IR 05000346/2023004

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Integrated Inspection Report 05000346/2023004
ML24030A749
Person / Time
Site: Davis Besse Cleveland Electric icon.png
Issue date: 01/31/2024
From: Billy Dickson
NRC/RGN-III/DORS/RPB2
To: Tony Brown
Energy Harbor Nuclear Corp
References
IR 2023004
Download: ML24030A749 (1)


Text

SUBJECT:

DAVIS-BESSE NUCLEAR POWER STATION-INTEGRATED INSPECTION REPORT 05000346/2023004

Dear Terry Brown:

On December 31, 2023, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Davis-Besse Nuclear Power Station. On January 16, 2024, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.

No findings or violations of more than minor significance were identified during this inspection.

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, Billy C. Dickson, Jr., Chief Reactor Projects Branch 2 Division of Operating Reactor Safety Docket No. 05000346 License No. NPF3

Enclosure:

As stated

Inspection Report

Docket Number:

05000346

License Number:

NPF-3

Report Number:

05000346/2023004

Enterprise Identifier:

I20230040049

Licensee:

Energy Harbor Nuclear Corp.

Facility:

Davis-Besse Nuclear Power Station

Location:

Oak Harbor, OH

Inspection Dates:

October 01, 2023 to December 31, 2023

Inspectors:

T. Briley, Senior Project Engineer

R. Cassara, Resident Inspector

J. Kutlesa, Emergency Preparedness Inspector

R. Ng, Senior Project Engineer

B. Towne, Senior Resident Inspector

Approved By:

Billy C. Dickson, Jr., Chief

Reactor Projects Branch 2

Division of Operating Reactor Safety

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated 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

No findings or violations of more than minor significance were identified.

Additional Tracking Items

Type Issue Number Title Report Section Status URI 05000346/202300401 Shield Building Operability Determination 71152A Open URI 05000346/202300402 Reactor Pressure System Flow Modules Installed with Incorrect Configuration 71152A Open

PLANT STATUS

The unit began the inspection period at rated thermal power. On November 18, 2023, the unit was down powered to 92 percent to support control rod drive and turbine stop valve testing. The unit was returned to rated thermal power on November 19, 2023. On November 21, 2023, the unit was down powered to 97 percent to support moderator temperature coefficient measurement. The unit was returned to rated thermal power on November 22, 2023, and remained at or near rated thermal power for the remainder of the inspection period.

INSPECTION SCOPES

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

REACTOR SAFETY

71111.01 - Adverse Weather Protection

Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to impending extreme cold weather for the following systems: ultimate heat sink, service water, borated water storage tank, and heat tracing systems during the week ending December 16, 2023.

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (1 Sample)

The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:

(1) High pressure injection system during at power operation on November 30, 2023

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:

(1) Auxiliary feed pump 1 room, room 237, fire area E during the week ending October 7, 2023
(2) Low voltage switchgear room Ebus, room 429, fire area Y on November 7, 2023
(3) Low voltage switchgear room Fbus, room 428, fire area X on November 7, 2023

71111.06 - Flood Protection Measures

Flooding Sample (IP Section 03.01) (1 Sample)

(1) The inspectors evaluated internal flooding mitigation protections in the: train 1 and train 2 emergency core cooling system (ECCS) rooms

71111.07A - Heat Exchanger/Sink Performance

Annual Review (IP Section 03.01) (1 Sample)

The inspectors evaluated readiness and performance of:

(1) ECCS room cooler 1 following outage for maintenance during the week ending November 17, 2023

71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance

Requalification Examination Results (IP Section 03.03) (1 Sample)

(1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered from September 18, 2023 through November 17, 2023.

