ML24337A240
| 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
Terry Brown Site Vice President Vistra Operations Company, LLC Davis-Besse Nuclear Power Station 5501 N. State Rte. 2, Mail Stop A-DB-3080 Oak Harbor, OH 43449-9760
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
T. Brown 2
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Karla K. Stoedter, Chief Engineering Branch 1 Division of Operating Reactor Safety Docket No. 05000346 License No. NPF-3
Enclosure:
As stated cc w/ encl: Distribution via LISTSERV Signed by Stoedter, Karla on 12/06/24
SUNSI Review
Non-Sensitive
Sensitive
Publicly Available
Non-Publicly Available OFFICE RIII RIII NAME LRodriguez:sw KStoedter DATE 12/06/2024 12/06/2024
Enclosure U.S. NUCLEAR REGULATORY COMMISSION Inspection Report Docket Number:
05000346 License Number:
NPF-3 Report Number:
05000346/2024010 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
2
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
3 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) (8 Samples)
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
4 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
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
IST (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
IST 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
5 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
non-destructive examination 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
6 (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, 2023 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
7 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.
8 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
9 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,
10 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
11 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
12 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.
13 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 0
C-EE-002.01-011 Low Voltage Coordination Calculation 7
C-EE-002.01-016 Station Battery Discharge Analysis for Beyond Design Basis Events 1
C-EE-024,01-011 Emergency Diesel Generators Transient Analysis 3
C-ICE-016.03-002 Component Cooling Water Flow I Pressure Indications for Flow Verification Testing 2
C-ME-016.04-041 Evaluation of the Temperature Increase of CCW System 0 and 0-A01 C-ME-024.03-007 SBO Diesel Air Start System 0
C-ME-050.03-112 MOV Thrust/Torque Calculation for AF608 9
C-ME-050.03-117 Limiting Differential Pressure for AF3870 and AF3872 0 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 12 C-ME-050.03-122 Differential Pressures for AF599 and AF608 1
C-ME-050.03-123 AFW Pump Discharge Pressure 3
C-ME-050.03-125 Auxiliary Feedwater Pumps (AFP) P14-1 & P14-2 Pump Performance Curves 0
C-ME-099.16-010 Check Valve Design Basis Analysis 2
C-ME-24.03-005 SBO Diesel Fuel Tank Sizing 1
C-NSA-016.04-001 CCW Pump Minimum Allowable Head Curve 2
C-NSA-016.04-006 CCW Maximum Temperature Analysis 1
C-NSA-050.03-029 AFW Recirculation and Bypass Flowrates 0
Calculations MPR-3373 Evaluation of Davis-Besse Modification ECP 08-0571, Auxiliary Feedwater Piping System Modification 0 and 1 Calibration Records TE-738 Forebay Temperature 1
71111.21M Corrective Action Documents CR-2002-05747 LIR CCW - Limitorque Covers on CC5095 & 5096 Have Been Cut in Half 09/10/2002
14 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 12/08/2011 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 02/25/2015 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 12/18/2021 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
