ML19052A371

NRC-2018-000733 - Resp 1 - Final. Agency Records Subject to the Request Are Enclosed

ML19052A371
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Issue date:	09/12/2018
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FOIA, NRC-2018-000733
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Two BWST Level Channels Non-Unit Number: Davis Besse Functional & Potentially Affecting ECCS Swapover Analysis Number: DB-1801 lnsp. Report Number: 05000346/2018-002 EA Number (if applicable): N/A Result: 7 x 10-7/year EVENT OR CONDITION

SUMMARY

Background Information The borated water storage tank (BWST) provides a safety-related, borated water suction source for various emergency core cooling systems (EGGS). These systems, in part, ensure the reactor core is adequately cooled during accident conditions. The safety features actuation system (SFAS) actuates various EGGS equipment based on specified design parameters. The technical specifications, as defined in the plant's operating license, require four channels of BWST level instrumentation. Each channel generally consists of a level transmitter (physically attached to the BWST to determine actual level), control room indication (reactor operator display of level measured in feet), and a bistable trip unit (initiates an automatic trip signal when the BWST is nearly depleted and a specified level band is reached, or a trip signal can be manually initiated by a reactor operator). If a trip signal is present in two or more channels, SFAS will actuate by enabling a permissive interlock feature that allows reactor operators to manually transfer the normal EGGS suction source from the BWST to the reactor containment emergency sump in accordance with Emergency Operating Procedures. When the BWST level is nearly depleted, recirculation from the containment emergency sump to the reactor core allows for long term core cooling post accident. A specified.level band for the transfer is established to ensure enough water is available in the containment emergency sump for recirculation and for EGGS equipment protection. This condition, caused by the performance deficiency, is a concern because two of the four BWST level instruments were tripped, satisfying the EGGS suction transfer permissive logic and potentially allowing a.premature EGGS suction transfer by the operators.

• Performance Deficiency The inspectors determined the licensee's failure to shutdown the reactor within six hours, as required by TS 3.3.5.b, was a performance deficiency. Specifically, with two channels of the BWST level instrumentation inoperable, the licensee failed to enter Mode 3 within six hours.

LER 05000346/2016-008-01 The finding was determined to be more than minor because it was associated with the Mitigating Systems function of Long Term Heat Removal, and affected the cornerstone's objective of ensuring the availability, reliability, arid capability of systems to respond to initiating events to prevent undesirable consequences. Specifically, the finding resulted in the loss of the ECCS suction swap permissive function, which could have resulted in the loss-of system safety function (i.e., ECCS due to a premature suction source transfer). The finding was evaluated using the SOP in accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." Th.e inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.3.5 allowed outage time of 6 hours for this function. Therefore, a detailed risk evaluation was required. ANALYSIS RESULTS ~----------------------~ Change in Core Damage Frequency. The increase in core damage frequency (~CDF) for this event is 1.2x10*1; therefore, this condition should be treated as a green violation (i.e., ~CDF less than 1 x 10-6). Dominant Sequence. The dominant accident sequence is, a Main Steam Line Break inside of containment and contributes 75% of the total internal events ~CDF. This was concluded by evaluating the relative size of the initiating events of concern. RISK ANALYSIS.___ __________________ _ Analysis Typ*e. The analyst performed a bounding hand calculation of the risk of this performance deficiency. No manipulation of the SPAR model was necessary. Model Used: Not applicable. Software Used: Not applicable. Exposure Time and/or Date of Occurrence: The exposure time that the analyst used was from 14 hours from when the performance deficiency was introduced (being in a Technical Specification Action Statement requiring shutting down the plant) until the condition no longer existed. Please note that this is a bounding assumption for this analysis and there is additional margin to the green-white threshold, because the base case (6 hours allowed by Technical Specifications) was not subtracted from the non-conforming case (14 hours). Key Modeling Assumptions. The following modeling assumptions and associated basic event modifications were required for this event analysis:

1. Accidents of Concern: The analyst assumed that the accidents of concern that could cause an ECCS actuation and the need for a swapover to the containment sump were LLOCA, MLOCA and MSLB inside containment. Other significant casualties that might cause ECCS actuation and an RCS inventory loss to the sump, e.g., SLOCA and SGTR,

LER 05000346/2016-008-01 were deemed less relevant and were not analyzed. This decision was made based on. the (relatively speaking) low amounts of RCS inventory lost over a much greater length of time. The generic initiating event fr~quencies were used from the NRC SPAR model.

2. Operator Recovery: No credit was applied for the Reactor Operators recognizing that the ECCS swapover signal occurred "prematurely" due to the performance deficiency. In reality, during an actuaf event, there would have been a more than minimal recovery probability but this was not quantified in the analysis.

3. Additional Conservatisms: The analyst calculated the non-conforming value and did not subtract out the "base case." This represented additional conservatism and margin to the Green-White threshold.*

4. Ex-Core Sources: As a standard assumption (one that is typically assumed in most SOP detailed risk evaluations) the analyst did not account for ex-core sources, such as spent fuel in the pool or other special nuclear material.

Calculations: CCDP = (exposure time factor) x (frequency of event) CCDP = (exposure time factor) x (IELLocA + IEMwcA + IEMsLB ( 14 ) -6 -4 4 CCDP = 8760.x (5.9 x 10 + 1.5 x 10. + 3.0 x 10- ) CCDP = 7.2 x 10-7 Uncertainty: No uncertainty calculations were performed. EXTERNAL EVENTS '--------------------------~ Because the risk result from internal events was greater than 1 E-7, an assessment of external events was required. Flood and Tornado - These external events could not reasonably cause a loss of RCS inventory event. No further analysis was performed of these events. Seismic and Fire - A seismic event or a significant unsuppressed fire could cause a loss of RCS inventory event, e.g., a beyond design basis earthquake rupturing the RCS, or an inadvertent PORV lift in the case of a fire. However, the frequency of such an initiating event would be at least one order of magnitude less than the IE frequencies used here. No further analysis was performed of these events.

LER 05000346/2016-008-01 LARGE EARLY RELEASE FREQUENCY..._** _,_, -------~-~'-----'-____, Davis Besse is a B&W plant with a large dry containment. The accident sequences that have non-zero LERF multipliers as described in the LERF NUREG are not any that were considered in this analysis. No further analysis was performed of these events. ATTACHMENTS ----------~------,---------------~

1. Phase 1 Screening Sheets

2. LER 2016-008-01, "Application of Technical Specification for the Safety Features Actuation System Instrumentation Analyst: John David Hanna.

Date: July 9, 2018 Reviewed By: Date:

Appendix A SAPHIRE 8 Worksheets B-1 LER 05000346/2016-008-01

J EA-[CT:a]-[###J) Mark Bezilla Site Vice President UNITED STATES NUCLEAR REGULATORY COMMISSION REGION Ill 2443 WARRENVILLE RD. SUITE 210 LISLE, ILLINOIS 60532-4352

• insert. Month DD, YYYY after concurrence

.. FirstEnergy Nuclear Operating Co. Davis-Besse Nuclear Power Station 5501 N. State Rte. 2, Mail Stcip A-DB-3080 Oak Harbor, OH 43449-9760

SUBJECT:

DAVIS-BESSE NUCLEAR POWER STATION - NRC INTEGRATED INSPECTION . REPORT 05000346/2018002

Dear Mr. Bezilla:

On June 30, 2018, the U.S. Nuclear R~gulatory Commission (NRC) completed an integrated in~pection at your Davi~-Besse Nuclear Po~er ~tation. On July 31, 2018, the NRC inspectors.. discussed the results of this inspection with YQ..Y and other members of your staff. The results of this inspection are documented in fhe enclosed report. Based on the results of this inspection, the NRC has identified three issues that were evaluated under the risk significance determination process as having very low safety significance (Green). The NRC has also determined that two violations are associated with these issues. Because the licensee initiated condition reports to address these issues, these violations are being treated as Non-Cited Violations (NCVs), consistent with Section i3.2 of the Enforcement Policy. These NCVs ate descriQed in the subject inspection report. If you coritest the violations or significance cif these NCYs, 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; Y.(ith copies to the Regional Administrator, Region Ill; the Director, Office of Enforcement; and the NRC Resident Inspector at the Davis-Besse Nuclear Power Station.

If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region Ill; and the NRC resident inspector at Davis-Besse Nuclear Power Station. 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 10 CFR 2.390, "Public Inspections, Exemptions, Requests for Withholding." DocketNos.50-346;72-014 License Nos. NPF-3

Enclosure:

IR 05000346/2018002 cc: Distribution via ListServ Sincerely, Jamnes L. Cameron, Chief Branch 4 Division of Reactor Projects

Letter to Mark Bezilla from Jamnes Cameron dated 8/t~ /2018

SUBJECT:

DISTRIBUTION: Jeremy Bowen RidsNrrDorllpl3 RidsNrrPMDavisBesse Resource RidsNrrDirslrib Resource Steven West Darrell Roberts Richard Skokowski Allan Barker DRPIII DRSIII ROPreports.Resource@nrc.gov DOCUMENT NAME: [Insert Path] ADAMS Accession. Number: [Delete Document Name when Final] IX! Publicly Available D Non-Publicly Available D Sensitive ~ Non-Sensitive To receive a copy of this document, indicate in the concurrence box "C" = Copy without tt h/ 1 "E" C 'th tt h/ I "N" N a ac enc = opvw1 a ac enc = OCOPV OFFICE RIii I RIii I RIii I RIii I NAME DATE. OFFICIAL RECORD COPY

U.S. NUC~EAR REGULATORY COMMISSION REGION Ill Docket Numbers: 50-346; 72-14 License Numbers: NPF-3 Report Numbers:

• 05000346/2018002 Enterprise Identifier: 1-2018-002-0015 Licensee:

FirstEnergy Nuclear Operating Company (FENOC) Facility: Location: Oates: Inspectors: Approved by: Davis-Besse Nuclear Power Station Oak Harbor, OH April 1 through June 30, 2018 D. Mills, Senior Resident Inspector M. Garza, Acting Senior Resident Inspector J. Harvey, Resident Inspector J. Rutkowski, Senior Project Engineer

• J. Beavers, Resident Inspector Duane Arnold Energy Center J. Cameron; Chief Branch 4 Division of Reactor Projects Enclosure

SUMMARY

• The U.S. Nuclear Regulatory Commission (NRC) continued monitoring licensee's performance by conducting an integrated quarterly inspection at Davis-Besse Power Plant in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRC's program for overseeing the safe operation of commercial nuclear power reactors. Refer to

. https://www.nrc.gov/reactors/operating/oversight.html for more information. Findings and violations being considered in the NRC's assessment are summarized in the table below. List of Findings and Violations Failure to Follow the Makeup and Purification Procedure Cornerstone Significance Cross-cutting Report Aspect

• Section Initiating Events Green H.12 71152-NCV 05000346/2018002-01 Annual Closed Follow-Up of Selected Issues A self-revealed Green finding and associated Non-Cited Violation of Technical Specification 5.4.1.a, Procedures, was identified when the licensee failed to follow station procedure DB-OP-06006, "Makeup and Purification System." Specifically, the licensee failed to open MU177, the Make-Up Filter 1 Outlet Isolation valve, which resulted in the isolation of letdown while swapping make-up filters.

Failure to Aooly Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Green H.14 71153-Systems NCV 05000346/2018002-2 Follow-Up of Closed Events and Notices of Enforcement. Direction The NRC identified a finding of Green significance and an associated Non-Cited Violation of Technical Specification 3.3.5.b, Safety Features Actuation System Instrumentation, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying two channels of Safety Features Actuation System Borated Water Storage Tank level instrumentation were inoperable. Specifically, the licensee exited Technical Specification 3.3.5.b, and failed to perform the associated six hour shutdown limiting condition for operation action, while two Borated Water Storage Tank level instruments were inoperable. Procedur.e Violation Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Green H.8 71153-Systems NCV 05000346/2018002-03 Follow-Up of Closed Events and 2

3 Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated non-cited violation of 1 O CFR Part 50, Appendix 8, Criterion V, "Instructions, Procedures, and Drawings," due to the licensee's failure to properly implement procedures DB-OP-06405, "Safety Features Actuation System Procedure," DB-SC-03110, "SFAS Channel 1 Functional Test," and DB-OP-03006, "Miscellaneous Instrument Shift Checks," Specifically, the licensee declared SFAS Channel 1 operable without correctly performing the required procedural steps and failed to correctly perform the channel checks. Additional Tracking Items Type Issue Number Title Report Status Section LER 05000346/2016008-01 Application of Technical 71153 Closed Specification for the Safety Features Actuation System Instrumentation 3

TABLE OF CONTENTS PLANT STATUS.................................................................................................................... 5 INSPECTION SCOPES.............,............................................................................................ 5 REACTOR SAFETY............................................................................................................... 5 OTHER ACTIVITIES - BASELINE......................................................................................,.. 8 INSPECTION RESULTS............................................................. ~...........*.....................*............ 9 EXIT MEETINGS AND DEBRIEFS............................................................... :........................... 13 DOCUMENTS REVIEWED....................................................................................................... 17 . 4

PLANT STATUS The unit remained at or near rated thermal power for the entirety of the inspection period. On March 28, 2018, FirstEnergy Solutions (FES)/ FirstEnergy Nuclear Operating Company (FENOC) verbally notified the Nuclear Regulatory Commission that they intended to shut down . all four of their operating nuclear power plants. Based on that notification, the first to shut down will*be Davjs-Besse; by May 31, 2020. On March 31, 2018, FES, FirstEnergy Nuclear Generation (FENGEN), and FENOC filed for bankruptcy. The Nuclear Regulatory Commission continues to maintain-focus on public health and safety and the protection of the environment. This will include a continuous evaluation by inspectors to determine whether the licensee's financial condition is impacting safe operation of the plant. 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 plant status activities described in IMC 2515 Appendix D, "Plant Status" and conducted routine reviews using IP 71152, "Problem Identification and Resolution." The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to asse*ss licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards. REACTOR SAFETY 71111.01-Adverse Weather Protection Summer Readiness (1 Sample) The inspectors evaluated summer readiness of offsite and alternate alternating current power systems. 71111.04-Equipment Alignment Partial Walkdown (4 Samples) The inspectors evaluated system configurations during partial walkdowns of the following systems/trains: (1) Auxiliary Feedwater Train 1 during planned maintenance and testing on Auxiliary Feedwater Train 4 during the week ending April 14, 2018; (2) Motor Driven Feedwater pump during Auxiliary Feedwater Train 2 maintenance during the week ending *April 21, 2018; (3) Containment Spray system during the week ending April 28, 2018; and (4) Decay Heat/Low Pressure Injection Train 2 when Train 1 was out of service during the week ending June 2, 2018. 5

Complete Walkdown (1 Sample) The inspectors evaluated system configurations during a complete walkdown of the High Pressure Coolant Injection system during the week ending April 28, 2018. 71111.050-Fire Protection Quarterly Quarterly Inspection (4 Samples) The inspectors evaluated fire protection program implementation in the following selected areas: (1) Emergency Core Cooling System Pump room 1-2, (fire area A), during the week ending April 28, 2018; (2) Auxiliary Building Roc;:,ms 104, 106, 106A, and 109, (fire area A), du.ring the week.ending April 28, 2018; (3) Auxiliary Feedwater Train 2, (fire area F) during the week ending May 19; and (4) Component Cooling Water Room, (fire area T), during the week ending May 26, 2018. 71111.06-Flood Protection Measures Underground Cables (1 Sample) The inspectors evaiuated cable submergence protection in: (1) Manholes mh3101, mh3108, mh3109, mh3010 during the\\,veek ending April 14, 2018. 71111.07-Heat Sink Performance Heat Sink (1 Sample) The inspectors evaluated Closed Cooling Water 3 performance following a pinhole leak

• repair during the week ending May 19, 2018.

