IR 05000346/2024010
| ML24337A240 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/06/2024 |
| From: | Karla Stoedter NRC/RGN-III/DORS/EB1 |
| To: | Tony Brown Vistra Operations Company |
| References | |
| IR 2024010 | |
| Download: ML24337A240 (1) | |
Text
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION - COMPREHENSIVE ENGINEERING TEAM INSPECTION REPORT 05000346/2024010
Dear Terry Brown:
On November 21, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Davis-Besse Nuclear Power Station and discussed the results of this inspection with Gregory Michael, Director of Site Engineering, and other members of your staff. The results of this inspection are documented in the enclosed report.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violation or the significance or severity of the violation documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at Davis-Besse Nuclear Power Station.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; and the NRC Resident Inspector at Davis-Besse Nuclear Power Station.
December 6, 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, Karla K. Stoedter, Chief Engineering Branch 1 Division of Operating Reactor Safety Docket No. 05000346 License No. NPF-3
Enclosure:
As stated
Inspection Report
Docket Number:
05000346
License Number:
Report Number:
Enterprise Identifier:
I-2024-010-0056
Licensee:
Vistra Operations Company LLC
Facility:
Davis-Besse Nuclear Power Station
Location:
Oak Harbor, OH
Inspection Dates:
September 09, 2024 to November 21, 2024
Inspectors:
K. Barclay, Senior Reactor Inspector
J. Corujo-Sandin, Senior Reactor Inspector
E. Fernandez, Senior Reactor Inspector
M. Garza, Technical Support Team Leader
I. Hafeez, Senior Reactor Inspector
B. Jose, Senior Reactor Inspector
L. Rodriguez, Senior Reactor Inspector
Approved By:
Karla K. Stoedter, Chief
Engineering Branch 1
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a comprehensive engineering team inspection at Davis-Besse Nuclear Power Station, 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 Ensure Adequate Auxiliary Feedwater Pump Minimum Flow Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000346/2024010-01 Open/Closed
[P.2] -
Evaluation 71111.21M The inspectors identified a finding of very low safety significance (Green) and an associated non-cited (NCV) violation of Title 10 of the Code of Federal Regulations (10 CFR) Part 50,
Appendix B, Criterion XVI, Corrective Actions, for the licensees failure to identify and correct a condition adverse to quality. Specifically, the licensee failed to ensure the design-basis minimum flow of the safety-related auxiliary feedwater (AFW) pumps was maintained for all design-bases events after determining the non-safety-related recirculation line was susceptible to crimping. Pump operation below the required minimum flowrate could have led to pump degradation and failure following certain design-basis events.
Additional Tracking Items
Type Issue Number Title Report Section Status URI 05000346/2024010-02 Failure to Correctly Implement 10 CFR 50.59 Administrative Procedures 71111.21M Open
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
===71111.21M - Comprehensive Engineering Team Inspection The inspectors evaluated the following components and listed applicable attributes, permanent modifications, 10 CFR 50.59 products, and operating experience:
Structures, Systems, and Components (SSCs) (IP section 03.01)===
For each SSC sample, the inspectors reviewed the licensing and design bases including:
- (1) the updated final safety analysis report (UFSAR),
- (2) the technical specifications (TS)
(where applicable), and
- (3) the technical requirements manual (where applicable). The inspectors also performed visual inspections of the accessible SSCs to identify potential hazards or signs of degradation. Additional SSC specific design attributes reviewed by the inspectors are listed below:
- (1) Turbine-Driven Auxiliary Feedwater (AFW) Pump 1-2 (P14-2)
- operating procedures
- maintenance effectiveness
- system health
- protection against flooding and seismic conditions
- mechanical design calculations and considerations o
flow capacity o
minimum flow o
runout flow o
vortexing o
suction (including strainer cleaning frequency)o lube oil level
- test and inspection procedures, including recent results o
in-service testing (IST)o TS instrument surveillances o
control instruments o
steam and feedwater rupture control system logic
- (2) Component Cooling Water (CCW) Heat Exchanger 1-2 (E22-2)
- operating procedures
- maintenance effectiveness
- modifications
- system health
- protection against a high energy line break
- mechanical design calculations and considerations o
maximum cooling water temperature o
maximum working fluid temperature o
tube plugging limit o
heat transfer capacity
- test and inspection procedures, acceptance criteria, and recent results o
internal inspections o
thermal performance testing o
- (3) AFW to Steam Generator 1 Injection Line Check Valve (AF39)
- system health
- mechanical design calculations and considerations o
maximum allowable leakage
- test and inspection procedures, acceptance criteria, and recent results o
leakage testing o
- (4) AFW to Steam Generator 1 Motor Operated Valve (AF608)
- operating procedures
- maintenance effectiveness
- system health
- environmental qualification
- protection against high energy line break
- mechanical design calculations and considerations o
weak link analysis o
required thrust and torque o
maximum differential pressure
- test and inspection procedures, acceptance criteria, and recent results o
- electrical design calculations and considerations o
voltage drop o
control logic
- (5) Station Blackout Emergency Diesel Generator (K5-3)
- operating procedures
- maintenance effectiveness
- modifications
- system health
- mechanical design calculations and considerations o