15 Inspection Procedure Type Designation Description or Title Revision or Date CR-2024-07197 2024 CETI Incorrect Revision of 10 CFR 50.59 Screen Included in EC 09/10/2024 CR-2024-07220 2024 CETI - External Oversight Identified Housekeeping Deficiency 09/11/2024 CR-2024-07253 2024 CETI Oil Spots Noted on AF3871 Motor and Actuator 09/12/2024 CR-2024-07255 2024 CETI Inspections Identified Housekeeping Deficiency 09/12/2024 CR-2024-07268 2024 CETI Aux Feedwater Housekeeping Identified During CETI Walkdown 09/12/2024 CR-2024-07283 2024 CETI - Missing Inspection Documents in Work Order 200726464 09/12/2024 CR-2024-07335 2024 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 2024 CETI Identified Loose Stud on the SBODG Intake Piping 09/17/2024 CR-2024-07399 2024 CETI Lack of Grease Identified on Terminals of Batteries in Hydrogen Switchyard Control Building 09/18/2024 CR-2024-07401 2024 CETI: Operating Experience Review Credited As Required Preventative Maintenance Activities 09/18/2024 CR-2024-07410 2024 CETI: Material Condition of Multiple Conduit Fittings in CCW Surge Tank Room 09/19/2024 CR-2024-07415 2024 CETI - Incorrect 50.59 Documentation for EC 24-1086-001 09/19/2024 CR-2024-07422 2024 CETI Calculation 069.033, R01 A01, Lists Incorrect Leak Rate 09/19/2024 CR-2024-07423 2024 CETI Drawing Discrepancy Finding 09/19/2024 CR-2024-07425 2024 CETI SBODG Available Within 10 Minutes of a Station Blackout Not Listed as a TCOA 09/19/2024 CR-2024-07427 2024 CETI: Dust Accumulation on CCW Pump Room Sprinklers 09/19/2024 CR-2024-07437 2024 CETI - Control Building 1A Local, Non-Simplex Smoke Detector Breaker Open 09/19/2024 CR-2024-07523 2024 CETI - ISFSI Pad Survey 09/24/2024 CR-2024-07538 2024 CETI: AFW Pump Discharge Pipe Not Evaluated for Crimped Recirc Line 09/24/2024 Corrective Action Documents Resulting from Inspection CR-2024-07544 2024 CETI: MDFP Procedure DB-OP-06225 Section 5.4.1 Not 09/24/2024
16 Inspection Procedure Type Designation Description or Title Revision or Date Updated to Reflect C-ME-037.01-003 Rev. 3 CR-2024-07558 2024 CETI: Insufficient Detail Contained in 10CFR 50.59 SCREEN 15-00776 09/25/2024 CR-2024-07581 2024 CETI: Question Raised on Adequacy of Security for Breaker 34568 in Hydrogen Switchyard 1A.
09/25/2024 CR-2024-07615 2024 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 2024 CETI: Impact of Crimped AFP Recirculation Line on AF Pumps 09/26/2024 CR-2024-07619 2024 CETI: AF599 and AF608 Not Evaluated for Worst Case Differential Pressure 09/26/2024 CR-2024-07623 2024 CETI E22-1 Channel Pitting Corrosion Rate Evaluation Considered Non-Conservative 09/26/2024 CR-2024-07625 2024 CETI: AFW Discharge MOV Calculations Credit Operator Actions 09/26/2024 CR-2024-07731 2024 CETI: Additional Concerns for Crimped Common AFP Recirculation Line on AF Pumps 10/01/2024 CR-2024-07784 2024 CETI Not All Single Failure Conditions Considered Under CR-2024-07538 10/03/2024 CR-2024-07787 2024 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 3
E-1042, Sheet1 Emer. Diesel Generator 1-1 Loading Table 30 E-17B, Sheet 3 Safety Features Actuation System Actuated Equipment Tabulation 11 E-2, Sheet 1 25KV & 13.8KV Relay & Metering One Line Diagram 17 E-20 Generator & Transformer Relay & Metering Three Line Diagram 56 E-44B, Sheet 4C Elementary Diagram, Feedwater System AFW Isolation Valves 13 Drawings E-6, Sheet 3 125/250 Vdc MCC No. 1 43
17 Inspection Procedure Type Designation Description or Title Revision or Date E-6, Sheet 4 125/250 Vdc MCC No. 2 34 E-64B, Sheet 17 Emer DSL Gens DSL. SFAS Sequencer Start/Stop 5
E-64B, Sheet 1E Emer DSL Gens DSL. Gen 1-1 Misc. Aux Relays 21 M-006D Auxiliary Feedwater System 60 M-006E Condensate System 31 M-007B Piping & Instrument Diagram Steam Generator Secondary System 66 M-206F Piping Isometric: Auxiliary Feedwater System 29 M-206K Piping Isometric Condensate System 21 M-269AS Standard Installation Details for Spray Shields and Spray Barriers 2
OS-017A Sheet 1 Auxiliary Feedwater System 35 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 0
08-0693-001 Repair Pipe Supports in BWST Pit 4
Engineering Changes 16-0332-000 EFW NFPA-805 Manual Isolation Circuit 0
EER 600724048 Provide Tube Plugging Criteria CCW Heat Exchanger 12/12/2011 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 0