71111.11-Licensed Operator Requalification Program and Licensed Operator Performance Operator Requalification (1 Sample) The inspectors observed and evaluated licensed operator requalification training during the week ending May 26, 2018. Operator Performance (1 Sample) The inspectors observed and evaluated operators perform a reactor downpower and place feedwater compon~nts in manual control to support planned maintenance o*n a feedwater flow component during the week ending May 26, 2018. 71111.12-Maintenance Effectiveness Routine Maintenance Effectiveness (2 Samples)

• 6

The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions: (1) Decay Heat/Low Pressure Injection Train 1; and (2) Component Cooling Water availability. 71111.13-Maintenance Risk Assessments and Emergent Work Control (4 Samples) The inspectors evaluated the risk assessments for the following planned and emergent work activities: (1) Auxiliary Feedwater Train 2 out of service for planned maintenance during the week ending May 12; (2) E-31A outage to relieve cable stress due to turbine building floor movement during the week ending May 12; (3) Control Room Emergency Ventilation system Train 1 out of service for planned maintenance during the week ending May 26; and (4) Decay Heat/Low Pressure Injection Train 1 out of service for planned maintenance during the week ending June 2. 71111.15-0perability Determinations and Functionality Assessments {4 Samples) The inspectors evaluated the following operability determinations and functionality assessments: (1) Forward flow/ closure valve SW277 - CR 2018-03174 during the week ending April 6; (2) Containment Isolation Valve Train 2 position indication lights not lit - CR 2018-04305 during the week ending May 12, 2018; (3) Leading Edge Flow Monitor Failure - CR 2018-04296 during the week ending May 12, 2018;and (4) Emergency Diesel Generator 2 silencer through-wall leak - CR 2018-04599 during the week ending May 26, 2018. 71111.18-PlantModifications (1 Sample) The inspectors evaluated the following temporary or permanent modific.ations: (1) Borated Water Storage Tank Loop Seal, ECP 16-0478, during the week ending June 23, 2018 71111.19-Post Maintenance Testing {3 Samples) The inspectors evaluated the following post maintenance tests: (1) Auxiliary Feedwater Train 2 following planned maintenance, during the week ending May 12, 2018; (2) Service Water Train 1 following planned maintenance, during the week ending May 26, 2018;and (3) Decay Heat/Low Pressure Injection Train 1 following planned maintenance, during the week ending June 9, 2018. 7

71111.22-Surveillance Testing The inspectors evaluated the following surveillance tests: Routine (1 Sample) (1) Emergency Diesel Generator 1 monthly surveillance during the week ending April 7, 2018. 71114.06-Drill Evaluation Emergency Planning Drill (1 Sample) The inspectors evaluated a tabletop drill at the Emergency Operating Facility on June 4, 2018. QTHER ACTIVITIES - BASELINE 71151_;,_Performance Indicator Verification (3 Samples). The inspectors verified licensee performance indicators submittals listed below: (1) MS05: Safety System Functional Failures (SSFFs) for the period from the second quarter 2017 through the first quarter 2018; (2) MS06: Emergency AC Power Systems for the period from the second quarter 2017 through the first quarter 2018; (3) MS07: High Pressure Injection Systems for the period from the second quarter 2017

• through the first quarter 2018.

71152-Problem Identification and Resolution Annual Follow-Up of Selected Issues (1 Sample) The inspectors reviewed the licensee(s implementation of its corrective action program related to the following issues: (1) CR 2018-03036; Misposition of Make Up Filter 1 Outlet Isolation (MU177) One violation for this issue is documented in this report. 71*153-Follow-Up of Events and Notices of Enforcement Discretion Licensee Event Reports (1 Sample) The inspectors evaluated the following ljcensee event reports which can be accessed at https:/ilersearch.inl.gov/LERSearchCriteria.aspx: (1) Licensee Event Report (LER).05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation. Two violations for this issue are documented in this report. This LER is closed. 8

INSPECTION RESULTS 71152-Problem Identification and Resolution Observation - Selected Issue Follow-Up for CR-2018-71152 -Annual Sample Review 03036: Misposition of Mak~ Up Filter 1 Outlet Isolation (MU 177)

• On March 31, 2018, while placing makeup system filter 1 in service using DB-OP;.06006, "Makeup and Purification System," Revision 42, the licensee received two unexpected alarms:

"Letdown or MU [make-up) Filter dP [differential pressure] Hi" followed by "Letdown Pressure Hi." The licensee immediately opened MU12B, the Makeup Filter 2 lnlet Isolation, to establish letdown flow. During this time the letdown relief valve lifted and reseated, diverting approximately six gallons of water to the reactor coolant drain tank. Through the investigation of the issue, the licensee found MU177, the Make-Up Filter 1 Outlet Isolation valve, had not been opened on March 30, 2018, as required by Step 4.9.16.j of DB-OP-06006. The licensee's corrective actions included operator remediation, a requirement to have shiftly engag~ment calls with Operations Management, and reinforcement of the value of reverse briefs by operators as a human performance tool. This issue was documented in CR-2018-03036, "Disposition of Make-Up Filter 1 Outlet Isolation (MU177)." As appropriate, the inspectors verified the following attributes during their review of the licensee's corrective actions for the above condition reports and other related condition reports: complete and accurate identification of the problem in a timely manner commensurate with its safety significance and ease of discovery; consideration of the extent of condition, generic implications, common cause, and previous occurrences; evaluation and disposition of operability/functionality/reportability issues; classification and prioritization of the resolution of the problem commensurate with safety significance; identification of corrective actions, which were appropriately focused to correct the problem; and completion of corrective actions in a timely manner commensurate with the safety significance of th~ issue. The inspectors verified the licensee assessed and corrected the issue in a time)y manner. A violation associated with this issue is documented in this report. Failure to. Follow the Makeup and Purification Procedure Cornerstone Significance Cross-cutting Report Aspect Section Initiating Events Green H.12 71152-NCV 05000346/2018002-01 Annual Closed Follow-Up of Selected Issues 9

A self-revealed Green finding and associated Non-Cited Violation (NCV) of Technical Specification 5.4.1.a, Procedures, was identified when the licensee failed to follow station procedure DB-OP-06006, "Makeup a_nd Purification System." Specifically, the licensee failed to open MU177, the Make-Up Filter 1 Outlet Isolation valve, which resulted in the isolation of letdown while swapping make-up filters.

== Description:== On March 31, 2018, while placing make-up system filter 1 in service using DB-OP-06006, "Makeup and Purification System," Revision 42, the licensee received two unexpected alarms: "Letdown or MU [make-up} Filter dP [differential pressure] Hi" followed by "Letdown Pressure Hi." The licensee immediately opened MU12B, the Makeup Filter 2 Inlet Isolation, to establish letdown flow. During investigation of the issue the licensee found MU 177, the Make-Up Filter 1 Outlet Isolation valve, unexpectedly closed. This was because on March 30; 2018; when preparing to swap filters, the licensee failed to follow Step 4.9.16.j of DB-OP-06006, which required opening of MU177. Additionally, the. licensee determined that while letdown flow was isolated, the letdown relief valve lifted and reseated. Approximately six gallons of water were diverted to the reactor coolant drain tank'. The licensee's corrective actions included operator remediation, a requirement to have.shiftly engagement calls with Operations Management, and reinforcement of the value of reverse briefs by operators as a human performance tool.. This iss_ue was documented in CR-2018-03036, "Disposition of Make-Up Filter 1 Outlet Isolation (MU177)." Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to follow DB-OP-06006, Makeup and Purification System, Revision 42, was a performance deficiency.

• Specifically, the licensee failed to open MU177, Make-Up Filter 1 Outlet Isolation, as required by Step 4.9.16.j.

Screening: The performance deficiency was more than minor because it was associated with Initiating Events cornerstone attribute of equipment pe_rformance, and adversely affected the cornerstone objective of limiting t~e likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the licensee's failure to open MU177 resulted in the letdown relief valve lifting, diverting reactor coolant to.the reactor coolant drain tank. Significance: Using Inspection Manual Chapter (IMC) 0609, Attachment 4, "Initial Characterization of Findings," and IMC 0609 Appendix A, "The Significance Determination Process for Findings at Power," issued June 19, 2012, the finding was screened against the Initiating Events cornerstone. The inspectors determined this issue was of very low safety significance (Green) because the inspectors answered "No" to all the screening questions. Cross Cutting Aspect: This finding has a cross-cutting aspect of avoid complacency in the area of the human performance because the licensee failed to recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, the licensee did not appropriately implement error reduction tools. [H.12] 10

Enforcement: Violation: Technical Specification 5.4.1.a, Procedures, states, in part; written procedures shall be established, implemented, and maintained covering the following activities: the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978. Section 3.n of Regulatory Guide 1.33, Revision 2, Appendix A, February 1978, states; in part, instructions for energizing, filling, venting, draining, start.up, shutdown, and changing modes of operation should be pr~pared, as appropriate, for the following systems: chemical and volume control system (including letdown/purification system). Step 4.9.16.j of DB-OP-06006, "Makeup and Purification System," Revision 42, stated, open MU177, makeup filter 1 outlet isolation. Contrary to the above, on March 30, 2018, the licensee failed to implement a written procedure as recommended in Regulatory Guide 1.33. Specifically, the licensee failed to follow the makeup and purification system procedure which resulted in the isolation of letdown while swapping make-up filters. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2018-03036, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-01: Failure to follow Makeup and Purification Procedure) 71153-Follow-Up of Events and Notices of Enforcement Discretion Failure to Apply Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Green H.14 71153-Systems NCV 05000346/2018002-02 Follow-Up of Closed Events and Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated NCV of Technical Specification 3.3.5, Safety Features Actuation System (SFAS) Instrumentation, and.3.0.1 Surveillance Requirement Applicability, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying that two channels of SFAS Borated Water Storage Tank level instrumentation were inoperable. Specifically, the licensee exited Technical Specification (TS) 3.3.5.b, the six hour shutdown technical specification, while two BWST level instruments were still inoperable.

== Description:== 11

LER 05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation On June 30, 2016 at 0829 EDT, Channel 1 of the Borated Water-Storage Tank (BWST) level instrumentation for the Safety Features Actuation System (SFAS) was declared inoperable and removed from service for scheduled maintenance. The Limiting Condition for Operation (LCO) for Technical $pacification 3.3.5 stated in part, four channels of SFAS instrumentation for each Parameter [BWST level] shali be operable. At this time, Reactor Operators entered TS 3.3.5.a, which required the inoperable channel be tripped. Later that day at 2344, Channel 2 became inoperable due to a loss of power from a failed power supply. At this time, operators should have entered TS 3.3.5.b, which required restoring at least one channel immediately or placing the reactor into Mode 3 (hot shutdown), within six hours: At 0140 on July 1, 2016, after the licensee had multiple discussions regarding the power supply failure, operators realized that they should apply TS 3.3.5.b, but did not enter the Technical Specification until 0245. At 0330, TS.3.3.5.b was exited with Channel 1 declared operable due to compensatory measures including proceduralized operator actions to be performed for a manual suction swap. At this time, the Channel 1 instrument was electrically a_nd physically disconnected and incapable of performing its function or passing the Technical Specification required surveillance which is required to be met in all modes of applicability of the LCO. The inspectors questioned the licensee's basis for operability. From discussions with the licensee on July 1, 2016, the inspectors determined the defined compensatory measures were *not sufficient for the licensee.to declare Channel 1 operable. At 1325 on J_uly 1, 2016, the licensee declared Channel 1 inoperable and reentered TS 3.3.5.b. At 1351, the licensee exited TS 3.3.5.b after maintenance was completed and Channel 1 was restored to service. The inspectors determined the plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. Corrective Action(s): The corrective actions included reentering Technical Specification 3.3.5.b and performing corrective maintenance on the Channel 1 instrumentation to restore it to operable. The Licensee performed a rcpt cause analysis and developed a case study from lessons learned. Additionally, the licensee issued an operations standing order; revised multiple procedures; and performed additional training regarding lessons learned from this event, Technical Specification compliance, and correct application of the operability determination process. Corrective Action Reference(s): The licensee documented this issue in CR 2016-08419 Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to shut down the reactor within six hours, as required by TS 3.3.5.b, was a performance deficiency. Specifically, with two channels of the BWST level instrumentation inoperable, the licensee failed to enter Mode 3 within six hours.

• Screening: The finding was determined to be more than minor because it was associated with the Mitigating $ystems function of Long Term Heat Removal, and affected the cornerstone's objective of ensuring the availability, reliability, and capability of systems to respond to initiating events to prevent undesirable consequences. Specifically, the finding resulted in the loss of the emergenc core cooling s stem ECCS suction swa permissive 12

function, which could have resulted in the loss of system safety function (i.e., ECCS due to a

• premature suction source transfer).

Significance: The inspectors determined the finding could be evaluated using the SOP in accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." The inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.3.5 allowed outage time of 6 hours for this function. Therefore, a detailed risk evaluation was performed using IMC 0609, Appendix A. The risk evaluation was performed by Region Ill SRAs and the bounding core damage frequency {LlCDF) was determined to be 7.0E-7/yr. Since the total estimated change in core damage frequency was less than 1.0E-6/year, the finding/violation was initially determined to be Green. Additionally since the ACDF was greater than 1.0E-7/year, the finding was r~viewed for potential Large Early Release Frequency (LERF) contribution. Davis Besse is a 2-loop Babcock and Wilcox Pressurized Water Reactor with a large dry containment. The core damage sequences important to LERF were steam generator tube rupture (SGTR) events and inter-system LOCA events. These events were not the dominant core damage sequences for this finding. Therefore, based on the detailed risk evaluation, the SRAs confirmed that the finding.was of very-low safety significance (Green). Cross Cutting Aspect: This finding had a cross-cutting aspect of Conservative Bias in the area of Human Performance, which states individuals use decision making practices that emphasize prudent choices over those that are simply allowable. A proposed action is determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, the licensee failed to use decision making practices that emphasized prudent choices, over those that they believed were simply allowable. [H.14] Enforcement: Violation: Technical Specification 3.3.5.b, SFAS lnstrumentation,,states in part, with one of more Parameters with two or more channels inoperable, be in Mode 3 within six hours. Enforcement Action(s): Contrary to the above, on July 1, 2016, the licensee failed to place the reactor into Mode 3 within six hours of identifying one Parameter with two ct,annels inoperable. Specifically, the licensee failed to shut down the reactor within six hours with two channels of SFAS BWST level instrumentation inoperable. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2016-08419, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-02: Failure to Apply Technical Specification for SFAS Instrumentation) [05.05-LER Closure] I Procedure Violation 13

Cornerstone Mitigating

• Systems Significance Green NCV 05000346/2018002-03 Closed Cross... cutting Aspect H.8 Report Section 71153-Follow-Up of Events and Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, "Instructions, Procedures, and Drawings," due to the licensee's failure to properly implement procedures DB-OP-06405, "Safety Features Actuation System Procedure," DB-SC-03110, "SFAS Channel 1 Functional Test," and DB-OP-03006; "Miscellaneous Instrument Shift Checks," Specifically, the licensee declared SFAS Channel 1 operable without correctly performing the required procedural steps and failed to correctly perform the channel checks.

