dear mr. welsch

October 30, 2020 Mr. James M. Welsch Senior Vice President, Generation and Chief Nuclear Officer Pacific Gas and Electric Company P.O. Box 56 Mail Code 104/6 Avila Beach, CA 93424 SUBJECT: DIABLO CANYON POWER PLANT, UNITS 1 AND 2 – BIENNIAL

PROBLEM IDENTIFICATION AND RESOLUTION INSPECTION REPORT 05000275/2020010 AND 05000323/2020010

Dear Mr. Welsch: On September 4, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed a problem identification and resolution inspection at your Diablo Canyon Power Plant, Units 1 and 2. On August 20, 2020, the NRC inspectors discussed the results of this inspection with you and other members of your staff. On October 1, 2020, based on new data supplied by your staff, the NRC inspectors held a re-exit to discuss changes to the original results of this inspection with Ms. Paula Gerfen, Site Vice President, and other members of your staff. These results are documented in the enclosed report. The NRC inspection team reviewed the station’s corrective action program and the station’s implementation of the program to evaluate its effectiveness in identifying, prioritizing, evaluating, and correcting problems, and to confirm that the station was complying with NRC regulations and licensee standards for corrective action programs. Based on the samples reviewed, the team determined that your staff’s performance in each of these areas adequately supported nuclear safety. The team also evaluated the station’s processes for use of industry and NRC operating experience information and the effectiveness of the station’s audits and self-assessments. Based on the samples reviewed, the team determined that your staff’s performance in each of these areas adequately supported nuclear safety. Finally, the team reviewed the station’s programs to establish and maintain a safety-conscious work environment, and interviewed station personnel to evaluate the effectiveness of these programs. Based on the team’s observations and the results of these interviews, the team found no evidence of challenges to your organization’s safety-conscious work environment. Your employees appeared willing to raise nuclear safety concerns through at least one of the several means available. No findings or violations of more than minor significance were identified during this inspection.

J. Welsch 2

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, “Light-Water Reactor Inspection Program - Operations Phase.” The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards. Starting on March 20, 2020, in response to the National Emergency declared by the President of the United States on the public health risks of the coronavirus (COVID-19), inspectors were directed to begin telework. In addition, regional baseline inspections were evaluated to determine if all or portion of the objectives and requirements stated in the IP could be performed remotely. If the inspections could be performed remotely, they were conducted per the applicable IP. In some cases, portions of an IP were completed remotely and on site. The inspections documented below met the objectives and requirements for completion of the IP. This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, “Public Inspections, Exemptions, Requests for Withholding.”

Sincerely, Ami N. Agrawal, Inspection Programs and Assessment Team Lead Inspection Programs and Assessment Team Division of Reactor Safety

Docket Nos. 05000275 and 05000323 License Nos. DPR-80 and DPR-82 Enclosure: As stated cc w/ encl: Distribution via LISTSERV®

http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html


J. Welsch 3

DIABLO CANYON POWER PLANT, UNITS 1 AND 2 – BIENNIAL PROBLEM IDENTIFICATION AND RESOLUTION INSPECTION REPORT 05000275/2020010 AND 05000323/2020010 – October 30, 2020 DISTRIBUTION: SMorris, RA AVegel, DRP MHay, DRP RLantz, DRS GMiller, DRS DCylkowski, RC RSkokowski, RIV/OEDO VDricks, ORA LWilkins, OCA SLee, NRR AMoreno, RIV/OCA BMaier, RSLO AAgrawal, IPAT JJosey, DRP JReynoso, DRP NCuevo, DRP HFreeman, DRP DKrause, DRP AAthar, DRP MArel, DRP RGrover, IPAT LFlores, IPAT BCorrell, IPAT R4Enforcement

ADAMS ACCESSION NUMBER: ML20283A774

█ SUNSI Review

█ Non-Sensitive

Sensitive

█ Publicly Available

Non-Publicly Available

OFFICE SRI:DRS/IPAT EPI:DRS/RCB SRI:DRS/EB2 RI:DRP/PBA TL:DRS/IPAT

NAME RAzua SHedger JDrake AAthar AAgrawal

DATE 10/01/2020 10/08/2020 10/01/2020 10/01/2020 10/30/2020

OFFICIAL RECORD COPY

Enclosure

U.S. NUCLEAR REGULATORY COMMISSION Inspection Report

Docket Numbers: 05000275 and 05000323 License Numbers: DPR-80 and DPR-82 Report Numbers: 05000275/2020010 and 05000323/2020010 Enterprise Identifier: I-2020-010-0003 Licensee: Pacific Gas and Electric Company Facility: Diablo Canyon Power Plant, Units 1 and 2 Location: Avila Beach, CA Inspection Dates: July 19, 2020 to August 29, 2020 Inspectors: A. Athar, Resident Inspector R. Azua, Senior Reactor Inspector J. Drake, Senior Reactor Inspector S. Hedger, Emergency Preparedness Inspector Approved By: Ami N. Agrawal, Inspection Programs and