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)

(1) The inspectors observed and evaluated licensed operator performance in the control room during power reduction, control rod drive testing, turbine stop valve testing, and implementation of coping strategy for reactor coolant pump seal improvement on November 18-19, 2023

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

(1) The inspectors observed and evaluated licensed operator simulator training on October 24, 2023

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (1 Sample)

The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:

(1) Emergency diesel generator (EDG) 2 outage during the week ending October 28, 2023

Aging Management (IP Section 03.03) (1 Sample)

The inspectors evaluated the effectiveness of the aging management program for the following SSCs that did not meet their inspection or test acceptance criteria:

(1) Assessment of service water piping corrosion in pipe tunnel

71111.13 - Maintenance Risk Assessments and Emergent Work Control

Risk Assessment and Management Sample (IP Section 03.01) (4 Samples)

The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:

(1) Risk assessment for high pressure injection train 1 outage for scheduled maintenance on November 8, 2023
(2) Assessment of maintenance risk strategy and prioritization for holiday work weeks on December 30, 2023
(3) Assessment of risk mitigating strategy for DBMI03207 reactor coolant pump (RCP)monitor inputs to steam feed rupture control system and reactor protection system (RPS) channel 2 functional test on November 15, 2023
(4) Assessment of risk mitigation and planning for coping strategies for RCP 12 seal degradation December 30, 2023

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (7 Samples)

The inspectors evaluated the licensee's justifications and actions associated with the following operability determinations and functionality assessments:

(1) EDG 1 starting air pressure regulator controlling abnormally high during the week ending October 21, 2023
(2) ECCS sump 13 pump 'A' discharge leak observed during performance of VT2 system leakage test on November 17, 2023
(3) Service water pump 3 strainer failed to start on high pressure during the week ending December 2, 2023
(4) Fire barrier 427E/430W in electrical penetration room 2 was found with voids and air flow during inspection on November 20, 2023
(5) Rubber Oring found in emergency diesel generator day tank 2 during the week ending December 2, 2023
(6) Auxiliary feed water turbine governor hunting excessively on October 20, 2023
(7) Borated water storage tank level indication freeze protection circuit indicating open during the week ending December 23, 2023

71111.24 - Testing and Maintenance of Equipment Important to Risk

The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:

Post-Maintenance Testing (PMT) (IP Section 03.01) (5 Samples)

(1) Startup transformer 1 after scheduled maintenance during the week ending October 7, 2023
(2) Containment spray pump 1 after scheduled maintenance during the week ending October 7, 2023
(3) Auxiliary feedwater pump 2 after scheduled maintenance during the week ending October 21, 2023
(4) EDG 2 after scheduled outage for maintenance during the week ending October 28, 2023
(5) High pressure injection pump functional test following scheduled maintenance outage on November 9, 2023

Surveillance Testing (IP Section 03.01) (4 Samples)

(1) Auxiliary feedwater pump terry turbine trip throttle valve exercise, DBOP06233 on October 29, 2023
(2) Auxiliary feedwater train 1 level control, interlock, and flow transmitter test, DBSP03152 on November 5, 2023
(3) Containment spray train 2 quarterly pump and valve test on November 15, 2023
(4) RPS channel 1 calibration surveillance on December 4, 2023

Reactor Coolant System (RCS) Leakage Detection Testing (IP Section 03.01) (1 Sample)

(1) RCS leakage during the week ending October 28, 2023

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.0102.03) (1 Sample)

(1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes.
  • Davis-Besse Nuclear Power Station, Unit No. 1Issuance of License Amendment No. 305 Revising the Emergency Plan (EPID L2022LLA0013)of 11/15/2022
  • Davis-Besse Nuclear Power Station Emergency Plan, Revision 37 (DB202302600) of 10/05/2023
  • KLD TR-1259: Davis-Besse Nuclear Power Station Development of Evacuation Time Estimates of 08/26/2022
  • DBRM-EMER1500A: Davis-Besse Emergency Action level Basis Document, Revision 9
  • RAEP01500: Emergency Classification, Revision 16 This evaluation does not constitute NRC approval.

71114.06 - Drill Evaluation

Drill/Training Evolution Observation (IP Section 03.02) (1 Sample)

The inspectors evaluated:

(1) Emergency response tabletop drill at emergency operations facility during the week ending October 21,

OTHER ACTIVITIES-BASELINE

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

MS06: Emergency AC Power Systems (IP Section 02.05)===

(1) October 1, 2022 through September 30, 2023

MS07: High Pressure Injection Systems (IP Section 02.06) (1 Sample)

(1) October 1, 2022 through September 30, 2023

MS08: Heat Removal Systems (IP Section 02.07) (1 Sample)

(1) October 1, 2022 through September 30, 2023

MS09: Residual Heat Removal Systems (IP Section 02.08) (1 Sample)