== Description:== LER 05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation On June 30, 2016 *at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation for the Safety Features Actuation System (SFAS) was declared inoperable and removed from service for scheduled maintenance. On July 1, 2016 at 0330, The channel was declared operabl~ with reference to compensatory measures. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. - DB-OP-06405, "Safety Features Actuation System Procedure" required that an SFAS functional test be performed and that a channel check of the inoperable instrument be performed utilizing DB-OP-03006. In order to satisfy the requirements of DB-SC-03110, the bistable must operate correctly and then be reset such that the channel is not tripped. In order for the BWST level instrumentation to satisfy the requirements of DB-OP-03006, the instruments can register no more than a 2.0 feet level difference. The Channel 1 instrument was disconnected and could not meet these requirements. The licensee, however, declared the results satisfactory for Channel 1 by ref~rring to compensatory measures. A Prompt Operability Determination was initiated in an attempt to rely on the same compensatory measures to justify operability. The inspectors questioned the licensee's basis for operability and noted that the Channel 1 level instrument was not even physically attached to the system. The inspectors determined that the compensatory measures were not sufficient for the licensee to declare Channel 1 operable. At 1325 on July 1, 2016, the licensee declared Channel 1 inoperable and at 1351 maintenance was completed on Channel 1 and it was properly restored to service. The inspectors determined that the licensee failed to perform the required procedural actions. Corrective Action(s): The corrective actions included declaring Channel 1 inoperable and performing corrective maintenance on the Channel 1 instrumentation to restore it to operable. The Licensee performed a root cause analysis and developed a case study from lessons learned. Additionally, the licensee issued an operations standing order; revised multiple 14

procedures; and performed additional training regarding lessons learned from this event, Technical Specification compliance, and correct application of the* operability determination process. Corrective Action Reference( s ): The licensee documented this issue in CR 2016-08419 Performance Assessment: Performance Deficiency: The licensee improperly applied multiple procedures: Example 1: DB-OP-06405, "Safety Features Actuation System Procedure" set forth the procedure for restoring an inoperable SFAS component to operable. This includes satisfactorily performing an SFAS channel functional test and-requires that a channel check of the inoperable instrument be performed. Contrary to this requirement, the licensee correctly performed neither the functional test nor the channel check before declaring the channel Operable. Example 2: DB-SC-03110, "SFAS Channel 1 Functional Test" required that the channel pass a number of tests and then be reset. Contrary to this, the channel was incapable of passing th~ required tests, and further, incapable of being reset. Example 3: DB-OP-3006 required that channel checks be performed every twelve hours. A Channel Check was clearly defined as a qualitative assessment of channel behavior during operation, including comparison of channel indication and status to other*indications or status derived from independent instrument channels measuring the same parameter. Contrary to this requirement, when performing the channel check for BWST Level indication Channel 1, the operators recognized that the channel did not show a satisfactory response but declared that it met the requirements because of a compensatory measure. Screening: The performance deficiency was determined to be more than minor because it was a~sociated with the'Mitigating Systems cornerstone attribute of Equipment Performance and affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to follow procedures to establish the Operability of SFAS Channel 1 negatively affected the ability of the system to perform its accident mitigating function. Additionally, this failure led to a violation of Technical Specifications as detailed elsewhere in this report. Significance: The inspectors assessed the significance of the finding using IMC 0609.04, "Initial Characterization of Findings," and IMC 0609, Appendix A, Exhibit 2, "Mitigating Systems Screening Questions." The inspectors determined tha.t this performance deficiency did not result in a loss of a single train of a safety system for greater than its Technical Specification allowed outage time. Therefore, the inspectors determined the finding to be of very low safety significance (Green). Cross Cutting Aspect: This finding had a cross-cutting aspect of Procedure Adherence in the area of Human Performance, which states individuals follow processes, procedures, and work instructions. Specifically, the licensee failed in multiple instances to follow their own clearly defined procedures. [H.8] Enforcement: Because it was of very low safety significance and was entered into the licensee's corrective action pro ram as CR-2016-08419, this violation is bein treated as an 15

NCV consistent With Section 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-03: Procedure Violation) [05.05-LER Closure] EXIT MEETINGS AND DEBRIEFS. The inspectors confirmed that proprietary information was controlled to protect from public disclosure. No proprietary information was documented in this report. On July 31, 2018, the inspectors presented the quarterly integrated inspection results to Mr. M. Bezilla and other members of the licensee staff. ) 16

DOCUMENTS REVIEWED 71111.01-Adverse Weather Protection - Davis-Besse Off-site Power Voltage Assessment; Summer 2018 - DB-OP...;01300; Switchyard Management; Revision 14 - DB-OP-02546; Degraded Grid; Revision 07 - DB-OP-06311; 345 KB Switchyard No. 1 (Main) Transformer, No. 11 (Auxiliary) Transformer, and Startup Transformer (01 and 02); Revision 48 - DB-OP-06913; Seasonal Plant Preparation Checklist; Revision 30 - DB-SC-03023; Off-site AC Sources Lined Up and Available; Revision 34 - NOBP-CC-2008; Transformer, Switchyard, and Grid Reliability Design Interface and Control; Revision 01 - NOP-CC-3002-01; AC Power Systems Analysis; Revision 05 - NOP-OP-1003; Grid Reliability Protocol; Revision 09 71111.04-Equipment Alignment - CR-2015-00459; 2015 CDBI SA: Auxiliary Feed Pump (AFP) 1 and 2 Response Time Testing - Davis-Besse Nuclear Power Station Lubrication Date Sheet; Decay Heat Pumps and Motors, Auxiliary Building, 545' Level - DB-OP-06011; High Pressure Injection System; Revision 31 - DB-OP-06012; Decay Heat Pump; Revision 71 - DB-OP-06013; Containment Spray System; Revision 26 - DB-OP-0623; 'Auxiliary Feedwater System; Revision 42 - DB-OP-06262; Valve Line Up Checklist for CCW Pump 2; Revision 38 - DB-SS-03090; Motor Driven Feed Pump Monthly Valve Verification; Revision 11 - M-0060; Auxiliary Feedwater System; Revision 59 - OS-003; High Pressure Injection System; 'Revision 36 - OS-005; Containment Spray System; Revision 14 71111.0SAQ-Fire Protection Annual/Quarterly - PFP-AB-238; Auxiliary Feed Pump 2 Room; Revision 4 - PFP-AB-328; Protected Area Pre-Fire'Plan-Component Cooling Water Heat Exchanger and Pump Room; Revision 4 - Pre-Fire Plan; PFP-AB-115, Revision 5, ECCS Pump Room 1-2 - Pre-Fire Plan; PFP-AB-109, Revision 7, Rooms 104, 106, 106A and 109 71111.06-Flood Protection Measures - DWG E-328; Raceway & Grounding Start-Up, Main & Aux Transformers; Rev 15 - WO 200676046; Electric Hand/Manholes 71111.07-Heat Sink Performance - CR 2018-00844 - W02007 41172 DB-SUB 16-03; Component Cooling Water Heat Exchanger 71111.11-Licensed Operator Requalification Program and Licensed Operator Performance 17

- DB-OP-06401; Integrated Control System Operating Procedure; Revision 27 - DB-OP-06902; Revision 62 - NOBP-TR-1151; 4.0 Crew Critique; 09/28/17 - NOP-OP-1002; Conduct of Operations; Revision 12 71111.12-Maintenance Effectiveness - 2017-2; Davis Besse System Health Report; Decay Heat Low Pressure Injection; 02/01/2018 - Cycle 20 Periodic Maintenance Effectiveness Assessment Report _ - CR 201709888; CCW 2 Cable T~sting Exceeded the Acceptance criteria; 09/27/2017 - CR 201700704; CRD Booster Pump 1 Trip; 01/21/2017 - CR 201805257; CRD Booster Pump 2 Trip on Overload; 06/06/2018 - CR 201702171; CCW Train 3 Exceeded Maintenance Rule Unavailability Limit - CCW System Health Report; 2017.;02 71111.13-Maintenance Risk Assessments and Emergent Work Control - CA 03-05256"'.01; Control Room Habitability Systems Licensing Basis Validation; Attachment 2 - CR 2018-05995; UFSAR Description of CREVS and CREATCS does not Match Technical Specifications; 06/29/2018 - Davis-Besse Unit 1 UFSAR; Revision 30 - DBBP-OPS-0011; Protected Equipment Posting; Revision 1 O - DB-SS,.03301; Control Room Unfiltered Air lnleakage Test for Control Room Emergency Ventilation, Train 1; Revision 00 - Drawing 05.,.020 SH 1; Operational Schematic Service Water System; Revision 100 - Drawing 05-0328; Operational Schematic Control Room Emergency Ventilation System; Revision 22 - NOP-LP-4008; Licensing Document Change Process; Revision 5 - NOP-LP-4008; Licensing Documents Change Process; Revision 1 - NOP-OP-1007; Risk Management; Revision 25 - Procedure NOP-OP-1007; Risk Management; Revision 25 71111.15-0perability Determinations and Functionality Assessments - CR 2018-04305; Y212 Fuse Blown During TD14950; 05-08/2018 - CR 2018-03174; SW277 Excessive Leakage - CR 2018-04296; LEFM Parameter Revision Results in Changes to Indicated Loop Flows; 05/08/2018 - CR 2018-04599 - DB-PF-03020; Service Water Train 1 Valve Test; Revision 42 - DB-SC-03121; SFAS Train 2 Integrated Response Time Te~t; Revision 07 - WO 200676009; PF3020-033 05.000 SW276, SW277 71111.18---Plant Modifications - CR 201800027; BWST Loop Seal Pipe Elevation Discrepancy; 01/02/2018 - CR 201803211; BWST Leak Near BW33 Outside; 04/06/2018 - Engineering change package 16-0478-001, Loop seal in BWST to SFP purification supply pipe civil structural - Engineering change package 16-0478-002, Loop seal in BWST to SFP purification supply pipe 18

piping and mechanical - Engineering change package 16-0478-003, Loop seal in BWST to SFP purification supply pipe (freeze protection) 71111.19-Post Maintenance Testing - CA 2011-02670; WO 200481565 was Initiated to Troubleshoot DH2733; 04/29/2016 - CR 2015-08968; Evaluation of Service Water Pump P3-1 Baseline Data; 07/02/2015 - CR 2018-0497 4; Critical Preventive Order Removed from Schedule at T-0; 05/29/2018 * - DB.,PF-03017; Service Water Pump 1 Testing; Revision 23 - Procedure DB-SP-03161, AFW Train 2 Level Control, Interlock, and Flow Transmitter Test, Revision 34 - WO 200683205; Perform SW Pump 1 Quarterly Test; 05/22/2018 - WO 200683879; DH/LPI 1-1 Quarterly; 05/30/2018 - WO 200747497, AFP 2 Quarterly Test; 05/07/2018 - WO 200704976 DB-SUB049-02; Decay Heat and Low Pressure Injection; 05/31/2018

• 71111.22-Surveillance Testing

- DB-SC-03070; Emergency Diesel Generator 1 Monthly Test; Revision 38 71114.0~Drill Evaluation - CR 2018-05418; ERO Tabletop Drill11mprovement Opportunities; 06/11/2018 71151-Performance Indicator Verification - Station Unit Logs 71152-Problem Identification and Resolution ~ CR 2018-03036; Misposition of Make Up Filer 1 Outlet Isolation (MU17); 03/31/2018 - NOBP-OP-0004; Plant Status Control and Worker Protection Events; Revision 17 - Drawing M-031C; Piping and Instrument Diagram Make Up and Purification System; Revision 43 - Drawing M031A; Piping and Instrument Diagram Make Up and Purification System; Revision 52 - DB-OP-06006; Makeup Filter 1 Replacement; Revision 42 71153-Follow-Up of Events and Notices of Enforcement Discretion - Station Unit Logs - LER 2016-008-01; Application of Technical Specification for the Safety Features Actuation System Instrumentation - Root Cause Analysis Report; CR-2016-08419; 10/07/2016 - DB-OP-06405; Safety Features Actuation System Procedure; Revisions 13 & 14 - DB-OP-03006; Miscellaneous Instrument Shift Checks; Revisions 55 & 61 - DB-Ml-03145; Functional Test/Calibration of LT-1525A BWST Level Transmitter to SFAS Channel 1; Revisions 9 & 12 - DB-Ml-03146; Functional Test/Calibration of LT-1525B BWST Level Transmitter to SFAS Channel 2; Revisions 9 & 12 19

- DB-SC-03110; SFAS Channel 1 Functional Test; Revisions 20 &*22 - DB-SC-03111; SFAS Channel 2 Functional Test; Revisions 16 & 18 -. NOP-OP-1002; Conduct of Operations; Revisions 11 & 12 - NOP-OP-1009; Operability Determinations and Functionality Assessments; Revisions 6 & 8 - NOBP-OP-0014; FENOC Duty Teams; Revision 2 & 5 - NOBP-OP-1002; Operations Administrative Guidelines and Common Processes; Revision 2&4 - NOBP-OP-0002; Operations Briefing and Challenge Calls; Revisions 3 & 4 - NOBP-OP-0002-05; Control Room Shift Brief Cl:lecklist - NOBP-OP-0002-05A; Control Room Shift Brief Checklist .: NORM-OP-1002; Conduct of Operations; Revision 6 - NOP-OP-1015; Event Nptifications; Revisions 3 & 6 - CR 2016-08419; Performance Review of LCO 3.3.5 application during L T1525A maintenance - CR 2016-08699; Crew Briefing Performance Shortfall - CR 2016-13611; Did Not Receive VP Approval Withiri 30 Days After GARB Approval - CR 2016-11711; Red Key Performance Indicator D-SP0-05L - Open CRs With Extensions - CR 2017-07598;.Technical Specification Upgrade Criteria Not Accurately Communicated On 1530 Duty T earn Phone Call - CR 2016-11681; Common Cause Evaluation For DB Performance Issues - CR 2016-10440; Red Key Performance Indicator D-SP0-05L-Open CRs With Extensions - CR 2016-13335; Fleet Operations Elevation Letter-Regulatory Document Implementation - Supplemental Review - CR 2016-08700; Delayed Request For Prompt Operability Determination - CR 2016-08402; SFAS Channel 2 +15V Power Supply Failure - CR 2016-08765; Restoration of SFAS CH1 (LT-1525A)-Assessment Of Organizational Response To Extended Work Window - CR 2016-08539; "A" Schedule Work Not Completed By Instrument and Control Shop - CR 2016-08922; Assessment of Schedule Adherence for Maintenance Activities - CR 2016-08415; Parameter 5 BWST Level-Low Low Operability cl 20

EA-[j_ij]-[###]) Mark Bezilla Site Vice* President UNITED STATES NUCLEAR REGULATORY COMMISSION REGION Ill 2443 WARRENVILLE RD. SUITE 210 LISLE, ILLINOIS 60532-4352 Insert Month DD, YYYY after concurrence FirstEnergy Nuclear Operating Co. 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 - NRG INTEGRATED INSPECTION REPORT 05000346/2018002

Dear Mr. Bezilla:

On June 30, 2018, the U.S. Nuclear Regulatory Commission (NRG) completed an integrated inspection at your Davis-Besse Nuclear Power Station. On July 31, 2018, the NRG inspectors discussed the results of this inspection with Y,~ii'. and other members of your staff. The results of this inspection are documented in the enclosed report. Based on the results of this inspection, the NRG has identified three issues that were evaluated under the risk significance determination process as having very low safety significance (Green). The NRC has also determined that two violations are associated with these issues. Because the licensee initiated condition reports to address these issues, these violations are being treated as Non-Cited Violations (NCVs), consistent with Section 2.3.2.of the Enforcement Policy. These NCVs are described in the subject inspection report. If you contest the violations or significance of these NCVs, 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, A TIN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region Ill; the Director, Office of Enforcement; and the NRC Resident Inspector at the Davis-Besse Nuclear Power Station. I

M. Bezilla If you disagree with a cross-cutting aspect assignment or a finding not associated with a regulatory requirement in this report, you should provide a* response within 30 days of the date of this inspection report, with.the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATIN: Document Control Desk, Washington, DC 20555-'-0001; with copies to the Regional Administrator, Region Ill; and the NRC resident inspector at Davis-Besse Nuclear Power Station. This letter, its enclosure, and your response (if any) will be made avi;iilable for public inspection and copying at http:l/www.nrc.gov/reading-rm/adams.htrill and at the NRC Public Document Room In accordance with 10 CFR 2.390, "Public Inspections, Exemptlons.-Requests for Withholding." Docket Nos. 50-346; 72-014 License Nos. NPF--3