room heat up calculations and environmental considerations o
fuel oil volume consumption o
fuel oil available volume o
starting air design
- test and inspection procedures, acceptance criteria, and recent results o
engine o
jacket water cooler o
fuel oil volume o
starting air
- (6) Essential Distribution Panel, +125VDC (D2P)
- protection against flooding conditions
- electrical design calculations and considerations o
loading calculations o
short circuit calculations o
voltage regulation and voltage drop o
coordination calculations o
cable ampacity o
protective devices and trip setpoints
- (7) Emergency Diesel Generator 1-1 Sequencers
- test and inspection procedures, acceptance criteria, and recent results o
TS surveillances
- electrical design calculations and considerations o
control power o
relay setpoint o
control logic
- (8) CCW Surge Tank (T12)
- system health
- protection against seismic conditions
- mechanical design calculations and considerations o
makeup capability o
level setpoints o
seismic
- test and inspection procedures, acceptance criteria, and recent results o
relief valve o
Modifications (IP section 03.02) (4 Samples)
- (1) C-ME-016.04-041, Evaluation of the Temperature Increase of CCW System, Revision 0 (2)08-0693-001, Repair Pipe Supports in BWST Pit, Revision 4 (3)16-0332-000, Emergency Feedwater (EFW) NFPA 805 Manual Initiation Circuit, Revision 0 (4)21-0072-001, Hydrogen Project Pilot Plant - High Voltage Tie-in & Medium Voltage Distribution, Revision 1 10 CFR 50.59 Evaluations/Screening (IP section 03.03) (12 Samples)
- (1) Evaluation 21-00987, 345 kV Switchyard 1A and Breaker 52-1A Control and Plant Interface, Revision 0
- (2) Screening 15-00776, Switchyard 345 kV Breaker Replacement, Revision 15
- (3) Screening 15-01500, Target Rock Auxiliary Feedwater Power Supply Isolation, Revision 7
- (4) Screening 20-00151, Component Cooling Water System Operating Procedure, Revision 0
- (5) Screening 20-01400, CCW Pump Minimum Allowable Head Curve, Revision 0
- (6) Screening 21-00208, Replace Station Black Out Control 125 Vdc Battery and Battery Rack, Revision 0
- (7) Screening 21-00968, Revise Table 18-1 Commitment 3, Underground Piping and Tanks Integrity Program, Revision 1
- (8) Screening 21-01045, Independent Spent Fuel Storage Installation Aging Management Program (AMP), Revision 0
- (9) Screening 22-00065, Control Room Cooling Loads: Emergency Mode, Revision 0
- (10) Screening 22-00931, Component Cooling Water System Procedure, Revision 0
- (11) Screening 23-00791, Limiting Differential Pressure for Auxiliary Feedwater Pump Discharge Valves, Revision 0
- (12) Screening 24-00829, Temporary Modification - Jumper SBO DG Battery Cell, Revision 0
Operating Experience Samples (IP section 03.04) (2 Samples)
- (1) OE-2020-0072-2, OE468879R20200310 Auxiliary Feedwater System Declared Inoperable Due To Check Valve Leakage, dated October 14, 2020
- (2) OE-2022-0366-1, OE534257R20221114 Vibration Induced Actuation of a Breaker Failure Relay Causing Loss of an Offsite Power Feed and Reactor Trip, dated August 31,
INSPECTION RESULTS
Failure to Ensure Adequate Auxiliary Feedwater Pump Minimum Flow Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000346/2024010-01 Open/Closed
[P.2] -
Evaluation 71111.21M The inspectors identified a finding of very low safety significance (Green) and an associated non-cited (NCV) violation of Title 10 of the Code of Federal Regulations (10 CFR)
Part 50, Appendix B, Criterion XVI, Corrective Actions, for the licensees failure to identify and correct a condition adverse to quality. Specifically, the licensee failed to ensure the design-basis minimum flow of the safety-related auxiliary feedwater (AFW) pumps was maintained for all design-bases events after determining the non-safety-related recirculation line was susceptible to crimping. Pump operation below the required minimum flowrate could have led to pump degradation and failure following certain design-basis events.
Description:
During the inspectors September 2024 review of licensee procedure DB-OP-06233, Auxiliary Feedwater System, Revision 47, they observed step 2.2.29 had a discussion related to the AFW pump recirculation line potentially becoming crimped during the following design-basis events:
- (1) seismic,
- (2) turbine building internal missile,
- (3) turbine building pipe break, or
- (4) tornado. The procedure step also discussed operating the pump with less than its design-minimum recirculation flow and, if necessary, directed the operators to stop the pump to prevent damage. The inspectors questioned the origin of the step and were provided CR-09-55170, OE-Crimping of Non-Seismic AFW Recirculation Piping Not Evaluated, which had added the step in 2012.
The inspectors reviewed CR-09-55170, which the licensee opened on March 11, 2009, after they became aware of industry operating experience related to an AFW recirculation line crimp vulnerability at a different nuclear plant. At Davis-Besse, the single, non-safety-related AFW recirculation line, which was routed through the turbine building, provided the minimum flow path for both of the safety-related AFW pumps and the non-safety-related motor-driven feedwater pump. The licensees condition report concluded the non-safety-related piping had to be postulated to fail in such a way as to present the worst possible condition, which was a crimp that would preclude minimum recirculation flow. The licensee also found their plant design included a seismic event or tornado occurring concurrently with a loss of offsite power, which meant a recirculation pipe crimp could occur concurrently with an AFW system demand. The licensees corrective actions included determining whether AFW minimum recirculation flow was required during the scenarios that would cause the recirculation line to crimp and determining if a lower, short-term minimum recirculation flow rate could be utilized.
