer (PT) associated with the Unit 1 SAT automatic tap changer.

Unposted High Radiation Area Cornerstone Significance Cross-Cutting Aspect Report Section Occupational Radiation Safety Green NCV 05000325,05000324/2024003-02 Open/Closed

[H.8] -

Procedure Adherence 71152A A self-revealed Green non-cited violation (NCV) of technical specification (TS) 5.7.1, was identified for the failure to post and control access to a high radiation area (HRA). Specifically, on June 6, 2024, the licensee failed to post the southeast (SE) stairwell of the Unit 1 reactor building (RB) 50 elevation as an HRA during a reactor water clean-up (RWCU) resin transfer which, allowed an unbriefed individual to access the affected area resulting in an unanticipated dose rate alarm and two millirem (mrem) of unplanned radiation exposure to the individual.

Additional Tracking Items

None.

PLANT STATUS

Unit 1 began the period at 100 percent (full) rated thermal power (RTP) and operated there until September 21, 2024, when power was reduced to 70 percent RTP to perform a control rod sequence exchange, turbine valve testing, and transmission system work. Following the valve testing, sequence exchange, switchyard maintenance, and two subsequent rod improvements, the unit was restored to full RTP on September 26, where it continued to operate for the remainder of the inspection period.

Unit 2 began the period at full RTP and operated there until September 6, 2024, when power was reduced to 70 percent RTP to perform a control rod sequence exchange, turbine valve testing, and transmission system work. Following the valve testing, sequence exchange, switchyard maintenance, and two subsequent rod improvements, the unit was restored to full RTP on September 11, where it continued to operate for the remainder of the inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed on-site portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.

REACTOR SAFETY

71111.01 - Adverse Weather Protection

Impending Severe Weather Sample (IP Section 03.02) (2 Samples)

(1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather as a result of Tropical Storm Debby on August 7 and 8, 2024.
(2) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather as a result of Tropical Cyclone Eight on September 16.

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) Transformer yard and emergency diesel generator (EDG) building during Unit 1 and Unit 2 SAT outages from July 9 to July 10, 2024
(2) EDGs-1,3,4 while EDG-2 was out-of-service (OOS) due to a maintenance outage on July 24
(3) Unit 1 high pressure coolant injection (HPCI) system while Unit 1 reactor core isolation cooling (RCIC) system was OOS due to a maintenance outage on August 14
(4) Unit 1 A residual heat removal (RHR) train while the B RHR train was OOS for a maintenance outage on August 28

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors completed an evaluation of system configurations during a complete walkdown of the Unit 1 core spray system on September 26, 2024.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (7 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 RB 20 elevation on July 18, 2024
(2) Unit 1 RB -17 elevation ('A' and 'B' core spray rooms, 'A' and 'B' RHR rooms, and HPCI room) on August 14
(3) Unit 1 RB 50 elevation on August 21
(4) Unit 1 RB 80 elevation on August 22
(5) Control building elevation 49 (control room) on September 26
(6) Unit 2 RB 20 elevation on September 29
(7) Unit 2 RB 50 elevation on September 30

Fire Brigade Drill Performance Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated the onsite fire brigade training and performance during an announced fire drill in the Unit 2 turbine building at the hydrogen seal oil skid on July 20, 2024.

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the EDG building.

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)

The inspectors observed and evaluated licensed operator performance in the control room during two separate power maneuver and reactivity manipulation evolutions as indicated below:

(1)

  • Unit 2 down power to 95 percent RTP for control rod improvement on September 11, 2024
  • Unit 1 down power to 80 percent RTP for control rod improvement on September 23

Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)

(1) The inspectors observed and evaluated two separate crews during an annual operating exam on the simulator on September 24, 2024.