Enclosure:

IR 05000346/2018002 cc: Distribution via ListServ Sincerely, Jamnes L. Cameron, Chief Branch 4 Division of Reactor Projects

Letter to Mark Bezilla from Jamnes Cameron dated 8/;X /2018

SUBJECT:

DISTRIBUTION: Jeremy Bowen RidsNrrDorllpl3 RidsNrrPMDavisBesse Resource RidsNrrDirslrib Resource Steven West Darrell Roberts Richard Skokowski Allan Barker DRPIII DRSIII ROPreports.Resource@nrc.gov DOCUMENT NAME: [Insert Path] ADAMS Accession Number: [Delete Document Name when Final] ~ Publicly Available D Non-Publicly Available D Sensitive ~ Non-Sensitive To receive a copy of this document, indicate In the concurrence box "C" = Copy without a tta h/ I "E" C Ith tta h/ 1 "N" N c enc = OPYW a c enc = OCOPY OFFICE RIii I RIii I RIii I RIii I NAME DATE OFFICIAL RECORD COPY

U.S. NUCLEAR REGULATORY COMMISSION REGION Ill Docket Numbers: 50-346; 72-14 License Numbers: NPF-3 Report NumberS: 05000346/2018002 Enterprise Identifier: 1-2018-002-0015 Licensee: FirstEnergy Nuclear Operating Company (FENOC) Facility: Location: Dates: Inspectors: Approved by: Davis-Besse Nuclear Power Station Oak Harbor, OH April 1 through June 30, 2018 'D. Mills, Senior Resident Inspector fvl. Garza, Acting Senior Resident Inspector J. Harvey, Resident Inspector J. Rutkowski, Senior Project Engineer

• J. Beavers, Resident Inspector Duane Arnold Energy Center J. Cameron, Chief Branch 4 Division of Reactor Projects Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring licensee's performance by conducting an integrated quarterly inspection at Davis-Besse Power Plant in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRC's program for overseeing the safe operation of commercial nuclear power reactors. Refer to https:/lwww.nrc.gov/reactors/operating/oversight.html for more information. Findings and violations being considered in the NRC's assessment are summarized in the table below. List of Findings and Violations

• Failure to Follow the Makeup and Purification Procedure Cornerstone Significance Cross-cutting Report Aspect Section Initiating Events Green H.12 71152-NCV 05000346/2018002-01 Annual
• closed Follow-Up of Selected Issues A self-revealed Green finding and associated Non-Cited Violation of Technical Specification 5.4.1.a, Procedures, was identified when the licensee failed to follow station procedure DB-OP-06006, "Makeup and Purification System." Specifically, the licensee failed to open MU177, the Make-Up Filter 1 Outlet Isolation valve, which resulted in the isolation of letdown while swappini:i make-up filters.

Failure to Apply Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Report Asoect Section Mitigating Green H.14 71153,-- Systems NCV 05000346/2018002-2 Follow-Up of Closed Events and Notices of Enforcement Direction The NRC identified a finding ofGreen significance and an associated Non-Cited Violation of Technical Specification 3.3.5.b, Safety Features Actuation System Instrumentation, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying two channels of Safety Features Actuation System Borated Water Storage Tank level instrumentation were inoperable. Specifically, the licensee exited Technical Specification 3.3.5.b, and failed to perform the associated six hour shutdown limiting condition for operation action, while two Borated Water Storai:ie Tank level instruments were inoperable.

Procedure Violation:__

Cornerstone Significance Cross-cutting Report Asoect Section Mitigating Green H.8 71153-Systems NCV 05000346/2018002-03 Follow-Up of Closed Events and 2 .------- Commented [WJ1): Name something else? Failure to Implement a Safety Related Procedure

3 I I I Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, "Instructions, Procedures, and Drawings," due to the licensee's failure to properly implement pro~dures DB-OP-06405, "Safety Features Actuation System Procedure," DB-SC-03110, "SFAS Channel 1 Functional Test,* an_d DB-OP-03006, "Miscellaneous Instrument Shift Checks," Specifically, the licensee declared SFAS Channel 1

• operable without correctly performing the required procedural steps and failed to correcUy perform the channel checks.

Additional Tracking Items Type Issue Number Title Report Status Section LER 05000346/2016008-01 Application of Technical 71153 Closed Specification for the Safety Features Actuation System Instrumentation 3

TABLE OF CONTENTS 'pLArJlsfAfus.. -:-...... :.:.. :..... :.:~.-.::..-:-::.~.-:.-... -.:.:-::::.*.*:.... -::.:.:-:.:.::.:... :..... :.:.::.::-:.::-.::... :*.::.:.*.. :.:... ::-:.*.::.~.5 INSPECTIOllfSCOi:,Es:... :.. :.... :..... :.:.. *.::... :.::::........ :.... :::.::... ::*... ::... :.:.:.............-.................. :.. :.. ::.::s REACTOR.SAFETY.......................................................................................................................§** QTHER ACTIViTIES - BASELINE:*.-..... :.. :*::... :::.. :.::-:.:....... ::*.:.::*.:.... ::.. *:.... :... :::::.:.. ::.::...... ::*::... :.. :*.:.::*s INSPECTlblirRESULTS.:.:....... :.. :.. :::-:..... :......... :..... :::...... :.:.:::.::... ::... :::.:......-.-......... :........-.. :... :::..,:*s EXiTMEETINGS AND DEBRIEFS~... :............. :..... :... :.. :.:.:...... :.......... :.:.. :... :.:........... :... ~.:.:.::.. :.:. 13 DOCUMENTS_REVIEWED....,.........,........................................................................................... 17; L -~--~( Commented [WJ2): formatted I 4

PLANT STATUS The unit remained at or near rated thermal power for the entirety of the inspection period. On March 28, 2018, FirstEnergy Solutions (FES)/ FirstEnergy Nuclear Operating Company (FENOC) verbally notified the Nuclear Regulatory Commission that they intended to shut down all four of their operating nuclear power plants. Based on that notification, the first to shut down will be Davis-Besse,by May31, 2020. On March 31, 2018, FE9, FirstEnergy Nuclear Generation (FENGEN}, and FENOC filed for bankruptcy. The Nuclear Regulatory Commission continues to maintain focus on public health and safety and the protection of the environment. This will.include a continuous evaluation by inspectors to determine whether the licensee's financial condition is impacting safe operation of the plant. 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/readinq* rm/doc-coilections/insp-manual/inspection-procedure/index.htrnl. 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 plant status activities described in IMC 2515 Appendix D, "Plant Status" and conducted routine reviews using IP 71152, "Problem Identification and Resolution." 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 WeatherProtection Summer Readiness (1 Sample) The inspectors evaluated summer readiness ofoffsite and alternate alternating current power systems. 71111.04-Eguipment Alignment Partial Walkdown (4 Samples) The inspectors evaluated system configurations during partial walkdowns of the foilpwing systems/trains: (1) Auxiliary Feedwater Train 1 during planned maintenance and testing on Auxiliary Feedwater Train 2 during the week ending April 14, 2018; (2) Motor Driven Feedwater pump during Auxiliary Feedwater Train 2 maintenance during the week ending April 21, 2018; (3) Containment Spray system during the week ending April 28, 2018; and (4) Decay Heat/Low Pressure Injection Train 2 when Train 1 was out of service during the week ending June 2, 2018. 5

Complete Walkdown (1 Sample) The in_~pec~~ra. ~va!u~t~~ -~ystem configurations during a complete walkdown of the H)g)i f're13s_Url;l _G9ql_~I1tJJ:1jl;lctj9[1 :sy§tem during_ the_ week ending Apri! 28, 2018. ___ ___ __ _ __ . _,.. -- -{ Commented [WJ3J: Isn't this Just high pressure lnJectian??. ]. 71111.0SQ-Fire Protection Quarterly Quarterly Inspection (4 Samples) The inspectors evaluated fire protection program implementation in the following selected areas: (1) Emergency Core Cooling System Pump room 1-2, (fire area A), during the week ending April 28, 2018; (2) Auxiliary Building Rooms 104, 106, 106A, and 109, (fire area A), during the week ending April 28, 2018; (3) Auxiliary Feedwater Train 2, (fire area F) during the week ending May 19; and (4) Component Cooling Water Room, (fire area T), during the week ending May 26; 2018. 71111.06-Flood Protection Measures Underground Cables (1 Sample) The inspectors evaluated cable submergence protection in: (1) Manholes mh310t mh3108, mh3109, mh3010 during the week ending April 14, 2018. 71111.07-Heat Sink Performance Heat Sink (1 Sample) The inspectors evaluated Closed Cooling Water 3 performance following a pinhole leak repair during the '!\\'eek ending May 19, 2018. 71111.11-Licensed Operator Regualification Program and Licensed Operator Performance Operator Regualification (1 Sample) The inspectors observed and evaluated licensed operator requalification training during the week ending May 26, 2018. - Operator Performance (1 Sample) The inspectors observed and evaluated operators perform a reactor downpower and place feedwater components in manual control to support planned maintenance on a feedwater flow component during the week ending May 26, 2018. 71111.12-Maintenance Effectiveness - Routine Maintenance Effectiveness (2 Samples) 6

The inspectors evaluated the effectiveness of routine maintenance activities associated with the following equipment and/or safety significant functions: (1) Decay Heal/low Pressure Injection Train 1; and (2) Component Cooling Water availability. 71111.13-Maintenance Risk Assessments and Emergent Work Control (4 Samples) The inspectors evaluated the risk assessments for the following planned and emergent work activities: (1) Auxiliary Feedwater Train 2 out of service for planned maintenance during the week ending May 12; (2) E-31A outage to relieve cable stress due to turbine building floor movement during t_he week ending May 12; (3) Control Room Emergency Ventilation system Train 1 out of service for planned maintenance during the week ending May 26; and (4) Decay Heal/low Pressure Injection Train 1 out of service for planned maintenance during"the week ending June 2. 71111.15-0perability Determinations and Functionality Assessments (4 Samples) The inspectors evaluated the following operability determinations and functionality assessments: (1) Forward flow I closure valve SW277 - CR 2018-03174 during the week ending April6; (2) Containment Isolation Valve Train 2 position indication lights not lit-CR 2018-04305 during the. week ending May 12, 2018; (3) Leading Edge Flow Moniior Failure -CR 2018-04296 during the week ending May 12, 2018;and (4) Emergency Diesel Generator 2 silencer through-wall leak - CR 2018-04599 during the week ending May 26, 2018. 71111.18-Plant Modifications (1 Sample) The inspectors evaluated the following temporary or permanent modifications: (1) Borated Water Storage Tank Loop Seal, ECP 16-0478, during th_e week ending June 23, 2018 71111.19-Post Maintenance Testing (3 Samples) The inspectors evaluated the following post maintenance tests: (1) Auxiliary Feedwater Train 2 following planned maintenance, during the*week ending May ! 12, 2018; (2) Service Waler Train 1 following planned maintenance, during the week ending May 26, 201B;and (3) Decay Heal/low Pressure Injection Train 1 following planned maintenance, during the week ending June 9, 2018. 7

71111.22-Surveillance Testing The inspectors evaluated the following surveillance tests: Routine (1 Sample) (1) EmergencyDiesel Generator 1 monthly surveillance during the week ending April 7, 2018. 71114.06-Drill Evaluation Emergency Planning Drill (1 Sample) The inspectors evaluated a tabletop drill at the Emergency Operating Facility on June 4, 2018. OTHER ACTIVITIES - BASELINE 71151-Performance Indicator Verification (3 Samples) The inspectors verified licensee performance indicators submittals listed below: (1) MS05: Safety System Functional Failures (SSFFs) for the period from the second quarter 2017 through the first quarter 2018; (2) MS06: Emergency AC Power Systems for the period from the second quarter 2017. through the first quarter 2018; (3) MS07: High Pressure Injection Systems for the period from the second quarter 2017 through the first quarter 2018. 71152-Problem Identification and Resolution Annual Follow-Up of Selected Issues (1 Sample) The inspectors reviewed the licensee's implementation of its corrective action program related to the following issues: (1) CR 2018-03036; Misposition of Make Up Filter 1 Outlet Isolation (MU177) One violation for this issue is documented in this report. 71153-Follow-Up of Events and Notices of Enforcement Discretion Licensee Event Reports (1 Sample) The inspectors evaluated the following licensee event reports which can be accessed at https://lersearch.inl.gov/LERSearchCriteria.aspx: (1) Licensee* Event Report (LER) 05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation. Two violations for this issue are documented in this report. This LER is closed. 8

INSPECTION RESULTS 71152-Problem Identification and Resolution

• 'Obse~ation -Selected Issue Follow-Up for CR-2018-1 71152-Annual Sample Review 03036: Misposition of Make Up Filter 1 Outlet Isolation (MU 1 nl On March 3.1, 2018. while placing makeup system filter 1 in service using DB-OP-06006, "Makeup and Purification System," Revision 42, the licensee received two unexpected alarms:

"Letdown or MU [make-up] Filter dP [differenUal pressure] Hi" followed by "Letdown Pressure Hi." The licensee immediat'?IY opened MU12B, the. Makeup*Fnter 2 Inlet Isolation; to establish letdown flow. During this time the letdown relief valve lifted and r~seated, diverting approximately six gallons of water to the reactor coolant drain tank. Through the investigation of the issue, the licensee found MU177, the Make-Up Filter 1 Outlet Isolation valve, had not been opened on March 30, 2018, as required by Step 4.9.16.j of DB-OP-06006. The licensee's corrective actions included operator remediation, a requirement to have shlftly engagement calls with Operations Management, and* reinforcement of the value of reverse briefs by operators as a human performance tool. This.issue was documented in CR-2018-03036, "Disposition of Make.:Up Filter 1 Outlet Isolation (MU177)." As appropriate, the inspectors verified the following attributes during their review of the licensee's corrective actions for the above condition reports and other related condition reports:* complete and accurate identification of the problem in a timely manner commensurate with its safety significance and ease of discovery; consideration of the extent of condition, generic implications, common cause, and previous occurrences; evaluation and disposition of operability/fun.qtionality/reportability issues; classification and prioritization of the resolution of the *problem commensurate with. safety significance; identification of corrective actions, which were appropriately focused to correct the probiem; and completion of corrective actions iri a timely manner commensurate with the safety sighificance of the issue. The inspectors verified the licensee assessed and corrected the issue in a timely manner. A violation associated with this issue is documented in this report. Failure to Follow the Makeup and Purification Procedure Cornerstone Significance Cross-cutting Report Aspect Section Initiating Events Green H.12 71152-NCV 05000346/2018002-01 Annual Closed Follow-Up of Selected Issues 9

A self-revealed Green finding and associated Non-Cited Violation (NCV) of Technical Specification 5.4.1.a, Procedures, was identified when the licensee failed to follow station procedure DB-OP-06006, "Makeup and Purification System." Specifically, the licensee failed to open MU177, the Make-Up Filter 1 Outlet Isolation valve, which resulted in the isolation of letdown while swapping make-up filters.