(1) October 1, 2022 through September 30, 2023

MS10: Cooling Water Support Systems (IP Section 02.09) (1 Sample)

(1) October 1, 2022 through September 30, 2023

BI02: RCS Leak Rate Sample (IP Section 02.11) (1 Sample)

(1) October 1, 2022 through September 30, 2023

71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)

The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:

(1)2021 thru 2023 Inspection campaign as part of long-term monitoring for the shield building laminar cracking condition

(2) Reactor protection system channel 1 tripped when placed in service following replacement of reactor coolant pump flow input modules on November 28, 2023

71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends in maintenance rule program implementation that might be indicative of a more significant safety issue. The inspectors observed a negative trend identified by the licensee regarding inconsistency in maintenance rule screening and categorization of plant issues warranting a maintenance rule failure review.

INSPECTION RESULTS

Unresolved Item (Open)

Shield Building Operability Determination URI 05000346/202300401 71152A

Description:

Updated Safety Analysis Report (USAR) Section 3.8.2.2.2 describes the design function of the shield building as completely enclosing the containment vessel, the personnel access openings, the equipment hatch, and that portion of all penetrations that are associated with primary containment. The design of the shield building provides for

(1) biological shielding, (2)controlled release of the annulus atmosphere under accident condition, and
(3) environmental protection of the containment vessel. USAR Section 3.8.2.2.4 and 3.8.2.3.4 delineate the design and licensing basis loading conditions and loading combinations for the shield building.

During the 2021 through 2023 shield building core bore inspection campaigns, the licensee identified locations where the laminar crack widths exceeded 0.050 inches. The inspectors reviewed Calculation No. CCSS099.20078, "Shield Building Laminar Crack Evaluation,"

Revision 0. The licensee used this calculation to establish the operability of the shield building for laminar crack widths exceeding 0.050 inches. In Calculation No. CCSS099.20078, the licensee changed a design and licensing basis load combination per USAR Section 3.8.2.3.4 to not evaluate the shield building for the applied loads due to the safe shutdown earthquake and the applied loads due to the accident temperature (due to the loss of coolant accident or a high energy line break) concurrently. The licensee did not perform a 10 CFR 50.59 regulatory evaluation to address this aforementioned change.

This issue is unresolved because the inspectors cannot determine whether there is a violation and will need to consult with the Office of Nuclear Reactor Regulation.

Planned Closure Actions: The inspectors will discuss the information provided during the inspection with the Office of Nuclear Reactor Regulation to determine whether the change in the design and licensing basis load combinations to establish operability of the shield building is in accordance with the design and licensing basis.

Licensee Actions: The licensee plans to review whether the change in the design and licensing basis load combinations to establish operability of the shield building is in accordance with the design and licensing basis.

Unresolved Item (Open)

Reactor Protection System Flow Modules Installed with Incorrect Configuration URI 05000346/202300402 71152A

Description:

On November 28, 2023, reactor protection system (RPS) channel 1 reactor coolant system (RCS) flow signal converter cards were replaced under an approved work order. During restoration from the maintenance, RPS channel 1 unexpectedly tripped on Power-Flow-Imbalance. The licensee placed RPS channel 1 in manual bypass per the technical specifications. The licensee submitted CR202308805 to describe the event.

Subsequent troubleshooting revealed that the refurbished signal converter cards that the technician installed during the maintenance had incorrect capacitor values, resulting in excessive noise in the RCS flow signal. On November 30, 2023, the licensee replaced the RCS flow modules with the modules they removed during the previous maintenance, and RPS channel 1 was restored to operability and returned to service.

The licensee reviewed the unplanned RPS channel 1 trip and generated CR202309194 to capture the review findings. During the review, it was revealed that the RCS flow modules were refurbished to the incorrect vendor manual specifications. Proper configuration guidance was available in a vendor technical manual but not included in the I&C Data package. The vendor manual that was referenced in the data package resulted in incorrect capacitor values, which led to excess noise in the circuit and the resultant trip of the RPS channel once they were placed in service. The failure to use the correct vendor specification when refurbishing the RCS flow modules is a performance deficiency within the licensees ability to foresee and correct.