A lower, short-term required minimum flow rate would allow the licensee to credit the bypass flow orifices around the AFW flow control valves instead of crediting the use of the non-safety-related recirculation line routed through the turbine building.
The pump vendor provided the licensee with a lower, short-term recirculation flow rate requirement of 75 gallons per minute (gpm). However, this minimum flow rate was about twice the flow rate possible through the flow control valve bypass line flow orifices. As a result, the licensee evaluated scenarios where the AFW pumps would operate with their respective flow control valves shut and the required short-term minimum flow was provided via the crimped, non-safety-related recirculation line. The licensee determined the events requiring further evaluation were a steam generator overfeeding event and a cross-connected steam generator condition where the two AFW pumps were feeding one steam generator.
The licensees evaluation found the overfeeding event would not occur concurrently with a recirculation line crimp and therefore was not a concern. For the cross-connected steam generator condition, the licensee found that at least one AFW pump would operate with sufficient minimum flow. The licensees overall conclusion was that in the event of a crimp of the non-safety-related recirculation line, concurrent with a limiting single failure, the AFW system would complete its mission requirements because one AFW train would survive.
The licensee completed their corrective actions and formally closed CR-09-55170 on October 27, 2010.
The inspectors, as part of their review, observed a simulator scenario which focused on the operation of select inspection components during a station blackout and reactor trip. The inspectors observed that after the reactor tripped, the AFW pumps would need to operate with reduced (approximately half of the vendor provided minimum flowrate) minimum recirculation flow because the AFW flow control valves stayed closed for 6 to 7 minutes before the steam generator inventory lowered enough to allow the flow control valves to open. Since the simulator scenario results conflicted with the licensees previous evaluation results discussed above, the inspectors questioned whether the AFW system would remain able to perform its safety function with a potentially crimped recirculation line.
The licensee entered the issue into their corrective action program on September 26, 2024, as CR-2024-07617, 2024 CETI: Impact of Crimped AFP Recirculation Line on AF Pumps, and credited the operability basis from CR-09-55170 which only evaluated the 6 diameter portion of the recirculation line. The inspectors reviewed the supporting evaluations where the licensee determined the 6 line was robustly mounted and able to withstand a seismic event.
Additionally, the licensee found the majority of the AFW non-safety-related recirculation line was in the below grade turbine building levels where it was protected from tornado missiles.
The inspectors performed a walkdown of the recirculation line and noted there was a 3 diameter portion of the line which the licensees operability evaluation had not addressed. The inspectors found the 3 portion was not mounted in the same robust manner as the 6 portion and that it went well above grade level, with segments near sheet metal exterior walls that offered minimal protection for the line. The inspectors discussed the additional concerns related to the 3 portion of the line with the licensee on October 1, 2024. That same day, the licensee entered the additional concerns into the corrective action program as CR-2024-07731, 2024 CETI: Additional Concerns for Crimped Common AFP Recirculation Line of AF Pumps, and implemented a compensatory measure which realigned the AFW minimum flow so the 3 line was not a part of the recirculation pathway. Subsequently, on October 24, 2024, the licensee restored the flow path through the 3" line after they installed a rupture disk in the system as a temporary modification to ensure a minimum flow path for the AFW pumps would be maintained if the recirculation line became crimped.
On November 14, 2024, the licensee completed FORM-2024-07731-2, Complete a Past Operability Review as Requested by SRO and Document or Attach the Results, where the licensee determined a worst-case crimp caused by seismic loads or tornado missiles would not reduce the cross-sectional area of the 3" line sufficiently to prevent the AFPs from performing their design function. The inspectors reviewed the evaluation and determined the AFW pumps would have remained functional during the postulated events.
Corrective Actions: The licensees immediate corrective actions included an evaluation of the robustness of the minimum recirculation pathway, as well as a compensatory measure that avoided reliance on the 3 portion of the line. Subsequently, the licensee installed a rupture disk in the system as a temporary modification that allowed them to continue using the 3" portion of the line. The licensees planned long-term corrective actions included evaluating design options that did not rely on the recirculation line in the turbine building to ensure adequate AFW pump minimum flow.
Corrective Action References:
CR-2024-07617 CR-2024-07731
Performance Assessment:
Performance Deficiency: The licensees failure to identify and correct a condition adverse to quality was contrary to 10 CFR 50, Appendix B, Criterion XVI, and was a performance deficiency. Specifically, the licensee failed to ensure the design-basis minimum flow of the safety-related AFW pumps was maintained for all design-bases events after determining the non-safety-related recirculation line was susceptible to crimping. Pump operation below the required minimum flowrate could have led to pump degradation and failure following certain design-basis events.
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 inspectors concluded the failure to ensure the required minimum flow of the AFW pumps after a design-basis event induced crimp of the recirculation line adversely affected the availability of the AFW pumps. The inspectors reviewed IMC 0612, Appendix E, Examples of Minor Issues, and concluded that example 3.a was similar to the finding and supported the conclusion that it was more than minor.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined this finding was of very low safety significance (Green) because although the finding was a deficiency affecting the design or qualification of a mitigating SSC, the SSC maintained its probabilistic risk assessment (PRA) functionality. Specifically, the licensees evaluation in FORM-2024-07731-2 demonstrated the AFW pumps would have remained functional during the postulated events.
Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Specifically, the licensee failed to thoroughly evaluate all events where the AFW system would need to operate with a crimped recirculation line. Although the performance deficiency occurred more than 3 years ago, the inspectors determined the cross-cutting aspect was reflective of present performance as provided in Section 3.14a of Inspection Manual Chapter 0612, Issue Screening, because even after evaluating the inspectors concerns, the licensee did not fully evaluate the 3 inch portion of the recirculation line when initially determining the current operability of the AFW system in CR-2024-07617.
Enforcement:
Violation: Title 10 CFR 50, Appendix B, Criterion XVI, Corrective Actions, requires, in part, that measures be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected.
Contrary to the above, from October 27, 2010, to October 1, 2024, the licensee failed to promptly identify and correct a condition adverse to quality. Specifically, after determining the safety-related AFW pumps non-safety-related recirculation line was susceptible to crimping which could affect the safety function of the AFW system, the licensee failed to correct this deficiency by identifying all design-basis events where the crimping could occur and ensuring the design-basis minimum flow for the AFW pumps was maintained. Pump operation below the design-basis minimum flowrate could have led to pump degradation and failure following certain design-basis events.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Unresolved Item (Open)
Failure to Correctly Implement 10 CFR 50.59 Administrative Procedures URI 05000346/2024010-02 71111.21M
Description:
In September 2024, the inspectors reviewed 10 CFR 50.59 Screening 15-00776, Switchyard 345 kV Breaker Replacement, Revision 15, for engineering change package (ECP) 14-0725. The ECP replaced 345 kV General Electric circuit breakers 34560, 34561, 34562, 34563, and 34564 with ABB SF6 puffer circuit breakers. The breakers, and their protective elements, were discussed in UFSAR sections 8.2.1.1, Offsite Power System - Reliability Considerations, 8.3.1.1.2, Onsite Power System / AC Power System /
13800 Volt Auxiliary System, and 8.1.2.1, Main Generation System, among others. In section 8.2.1.1, the protective elements of the breakers were credited to ensure a short circuit failure of the individual breakers limited the impact to available offsite power sources.
Sections 8.3.1.1.2 and 8.1.2.1 credited breakers 34560 and 34561 as part of the fast bus transfer scheme that would have restored power to the safety buses from the offsite power sources when the normal power source to those buses was lost.
In Screening 15-00776, the licensee incorrectly documented the ECP did not impact the manual or automatic transfer of offsite power. In addition, the licensee concluded the proposed activity did NOT involve a change to an SSC that adversely affected a UFSAR described design function. The inspectors questioned those conclusions because the replacement breakers contained different protective elements that could adversely affect their design function. Specifically, the inspectors were concerned the new breakers and their relay protective schemes could have caused coordination issues between the plant electrical equipment and the switchyard. In addition, since a time delay feature was added to the 34560 breaker, the inspectors questioned whether the time delay adversely impacted the automatic fast transfer scheme credited in the UFSAR. The inspectors also noted subsequent changes to the existing switchyard, and the addition of a new switchyard, which could have been impacted by the concerns above.
The inspectors determined the screening did not contain sufficient information to justify the conclusions reached, which was contrary to procedure NOBP-LP-4003A, 10 CFR 50.59 User Guidelines, Revision 12. Specifically, in NOBP-LP-4003A, Attachment 2, 10 CFR 50.59 Screen, under the section titled, Screen Conclusion, the procedure required the technical basis for the response to each of the questions to be addressed and documented, and for the justification to be complete enough to permit an independent reviewer with similar expertise to understand the judgment and develop concurrence with the technical basis without recourse to the preparer. The licensee generated condition report CR-2024-07558, 2024 CETI: Insufficient Detail Contained in 10 CFR 50.59 Screen 15-00776, to capture the inspectors concerns.
The inspectors also reviewed 10 CFR 50.59 Screening 23-00791, Limiting Differential Pressure for Auxiliary Feedwater Pump Discharge Valves, Revision 0, for changes to the differential pressure (dP) calculations of auxiliary feedwater (AFW) system motor operated valves (MOVs) AF3869, AF3870, AF3871, AF3872, AF599, and AF608. The calculations included C-ME-050.03-117, Limiting Differential Pressure for AF3870 and AF3872, Revision 0 A04, C-ME-050.03-118, Limiting Differential Pressure for AF3869 and AF3871, Revision 0 A04, and C-ME-050.03-122, Differential Pressures for AF599 and AF608, Revision 1. As described in UFSAR section 9.2.7, the AFW system provided feedwater to the steam generators when the turbine-driven main feedwater pumps were not available or following a loss of normal and reserve electric power. The system consisted of two turbine-driven AFW pumps, condensate storage tanks, suction and discharge water piping, steam piping, valves, and associated instrumentation and controls. In addition, UFSAR section 7.4.1.3 described the steam and feedwater line rupture control system (SFRCS)which automatically started the AFW system in the event of a main steam or feedwater line rupture, the loss of both main feed pumps, the loss of all four reactor coolant pumps, or during a steam generator overfill condition. The SFRCS system provided signals to valves AF3869, AF3870, AF3871, and AF3872 to reposition them as required to provide AFW to both steam generators, or to the unaffected steam generator during a main steam line rupture event. Per UFSAR section 9.2.7.3, the AF599 and AF608 AFW isolation valves were no longer actuated by SFRCS and were normally open with control power removed.