Nuclear Industry Check Valve Group (NIC) Inservice Testing Owners Group Check Valve Condition Monitoring Guideline 1
Hazard Study for the Motor Driven Feedwater Pump System 03/01/1986 15-00776 50.59 Screening - Switchyard 346kV Breaker Replacement 19 15-01500 50.59 Screening - Target Rock AFW Power Supply Isolation 7
20-00151 CCW System Operating Procedure 07/17/2020 20-01400 50.59 Screening - CCW Pump Minimum Allowable Head Curve 2
200667101 Auxiliary Feedwater MOV 608: Diagnostic Test Report 03/07/2020 Miscellaneous 2007-05 Prompt Operability Determination: Auxiliary Feedwater Suction Piping 11/29/2007
18 Inspection Procedure Type Designation Description or Title Revision or Date 21-00208 50.59 Screening - Replace SBO 125 Vdc Battery and Battery Rack 0
21-00968 50.59 Screening - Revise Table 18-1, Commitment 3, Underground Piping and Tanks Integrity Program 1
21-00987 50.59 Screening - 345 kV Switchyard 1A and Breaker 52-1A Control and Plant Interface 0
21-01045 50.59 Screening - Independent Spent Fuel Storage Installation Aging Management Program (AMP) 0 22-00065 Control Room Cooling Loads: Emergency Mode 02/09/2022 22-00931 59.59 Screening - Component Cooling Water System Procedure 46 24-00829 50.59 Screening - Temporary Modification - Jumper SBODG Battery Cell 0
600643326 Document Change Request: DB-OP-06233: Auxiliary Feedwater System 10/15/2010 854920 345kV Hydrogen Battery Test 09/27/2023 C-1594 Sheet 1 Barrier Functional List 6
C-1596 Door Functional List 9
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 12/06/2023 DB1-023 Equipment Qualification Package: Kerite Cables 10 DB1-037C Equipment Qualification Package: Limitorque Motor Operated Valve Actuator 14 DB1-037E Equipment Qualification Package: Limitorque Motor Operated Valve Actuator 13 ISTB1 ISTB1 Pump and Valve Basis Document 26 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 02/07/2017
19 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 7
DB-OP-02000 RPS, SFAS, SFRCS Trip, or SG Tube Rupture 33 DB-OP-02001 Electrical Distribution Alarm Panel 1 Annunciator 44 DB-OP-02010 Feedwater Alarm Panel 10 Annunciators 27 DB-OP-02043 Emergency Diesel Generator 1 Alarm Panel 43 Annunciator 16 DB-OP-02521 Loss of AC Bus Power Sources 30 DB-OP-02600 Operational Contingency Response Action Plan 16 DB-OP-02700 Station Blackout 4
DB-OP-02704 Extended Loss of AC Power DC Load Management 1
DB-OP-03007 Miscellaneous Instrument Daily Checks 37 DB-OP-06225 MDFP Operating Procedure 18 and 27 DB-OP-06233 Auxiliary Feedwater System 32, 46 and 47 DB-OP-06262 Component Cooling Water System Procedure 42, 43, 44, 45 and 46 DB-OP-06273 Diesel Fuel Oil Transfer 36 DB-OP-06316 Diesel Generator Operating Procedure 74 DB-OP-06334 Station Blackout Diesel Generator Operating Procedure 37 DB-PF-03072 Component Cooling Water Pump 1 Test 22 and 23 DB-PF-03572 Component Cooling Water Pump 1 Baseline Test 7
DB-PF-06704 : AFW Pump Design Curves 45 DB-SC-03112 SFAS Channel 3 Functional Test 22 DB-SC-03262 Integrated Test of the SFRCS Actuation Channel 2 14 DB-SP-03160 AFP-2 Quarterly Test 38 Procedures DB-SP-03166 AFP-2 Response Time Test 33
20 Inspection Procedure Type Designation Description or Title Revision or Date DBBP-OPS-1013 Control of Time Critical Actions 6
DBBP-OPS-1113 Control of Time Sensitive Operator Actions 3
EN-DP-01511 Structures Monitoring 15 NOBP-LP-2100 Operating Experience Process 21 NOBP-OP-1113 Control of Time Sensitive Operator Actions 2
NOP-LP-2001 Corrective Action Program 21 NOP-LP-4003 Evaluation of Changes, Test and Experiments 10 NOP-OP-1009 Operability Determinations and Functionality Assessments 9
NOP-OP-1013 Control of Time Critical Operator Actions 3
RA-EP-02880 Internal Flooding 3
200352460 CCW Heat Exchanger 1 ECT 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) 02/08/2017 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 SPAS ACT CH 1 PA NORM RPL 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
21 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