Planned Closure Actions: The licensee has established a corrective action to perform an extent of condition review and investigation. Upon completion of this activity planned within the first calendar quarter of 2024, the inspectors will review the results to provide input on the more than minor determination associated with the identified performance deficiency.

Licensee Actions:

  • RCS flow modules with the correct configuration were installed in the system on November 30, 2023, and RPS channel 1 was restored to operability and placed in service.
  • The licensee will perform an extent of condition review and investigation within the first calendar quarter of 2024.
  • The licensee will update the associated vendor manual within the first calendar quarter of 2024.

Corrective Action References: CR202308805, CR2023009194 Observation: 2021 thru 2023 Inspection Campaign as Part of Long-Term Monitoring for the Shield Building Laminar Cracking Condition 71152A As part of the continued long-term monitoring of the shield building laminar cracking condition, the licensee subjected a sample of existing shield building core bores to visual examination. One purpose of the core bore visual examinations was to determine if any growth or change in the nature of the cracks had occurred by measurement of crack width and comparison to historical values. In areas of identified laminar crack planar propagation, the licensee performed additional impulse response mapping to provide a relative indication of the extent of propagation.

On October 14, 2022, the Office of Nuclear Reactor Regulation issued an amendment that revised the design basis for the facility to allow laminar concrete cracking of a limited width in the outer reinforcement layer of the shield building containment structure (ML22277A601).

The NRC staff found that the strength and stiffness of the shield building will be maintained if laminar concrete cracking in the outer reinforcement layer does not exceed 0.050 inches in width.

During the 2021 through 2023 shield building core bore inspection campaigns, the licensee identified additional growth in laminar crack width. In some instances, the measured laminar crack width exceeded the 0.050-inch crack width. The licensee documented measured laminar crack widths that exceeded the 0.050-inch crack width in the corrective action program. As a result of the increased crack widths, the licensee performed operability evaluations of the shield building and determined that the shield building remained operable because the increased crack widths were localized in nature. The inspectors reviewed the licensee's operability determinations, engineering analyses, and assessment that the shield building remained capable of performing its intended safety functions. The inspectors identified one unresolved issue.

Observation: Maintenance Rule Evaluation Screening and Categorization Inaccuracies 71152S As part of the licensee's maintenance rule program to monitor performance of structures, systems, or components (SSCs) against licensee-established goals, condition reports were routinely screened to determine if a maintenance rule failure evaluation was warranted.

Maintenance rule failure evaluations, typically performed by a system engineer and reviewed by the maintenance rule program owner, were used to evaluate further if an SSC failed to perform its maintenance rule function. Maintenance rule failures for each system were then categorized and tallied to determine if any SSC performance criteria (goals) were exceeded that would warrant additional corrective action.

The inspectors noted a negative trend of several challenges in the licensee's ability to monitor, compile information, and manage the maintenance rule program. Notable examples included but were not limited to:

1) The licensee identified in condition report 202308227 multiple inaccuracies in previously completed maintenance rule failure evaluations on the radiation monitoring system. In particular, in some cases, there was confusion by system engineering, who performed the maintenance rule failure evaluations, on the differences between assigned categories such as a maintenance rule functional failure (MRFF) and maintenance preventable functional failure (MPFF). A MRFF was generally defined as the failure of an SSC to perform a function specified on the licensee's system scoping sheets. The functions listed on the system scoping sheets were the functions that resulted in the SSCs inclusion in the maintenance rule. A MPFF was generally defined as an unintended event or condition such that an SSC within the scope of the maintenance rule [as defined in 10 CFR 50.65(b)] was not capable of performing its intended function, and that should have been prevented by the performance of appropriate maintenance actions. This confusion led to inaccurate categorization and subsequent tallies of how many failures occurred in each maintenance rule category used to compare with licensee-established goals. Licensee-established goals included MPFFs but not MRFFs. For example, the licensee established a goal of less than or equal to five MPFFs for the radiation monitoring system. Exceeding this goal would have required a 10 CFR 50.65 (a)(1) evaluation and warranted additional corrective action.