However, per DB-OP-02000, RPS, SFAS, SFRCS TRIP, OR SG TUBE RUPTURE, Revision 33, table 1, SFRCS Actuated Equipment, valves AF599 or AF608 would be closed if AF3872 or AF3870, respectively, failed to close. Therefore, all of the AFW valves related to Screening 23-00791 had a safety function in both the open and closed direction, as further described in DBNPS ISTP5, Fifth Ten Year Inservice Testing Program, Revision 3.
The inspectors noted the dP calculations credited operator actions to address the bounding dP across the AFW valves. However, Screening 23-00791 did not address crediting operator actions when determining whether the proposed activity involved a change to a procedure that adversely affected how UFSAR described SSC design functions were performed or controlled. Per NOBP-LP-4003A, attachment 2, a change that fundamentally altered the existing means of performing or controlling a UFSAR described design function, including replacement of an automatic action with a manual action, was adverse. Therefore, the inspectors determined the change to credit operator actions to address the bounding dP across the valves was an adverse change that needed to be evaluated in a 10 CFR 50.59 evaluation. The licensee generated CR-2024-07619, 2024 CETI: AF599 and AF608 Not Evaluated for Worst Case Differential Pressure, and CR-2024-07625, 2024 CETI: AFW Discharge MOV Calculations Credit Operator Actions, to capture the inspectors concerns.
The ROPs significance determination process did not specifically consider the regulatory process impact in its assessment of licensee performance. Therefore, it was necessary to address this violation, which impeded the NRCs ability to regulate using traditional enforcement, to adequately deter non-compliance. The inspectors determined the licensees failure to correctly implement 10 CFR 50.59 administrative procedures to prepare adequate written evaluations that provided the bases for the determination that the changes did not require a license amendment was contrary to 10 CFR 50.59(d)(1). Specifically, the inspectors determined Screenings 15-00776 and 23-00791 did not provide the bases that changes made to offsite power circuit breakers and AFW valves, respectively, were not adverse and did not require a license amendment. The inspectors assessed the violation in accordance with the NRC Enforcement Policy dated August 23, 2024, and the NRC Enforcement Manual Revision 11, to determine the significance of the violation. They noted section 2.1.3.D.5.a of the manual indicated failures to implement 10 CFR 50.59 administrative procedures that resulted in non-isolated (i.e., repetitive) failures to prepare adequate written evaluations would be categorized as Severity Level (SL) IV violations. Since, of 11 screenings reviewed during the inspection, two were inadequate, the inspectors determined there was insufficient information to conclude whether the failures were non-isolated (i.e., repetitive), and whether the violation was a minor violation or a SL IV violation. Therefore, the violation was treated as an unresolved item (URI) until a determination could be made on the severity of the violation.
Planned Closure Actions: Since the licensee entered the issues with Screenings 15-00776 and 23-00791 into the corrective action program (CAP), the inspectors plan to review the revised 50.59 products, and their underlying technical basis, to determine their adequacy.
After the reviews are complete, the inspectors will evaluate whether the failure to implement 10 CFR 50.59 administrative procedures was non-isolated (i.e., repetitive) to determine whether the violation is a minor or SL IV violation.
Licensee Actions: As stated above, the licensee entered the issues into the CAP. For Screening 15-00776, the licensee planned to revise the screening to provide proper justification on whether a 50.59 evaluation was needed. For Screening 23-00791, the licensee verified the AFW valves had sufficient margin to operate against the bounding dP across them. The licensee planned to verity the design requirements for the valves and update the calculations and their associated 50.59 assessments.
Corrective Action References:
CR-2024-07558 CR-2024-07619 CR-2024-07625
EXIT MEETINGS AND DEBRIEFS
The inspectors confirmed that proprietary information was controlled to protect from public disclosure.
- On September 26, 2024, the inspectors presented the interim inspection results to Gregory Michael, Director of Site Engineering, and other members of the licensee staff.
- On October 17, 2024, the inspectors presented the interim inspection results to Terry Brown, Site Vice President, and other members of the licensee staff.
- On November 21, 2024, the inspectors presented the comprehensive engineering team inspection results to Gregory Michael, Director of Site Engineering, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
069.033
Maximum Leakage of AFW Check Valves
1-A01
C-EE-002-01-014
DC System Ampacity Calculation
C-EE-002.01-011
Low Voltage Coordination Calculation
C-EE-002.01-016
Station Battery Discharge Analysis for Beyond Design Basis
Events
C-EE-024,01-011
Emergency Diesel Generators Transient Analysis
C-ICE-016.03-002
Component Cooling Water Flow I Pressure Indications for