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) EDG-1 Tripped due to Loss of Excitation on August 13, 2023 (nuclear condition report

[NCR] 2482753)

(2) Vendor Quality/Design Issues Associated with Control Building A/C Units (NCR

===2492699)

(3) Unit 1 SAT Ground Relay Flag Picked Up (NCR 2515448)

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01)===

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) Elevated risk due to Unit 1 and Unit 2 SAT outages on July 9 and July 10, 2024
(2) Elevated risk during the EDG-2 outage from July 23 through July 25
(3) Elevated risk during Unit 1 RCIC outage from August 13 through August 14
(4) Elevated risk during Unit 2 RHR service water outage from August 20 through August
(5) Elevated risk during Unit 1 B train RHR outage on August 28
(6) Elevated risk due to 1B core spray train, supplemental EDG, and 1D service air compressor maintenance on September 24

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) EDG-2 Damper Malfunctioning (NCR 2515096)
(2) EDG-2 Collector Ring TIR Exceeds 0PM-GEN005 Criteria (NCR 2523513)
(3) Relay Installation not in Conformance with Qualification Report (NCR 2526612)
(4) CR99 and Trident X Control Blade Part 21 (NCR 2527801)
(5) Drywell Equipment Drain Total Lowering Unexpectedly (NCR 2529000)

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) (13 Samples)

(1) Post maintenance leak testing following the plugging of a tube in the Unit 1 'C' reactor building closed cooling water heat exchanger in accordance with (IAW) work order (WO) 20672301 (2)0PT-08.1.4A, RHR Service Water System Operability Test Loop A," Rev. 93, following preventative maintenance on 2-E11-PDV-F068A, (RHR heat exchanger A service water discharge valve) motor actuator and the associated 480-volt circuit breaker IAW WO 20651207 and WO 20537550 (3)0PT-12.2C, No. 3 Diesel Generator Monthly Load Test, Rev. 124, following replacement of three overspeed relays (2-DG3-SS1A/2A/3A) IAW WO 220528773 and WO 22058774 (4)0PT-09.7, "HPCI System Valve Operability Test," Rev. 45, following preventative maintenance on molded case circuit breaker 2-2XDA-B24-72 (HPCI minimum flow bypass valve to suppression chamber, 2-E41-F012) IAW WO 20595428 (5)0PT-10.1L, RCIC Pump Discharge Valve, Injection Valve, and Minimum Flow Bypass Valve Local Control Operability Test, following preventative maintenance on DC circuit breaker 1-1XDB-B47 (RCIC minimum flow bypass valve to Torus valve, 1-E51-F019) IAW WO 20655765 (6)0PT-25.1, Nuclear Steam Supply System Main Steam Isolation Valve (MSIV)

Operability Test Rev. 39, following Unit 1 MSIV 'D' failure and subsequent rework IAW WO 20463848 (7)1MST-BAT11AQ, 125 VDC Battery 1A-1 Quarterly Operability Test, Rev. 5, following removal of excess water due to a high water level IAW WO 20634635 (8)0PT-10.14L, RCIC Turbine Exhaust Vacuum Breaker Valves Local and ASSD Operability Test, Rev. 8, and 0PT-10.1.8, RCIC System Valve Operability Test, Rev. 47, following preventative maintenance on circuit breaker 1-1XD-DW2-52 (ASSD feed for RCIC turbine exhaust vacuum breaker, 1-E51-F062) IAW WO

===20617726 and circuit breaker 1-1XA-DE4 52 (normal feed for RCIC turbine exhaust vacuum breaker, 1-E51-F062) IAW WO 20617727