== Description:== On March 31, 2018, while placing make-up system filler 1 in serv.ice using DB-OP-06006, "Makeup and Purification System," Revision 42, the licensee received two unexpected alarms: "Letdown or MU [make-up] Filter dP [differential pressure] Hi" followed by "Letdown Pressure Hi." The licensee immediately opened MU12B, the Makeup Filter 2 Inlet Isolation, to establish letdown flow. During investigation of tlie issue the licensee found MU177, the Make-Up Filter 1 Outlet Isolation valve, unexpectedly closed. This was because on March 30, 2018, when preparing to swap fillers, the licensee failed to follow Step 4.9.16.j of DB-OP-06006, which required opening of MU177. Additionally, the licensee determined that while letdown flow was isolated, the letdown relief valve lifted and reseated. Approximately six gallons of water were diverted to the reactor coolant drain lank. The licensee's corrective actions included operator remediation, a requirement to have shituy engagement calls with Operations Management, and reinforcement of the value of reverse briefs by operators as a human performance tool. This issue was documented in CR-2018-03036, "Disposition of Make-Up Filter 1 Outlet Isolation (MU177)." Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to follow DB-OP-06006, Makeup and Purification System, Revision 42, was a performance deficiency. Specifically, the licensee failed to open MU177, Make-Up Filter 1 Outlet Isolation, as required by Step 4.9.16.j. Screening: The performance deficiency was more than minor because it was associated with Initiating Events cornerstone attribute of equipment performance, and adversely affected the cornerstone objective of limiting the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the licensee's failure to open MU177 resulted in the letdown relief valve lifting, diverting reactor coolant to the reactor coolant drain tank. Significance: Using Inspection Manual Chapter (IMC) 0609, Attachment 4, "Initial Characterization of Findings," and IMC 0609 Appendix A, "The Significance Determination Process for Findings at Power," issued June 19, 2012, the finding was screened against the Initiating Events cornerstone. The inspectors determined this issue was of very low safety significance (Green) because the inspectors answered "No" to all the screening questions. Cross Cutting Aspect: This finding has a cross-cutting aspect of avoid complacency in the area of the human performance because the licensee failed to recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, the licensee did not appropriatelv implement error reduction tools. IH.121

• 10

Enforcement: Violation: Technical Specification 5.4.1.a, Procedures, states, in part, written procedures shall be established, implemented, and maintained covering the following activities: the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978... Section 3.n of Regulatory Guide 1.33, Revision 2, Appendix A, February' 1978, states, in part, instructions for energizing, filling, venting, draining, startup, shutdown, and changing modes of operation should be prepared, as appropriate, for the following systems: chemical and volume control system (including letdown/purification system). Step 4.9.16.j of DB-OP-06006, "Makeup and Purification System," Revision 42, stated, open MU177, makeup filter 1 outlet isolation. Contrary to the above, on March 30, 2018, the licensee failed to implement a written procedure as recommended In Regulatory Guide 1.33. Specifically, the licensee failed to follow the makeup and purification system procedure which resulted in the isolation of letdown while swapping make-up filters. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2018-03036, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy.* (NCV 05000346/2018002-01: Failure to follow Make.up and Purification Procedure) 71153-Follow-Up of Events and Notices of Enforcement Discretion Failure to Apply Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Report Aspect Section Mitigating Green H.14 71153-Systems NCV 05000346/2018002-02 Follow-Up of Closed Events and Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated NCV of Technical Specification 3.3.5, Safety Features Actuation System (SFAS) Instrumentation, and 3.0.1 Surveillance Requirement Applicability, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying that two channels of SFAS Borated Water Storage Tank level instrumentation were inoperable. Specifically, the licensee exited Technical Specification (TS) 3.3.5.b, the six hour shutdown technical specification, while two BWST level instruments were still inoperable.

== Description:== 11

LER 05000346/2016-00B-01, Application ofTechnical Specifications for the Safety Feat~res Actuation System Instrumentation On June 30, 2016 at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation for the Safety Features Actuation System (SFAS) was declared inoperable and removed from service for scheduled maintenance. The Limiting Condition for Operation (LCO) for Technical Specification 3.3.5 stated in part, four channels of SFAS instrumentation for each Pal"'3meter [BWST level] shall be operable. At this time, Reactor Operators entered TS 3.3.5.a, which required the inoperable channel be tripped. Later that day at 2344, Channel 2 became inoperable due to a loss of power from a failed power supply. At this time, operators should have entered TS 3.3.5.b, which required restoring at least one channel immediately or placing the reactor into Mode 3 (hot shutdown), within six hours. At 0140 on July 1, 2016, after the licensee had multiple discussions regarding the power supply failure, operators realized that they should apply TS 3.3.5.b, but did not enter the Technical

• Specification until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared operable due to compensatory measures including proceduralized operator actions to be performed for a manual suction swap. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function or passing the Technical Specification required surveillance which is required to be met in all modes of applicability of the LCO.

The inspectors questioned the licensee's basis for operability. From discussions with the licensee on July 1, 2016, the inspectors determined the defined compensatory measures were not sufficient for the licensee to declare Channel 1 operable. At 1325 on July 1, 2016, the licensee declared Channel 1 inoperable and reentered TS 3.3.5.b. At 1351, the licensee exited TS 3.3.5.b after maintenance was completed and Channel 1 was restored to service. The inspectors determined the plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. Corrective Action(s): The corrective actions included reentering Technical Specification 3.3.5.b and performing corrective maintenance on the Channel 1 instrumentation to restore it to operable. The Licensee performed a root cause analysis arid developed a case study from lessons learned. Additionally, the licensee issued an operations standing* order; revised multiple procedures; and performed additional training regarding lessons learned from this event, Technical Specification compliance, and correct application of the operability determination process. Corrective Action Reference(s): The licensee documented this issue in CR 2016-08419 Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to shut down the reactor within six hours, as required by TS 3.3.5.b, was a performance deficiency. Specifically, with two channels of the BWST level Instrumentation inoperable, the licensee failed to enter Mode 3 within six hours. Screening: The finding was determined to be more than minor because it was associated with the Mitigating Systems function of Long Term Heat Removal, and affected the cornerstone's objective of ensuring the availability, reliability, and capability of systems to respond to initiating events to prevent undesirable consequences. Specifically, the finding resulted in the loss of the emer enc core coolin s stem ECCS suction swa ermissive 12

function, which could have resulted in the loss of system safety function (i.e., ECCS due to a premature suction source transfer). Significance: The inspectors determined the finding could be evaluated using the SDP in accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, . "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." The inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greaterlhan the TS 3.3.5 allowed outage time of 6 hours for this function. Therefore, a detailed risk evaluation was performed using IMC 0609, Appendix A. The risk evaluation was performed by Region Ill SRAs and the bounding core damage frequency (ACDF) was determined to be 7.0E-7/yr. Since the total estimated change in core damage frequency was less than 1.0E-6/year, the finding/violation was initially determined to be Green. Additionally since the t..CDF was greater than 1.0E-7/year, the finding was reviewed for potential Large Early Release Frequency (LERF) contribution. Davis Besse is a 2-loop Babcock and Wilcox Pressuriz~d Water Reactor with a large dry containment. The core damage sequences important to LERF were steam generator tube rupture (SGTR) events and inter-system LOCA events. These events were not the dominant

• core damage sequences for this finding. Therefore, based on the detailed risk evaluation, the SRAs confirmed that the finding was of very-low safety significance (Green).

Cross Cutting Aspect: This finding had a cross-cutting aspect of Conservative Bias in the area of Human Performance, which states Individuals use decision making practices that emphasize prudent choices over those that are simply allowable. A proposed action is determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, the licensee failed to use decision making practices that emphasized prudent choices, over those that they believed were slmply allowable. [H.14] Enforcement: Violation: Technical Specification 3.3.5.b, SFAS Instrumentation, states in part, with one of more Parameters with two or more channels inoperable, be in Mode 3 within six hours. Enforcement Action(s): Contrary to the above, on July 1, 2016, the licensee failed to place the reactor into Mode 3 within six hours of identifying one Parameter with two channels inoperable. Specifically, the.licensee failed to shut down the reactor within six hours with two channels of SFAS BWST level instrumentation inoperable. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2016-08419, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy. (NCV 05000346/201SOON12: Failure to Apply Technical Specification for SFAS Instrumentation) (05.05-LER Closure) I 'Procedure Violatiori I_..

• _.. _. +

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Cornerstone Mitigating Systems Significance Green NCV 05000346/2018002-03 Closed Cross-cutting Aspect H.8 Report Section 71153-Follow-Up of Events and Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated non-cited violation of 10 CFR Part 50, Appendix 8, Criterion V, "Instructions, Procedures, and Drawings," due to the licensee's failure to property implement procedures DB-OP-06405, "Safety Features Actuation System Procedure," DB-SC-03110, "SFAS Channel 1 Functional Test," and DB-OP-03006, "Miscellaneous Instrument Shift Checks," Specifically, the licensee declared SFAS Channel 1 operable without correctly performing the required procedural steps and failed to correctly perform the.channel checks.

== Description:== LER 05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation On June 30, 2016, at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation for the Safety Features Actuation*system (SFAS) was declared inoperable and removed from service for scheduled maintenance. On July 1, 2016, at 0330, The channel was declared operable with reference to compensatory measures. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. DB-OP-06405, "Safety Features Actuation System Procedure," required that an SFAS functional test be performed and that a channel check of the inoperable instrument be performed utilizing p~~QP:Q3006,. In order to satisfy_!he reguirements 'ofi'.is:sc:03110', the bistable must operate correctly and then be reset such that the channel is not tripped. In order for the BWST level instrumentation to satisfy the requirements of DB-OP-03006, the instruments can register no more than a 2.0 feet level difference. The Channel 1 instrument was disconnected and could not meet these requirements. The licensee, however, declared the results satisfactory for Channel 1 by referring to ~Qmp~nsato_ry [!'l~.3~1,!!~~- A Prompt Operability Determination was initiated in an attempt IQ rely on the same compensatory measures to justify operability. The inspectors questioned the licensee's basis for operability and noted that the Channel 1 level instrument was not even physically attached to the system. The inspectors determined that the compensatory measures were not sufficient for the licensee to declare Channel 1 operable. At 1325 on July 1, 2016, the licensee declared Channel 1 inoperable and at 1351 maintenance was completed on Channel 1 and it was properly restored to service. The inspectors determined that the licensee failed to perform the required procedural actions. Corrective Action(s): The corrective actions included declaring Channel 1 inoperable and performing corrective maintenance on the Channel 1 instrumentation to restore it to operable. The Licensee performed a root cause analysis and developed a case study from lessons learned. Addilionallv, the licensee issued an ooerations standina order; revised multiple 14 --~ -[ Commented [WJSJ: What procedure is this?

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procedures; and performed additional training regarding lessons learned from this event, Technical Specification compliance, and correct application of the operability determination process. Corrective Action Reference(s): The licensee documented this issue in g_if~_W:9~_19; __ _ 'Performance Assessment; [ __________ _ Performance Deficiency: The licensee improperly applied multiple procedures: f xample 1: DB-OP-06405, "Safety Features Actuation Syste1T1 Procedure" set forthJhe. procedure for restoring an inoperable SFAS component to_ operable. This include~ ~atisfactorily performing an SFAS channel functional test and requires that a channel check Qf the inoperable instrument be performed. Cont_rary to this requirement, the licensee corr'?Qtly performed neither. the functional test nor.the channel_ check before dec!aring the.channel Operable! Example 2: DB-SC-03110, "SFAS Channel 1 Functional T~st" required that the channel paS§ ~ number of tests and then be reset. Contrary to this, the Q!li;i.!J!:1l&.W.~§_i!)~p~ble_2_~ passl11g the re>1uired tests,. and. further,_ incapable of being_ reset; ... -- --{ Commented [WJ9]: CR name?

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! Commented [WllO]: Formatted Example 3: 0B-OP-3006~reguired that channel checks be performed every twelve hours. Pl.

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Channel Ch 0 eck was dearly'clefined as a qualitaGve assessment ofchannel behavior durin1r-- 6peration, including comparison of channel indication and status to other indications or statuj derived from independen.t instrument channels measuring the same parameter. Contrary to this requirement, when performing the channel check for BWST Lev.el indication Channel 1,: the operators recognized that the channel did __ not show a.. s*atisfactory resp_onse 'but declared !~_c!tj! met:the reguirements because of a coml)ensatory_m_e_a_s_u_re_. __________ 1 __ -~ commented [WJ12J: This should probably be 1n the de.saiption to shorten the assessment section. Screening: The performance deficiency was determined to be more than minor because it was associated with the Mitigating Systems cornerstone attribute of Equipment Performance and affected the cornerstone objective of ensuring the availability, reliability, and capability of. systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to follow procedures to establish the operability of SFAS Channel 1 negatively affected the ability of the system to perform its accident mitigating function. Additionally, this failure led to a l(iolation of Technical Specifications as detailed elsewhere in this report. Significance: The Inspectors assessed the significance of the finding using IMC 0609.04, "Initial Characterization of Findings," and IMC 0609, Appendix A, Exhibit 2, "Mitigating Systems Screening Questions." The inspectors determined that this performance deficiency did not result in a loss of a single train of a safety system for greater than its Technical Specification allowed outage time. Therefore, the inspectors determined the finding to be of very low safety significance (Green). Also what revisions were these procedures? Cross Cutting Aspect: This finding had a cross-cutting aspect of Procedure Adherence in the area of Human Performance, which states individuals follow processes, procedures, and work instructions. ;specifically,_ t~_e liqensee_ ~ailed in m_ultjplt3 ir:islc!11~s to follqw thei~ qwri_<,lea!Jy cteffln_~~:i>r_g_c11_d~r_es.,_ [H,B_,l~-------~--------------*- _ __..,.,---1 Commented [WJ13]: (my opinion) this is restating the PD / Commented [WJ14]: Where Is the violation? You need to state-Enforcemenl: Because it was "of very low safety s"ignificance and was entered-fritci the the 10CFR requirement and the procedure{s) requirement with the /,. contrart to statement to make it a legally OK violation. licensee's corrective action orooram as CR-2016-08419, this ~iolation is being treated as an _/ 15

NCV consistent with Section 2.3.2 of the Enforcement Policy. (f',I_C:V _05~Q03~6/io1~0Q~-03:: Procedure Violation) [05.05 -LER Closure] EXIT MEETINGS AND DEBRIEFS The inspectors confirmed that proprietary information was controlled to protect from public disclosure. No proprietary information was documented in this report. On July 31, 2018, the inspectors presented the quarterly integrated inspection results to Mr. M. Bezilla and other members of the licensee staff. 16

DOCUMENTS REVIEWED 71111.01-Adverse Weather Protection ~ Davis-Besse Off-site Power Voltage Assessment; Summer 2018 - DB-OP-01300; Switchyard.Managem~nt; Revision 14 - DB-OP-02546; Degraded Grid; Revision 07 - DB-OP-06311; 345 KB Switchyard No. 1 (Main) Transformer, No. 11 (Auxiliary) Transformer, and Startup Transformer (01 and 02); Revision 48 - DB-OP-06913; Seasonal Plant Preparation Checklist; Revision 30 - DB-SC-03023; Off-site AC Sources Lined Up and Available; Revision 34 - NOBP-CC-2008; Transformer, Switchyard, and Grid Reliability Design Interface and Control; Revision 01 - NOP-CC-3002-01; AC Power Systems Analysis; Revision 05 - NOP-OP-1003; Grid Reliability Protocol; Revision 09 71111.04-Eguipment Alignment - CR-2015-00459; 2015 CDBI SA: Auxiliary Feed Pump (AFP) 1 and 2*Response Time Testing - Davis-Besse Nuclear Power Station Lubrication Date Sheet; Decay Heat Pumps and Motors, Auxiliary Building, 545' Level - DB-OP-06011; High Pressure Injection System; Revision 31 - DB-OP-06012; Decay Heat Pump; Revision 71 - DB-OP:.06013; Containment Spray System; Revision 26 - DB-OP-0623; Auxiliary Feedwater System; Revision 42 - DB-OP--06262; Valve Line Up Checklist for CCW Pump 2; Revision 38 - DB-SS-03090; Motor Driven Feed Pump Monthly Valve Verification; Revision 11 - M-0060; Auxiliary Feedwater System; Revision 59 - OS-003; High Pressure Injection System; Revision 36 - OS-005; Containment Spray System; Revision 14 71111.05AQ-Fire Protection Annual/Quarterly - PFP-Al;l-238; Auxiliary Feed Pump 2 Room; Revision 4 - PFP-AB-328; Protected Area Pre-Fire Plan-Component Cooling Water Heat Exchanger and Pump Room; Revision 4 - Pre-Fire Plan; PFP-AB-115, Revision 5, ECCS Pump Room 1-2 - Pre-Fire Plan: PFP0AB-109, Revision 7, Rooms 104, 106, 106A and 109 71111.06-Flood Protection Measures - DWG E-328; Raceway & Grounding Start-Up, Main & Aux Transformers; Rev 15 - WO 200676046; Electric Hand/Manholes 71111.07-Heat Sink Performance - CR 2018-00844; CCW Hx 1-3 Pin-Hole Leak - W0200741172 DB-SUB16-03; Component Cooling Water Heat Exchanger 71111.11-Licensed Operator Regualification Program and Licensed Operator Performance 17