Flow Verification Testing
C-ME-016.04-041
Evaluation of the Temperature Increase of CCW System
and 0-A01
C-ME-024.03-007
SBO Diesel Air Start System
C-ME-050.03-112
MOV Thrust/Torque Calculation for AF608
C-ME-050.03-117
Limiting Differential Pressure for AF3870 and AF3872
and 0-A04
C-ME-050.03-118
Limiting Differential Pressure for AF3869 and AF3871
0-A04
C-ME-050.03-121
MOV Thrust / Torque Calculation for AF3872
C-ME-050.03-122
Differential Pressures for AF599 and AF608
C-ME-050.03-123
AFW Pump Discharge Pressure
C-ME-050.03-125
Auxiliary Feedwater Pumps (AFP) P14-1 & P14-2 Pump
Performance Curves
C-ME-099.16-010
Check Valve Design Basis Analysis
C-ME-24.03-005
SBO Diesel Fuel Tank Sizing
C-NSA-016.04-
001
CCW Pump Minimum Allowable Head Curve
C-NSA-016.04-
006
CCW Maximum Temperature Analysis
C-NSA-050.03-
29
AFW Recirculation and Bypass Flowrates
Calculations
Evaluation of Davis-Besse Modification ECP 08-0571,
Auxiliary Feedwater Piping System Modification
and 1
Calibration
Records
TE-738
Forebay Temperature
Corrective Action
Documents
CR-2002-05747
LIR CCW - Limitorque Covers on CC5095 & 5096 Have Been
Cut in Half
09/10/2002
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR-2004-04280
Conduit Foundation in BWST Pit Degraded
08/29/2006
CR-2004-23624
AF-39 Check Valve Inspection
2/08/2011
CR-2005-10801
AF 43 Check Valve Inspection
05/06/2014
CR-2006-13227
AF 43 Check Valve Inspection and Leak Repair
05/09/2016
CR-2009-55170
OE - Crimping of Non-Seismic AFW Recirculation Piping Not
Evaluated
03/11/2009
CR-2012-13122
NRCCDBI2012 - AFW Discharge Check Valve Allowable
Leakage Basis Not Identified in C-ME-099.16-010
08/27/2012
CR-2014-11478
Check Valve Didnt Develop the Required Differential Pressure
07/09/2014
CR-2015-02419
NRC CDBI 2015 - EDG Jacket Water Heat Load at EDG 30
Minute Load Rating
2/25/2015
CR-2016-04443
HIS599E, OFF Switch Sticks In
04/02/2016
CR-2016-05172
Less Than Min Wall Thickness Measured on CCW#1 Shell per
Order 200486506
04/13/2016
CR-2017-03256
Corrosion on CCW Surge Tank Lines
06/12/2017
CR-2018-01889
AF608 Control Power OFF Pushbutton Stuck in the
Depressed Button
03/03/2018
CR-2018-02301
Cracking Found on T12 (CCW Surge Tank) Concrete Pedestal
07/28/2018
CR-2019-00716
AFPT2 Steam Lines Drained More Than Expected After Being
Run the Previous Day
01/24/2019
CR-2019-05467
AFWP 2 Inboard and Outboard Red Sight Glass Markings
NOT Present
06/25/2019
CR-2020-02918
Low CCW Surge Tank Level Alarm When CCW Pump 1 Was
Started for Pump Swap
10/08/2020
CR-2020-05972
QC ID Work Order 200643129 Minimum Wall Thickness Not
Met for E22-1, CCW Heat Exchanger 1-1
10/21/2020
CR-2020-07291
DB-PF-03572 Acceptance Criteria not met for No. 1 CCW
Pump
09/18/2020
CR-2021-05623
SBODG AC Soakback Pump Making an Abnormal Noise
07/23/2021
CR-2021-09570
E208-3 SBODG Area Heating Fan Making Squealing/Grating
Noise
2/18/2021
CR-2023-00112
SBODG DA215 Air Start Side Low Air Pressure
01/05/2023
CR-2023-02595
E208-4 SBODG Room Heater Not Working
04/03/2023
CR-2024-04926
Failed Battery Number 5 on Station Blackout Diesel Generator
06/05/2024
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
CR-2024-07197
24 CETI Incorrect Revision of 10 CFR 50.59 Screen
Included in EC
09/10/2024
CR-2024-07220
24 CETI - External Oversight Identified Housekeeping
Deficiency
09/11/2024
CR-2024-07253
24 CETI Oil Spots Noted on AF3871 Motor and Actuator
09/12/2024
CR-2024-07255
24 CETI Inspections Identified Housekeeping Deficiency
09/12/2024
CR-2024-07268
24 CETI Aux Feedwater Housekeeping Identified During
CETI Walkdown
09/12/2024
CR-2024-07283
24 CETI - Missing Inspection Documents in Work Order 200726464
09/12/2024
CR-2024-07335
24 CETI: EC 19-0202-001 Missed Opportunity to Include
New 51NT Relay in USAR Section 8.1.2.1
09/16/2024
CR-2024-07372
24 CETI Identified Loose Stud on the SBODG Intake Piping
09/17/2024
CR-2024-07399
24 CETI Lack of Grease Identified on Terminals of Batteries
in Hydrogen Switchyard Control Building
09/18/2024
CR-2024-07401
24 CETI: Operating Experience Review Credited As
Required Preventative Maintenance Activities
09/18/2024
CR-2024-07410
24 CETI: Material Condition of Multiple Conduit Fittings in
CCW Surge Tank Room
09/19/2024
CR-2024-07415
24 CETI - Incorrect 50.59 Documentation for
EC 24-1086-001
09/19/2024
CR-2024-07422
24 CETI Calculation 069.033, R01 A01, Lists Incorrect Leak
Rate
09/19/2024
CR-2024-07423
24 CETI Drawing Discrepancy Finding
09/19/2024
CR-2024-07425
24 CETI SBODG Available Within 10 Minutes of a Station
Blackout Not Listed as a TCOA
09/19/2024
CR-2024-07427
24 CETI: Dust Accumulation on CCW Pump Room
Sprinklers
09/19/2024
CR-2024-07437
24 CETI - Control Building 1A Local, Non-Simplex Smoke
Detector Breaker Open
09/19/2024
CR-2024-07523
09/24/2024
CR-2024-07538
24 CETI: AFW Pump Discharge Pipe Not Evaluated for
Crimped Recirc Line
09/24/2024
Corrective Action
Documents
Resulting from
Inspection
CR-2024-07544
24 CETI: MDFP Procedure DB-OP-06225 Section 5.4.1 Not
09/24/2024
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Updated to Reflect C-ME-037.01-003 Rev. 3
CR-2024-07558
24 CETI: Insufficient Detail Contained in 10CFR 50.59
SCREEN 15-00776
09/25/2024
CR-2024-07581
24 CETI: Question Raised on Adequacy of Security for
Breaker 34568 in Hydrogen Switchyard 1A.