Assessment Team Leader Inspection Programs and Assessment Team Division of Reactor Safety

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SUMMARY The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensee’s performance by conducting a biennial problem identification and resolution inspection at Diablo Canyon Power Plant, Units 1 and 2, 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.

List of Findings and Violations No findings or violations of more than minor significance were identified.

Additional Tracking Items None.

https://www.nrc.gov/reactors/operating/oversight.html

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INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, “Light-Water Reactor Inspection Program - Operations Phase.” The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards. OTHER ACTIVITIES – BASELINE 71152B - Problem Identification and Resolution Biennial Team Inspection (IP Section 02.04) (1 Sample)

(1) The inspectors performed a biennial assessment of the licensee’s corrective action

program, use of operating experience, self-assessments and audits, and safety conscious work environment.

• Corrective Action Program Effectiveness: The inspectors assessed the corrective action program’s effectiveness in identifying, prioritizing, evaluating, and correcting problems. The inspectors also conducted a five-year review of the plant's ventilation systems.

• Operating Experience, Self-Assessments and Audits: The inspectors

assessed the effectiveness of the station’s processes for use of operating experience, audits and self-assessments.

• Safety Conscious Work Environment: The inspectors assessed the

effectiveness of the station’s programs to establish and maintain a safety-conscious work environment.

INSPECTION RESULTS

Assessment 71152B Effectiveness of Problem Identification: Based on the samples reviewed, the team determined that the licensee's performance in this area adequately supported nuclear safety. Overall, the team found that the licensee was identifying and documenting problems at an appropriately low threshold that supported nuclear safety. Effectiveness of Prioritization and Evaluation of Issues: Overall, the team found that the licensee was appropriately prioritizing and evaluating issues to support nuclear safety. Of the samples reviewed, the team found that the licensee correctly characterized each notification as to whether it represented a condition adverse to quality, and then prioritized the evaluation and corrective actions in accordance with program guidance. However, the team identified some examples where the licensee’s evaluations were narrowly focused, resulting in an



4

assessment that may not have addressed all salient factors. Some examples of this were related to a number of procedural compliance errors in the operations department which ultimately resulted in an identified trend in this area and when addressing a simulator fidelity issue between Units 1 and 2. Effectiveness of Corrective Actions: Overall, the team concluded that the licensee's corrective actions supported nuclear safety. Specifically, the Diablo Canyon power plant, developed effective corrective actions for the problems evaluated in the corrective action program and generally implemented these corrective actions in a timely manner commensurate with their safety significance.

• As part of this inspection, the team selected the plant ventilation systems for a focused review within the corrective action program. For these systems, the team performed sample selections of notifications, looking at the adequacy of the licensee's evaluation process for determining which items are placed in the corrective actions process and the corrective actions taken. The team also reviewed the licensee's use of operational experience and the Part 21 process’ with respect to this system. As a result of the off-site nature of this inspection, due to COVID-19 restrictions at the time of the inspection, the team was not able to walk down portions of these systems. However, the team did not identify any concerns with this system.

Corrective Action Program Assessment: Based on the samples reviewed, the team determined the licensee's corrective action program complied with regulatory requirements and self-imposed standards, and the licensee's implementation of the corrective action program adequately supported nuclear safety. The team found that management's oversight of the corrective action program process was effective.

Assessment 71152B Operating Experience: The team reviewed a variety of sources of operating experience, including Part 21 notifications and other vendor correspondence, NRC generic communications, and publications from various industry groups, including Institute of Nuclear Power Operations (INPO) and Electric Power Research Institute (EPRI). The team determined that the Diablo Canyon plant is adequately screening and addressing issues identified through operational experience that apply to the station and that this information is evaluated in a timely manner once it is received. Self-Assessments and Audit Assessment: The team reviewed a sample of the licensee's departmental self-assessments and audits to assess whether they regularly identified performance trends and effectively addressed them. The team also reviewed audit reports to assess the effectiveness of assessments in specific areas. Overall, the team concluded that the licensee had an adequate departmental self-assessment and audit process. However, examples were identified where the licensee did not take the findings to heart. Corrective actions in some of these audits and self-assessments were vague and/or narrowly focused, losing the benefit of these audits.