(9) Valve cycle testing following 12-year preventative maintenance on 480-volt breaker, 1-1XA-DF1 (breaker for motor-operated valve 1-E11-F007A, minimum flow bypass for A train RHR) IAW WO 20524983 (10)0PT-08.2.2C, LPCI/RHR System Operability Test - Loop A, Rev. 100, following a mechanical inspection and lubrication of the motor actuator on 1-E11-F020A, RHR pump 1A & 1C suppression pool suction valve IAW WO 20548107 and 0OP-MO504, Mechanical Inspection and Lubrication of Limitorque Operators, Rev. 48
(11) Post maintenance testing following preventative maintenance on EDG-1 4160-volt output breaker following preventative maintenance IAW WO 20648508 (12)0PT-08.2.2C, LPCI/RHR System Operability Test - Loop A, Rev. 100, following a mechanical and lubrication of the motor actuator on 1-E11-F017A, RHR outboard injection valve IAW WO 20552396 and 0OP-MO504, Mechanical Inspection and Lubrication of Limitorque Operators, Rev 48 (13)0PT-08.2.2C, LPCI/RHR System Operability Test - Loop A, Rev. 100, following adjustment of the stem lock nut on the actuator of 1-E11-F028A, RHR to torus discharge valve, IAW WO 20354952 Inservice Testing (IST) (IP Section 03.01)===

(1)0PT-07.2.4A, "Core Spray Operability Test - Loop A," Rev. 88, on June 8, 2024

Diverse and Flexible Coping Strategies (FLEX) Testing (IP Section 03.02) (1 Sample)

(1) CSD-BNP-SSD-FLX-003, "Triannual Flex Testing," IAW WO 20049395

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.01-02.03) (1 Sample)

(1) The inspectors evaluated submitted Emergency Action Level, Emergency Plan, and Emergency Plan Implementing Procedure changes during the week of July 29, 2024. This evaluation does not constitute NRC approval.

71114.07 - Exercise Evaluation - Hostile Action (HA) Event

Inspection Review (IP Section 02.01 - 02.11) (1 Sample)

(1) The inspectors evaluated the biennial emergency plan exercise during the week of July 29, 2024. The scenario began with a simulated report of a probable airborne threat to the site, thus meeting the criteria for declaration of an Alert. Sometime after the simulated threat is validated, the aircraft impacts the spent fuel area, and a Site Area Emergency is declared. As the scenario progressed, radiation levels increase from damaged casks as a result of the aircraft impact. When field sampling results from the field monitoring teams confirm effluent radiation levels reached a prescribed threshold, conditions for a General Emergency were met, and the Offsite Response Organizations were able to demonstrate their ability to implement emergency actions.

71114.08 - Exercise Evaluation - Scenario Review

Inspection Review (IP Section 02.01 - 02.04) (1 Sample)

(1) The inspectors reviewed and evaluated in-office, the proposed scenario for the biennial emergency plan exercise at least 30 days prior to the day of the exercise.

OTHER ACTIVITIES - BASELINE

===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:

BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10)===

(1) Unit 1 (July 1, 2023 - June 30, 2024)
(2) Unit 2 (July 1, 2023 - June 30, 2024)

BI02: RCS Leak Rate Sample (IP Section 02.11) (2 Samples)

(1) Unit 1 (July 1, 2023 - June 30, 2024)
(2) Unit 2 (July 1, 2023 - June 30, 2024)

PR01: Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual Radiological Effluent Occurrences (RETS/ODCM) Radiological Effluent Occurrences Sample (IP Section 02.16) (1 Sample)

(1) April 1, 2023 - March 31, 2024

EP01: Drill/Exercise Performance (DEP) Sample (IP Section 02.12) (1 Sample)

(1) July 1, 2023 - March 31, 2024 EP02: Emergency Response Organization (ERO) Drill Participation (IP Section 02.13) (1 Sample)
(1) July 1, 2023 - March 31, 2024 EP03: Alert And Notification System (ANS) Reliability Sample (IP Section 02.14) (1 Sample)
(1) July 1, 2023 - March 31, 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) Unposted high radiation area and electronic dosimeter alarm on June 6, 2024. The inspectors verified that corrective actions have been initiated and/or completed or will be completed as scheduled (NCR 2518688).