09/25/2024
CR-2024-07615
24 CETI: Several Test Switches on DPAC #2 Found to be in
the Open Position in Hydrogen Switchyard Control Building
09/26/2024
CR-2024-07617
24 CETI: Impact of Crimped AFP Recirculation Line on AF
Pumps
09/26/2024
CR-2024-07619
24 CETI: AF599 and AF608 Not Evaluated for Worst Case
Differential Pressure
09/26/2024
CR-2024-07623
24 CETI E22-1 Channel Pitting Corrosion Rate Evaluation
Considered Non-Conservative
09/26/2024
CR-2024-07625
24 CETI: AFW Discharge MOV Calculations Credit
Operator Actions
09/26/2024
CR-2024-07731
24 CETI: Additional Concerns for Crimped Common AFP
Recirculation Line on AF Pumps
10/01/2024
CR-2024-07784
24 CETI Not All Single Failure Conditions Considered
Under CR-2024-07538
10/03/2024
CR-2024-07787
24 NRC CETI: CCW Pump 1 Impeller Design Control Not
Maintained
10/03/2024
CR-2024-07788
CETI 2024: Inconsistency Between EDG Design Basis and
Operating Procedures
10/03/2024
E-1011
345KV Switchyard 1A Three Line Diagram 345/13.8KV
Transformer 1A & 13.8KV CB 52-F1A
E-1042, Sheet1
Emer. Diesel Generator 1-1 Loading Table
E-17B, Sheet 3
Safety Features Actuation System Actuated Equipment
Tabulation
E-2, Sheet 1
25KV & 13.8KV Relay & Metering One Line Diagram
E-20
Generator & Transformer Relay & Metering Three Line
Diagram
E-44B, Sheet 4C
Elementary Diagram, Feedwater System AFW Isolation
Valves
Drawings
E-6, Sheet 3
25/250 Vdc MCC No. 1
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
E-6, Sheet 4
25/250 Vdc MCC No. 2
E-64B, Sheet 17
Emer DSL Gens DSL. SFAS Sequencer Start/Stop
E-64B, Sheet 1E
Emer DSL Gens DSL. Gen 1-1 Misc. Aux Relays
M-006D
Auxiliary Feedwater System
M-006E
Condensate System
M-007B
Piping & Instrument Diagram Steam Generator Secondary
System
M-206F
Piping Isometric: Auxiliary Feedwater System
M-206K
Piping Isometric Condensate System
M-269AS
Standard Installation Details for Spray Shields and Spray
Barriers
OS-017A Sheet 1
Auxiliary Feedwater System
08-0693-000
Replace the Heavily Corroded Nuts on Anchor Bolts for
Supports 35-HCC-21-H3, 33C-HCC-91-H15 and
34-HCC-37-H18
08-0693-001
Repair Pipe Supports in BWST Pit
Engineering
Changes
16-0332-000
EFW NFPA-805 Manual Isolation Circuit
EER 600724048
Provide Tube Plugging Criteria CCW Heat Exchanger
2/12/2011
EER 601034440
Evaluate Locations Below Min. Wall E22-1
04/13/2016
EER 601281520
E22-1 Locations Below Min. Wall
07/28/2020
Engineering
Evaluations
EER 601308965
Evaluation for Bounding EDG wk Tank Exam
06/22/2021
System Health Report: 37-01-Auxiliary Feedwater: 2023-2
Nuclear Industry Check Valve Group (NIC) Inservice Testing
Owners Group Check Valve Condition Monitoring Guideline
Hazard Study for the Motor Driven Feedwater Pump System
03/01/1986
15-00776
50.59 Screening - Switchyard 346kV Breaker Replacement
15-01500
50.59 Screening - Target Rock AFW Power Supply Isolation
20-00151
CCW System Operating Procedure
07/17/2020
20-01400
50.59 Screening - CCW Pump Minimum Allowable Head
Curve
200667101
Auxiliary Feedwater MOV 608: Diagnostic Test Report
03/07/2020
Miscellaneous
2007-05
Prompt Operability Determination: Auxiliary Feedwater Suction
Piping
11/29/2007
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
21-00208
50.59 Screening - Replace SBO 125 Vdc Battery and Battery
Rack
21-00968
50.59 Screening - Revise Table 18-1, Commitment 3,
Underground Piping and Tanks Integrity Program
21-00987
50.59 Screening - 345 kV Switchyard 1A and Breaker 52-1A
Control and Plant Interface
21-01045
50.59 Screening - Independent Spent Fuel Storage Installation
Aging Management Program (AMP)
2-00065
Control Room Cooling Loads: Emergency Mode
2/09/2022
2-00931
59.59 Screening - Component Cooling Water System
Procedure
24-00829
50.59 Screening - Temporary Modification - Jumper SBODG
Battery Cell
600643326
Document Change Request: DB-OP-06233: Auxiliary
Feedwater System
10/15/2010
854920
09/27/2023
C-1594 Sheet 1
Barrier Functional List
C-1596
Door Functional List
CMP-AF-2
Auxiliary Feed Pump 1/2 to Steam Generator 1/2 Supply
Check Valves Condition Monitoring Plan
04/27/2022
DB-1511-3
Structures Monitoring Inspection Worksheet
04/16/2017