- DB-OP-06401; Integrated Control System Operating Procedure; Revision 27 - DB-OP-06902; Revision 62 - NOBP-TR-1151; 4.0 Crew Critique; 09/28/17 - NOP-OP-1002; Conduct of Operations; Revision 12 71111.12-Maintenance Effectiveness - 2017-2; Davis Besse System Health Report; Decay Heat Low Pressure Injection; 02/01/2018 - Cycle 20 Periodic Maintenance Effectiveness Assessment Report - CR 201709888; CCW 2 Cable Testing Exceeded the Acceptance criteria; 09/27/2017 - CR 201700704; CRD Booster Pump 1 Trip; 01/21/2017 - CR 201805257; CRD Booster Pump 2 Trip on Overload; 06/06/2018 - CR 201702171; CCW Train 3 Exceeded Maintenance Rule Unavailability Limit - CCW System Health Report; 2017-02 71111.13-Maintenance Risk Assessments and Emergent Work Control - CA 03-05256-01; Control Room Habitability Systems Licensing Basis Validation; Attachment 2

• CR 2018-05995; UFSAR Description of CREVS and CREATCS does not Match Technical Specifications; 06/29/2018

- Davis-Besse Unit 1 UFSAR; Revision 30 - DBBP-OPS-0011; Protected Equipment Posting; Revision 10 - DB-SS-03301; Control Room Unfiltered Air lnleakage Test for Control Room Emergency Ventilation, Train 1; Revision 00

• Drawing 05-020 SH 1: Operational Schematic Service Water System; Revision 100

- Drawing 05-032B; Operational Schematic Control Room Emergency Ventilation System; Revision 22 - NOP-LP-4008; Licensing Document Change Process; Revision 5 - NOP-LP-4008; Licensing Documents Change Process: Revision 1 - NOP-OP-1007; Risk Management; Revision 25 - Procedure NOP-OP-1007; Risk Management; Revision 25 71111.15-0perability Determinations and Functionality Assessments - CR 2018-04305; Y212 Fuse Blown During TD14950; 05-08/2018 - CR2018-03174; SW277 Excessive Leakage

• CR 2018-04296; LEFM Parameter Revision Results in Changes to Indicated Loop Flows; 05/08/2018 *
• CR2018-04599

- DB-PF-03020; Service Water Train 1 Valve Test; Revision 42 - DB-SC-03121; SFAS Train 2 Integrated Response Time Test; Revision 07

• WO 200676009; PF3020-033 05.000 SW276, SW277 71111.18-Plant Modifications

- CR 201800027; BWST Loop Seal Pipe Elevation Discrepancy; 01/02/2018

• CR 201803211; BWST Leak Near BW33 Outside; 04/06/2018

- Engineering change package 16-0478-001, Loop seal in BWST to SFP purification supply pipe civil structural - Engineering change package 16-0478-002, Loop seal in BWST to SFP purification supply pipe 18

piping and mechanical - Engineering change package 16-0478-003, Loop seal in BWST to SFP purification supply pipe (freeze protection) 71111.19-Post Maintenance Testing - CA 2011-02670; WO 200481565 was Initiated to Troubleshoot DH2733; 04/29/2016 - CR 2015-08968; Evaluation of Service Water Pump P3-1 Baseline Data; 07/02/2015 - CR 2018-04974; Critical Preventive Order Removed from Schedule at T-0; 05/29/2018 - DB-PF-03017; Service Water Pump 1 Testing; Revision 23 - Procedure DB-SP--03161, AFW Train 2 Level Control, Interlock, and Flow Transmitter Test, Revision34 - WO 200683205; Perform SW Pump 1 Quarterly Test; 05/22/2018 - WO 200683879; DH/LPI 1-1 Quarterly; 05/30/2018 - WO 200747497, AFP 2 Quarterly Test; 05/07/2018 - WO 200704976 DB-SUB049-02; Decay Heat and Low Pressure Injection; 05/31/2018 71111.22-Surveillance Testing - DB-SC-03070; Emergency Diesel Generatoi 1 Monthly Test; Revision 38 71114.06-Drill Evaluation - CR 2018-05418; ERO Tabletop Drill Improvement Opportunities; 06/11/2018 71151-Perforrnance Indicator Verification - Station Unit Logs 71152-Problem Identification and Resolution - CR 2018-03036; Misposition of Make Up Filer 1 Outlet Isolation (MU17); 03/31/2018 - NOBP-OP-0004; Plant Status Control and Worker Protection Events; Revision 17 - Drawing M-031C; Piping and Instrument Diagram Make Up and Purification System; Revision43 - Drawing M031A; Piping and _Instrument Diagram Make Up and Purification System; Revision 52 - DB-OP-06006; Makeup Filter 1 Replacement; Revision 42 71153-Follow-Up of Events and Notices of Enforcement Discretion - Station Unit Logs - LER 2016-008-01; Application of Technical Specification for the Safety Features Actuation System Instrumentation - Root.Cause Analysis Report; CR-2016-08419; 10/07/2016 - DB-OP-06405; Safety Features Actuation System Procedure; Revisions 13 & 14 * - DB-OP-03006; Miscellaneous Instrument Shift Checks; Revisions 55 & 61 - DB-Ml-03145; Functional Test/Calibration of LT-1525A BWST Level Transmitter to SFAS Channel 1; Revisions 9 & 12 - DB-Ml-03146; Functional Test/~alibration of LT-1525B BWST Level Transmitter to SFAS Channel 2; Revisions 9 & 12 19

- DB-SC-03110; SFAS Channel 1 Functional Test; Revisions 20 & 22 - DB-SC-03111; SFAS Channel 2 Functional Test; Revisions 16 & 18 - NOP-OP-1002; Conduct of Operations; Revisions 11 & 12 - NOP-OP-1009; Operability Determinations and Functionality Assessments; Revisions 6 & 8 - NOBP-OP-0014; FENOC Duty Teams; Revision 2 & 5 - NOBP-OP-1002; Operations Administrative Guidelines and Common Processes; Revision 2&4 - NOBP-OP-0002; Operations Briefing and Challenge Calls; Revisions 3 & 4 - NOBP-OP-0002-05; Control Room Shift Brief Checklist - NOBP-OP-0002-05A; Control Room Shift Brief Checklist - NORM-OP-1002; Conduct of Operations; Revh1ion 6 - NOP-OP-1015; Event Notifications; Revisions 3 & 6 - CR 2016-08419; Performance Review of LCO 3.3.5 application during L T1525A maintenance - CR 2016-08699; Crew Briefing Performance Shortfall - CR 2016-13611; Did Not Receive VP Approval Within 30 Days AfterCARB Approval - CR 2016-11711; Red Key Performance Indicator D-SP0-05L - Open CRs With Extensions - CR 2017-07598; Technical Specification Upgrade Criteria Not Accurately Communicated On 1530 Duty Team Phone Call - CR2016-11681; Common Cause Evaluation For DB Performance Issues - CR 2016-10440; Red Key Performance Indicator D-SP0-05L - Open CRs With Extensions - CR 2016-13335; Fleet Operations Elevation Letter - Regulatory Document Implementation - Supplemental Review - CR 2016-08700; Delayed Request For Prompt Operability Determination - CR 2016-08402; SFAS Channel 2 +15V Power Supply Failure - CR 2016-08765; Restoration of SFAS CH1 (L T-1525A)-Assessment Of Organizational" Response To Extended Work Window - CR 2016-08539; "A" Schedule Work Not Complet~d By Instrument and Control Shop - CR 2016-08922; Assessment of Schedule Adherence for Maintenance Activities - CR 2016-08415; Parameter 5 BWST Level-Low Low Opera611ity 20

Failure to Aoolv Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Report Aspect Section Mitigating TBD H.14 71153-Systems NOVvsNCV Follow-Up of Closed Events and Notices of Enforcement Direction The NRC identified a finding ofTBD significance and an associated NOV/NCVofTechnical SQecification 3.3.5.b, Safety Features Actuation System (SFAS} Instrumentation, for the licensee's failure to 11lace the reactor in Mode 3 within six hours of identifl!jng two channels of SFAS BWST level instrumentation were inogerable. Sgecifically, the licensee exited TS 3.3.5.b, the six hour shutdown technical sgecification, while two BWST level instrumentation were still inoi;ierable. Descri11tion: On June 30, 2016 at 08,29, Channel J'ofthe Borated Water Storage Tank (BWST) level instrumentation for the Safety Features Actuation System*(SFAS) was declared inoperable and removed for service for scheduled maintenance. The Limiting Condition for Operation (LCO) for Technical S11ecification {TS) 3.3.5 states, in 11arl, four channels of SFAS instrumentation for each Parameter [BWST level) shall be operable._ At this lime Reactor k,peraiors entered ~~haieai Sfleeiileatia~(T§)' 3.3.5.a,yhich r~quires the~lnoperabfe channel be tripped!. Later that dayyt 2344, Channel 2 beca_me inoperable due to a loss of power from that '.¥as.later feund ta he a failed power supply: At this time Operators should have entered TS 3.3.5.b. which requires restoring at least one channel immediately or jH!ltiHg-placing the reactor into Mode 3, or hot shutdown, within six e hours. At 0140w:F-on July l, 2016, after the licensee had multinle discussions regarding the nower supply failure, Operators became aware that they should be applying TS 3.3.5.b;but did riot officially enter the Technical Specification until 0245. At 0330, TS 3.3.5.b was exited with Channel I declared Operable due to k<!!!lpen§(!!!}ry !!l~~~l}lS..!At this time, the Channel I instr_ument was electrically~ physically disconnected and incapable of performing its function, The insnectors guestioned the licensee's basis for onerabili\\)'.. From discussions with the licensee on July l, 2016. the inspectors determined the defined compensatoi:y measures were not sufficient for the licensee to declare Channel l operable. This remained the eenditien efthe plant anti! At 1325 on July I, 2016, *.*,hen the deeisien ta the licensee declare.!!. ChanneU i.!loperable eeald net he sa1313erled, and reentered TS 3.3.5.b was Feentem!. _At 1351; the licensee exited TS 3.3.5.h after the licensee comr1leted maintenance on Channel.I and restored it to service. sehooaled-maiRtenanee ;*,ras 881J!Jlleted en the Chamiel I instrument and it was 13lased bask inte seFviee and TS 3.3.5.e *.vas e1,ited. 111c insncctors determined =I=the plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. Corrective Action(s): (Qa.Q21:l Ceffee!ive,A,elieR(s)lThe corrective actions included reentering TS 3.3.5.b and i;ierforming corrective maintenance on the Channel 1 instrumentation to restore it to operable. t,.dditionally, the licensee i;ieformed extra training...., Corrective Action Reference(s): The licensee docuniented this issue in CR XXXXXXXXX

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Commented [WJl]: D~ Jamnes want past tense for procedures/TS? Or present tense?

~-1 Commented [WJ2]: What were the* coinp m~asures? 1. ~-----*[ Formatted: Left, Indent: Left: O"

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( Formatted: Highlight

Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to shutdown the reactor within six hours. as required by TS 3.3.5.b. was a performance deficiency.. Specifically, with two channels of the BWST level instrumentation inoperable, the licensee failed to enter Mode 3 within six hours. Screening: The finding was determined to be more than minor because it was associated with the Mitigating Systems attribute. and affected the cornerstone's objective of ensuring the availability. reliability. and capability of systems to respond to initiating events to prevent undesirable consequences. Specifically. tlie finding rioicni1ally resulted fii the ioss ofsyslcrii safetyfunctionCT~cJ ECCS due to low suction head}.! Significance: The inspectors determined the.finding could be evaluated using the SDP in accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04. "Phase I-Initial Screening and Characterization of Findings." for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A. "The Significance Determination Process for Findings At-Power." The inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented ihe inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.3.5 allowed outage time of6 hours for this function. Therefore. a detailed risk evaluation was performed using IMC 0609. Appendix A. Cross Cutting Aspect: This finding had a cross-cutting aspect of Conservative Bias in the area of Human Performance, which states individuals use decision making practices that emphasize prudent choices over those that are simply allowable. A proposed action is *. determined to be safe in order to*proceed, ratnerthaii unsaf1fln order fo' stop. Specificafiy) ihe licensee failed to use decision making practices that emphasized prudent choices, overl

• _ _..-- Commented (WJ3]: May need to reword ihis (take out
• i potentially?)

1 Fonnatted: left those that were simply allowable. (H.14)_ __________________ -* ______ ----**--

• __ Commented (WJ4]: The choices ~e)icensee made Enforcement:

Violation: Technical Specification 3.3.5.b states; in part. with one of more Parameters with two or more* channels inoperable. be in*Mode 3 witliin six hours. were not allowable though, That's why they are getting a Violation. If we* QO With this one*, We might want to explain ihe simply allowable thing. Did you look at Pl&R at all? Enforcement Aclion(s): Contrary to the above. on July 1, 2016,. the licensee failed to be in -* -{ Fonnatted: Left, Indent: Le;t: o* Mode 3 within six hours of identifying one Parameter with two channels inoperable. Specifically. failed to shutdown the reactor within six hours with two channels of SFAS BWST level instrumentation inoperable. Disposition: (05.05 -Unresolved Item Closure] -c--{ Fonnatted: Left l

Failure to Apply Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Mitigating Systems TBD NOV/NCV Closed Aspect H.14 Report Section 71153-Follow-Up of Events and Notices of Enforcement Direction The NRG identified a finding of TBD significance and an associated NOV/NCV of Technical Specification 3.3.5.b, Safety Features Actuation System (SFAS) Instrumentation, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying two channels of SFAS BWST level instrumentation were inoperable. Specifically, the licensee exited TS 3.3.5.b, the six hour shutdown technical specification, while two BWST level instruments were still inoperable.

== Description:== On June 30, 2016 at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation for the Safety-Features Actuation System (SFAS) was declared inoperable and removed for'service for scheduled maintenance. The Limiting Condition for Operation (LCO) for Technical Specification (TS) 3.3.5 stated in part, four channels of SFAS instrumentation for each Parameter [BWST level] shall be operable. At this time Reactor Operators entered TS 3.3.5.a, which required the inoperable channel be tripped. Later that day at 2344, Channel 2 became inoperable due to a loss of power from a failed power supply. At this time Operators should have entered TS 3.3.5.b, which required restoring at least one channel immediately or placing the reac.tor into Mode 3, or hot shutdown, within six hours. At 0140 on July 1, 2016, after the licensee had multiple discussions regarding the power supply failure, Operators became aware that they should apply TS 3.3.5.b, but did not enter the Technical Specification until 0245. At 0330, TS.3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures including proceduralized operator actions to be performed for a manual suction swap. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. The inspectors questioned the licensee's.basis for operability. From discussions with the licensee on July 1, 2016, the inspectors determined the defined compensatory measures were not sufficient for the licensee to declare Channel 1 operable. At 1325 on July 1, 2016, the licensee declared Channel 1 inoperable and reentered TS 3.3.5.b. At 1351 the licensee exited TS 3.3.5.b after maintenance was completed on Channel 1 and restored the channel to service. The inspectors determined the plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. Corrective Action(s): The corrective actions included reentering TS 3.3.5.b and performing corrective maintenance on the Channel 1 instrumentation.to restore it to operable. The Licensee performed a root cause analysis and developed a case study from lessons learned. Additionally, the licensee issued an operations standing order, performed additional training regarding lessons learned from this event, Technical Specification compliance, and correct application of the operability determination process.