71153 - Follow Up of Events and Notices of Enforcement Discretion Personnel Performance (IP Section 03.03)

(1) The inspectors evaluated the licensee's performance during a significant weather event (Tropical Cyclone Eight) that impacted the main access roads to the site on September 17 and 18, 2024. The licensee declared a Notice of Unusual Event (NOUE) at 1240 on September 17 as a result of personnel being unable to access the plant via personal vehicles (HU4). The NOUE was lifted at 1400 on September 18 when the county emergency management officials informed the site that one access road was restored to service.

INSPECTION RESULTS

Failure to Install Approved AC Cable in the Unit 1 Station Auxiliary Transformer Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green FIN 05000325/2024003-01 Open/Closed

[H.12] - Avoid Complacency 71111.12 A self-revealed Green finding was identified for the licensees failure to design and select an appropriately rated 4.16 kV cable used in the SAT. Specifically, on May 8, 2024, an electrical power cable failed and resulted in a ground and damage to a fuse and PT associated with the Unit 1 SAT automatic tap changer.

Description:

On May 8, 2024, with both units at full power, Unit 1 control room operators received two annunciators (ground and trouble) indicating a problem with the Unit 1 SAT. The operators inspected the back panels and noted a ground flag on the ground current auxiliary

'Y' relay. No flags were noted on any of the emergency buses. At the time of the event, the SAT 'Y' winding was not under load while the unaffected 'X' winding was supplying power to the recirculation pumps, which is the normal alignment. The unit auxiliary transformer (UAT)was supplying normal plant loads at the time. The SAT is designed to supply power to the plant buses during shutdown periods and post-trip. Following removal of the SAT from service, technicians discovered the 'A' phase 4.16 kV cable from the 'Y' winding to the load tap changer (LTC) PT was failed/damaged due to a short-to-ground. The LTC is used to adjust voltage on the secondary side of the SAT. Additionally, it was noted the corresponding

'C' phase PT had a blown fuse and the PT was noted to be faulted due to the measured turns ratio. The licensee concluded that the faulted 'A' phase cable failure caused a transient that also affected the 'C' phase PT and fuse. On May 9, the failed cable, PT, and fuse were replaced on the Unit 1 SAT during a maintenance outage that resulted in declaring the offsite circuit inoperable and entry into the TS 3.8.1 Condition C 72-hour Action Statement. The PT is used to measure voltage and provide this information to the LTC for voltage control purposes. Both the failed 'A' phase cable and the 'C' phase PT were sent to an independent lab for examination.

Laboratory analysis could not uncover any obvious physical defects in the cable or PT that would have led to this type of failure. However, subsequent investigation revealed that the original alternating current (AC) cable for the LTC to the PT was actually a direct current (DC)cable rated for 50 kV DC and was not "rated" for AC applications. Extent of condition and extent of cause evaluations were performed as a result of this failure. The extent of condition evaluation revealed that the same inappropriate cables were also installed on the Unit 2 SAT

'A' and 'C' phase PTs as well. Both the Unit 1 and Unit 2 SATs were recently installed in March 2022 and March 2021 respectively, using the engineering change (EC) process. A review of the EC development history noted that past discussions between the Duke engineers and the wire manufacturer concluded an "expected rating" of the DC cable in an AC application to be 15 kV AC. However, post-failure discussions with the vendor concluded that the AC rating should be no more than 2.4 kV AC. This value would correspond to the full voltage seen on the cable (2.4 kV AC phase to ground is equivalent to 4.16 kV AC line to line)with no additional design margin. This could explain why it took over two years for the cable to fail on Unit 1 and the similar cables were still in operation on Unit 2.

Corrective Actions: The 'C' phase fuse and PT were replaced. The failed 'A' phase cable was initially replaced. However, following discovery of the unapproved application of a DC cable in an AC circuit, both Unit 1 and Unit 2 entered sequential maintenance outages that resulted in declaring the offsite circuit inoperable and entry into the TS 3.8.1 Condition C 72-hour Action Statement from July 9 to July 10, 2024 in order to remove both the 'A' and 'C' phase PT cables from the SATs. The LTCs were also placed in the "manual mode" of operation by removal of the automatic LTC function.