DB-1511-3
Structures Monitoring Inspection Worksheet
08/19/2019
DB-1511-3
Structures Monitoring Inspection Worksheet
06/11/2021
DB-1511-4
Structures Monitoring Inspection
Worksheet
2/06/2023
DB1-023
Equipment Qualification Package: Kerite Cables
DB1-037C
Equipment Qualification Package: Limitorque Motor Operated
Valve Actuator
DB1-037E
Equipment Qualification Package: Limitorque Motor Operated
Valve Actuator
ISTB1
ISTB1 Pump and Valve Basis Document
ISTP5
Fifth Ten Year Inservice Testing Program
05/09/2024
M-210-00213
Vendor Manual - Composite Powell Manual
10/31/2023
NG-EN-00562
Bolting Integrity Program
2/07/2017
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
OE-2020-0072-2
OE - Auxiliary Feedwater System Declared Inoperable Due to
Check Valve Leakage
10/14/2020
OE-2022-0366
Vibration Induced Actuation of a Breaker Failure Relay
Causing LOOP, Feed and Reactor Trip
08/31/2023
RFA-88-0805
AFW Recirculation Line Design Evaluation
06/24/1988
Operability
Evaluations
FORM-2024-
07331-2
Aux. Feed Pump Min. Recirculation Line Past Operability
11/14/2024
DB-ME-09512
Electrical Maintenance Procedure: Installation Procedure for
Raceways Carrying Electrical Cables
DB-OP-02000
RPS, SFAS, SFRCS Trip, or SG Tube Rupture
DB-OP-02001
Electrical Distribution Alarm Panel 1 Annunciator
DB-OP-02010
Feedwater Alarm Panel 10 Annunciators
DB-OP-02043
Emergency Diesel Generator 1 Alarm Panel 43 Annunciator
DB-OP-02521
Loss of AC Bus Power Sources
DB-OP-02600
Operational Contingency Response Action Plan
DB-OP-02700
Station Blackout
DB-OP-02704
Extended Loss of AC Power DC Load Management
DB-OP-03007
Miscellaneous Instrument Daily Checks
DB-OP-06225
MDFP Operating Procedure
and 27
DB-OP-06233
Auxiliary Feedwater System
2, 46 and
DB-OP-06262
Component Cooling Water System Procedure
2, 43, 44,
and 46
DB-OP-06273
Diesel Fuel Oil Transfer
DB-OP-06316
Diesel Generator Operating Procedure
DB-OP-06334
Station Blackout Diesel Generator Operating Procedure
DB-PF-03072
Component Cooling Water Pump 1 Test
and 23
DB-PF-03572
Component Cooling Water Pump 1 Baseline Test
DB-PF-06704
4: AFW Pump Design Curves
DB-SC-03112
SFAS Channel 3 Functional Test
DB-SC-03262
Integrated Test of the SFRCS Actuation Channel 2
DB-SP-03160
AFP-2 Quarterly Test
Procedures
DB-SP-03166
AFP-2 Response Time Test
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
DBBP-OPS-1013
Control of Time Critical Actions
DBBP-OPS-1113
Control of Time Sensitive Operator Actions
EN-DP-01511
Structures Monitoring
NOBP-LP-2100
Operating Experience Process
NOBP-OP-1113
Control of Time Sensitive Operator Actions
NOP-LP-2001
Corrective Action Program
NOP-LP-4003
Evaluation of Changes, Test and Experiments
NOP-OP-1009
Operability Determinations and Functionality Assessments
NOP-OP-1013
Control of Time Critical Operator Actions
RA-EP-02880
200352460
09/14/2014
200613227
Auxiliary Feedwater Check Valve AF43: Inspection and Leak
Repair
05/09/2016
200613565
CCW Heat Exchanger Inspect and Clean
10/12/2017
200618691
DB-SUB048-01 Safety Features Actutation System
10/06/2015
200695455
DB-System099 Miscellaneous Subsystems
06/28/2019
200700737
Bench Testing IST Program Pressure Relief Devices
(CCW Surge Tank)
11/26/2019
200704584
Bench Testing IST Program Pressure Relief Devices
(CCW Surge Tank)
2/08/2017
200708485
Bench Testing IST Program Pressure Relief Devices
(CCW Surge Tank)
07/22/2022
200725844
System Pressure Test CCW Surge Tank
09/22/2021
200726464
Component Cooling Water Heat Exchanger Clean and Inspect
03/04/2024
200739960
1-2 Turbine-Driven Auxiliary Feedwater Pump Bearing
Housing Dimension Verification
05/08/2018
200756127
SC3114-002 04.1 +2 ACT CHI INTRGRTD SPAS Integrated
03/20/2020
200758665
AF39 Reverse Flow Test
06/17/2020
200761823
Perform CCW HX 2 Performance Test
08/06/2021
200766444
Auxiliary Feedwater MOV 608 Diagnostic Test
03/17/2020
200790947
AFW Pump 2 Comprehensive IST Test
07/01/2021
Work Orders
200826202
AF39 Reverse Flow Test
07/16/2022
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
200851425
AFW Pump 2 Comprehensive IST Test
05/03/2023
200873364
SBO DG Preventative Maintenance
08/13/2024