Corrective Action*Reference(s): The licensee documented this issue in CR 2016-08416 Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to shutdown the reactor within six hours, as required by TS 3.3.5.b, was a performance deficiency. Specifically, with two channels of the BWST level instrumentation inoperable, the licensee failed to enter Mode 3 within six hours. Screening: The finding was determined to be more than minor because it was associated with the Mitigating Systems function of Long Term Heat Removal, and affected the cornerstone's objective of ensuring the availability, reliability, and capability of systems to respond to initiating events to prevent undesirable consequences. Specifically, the finding resulted in the loss of the ECCS suction swap permissive function, which could have resulted in the loss of system safety function (i.e., ECCS due to a premature suction source transfer). Significance: The inspectors determined the finding could be evaluated using the SDP in accordance with IMC 0609; "Significance Determination Process," Attachment 0609.04, "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." The inspectors.answered 'Yes' to Question A.2 in Exhibit 2 because the fin.ding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.3.5 allowed outage time of 6 hours for this function. Therefore, a detailed risk evaluation was performed using IMC 0609, Appendix A. Cross Cutting Aspect: This finding had a cross-cutting aspect of Conservative Bias in the area of Human Performance, which states individuals use decision making practices that emphasize prudent choices over those that are simply allowable. A proposed action is

• determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, the licensee failed to use decision making practices that emphasized prudent choices, eyer those that they believed were simply allowable. [H.14]

Enforcement: Violation: Technical Specification 3.3.5.b, SFAS Instrumentation, states in part, with one of more Parameters with two or more channels inoperable, be in Mode 3 within six hours. Enforcement Action(s): Contrary to the above, on July 1, 2016, the licensee failed to place the reactor into Mode 3 within six hours of identifying one Parameter with two channels inoperable. Specifically, the licensee failed to shut down the reactor within six hours with two channels of SFAS BWST level instrumentation inoperable. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2016-08419, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-02: Failure to Apply Technical Specification for SFAS Instrumentation) [05.05 -LER Closure]

Failure to Aoolv Technical Specification for SFAS Instrumentation Cornerstone Significance Cross-cutting Mitigating Systems Green NCV Closed Aspect H.14 Report Section 71153-Follow-Up of Events and Notices of Enforcement Direction The NRC identified a finding of Green significance and an associated NCV of Technical Specification 3.3.5.b, Safety Features Actuation System (SFAS) Instrumentation, for the licensee's failure to place the reactor in Mode 3 within six hours of identifying two channels of SFAS Borated Water Storage Tank level instrumentation were inoperable. Specifically, the licensee exited Technical Specification (TS) 3.3.5.b, the six hour shutdown technical specification, while two BWST level instruments were still inoperable.

== Description:== LER 05000346/2016-008-01, Application of Technical Specifications for the Safety Features Actuation System Instrumentation On June 30, 2016 at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation for the Safety Features Actuation System (SFAS) was declared inoperable and removed for service for scheduled maintenance. The Limiting Condition for Operation for Technical Specification 3.3.5 stated in part, four channels of SFAS instrumentation for each Parameter [BWST level] shall be operable. At this time, Reactor Operators entered TS 3.3.5.a, which required the inoperable channel be tripped. Later that day at 2344, Channel 2 became inoperable due to a loss of power from a failed power supply. At this time, Operators should have entered TS 3.3.5.b, which required restoring at least one channel immediately or placing the reactor into Mode 3, or hot shutdown, within six hours. At 0140 on July 1, 2016, after the licensee had multiple discussions regarding the power supply failure, Operators became aware that they should apply TS 3.3.5.b, but did not enter the Technical Specification until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures including proceduralized operator actions to be performed for a manual suction swap. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. The inspectors questioned the licensee's basis for operability. From discussions with the licensee on July 1, 2016, the inspectors determined the defined compensatory measures were not sufficient for the licensee to declare Channel 1 operable. At 1325 on July 1, 2016, the licensee declared Channel 1 inoperable and reentered TS 3.3.5.b. At 1351, the licensee exited TS 3.3.5.b after maintenance was completed on Channel 1 and restored the channel to service. The inspectors determined the plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. Corrective Action(s): The corrective actions included reentering Technical Specification 3.3.5.b and performing corrective maintenance on the Channel 1 instrumentation to restore it to operable. The Licensee performed a root cause analysis and developed a case study from lessons learned. Additionally, the licensee issued an operations standing order, performed additional training regarding lessons learned from this event, Technical Specification

compliance, and correct application of the operability determination process. Corrective Action Reference(s): The licensee documented this issue in CR 2016-08416 Performance Assessment: Performance Deficiency: The inspectors determined the licensee's failure to shut down the reactor within six hours, as required by TS 3.3.5.b, was a performance deficiency. Specifically, with two channels of the BWST level instrumentation inoperable, the licensee failed to enter Mode 3 within six hours. Screening: The finding was determined to be more than minor because it was associated with the Mitigating Systems function of Long Term Heat Removal, and affected the cornerstone's objective of ensuring the availability, reliability, and capability of systems to respond to initiating events to prevent undesirable consequences. Specifically, the finding resulted in the loss of the emergency core cooling system (ECCS) suction swap permissive function, which could have resulted in the loss of system safety function (i.e., ECCS due to a premature suction source transfer). Significance: The inspectors determined the finding could be evaluated using the SDP in accordance with IMC 0609, "Significance Determination Process," Attachment 0609.04, "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." The inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.3.5 allowed outage time of 6 hours fot this function. ifherefore, a detailed risk evaluation was performed using IMC 0609,r ~pp-endix A: the -risk evaluation was performed by Region 111 SRAs and the bounding cor~ I pamage frequency (LlCDF) was determined to be 7.0E-7/yr. Since the total estimated ch~rig~ in core damage frequency was less than 1.0E-6/year, the finding/violation was initially ~etermined to be Green. Additionally since the ~CDF was greater than 1.0E-7/year, th~ finding was reviewed for potential Large Early Release Frequency (LERF) contribl!tic;m: Davis: '3esse is a 2-loop Babcock and Wilcox Pressurized Water Reactor with a large dry containment. The core damage sequences important to LERF were steam generator tube ~upture (SGTR) events and inter-system LOCA events. These events were not the dominant pore damage sequences for this finding. Therefore, based on the detailed ris_~_~v9J~?ti9n, ti}~: ~RAs confirmed that the finding was of very:l9w safety significance(Green); Cross Cutting Aspect: This finding had a cross-cutting aspect of Conservative Bias in the area of Human Performance, which states individuals use decision making practices that emphasize prudent choices over those that are simply allowable. A proposed action is determined to be safe in order to proceed, rather than unsafe in order to stop. Specifically, the licensee failed to use decision making practices that emphasized prudent choices, over those that they believed were simply allowable. [H.14] Enforcement: Violation: Technical Specification 3.3.5.b, SFAS Instrumentation, states in part, with one of more Parameters with two or more channels inoperable, be in Mode 3 within six hours. Enforcement Action s : Contrar to the above, on Jul 1, 2016, the licensee failed to lace

the reactor into Mode 3 within six hours of identifying one Parameter with two channels inoperable. Specifically, the licensee failed to shut down the reactor within six hours with two channels of SFAS BWST level instrumentation inoperable. Disposition: Because it was of very low safety significance and was entered into the licensee's corrective action program as CR-2016-08419, this violation is being treated as an NCV consistent with Section 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-02: Failure to Apply Technical Specification for SFAS Instrumentation) [05.05 -LER Closure]

Failure to Follow the Makeup and Purification Procedure Cornerstone Significance Barrier Integrity Green NCV 05000346/2018002-01 Closed Cross-cutting Aspect H.12 Report Section 71152-Annual Follow-Up of Selected Issues A self-revealed Green finding and associated Non-Cited Violation (NCV} of Technical Specification SA.1.a, Procedures, was identified when the licensee failed to follow station procedure DB-OP-06006, "Makeup and Purification System." Specifically, the licensee failed to open MU177, the Make-Up Filter 1 Outlet Isolation valve, which resulted in the isolation of letdown while swapping make-up filters.

== Description:== On March 31, 2018, while placing make-up filter 1 in service using DB-OP-:-06006, "Makeup and Purification System," Revision 42, the licensee received two unexpected alarms, "Letdown or MU [make-up] Filter dP [differential pressure] Hi" followed by "Letdown Pressure Hi." The licensee immediately opened MU12B, the Makeup Filter 2 Inlet Isolation, to establish letdown flow. During investigation of the issue the licensee found MU 177, the Make-Up Filter 1 Outlet Isolation valve, unexpectedly closed. This was because the licensee failed to follow Step 4.9.16.j of DB-OP-06006, which required opening of MU177, on March 30, 2018, when preparing to swap filters. Additionally, the licensee determined that while letdown flow was isolated, the letdown relief valve lifted and reseated. Approximately six gallons of water were diverted to the reactor coolant drain tank. The licensee's corrective actions included operator remediation, a requirement to have shiftly engagement calls with Operations Management, and reinforcing the use of a reverse brief by operators as a human performance tool. This issue was documented in CR -2018-03036, "Disposition of Make-Up Filter 1 Outlet Isolation (MU177)." Performance Assessment: The inspectors determined the licensee's failure to follow DB-OP-06006, Makeup and Purification System, Revision 42 was a performance 'deficiency. Specifically, the licensee failed to open MU 177, Make-Up Filter 1 Outlet Isolation, as required by Step 4.9.16.j. The performance deficiency was more than minor because it was associated with the Barrier Integrity cornerstone attribute of RCS Equipment and Barrier Performance, and adversely affected the cornerstone objective of providing reasonable assurance that physical design barriers (reactor coolant system) protect the public from radionuclide releases caused by accidents or events. Specifically, the licensee's failure to open MU177 resulted in the letdown relief valve lifting diverting RCS to the reactor coolant drain tank. Using Inspection Manual Chapter (IMC) 0609, Attachment 4, "Initial Characterization of Findings/' and IMC 0609 Appendix A, "The Significance Determination Process for Findings at Power," issued June 19, 2012, the finding was screened against the Initiating Events and Barrier Integrity cornerstones. The inspectors answered "No" to all the screening questions associated with Initiating Events butwere*directed to the detailed risk evaluation section by

Exhibit 3, Barrier Integrity Screening Questions. The inspectors discussed the issue with* the Senior Reactor Analyst (SRA). The SRA determined the issue to be of very low safety significance (Green), due to the short timeframe and stability in plant parameters. This finding has a cross-cutting aspect of avoid complacency in the area of the human performance because the licensee failed to recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. Specifically, the licensee did not appropriately implement error reduction tools. [H.12] Enforcement Technical Specification 5.4.1.a, Procedures, states, in part, written procedures shall be established, implemented, and maintained covering the following activities: the applicable procedures recommended in Regulatory Guide 1.33, Revision 2, Appendix A, February 1978. Section 3.n of Regulatory Guide 1.33, Revision* 2,

• Appendix A, February 1978, states, in part, instructions for energizing, filling, venting, draining, startup, shutdown, and changing modes of operation should be prepared, as appropriate, for the following systems: chemical and volume control system (including letdown/purification system).

Step 4.9.16.j of DB-OP-06006, "Makeup and Purification System," Revision 42, stated, open MU177, makeup filter 1 outlet isolation.. Contrary to the above, on March 30, 2018, the ljcensee failed to implement a written procedure as recommended in Regulatory Guide 1.33. Specifically, the licensee failed to follow the letdown and purification system procedure which resulted in the isolation of letdown while swapping make-up filters. Because it was of very low safety significance and. had been entered into the licensee's corrective action program as CR-2018-03036, this violation is being treated as an NCV consistent with Seqtion 2.3.2 of the Enforcement Policy. (NCV 05000346/2018002-01: Failure to follow Makeup and Purification Procedure)

From: To:

Subject:

Date: Attachments: MiHs, Daniel Hanna.John Davis Besse BWST level instrument DRE Monday, June 25, 2018 11:43:00 AM LER 2016-008*01.pdf CR-2016-08419 Root cause Evaluation FINAL CARB.pdf PEN PB NRC Eyent Notification 52079,pdf Note to Requester: The attachments to this email record are non-resoonsive. Hi John, we talked last week about a need for a detailed risk evaluation for issues described in Davis Besse LER 2016-008. This LER describes the tech spec prohibited condition they were in for a total of 14 hours. We need to close the LER in the second quarter report and at issue is the fact that the licensee had two channels of the BWST level instruments inoperable and therefore the 2 SFAS channels tripped for 14+ hours. Having 2 out.of 4 channels tripped makes up the SFAS permissive allowing a manual ECCS suction swap over from BWST to containment emergency sump. The swap over is always manual and is procedurally driven. Tech specs drives them to a 6 hour shutdown LCO in this condition, but they violated the tech specs. The issue to be examined is that ECCS systems drawing suction from the BWST would potentially have failed if the swapover had been performed prematurely (not enough water in the emergency sump). I have tried to attach system description documents but they are too large to email. Therefore I put copies of the all documents here G:\\DRPIII\\Branch 4\\Davis Besse\\DB BWST LER A brief writeup of the event is below: On June 30, 2016 at 0829 ET, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation was declared inoperable and removed for service for scheduled maintenance. At this time Reactor Operators entered Technical Specification (TS) 3.3.5.a, which requires the affected channel be tripped. Later that day at 2344 ET, Channel 2 became inoperable due to a loss of power that was later found to be a failed power supply. At this time Operators should have entered TS 3.3.5.b which requires restoring at least one channel or putting the reactor into Mode 3 within 6 hours. At 0140 on July 1, 2016, Operators became aware that they should be. applying TS 3.3.5.b, but did not officially enter until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures. At this time, the ehannel 1 instrument was electrically and physically disconnected and incapable of performing its function. This remained the condition of the plant until 1325 when the decision to declare Channel operable could not be supported, and TS 3.3.5.b was reentered. At 1351, scheduled maintenance was completed on the Channel 1 instrument and it was placed back into service and TS 3.3.5.b was exited. The plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes.

From: To: Cc:

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Date: Attachments: Mills, Daniel cameron, Jamnes; Rutkowski, John Harvey, Jacquelyn DB findings Tuesday, July 03, 2018 5:44:00 PM Failure to Apply Technical Specificatjon for SFAS Instrumentation DRAFT.docx MU 177 Misoos;t;oning DRAFT,docx Attached are drafts for ~o violations to go into the second quarter report, we are still working to finish another related to the BWST LER and I will send that one separately. r

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Date: Mills, Dani~) Harvey. Jacquelyn Please fix this up. Tuesday, July 03, 2018 12:32:00 PM (Closed) LER 05000346/2016-008-01: Application of Technical Specifications for the Safety Features Actuation System Instrumentation On June 30, 2016 at 0829 EDT, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation was declared inoperable and removed for service for scheduled maintenance. At th.is time Reactor Operators entered Technical Specification (TS) 3.3.5.a, which requires the affected channel be tripped. Later that day at 2344, Channel 2 became inoperable due to a loss of power that was later found to be a failed power supply. At this time Operators should have entered TS 3.3.5.b which requires restoring at least one channel or putting the reactor into Mode 3 within 6 hours. At 0140 EDT on July 1, 2016, Operators became aware that they should be applying TS 3.3.5.b, but did not officially enter until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. This remained the condition of the plant until 1325 when the decision to declare Channel operable could not be supported, and TS 3.3.5.b was reentered. At 1351, scheduled maintenance was completed on the Channel 1 instrument and it was placed back into service and TS 3.3.5.b was exited. The plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes. The borated water storage tank (BWST) provides a safety-related, borated water suction source for various emergency core cooling systems (ECCS). These systems, in part, ensure the reactor core is adequately cooled during abnormal, transient, and accident conditions. The safety features actuation system (SFAS) actuates various ECCS equipment based on specified design parameters. The technical specifications, as defined in the plant's operating license, require four channels of BWST-level Instrumentation. Each channel generally consists of a level transmitter (physically attached to the BWST to determine actual level), control room indication (reactor operator display of level measured in feet), and a bistable trip unit (initiates an automatic trip signal when the BWST is nearly depleted and a specified level band is reached, or a trip signal can be manually initiated by

• a reactor operator). !fa trip signal is present in two or more channels, SFAS will actuate by enabling a permissive interlock feature that simply allows reactor operators to manually transfer the normal ECCS suction source from the BWST to the reactor containment emergency sump in accordance with plant procedures. When the BWST level Is nearly depleted, recirculation from the containment emergency sump to the reactor core allows for indefinite core cooling. A specified level band for the transfer is established to ensure enough water is available in the containment emergency sump for recirculation and for ECCS equipment protection. This event was risk significant because two of the four BWST level instruments were tripped, making up the ECCS suction transfer permissive logic and potentially allowing a premature ECCS suction transfer.