Corrective Action References: NCR 2515448, "Unit 1 SAT Ground Relay Flag Picked Up,"

May 8, 2024

Performance Assessment:

Performance Deficiency: The inspectors determined that the failure to adhere to procedure AD-EG-ALL-1132, Preparation and Control of Engineering Change, when performing a design change on the Unit 1 SAT, was a performance deficiency that was within the licensees ability to foresee and correct. Specifically, the licensee deviated from the cable manufacturers specifications by using electrical cables rated for medium voltage DC in an AC circuit without providing the procedurally required justification and approval of the deviation. As a result, a ground fault caused damage to a fuse and potential transformer associated with the Unit 1 SAT automatic tap changer. This resulted in unplanned unavailability time associated with the subsequent required repairs to the Unit 1 SAT.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Design Control 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 condition affected the availability and reliability of the Unit 1 SAT on May 9, 2024, as a result of an electrical fault which resulted in a failed PT and 4.16 kV cable failure. The inspectors used IMC 0612, Appendix E, Examples of Minor Issues, dated November 1, 2023, to inform answers to the more than minor screening questions and found this condition consistent with more than minor Examples 4.e and 4.k. Specifically, the installed 4.16 kV AC cable installed between the Unit 1 SAT 'Y' winding and the LTC potential transformer was a DC rated cable with an unknown AC rating for the installed AC application. This cable ultimately failed, and the Unit 1 SAT was rendered OOS and unavailable.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.

Specifically, using IMC 0609.04, "Initial Characterization of Findings," Table 2, the finding was determined to adversely affect the Mitigating Systems cornerstone since the finding was related to the qualified offsite circuit required by TS 3.8.1 and was a mitigating system within the probabilistic risk assessment (PRA). Using Table 3 of Attachment 0609.04, the finding was required to be further evaluated using Appendix A since the finding was related to mitigating systems and was not related to shutdown operations, not associated with licensed operator requalification, not related to maintenance rule risk assessments, and not related to fire protection, etc. Using MC 0609 Appendix A (Exhibit 2), the finding was determined to be of very low safety significance (Green) since the finding resulted in a loss of operability of and PRA functionality of a multi-train system that was less than the allowed outage time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, affected only one technical specification system, did not represent a loss of a PRA system and/or function as defined in the plant risk information ebook or the licensees PRA for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and did not represent a loss of the PRA function of one or more non-TS trains of equipment.

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.

Enforcement:

Inspectors did not identify a violation of regulatory requirements associated with this finding.

Unposted High Radiation Area Cornerstone Significance Cross-Cutting Aspect Report Section Occupational Radiation Safety Green NCV 05000325,05000324/2024003-02 Open/Closed

[H.8] -

Procedure Adherence 71152A A self-revealed, Green, NCV of TS 5.7.1, was identified for the failure to post and control access to an HRA. Specifically, on June 6, 2024, the licensee failed to post the SE stairwell of the Unit 1 RB 50 elevation as an HRA during a RWCU resin transfer, which allowed an unbriefed individual to access the affected area resulting in an unanticipated dose rate alarm and two mrem of unplanned radiation exposure to the individual.

Description:

On June 6, 2024, a security officer received an electronic dosimeter (ED) rate alarm of 340 mrem/hr in an area that was not posted as an HRA. A radiation protection technician (RPT) providing job coverage noticed the security officer walking into the HRA and was directing the officer to exit the area coincident with the officers ED going into alarm. The officer immediately exited the area and reported to the Radiation Protection office as directed by the RPT. The licensees follow-up investigation identified that the area had been improperly posted by Radiation Protection for the RWCU resin transfer. Unfamiliarity of differences in access points and posting requirements between Unit 1 and Unit 2 by the RPT, and failure to have the posted HRA barriers peer checked, resulted in an unposted HRA and ineffective access control of the HRA.