The licensee provided additional training to the radiation monitoring system engineer, and they revised the inaccurate maintenance rule evaluations. The inspectors did not identify any maintenance rule performance criteria that were exceeded as a result of the categorization inaccuracies. However, inaccuracies could lead to errors in the administration of the maintenance rule program. For instance, SSCs not being evaluated for (a)(1) status when warranted or being evaluated for (a)(1) status when performance monitoring threshold requirements were not met.

2) The licensee also identified in condition report 202106748 multiple examples of condition reports that warranted a maintenance rule evaluation and were screened incorrectly (no maintenance rule evaluation performed when warranted). For example, in 2021, nine condition reports associated with a reactor trip did not receive a maintenance rule evaluation when warranted. An over-reliance on initial senior reactor operator comments in the condition reports contributed to the missed maintenance rule evaluations.

Licensee corrective actions included, but were not limited to, the performance of maintenance rule evaluations for the incorrectly screened condition reports. In addition, the licensee performed a subsequent maintenance rule audit, identifying additional condition reports from cycle 22 that did not receive a maintenance rule evaluation when warranted. Each system that the audit determined to have condition reports that warranted a maintenance rule failure evaluation, the licensee assigned a new condition report for further corrective action specific to that system, along with the performance of the maintenance rule evaluation for the identified condition. The licensee also implemented a detailed review of ten condition reports per month to ensure appropriate maintenance rule evaluation screening and, as applicable, maintenance rule categorization (evaluation results). The inspectors did not identify any maintenance rule performance criteria that were exceeded as a result of the screening inaccuracies.

Adequate monitoring was part of the foundation of the maintenance rule program. The determination of whether or not a maintenance rule evaluation was warranted for an identified SSC condition was generally screened by the maintenance rule program owner. If a maintenance rule evaluation was performed and concluded a maintenance rule failure occurred, failure categorization and subsequent tallies were generally assigned by the cognizant system engineer and reviewed by the maintenance rule program owner. The combination of maintenance rule evaluation screening and categorization inaccuracies, especially when multiple individuals are involved, could leave the station vulnerable to a more significant maintenance rule program implementation issue.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

  • On January 16, 2024, the inspectors presented the integrated inspection results to T. Brown, Site Vice President, and other members of the licensee staff.
  • On November 27, 2023, the inspectors presented the requalification examination inspection results to J. Twardzik, Licensed Operator and Non-Licensed Operator Requalification Training Supervisor, and other members of the licensee staff.
  • On December 12, 2023, the inspectors presented the emergency action level and emergency plans inspection results to R. Oesterle, Manager Regulatory Compliance and Emergency Preparedness, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