The inspectors identified a finding of TBD, and an associated Violation of TS 3.3.5 "SFAS Instrumentation," for the failure to comply with the limiting condition for operation (LCO) while two channels of the BWST level instrumentation were inoperable for a period of fourteen hours. The licensee entered this finding into their CAP, and performed a root

cause analysis as a result of the issue. The finding was determined to be more than minor. because it was associated with the Mitigating Systems attribute, and affected the

• cornerstone's objective of ensuring the availability, reliability, and capability of systems to respond to initiating events to prevent undesirable consequences. The finding potentially resulted in the loss of system safety function (i.e., ECCS due to low suction head). The inspectors determined the finding could be evaluated using the $DP in accordance with l!VIC 0609, "Significance Determination Process," Attachment 0609.04, "Phase 1-lnitial Screening and Characterization of Findings," for the Mitigating Systems cornerstone. The inspectors evaluated the finding using Appendix A, "The Significance Determination Process for Findings At-Power." The inspectors answered 'Yes' to Question A.2 in Exhibit 2 because the finding represented the inoperability of the ECCS suction swap permissive for fourteen hours, which was greater than the TS 3.~.5 allowed. outage time of 6 hours for this function. Therefore, a detailed risk evaluation was performed using IMC *0609, Appendix A.

This finding has a cross-cutting aspect of Conservative Bias in the area 6f the human performance because the licensee failed to use decision making-practices that emphasize prudent choices over those that are simply allowable. [H.14]

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Date: Attachments: Mills, Daniel Hanna.John RE: Davis Besse 13WST level instrument DRE Thursday, July OS, 2018 9:44:58 PM Failure to Apply Technical Specification fqr SFAS Instrumentation DRAFT.docx Hi John, attached is the draft writeup, it's listed as a NCV/NOV since I wasn't sure what the significance would come out as, though with the assumption that it will be green it will end up being an NCV. I really appreciate your help! From: Hanna, John Sent: Thursday, July 05, 2018 12:15 PM To: Mills, Daniel <Daniel.Mills@nrc.gov>

Subject:

Re: Davis Besse BWST level instrument DRE

Daniel, Can you. please send me your 4 part write-up on this issue? I will need that for the DRE.

Also just to update you... I have a preliminary number using a bounding approach and it's SE-

7. I am working on the write-up but not sure if I will get it done between now and when I go on leave (July 11-July 24). We'll have to see how it progresses because there are several other inspectors needing assistance for their second quarter reports as well.

Talk to you later... John From: Mills, Daniel Sent: Monday, June 25, 2018 11:44:29 AM To: Hanna, John

Subject:

Davis Besse BWST level instrument DRE Hi John, we talked last week about a need for a detailed risk evaluation for issues described in Davis Besse LER 2016-008. This LER describes the tech spec prohibited condition they were in for a total of 14 hours. We need to close the LER in the second quarter report and at issue is the fact that the licensee had two channels of the BWST level instruments inoperable and therefore the 2 SFAS channels tripped for 14+ hours. Having 2 out of 4 channels tripped makes up the Sf AS permissive allowing a manual ECCS suction swap over from BWST to containment emergency sump. The swap over is always manual and is procedurally *driven. Tech specs drives them to a 6 hour shutdown LCO in this condition, but they violated the tech specs. The issue to be examined is that ECCS systems drawing suction from the BWST would potentially have failed if the swapover had been performed prematurely (not enough water in the emergency sump). I have tried to attach system description documents but they are too large to email. Therefore I put copies of the all documents here G:\\DRPIII\\Branch 4\\Davis Besse\\DB BWST LER

A brief writeup of the event is below: On June 30, 2016 at 0829 ET, Channel 1 of the Borated Water $torage Tank (BWST) level instrumentation was declared inoperable and removed for service for scheduled maintenance. At this time Reactor Operators entered Technical Specification (TS) 3.3.5.a, which requires the affected channel be tripped. Later that day at 2344 ET, Channel 2 became inoperable due to a loss of power that was later.found to be a failed power supply. At this time Operators should have entered TS 3;3~5.b which requires restoring at least qne channel or putting the reactor into Mode 3 within 6 hours. At 0140 on July 1, 2016, Operators became aware that they should be applying TS 3.3.5.b, but did not officially enter until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures. At this time, the Channel 1 instrumentwas electrically and physically disconnected and incapable of performing its function. This remained the

• condition of the plant until 1325 when the decision to declare Channel operable could not be supported, and TS 3.3.5.b was reentered. At 1351, scheduled maintenance was completed on the Channel 1 instrument and it was placed back into service and TS 3.3.5.b was exited. The plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 1 minutes.

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Date: John Kozak. Laura Hanna.John RE: Davis Besse BWST level Instrument DRE Tuesday, July 10, 2018 10:46:00 AM I don't disagree that this is green. I do think it should screen to green in appendix A. I don't think the ECCS suction swap over function was lost, in fact the permissive was met. The LER describes the licensee's view that there is no change in GDF because there really is no impact to the operator reliability. I tend to agree with that. This issue highlights the difference between operability and PRA functionality. The instruments were inoperable but that doesn't translate in this case to any PRA function being lost. I realize you are in a bind, and I don't disagree with your approach. Laura From: Hanna, John Sent: Monday, July 09, 2018 2:51 PM To: Kozak, Laura <Laura.Kozak@nrc.gov>

Subject:

FW: Davis Besse BWST level instrument DRE

Laura, Here's the background info that supports the DRE that I left on your chair. Thanks for looking at it.

John From: Mills, Daniel Sent: Monday, June 25, 2018 11:44 AM To: Hanna, John <John.Hanna@nrc.gov>

Subject:

Davis Besse BWST level instrument DRE Hi John, we talked last week about a need for a detailed risk evaluation for issues described in Davis Besse LER 2016-008. This LER describes the tech spec prohibited condition they were in for a total of 14 hours. We need to close the LER in the second quarter report and at issue is the fact that the licensee had two channels of the BWST level instruments inoperable and therefore the 2 SFAS channels tripped for 14+ hours. Having 2 out of 4 channels tripped makes up the SFAS permissive allowing a manual ECCS suction swap over from BWST to containment emergency sump. The swap over is always manual and is procedurally driven. Tech specs drives them to a 6 hour shutdown LCO in this condition, but they violated the tech specs. The issue to be examined is that ECCS systems drawing suction from the BWST would potentially have failed if the swapover had

been performed prematurely (not enough water in the emergency sump). I have tried to attach system description do~uments but they are too large to email.. Therefore I put copies of the all documents here G:\\DRPUI\\Branch 4\\Davis Besse\\DB BWST LER A brief writeup of the event is below:

• On June 30, 2016 at 0829 ET,.Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation was declared inoperable and removed for service for scheduled maintenance. At this time Reactor Operators entered Technical Specification (TS) 3.3.5.a, which requires the affected channel be tripped. Later that day at 2344 ET, Channel 2
• became inoperable due to a loss of power that was later found to be a failed power supply.

At this time Operators should have entered TS 3.3.5.b which requires restoring at least one* channel or putting the reactor into Mode 3 within 6 hours. At 0140 on July 1, 2016, Operators became aware that they should be applying TS 3.3.5.b, but did not officially enter until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures. At this time, the Channel 1 instrument was electrically and physically disconnected and incapable of performing its function. This remained the condition ofthe plant until 1325 when the decision to declare Channel operable could not be supported, and TS 3.3.5.b was reentered. At 1351, scheduled maintenance was completed on the Channel 1 instrument and it Was placed back into service and TS 3.3.5.b was exited. The plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes.

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Date: Kozak. Laura Hanna.John RE: Davis Besse BWST level Instrument DRE Monday, July 09, 2018 3:44:48 PM I am confused about the PD and the screening. Is the PD that they did not shutdown the plant as required by TS? Was the level indication inaccurate such that operators would not have performed the suction transfer properly? I also see the word "potentially" below - it's not clear why this should screen as needing a DRE. What PRA function is being impacted here and how is it degraded? From: Hanna, John Sent: Monday, July 09, 2018 2:51 PM To: Kozak, Laura <Laura.Kozak@nrc.gov>

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FW: Davis Besse BWST level instrument DRE

Laura, Here's the background info that supports the DRE that I left on your chair. Thanks for looking at it.

John From: Mills, Daniel Sent: Monday, June 25, 2018 11:44 AM To: Hanna, John <John.Hanna@nrc.gov>

Subject:

Davis Besse BWST level instrument DRE Hi John, we talked last week about a* need for a detailed risk evaluation for issues . described in Davis Besse LER 2016-008. This LER describes the tech spec prohibited condition they were in for a total of 14 hours. We need to close the LER in the second quarter report and at issue is the fact that the licensee had two channels of the BWST level instruments inoperable and therefore the 2 SFAS channels tripped for 14+ hours. Having 2 out of 4 channels tripped makes up the SFAS permissive allowing a manual ECCS suction swap over from BWST to containment emergency sump. The swap over is always manual and is procedurally driven. Tech specs drives them to a 6 hour shutdown LCO in this

• condition, but they violated the tech specs. The issue to be examined is that ECCS systems drawing suction from the BWST would potentially have failed if the swapover had been performed prematurely (not enough water in the emergency sump). I have tried to attach system description documents but they are too large to email. Therefore I put copies of the all documents here G:\\DRPIII\\Branch 4\\Davis Besse\\DB BWST LER A brief writeup of the event is below:

On June 30, 2016 at 0829 ET, Channel 1 of the Borated Water Storage Tank (BWST) level instrumentation was declared inoperal:>le and removed for service for scheduled maintenance. At this time Reactor Operators entered Technical Specification (TS) 3.3.5.a, which requires the affected channel be tripped. Later that day at 2344 ET, Channel 2

became inoperable due to a loss of power that was later found to be a failed power supply. At this time Operators should have entered TS 3.3;5.b which requires restoring at least one channel or putting the reactor into Mode 3 within 6 hours. At 0140 on July 1, 2016, Operators became aware that they should be applying TS 3.3.5.b, but did not officially enter until 0245. At 0330, TS 3.3.5.b was exited with Channel 1 declared Operable due to compensatory measures. At this time, the Channel 1 instrument W9-S electrically and physically disconnected and incapable of performing its function. This remained the condition of the plant until 1325 when the decision to declare Channel operable could not be supported, andTS 3.3.5.b was reentered. At 1351, scheduled maintenance was completed on the Channel 1 instrument and it was placed back into service and TS 3.3.5.b was exited. The plant was therefore in a condition requiring a 6 hour shutdown for a total of 14 hours and 7 minutes.

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Date: Harvey. Jacquelyn Rutkowski, John; Mills, Daniel; Cameron, Jamnes RE: DB findings Thursday, July OS, 2018 7:59:00 AM We don't believe this will end up being greater than green; however, through the screening process we had to kick it out to John because the ECCS suction swap permissive was inoperable for greater than the allowed outage time. John knows this is going in the 2Q ~~ From: Rutkowski, John. Sent: Thursday, July 05, 2018 8:41 AM. To: Mills, Daniel <Daniel.Mills@nrc.gov>; Cameron, Jamnes <Jamnes.Cameron@nrc.gov> Cc: Harvey, Jacquelyn <jacquelyn.harvey@nrc.gov>

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RE: DB findings

Daniel, Jackie's looks fine. But is the BWST potentially greater-than green? Writeup has it as an NCV anq also an AV. If an AV violation we got some more work to do in getting it/the plan reviewed.

From: Mills, Daniel Sent: Tuesday, July 03, 2018 6:45 PM To: Cameron, Jamnes <Jamnes.Cameron@nrc.gov>; Rutkowski, John <John.Rutkowski@nrc.gov> Cc: Harvey, Jacquelyn <jacguelyn,harvey@nrc.gov>

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DB findings Attached are drafts for two violations to go into the second quarter report, we are still working to finish another related to the BWST LER and I will send that one separately.

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Date: Mills Daniel Rutkowski. John; cameron, Jamnes Harvey. Jacguelvo Re! DB findings Thursday, July OS, 2018 8:29:39 AM Hi Jack, it's almost certainly a green ncv, but was left in draft that way because John is currently working on the DRE. He knows it is a priority for the second quarter report. 0~: 05 July 2018 08:40, "Rutkowski, John" <John,Rutkowski@nrc.gov> wrote: Daniel; Jackie's looks fine. But is the BWST potentially greater-than green? Writeup has it as an NCV and also an AV. If an AV violation we got some more work to do in getting it/the plan reviewed.

• ----*--~------------------~-v-----------*-**--------*---~**----------

From: Mills, Daniel S~nt: Tuesday, July 03, 2018 6:45 PM To: Cameron, Jamnes <Jamnes.Cameron@nrc.gov>; Rutkowski, John <John.Rutkowski@nrc.gov> Cc: Harvey, Jacquelyn <jacquelyn.harvey@nrc.gov>

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DB findings Attached ~re drafts for two violations to go into the second quarter report, we are still working to finish another related to the BWST LER and I w!II send that one separately. J

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Date: Hi John, Harvey. Jacquelyn Hanna.John Mills. Daniel RE: Screening Question for Davis Besse Issue Tuesday, July 03, 2018 6:33:51 AM I actually do not believe this issues needs your review. Per our guidance, any issue pertaining to a possible RCS leak is assessed under Initiating Events, which I am answering 'no' to all questions. Thank you anyways and let me know if you have any questions. -Jackie From: Hanna, John S~nt: Thursday, June 28, 2018 12:55 PM To: Harvey, Jacquelyn <jacquelyn.harvey@nrc.gov>

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RE: Screening Question for Davis Besse Issue Hi Jackie, I'm currently at TIC, so let me review the screening questions, think about the issue and I'll get back to you. Just so you know when to expect an answer... it will likely be sometime next week when I get back to you. Talk to you later... John From: Harvey, Jacquelyn Sent: Thursday, June 28, 2018 8:49 AM To: Hanna, John <John.Hanna@nrc.gov> Cc; Mills, Daniel <Daniel.Mills@orc.gov>

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Screening Question for Davis Besse Issue Hi John, I have a screening question for you. Background - about 2 months ago the licensee inadvertently isolated letdown for approximately 15 seconds such that RCS was redirected through a pressure relief valve to a tank. We are currently moving forward with a PD (failure to follow procedure) with a MTM of related to the RCS equipment and barrier performance and adversely affected the Barrier Integrity cornerstone objective. When I go through the screening questions, the barrier integrity RCS question has me immediately go to a detailed risk evaluation. I don't believe a full_ risk evaluation is nece_ssary due to the very short nature of the 'leak' and the fact the licensee did not see

any changes associated with RCS. What are your thoughts on this? And then what language would be best for the write up? I'll be in next week. Welcome back and I hope you had a nice time off!

Thanks, Jackie}}