Corrective Actions: Initial corrective actions taken by the licensee included: 1) establishing correct posting and control of the SE stairwell of the Unit 1 RB as an HRA; 2) disqualification of the RPT involved; 3) NCR 2518688 was written; and 4) formation of a Prompt Investigation Response Team (PIRT) to complete a causal evaluation, including a human performance and organizational/programmatic review.

Performance Assessment:

Performance Deficiency: Failure to post and control a HRA with dose rates greater than 100 mrem/hr, but equal to or less than 1,000 mrem/hr, at 10 centimeters from the radiation source, or from any surface which the radiation penetrates, as required by TS 5.7.1, is a performance deficiency.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Program & Process attribute of the Occupational Radiation Safety cornerstone and adversely affected the cornerstone objective to ensure the adequate protection of the worker health and safety from exposure to radiation from radioactive material during routine civilian nuclear reactor operation. Specifically, failure to post and control HRAs can allow workers to enter HRAs without knowledge of the radiological conditions in the area and receive unintended occupational exposure.

Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix C, Occupational Radiation Safety SDP. Specifically, using Attachment 0609.04, Initial Characterization of Findings, and Appendix C, Occupation Radiation Safety Significance Determination Process, the finding was determined to adversely affect the Occupational Radiation Safety cornerstone since the finding was related to a work control issue. Using MC 0609 Appendix C (Section IV), the finding was determined to be of very low safety significance (Green) since the finding was not related to ALARA, did not involve an overexposure nor a substantial potential of overexposure, and did not compromise the licensee's ability to assess the dose.

Cross-Cutting Aspect: H.8 - Procedure Adherence: Individuals follow processes, procedures, and work instructions. Radiation protection technician(s) failed to follow established processes, procedures, and work instructions, including peer check of the HRA postings and use of the HRA, LHRA, and VHRA Posting Checklist (Attachment 1) contained in procedure AD-RP-ALL-0004, "Radiological Posting and Labeling", when installing HRA postings.

Enforcement:

Violation: TS 5.7.1 requires, in part, that each HRA in which the intensity of radiation is greater than 100 mrem/hour but equal to or less than 1,000 mrem/hour at 10 centimeters from the radiation source or from any surface which the radiation penetrates shall be barricaded and conspicuously posted as a HRA, and access to, and activities in, each such area shall be controlled by means of a RWP. Contrary to the above, on June 6, 2024, the licensee failed to post and control access to the SE stairwell of the Unit 1 RB 50 elevation as an HRA during a RWCU resin transfer, which had dose rates of up to 340 mrem/hour.

Specifically, a security officer received an electronic ED rate alarm of 340 mrem/hour in an area that was not posted as an HRA, and the worker was not on an RWP that allowed access to HRAs.

Enforcement Action: This violation is being treated as a non-cited violation, 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 29, 2024, the inspectors presented the integrated inspection results to Jay Ratliff and other members of the licensee staff.
  • On August 2, 2024, the inspectors presented the emergency preparedness exercise inspection results to John Krakuszeski and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

71111.12

Engineering

Changes

EC 401266

Unit 1 SAT Replacement and AC Low Margin Resolution

71111.12

Engineering

Changes

EC 403762

Unit 2 SAT replacement

71111.12

Procedures

AD-EG-ALL-1210

Maintenance Rule Program

71111.12

Procedures

AD-EG-ALL-1211

System Performance Monitoring and Trending

71111.12

Procedures

PD-EG-ALL-1130

Engineering Change Program

71152A

Corrective Action

Documents

NCR 2518688

Causal evaluation (PIRT) including a human performance

and organizational/programmatic review.

06/12/2024

71152A

Procedures

0E&RC-0504

Radiation Protection Actions During Plant Evolutions

Involving Movement of Steam, Water, or Solid Waste

Revision 4

71152A

Procedures

AD-RP-ALL-0004

Radiological Posting and Labeling

Revision 8

71152A

Procedures

AD-RP-ALL-0005

Access Controls for High and Locked High Radiation Areas

Revision 2