DBOP06331

Freeze Protection and Electrical Heat Trace

71111.01

Procedures

DBOP06913

Seasonal Plant Preparation Checklist

71111.04

Procedures

DBOP06011

High Pressure Injection System Operating Procedure

PFP-AB237

Auxiliary Feed Pump 1 Room, Room 237, Fire Area E

PFP-AB428

Low Voltage Switchgear Room FBus, Room 428, Fire Area

X

71111.05

Fire Plans

PFP-AB429

Low Voltage Switchgear Room EBus, Room 429, Fire Area

X

Drawings

C1596

Door Functional List

71111.06

Procedures

RAEP02880

Internal Flooding

201703328

NRC 2017 Inspection: Vulnerabilities Identified with ECCS

Room Cooer Clean/Inspection Strategy

2/23/2017

Corrective Action

Documents

201703953

Historical Inspection Data for ECCS Room Coolers

04/16/2017

200757300

ECCS Room Cooler 1 Clean and Inspect

11/17/2022

71111.07A

Work Orders

200883390

ECCS Rooms H&V

11/21/2023

71111.11Q

Procedures

CYC 2305 DBS

Unannounced Drills

Corrective Action

Documents

2309129

SW Piping Below Nominal Wall Thickness

2/12/2023

71111.12

Miscellaneous

DB07723

Weld Traveler - Pressure Retaining

07/27/2023

HPI Outage Risk Management Plan

11/01/2023

DB0138B

Checklist for Protected Equipment Postings - Protecting

Train 2

Miscellaneous

ODMI 2208

Operation with RCP 12 Indications of Degraded Seal

Performance

Procedures

DBBP-OPS0011

Protected Equipment Posting

71111.13

Work Orders

200868705

Channel 2 RCP Functional and Calibration Test

11/15/2023

2307749

Service Water Pump 3 Strainer Did Not Start on High

Pressure

10/14/2023

2307894

AFPT 2 Governor is Hunting Excessively at the HSS

10/20/2023

71111.15

Corrective Action

Documents

2307973

Rubber ORing Found in EDG Day Tank 2

10/23/2023

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

2308153

Freeze Protection Circuit 16Q Indicates Open for BWST

Level Transmitter LT15250

10/31/2023

2308437

P893A: ECCS Sump 13 Pump A Discharge Leak

Observed

11/10/2023

2308562

Failed low Safety Significant Fire Barrier

11/18/2023

2306936

Tier 3 RCS Leakage Exceedance

09/08/2023

Corrective Action

Documents

2308805

RPS Channel 1 Trip

11/28/2023

DBOP06233

Auxiliary Feedwater System

DBOP6311

Transformer Restoration

DBSC03071

Emergency Diesel Generator 2 Monthly Test

DBSP03152

AFW Train 1 Level Control, Interlock, and Flow Transmitter

Test

Procedures

DBSP03338

Containment Spray Train 2 Quarterly Pump and Valve Test

200811669

Startup Transformer

10/04/2023

200833803

AFW Train 1 Level Control, Interlock and Flow Transmitter

Test

10/09/2022

200853893

Auxiliary Feed Pump Turbine 12

10/17/2023

200867847

BW26 Forward Flow

11/08/2023

71111.24

Work Orders

200883351

Change Inboard and Outboard Bearing Oil on Motor

MP561 and Pump P561

10/06/2023

Calculations

KLD TR - 1259

Davis-Besse Nuclear Power Station Development of

Evacuation Time Estimates

08/26/2022

DB202302600

Davis-Besse Nuclear Power Station Emergency Plan,

Revision 37

10/05/2023

Miscellaneous

EPID

L2022LLA0013

Davis-Besse Nuclear Power Station, Unit No. 1Issuance

of License Amendment No. 305 Revising the Emergency

Plan

11/15/2022

DBRM-

EMER1500A

Davis-Besse Emergency Action Level Basis Document

71114.04

Procedures

RAEP01500

Emergency Classification

Calculations

CCSS099.20078

Shield Building Laminar Crack Evaluation

2107387

21 Shield Building Inspection Findings

10/04/2021

71152A

Corrective Action

Documents

2206671

22 Shield Building Inspection Findings

08/30/2022

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

2307019

23 Shield Building Inspection Campaign Findings

09/13/2023

2308805

RPS Channel 1 Trip

11/28/2023

2309194

RPS Channel 1 RCS Flow Mode Configured to Incorrect

Vendor Specification

2/14/2023

200743532

21 Shield Building Boroscope Inspection Report

07/28/2021

thru

09/02/2021

200743533

22 Shield Building Boroscope Inspection Report

07/11/2022

thru

07/14/2023

Work Orders

200858083

23 Shield Building Boroscope Inspection Report

07/10/2023

thru

07/14/2023

2106024

NRC SIT: Maintenance Rule Failure Review for CR

2105319 Defective Battery Cell Identified at D3201B

during Troubleshooting of DEHC UPS

08/09/2021

2106748

Maintenance Rule Administrative Error - Reactor Trip

7/8/2021

09/07/2021

2203486

RCM1003B Sample Pump Tripped Unexpectedly

04/21/2022

2203724

Maintenance Rule Review Radiation Monitoring System

04/29/2022

2204280

Containment Noble Gas RIC4597AAC Low Skid Flow

05/20/2022

2204590

Main Condenser Vent System - RCM1003A Low Flow

Locked in Alarm

06/02/2022

2209683

Annunciator 21A Letdown Rad Hi Alarmed During Water

Add to the Makeup Tank

2/22/2022

2209818

Vacuum System RCM1003A Low Flow Alarms

2/28/2022

2304633

RE4597AA Total Skid Flow Low

06/07/2023

Corrective Action

Documents

2308227

Errors Found in Maintenance Rule Failure Review Forms

11/02/2023

Miscellaneous

MRPM

Maintenance Rule Program Manual

NOP-ER3004

Maintenance Rule Program

71152S

Procedures

NOP-LP2001

Corrective Action Program

50