Assessment 71152B Safety-Conscious Work Environment: The team interviewed 10 individuals. The purpose of these interviews was (1) to evaluate the willingness of the licensee staff to raise nuclear safety issues, either by initiating a notification or by another method, (2) to evaluate the perceived effectiveness of the corrective action program at resolving identified problems, and

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(3) to evaluate the licensee's safety-conscious work environment (SCWE). The focus group participants were from the Security organization. Due to the challenges brought on by the COVID-19 pandemic and the Diablo Canyon's plant performance in this area prior to this inspection, the NRC chose to limit the number of personnel interviewed. Overall, the Diablo Canyon Plant has an adequate Safety-Conscious Work Environment. Willingness to Raise Nuclear Safety Issues: In the assessed focus group, the team found no evidence of challenges to SCWE. Individuals in this group expressed a willingness to raise nuclear safety concerns and other issues through at least one of the several means available. Overall, the team concluded that the Diablo Canyon Plant maintained a healthy SCWE. Employee Concerns Program: The team looked at the Diablo Canyon's Employee Concerns Program. The team interviewed the Employee Concerns Program manager and discussed her cases. The team reviewed the Employee Concerns Program’s investigative packages. Overall, the team did not identify any concerns with the program.

EXIT MEETINGS AND DEBRIEFS The inspectors verified no proprietary information was retained or documented in this report.

• On August 20, 2020, the inspectors presented the biennial problem identification and resolution inspection results to James Welsch, Senior Vice President, Generation and Chief Nuclear Officer, and other members of the licensee staff.

• On October 1, 2020, the inspectors presented the re-exit inspection results to Ms. Paula Gerfen, Site Vice President, and other members of the licensee staff.

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DOCUMENTS REVIEWED Inspection Procedure

Type Designation Description or Title Revision or Date

71152B Corrective Action Documents

Notification 50478716, 50480542, 50480775, 50585126, 50642112, 50850721, 50911010, 50926221, 50951980, 50957978, 50960312, 50960875, 50962229, 50964853, 50965495, 50975468, 50949422, 50975510, 50978256, 50979167, 50979311, 50980641, 50980670, 50980823, 50981060, 50981467, 50981833, 50982064, 50982066, 50982069, 50982167, 50982168, 50982169, 50982210, 50983576, 50983758, 50985728, 50987461, 50988442, 50991907, 50997430, 50998154, 51000341, 51002238, 51004599, 51004942, 51005943, 51006288, 51006788, 51007011, 51008138, 51008270, 51010444, 51016637, 51017606, 51017693, 51018577, 51020536, 51020565, 51020728, 51021460, 51022176, 51022281, 51023742, 51025262, 51027645, 51029491, 51029492, 51029493, 51029494, 51029499, 50133066, 51033547, 51033724, 51034354, 51034357, 51034647, 51034648, 51034799, 51034885, 51035004, 51036021, 51036715, 51038698, 51036900, 51037687, 51038978, 51039295, 51040102, 51040302, 51041602, 51042748, 51044746, 51046372, 51046986, 51047276, 51047439, 51047461, 51047463, 51047545, 51047741, 51047765, 51047935, 51048407, 51048414, 51048465, 51048569, 51048651, 51048776, 51049096, 51049099, 51049130, 51049999, 51050291, 51050412, 51050561, 51050862, 51054057, 51054343, 51054427, 51054462, 51055054, 51055674, 51056268, 51056522, 51057094, 51057203, 51057622, 51058572, 51058978, 51058992, 51061519, 51061598, 51062145, 51062854, 51062855, 51063455, 51064289, 51064724, 51067078, 51067161, 51067175, 51068576, 51069969, 51070023, 51070025, 51070026, 51071562, 51074480, 51076185, 51076248, 51076517, 51076518, 51077098, 51077782, 51078474, 51081503, 51081531, 51081631, 51081661,

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Inspection Procedure


51082130, 51082488, 51084268, 51084810, 51085392, 51085664, 51085668, 51091298

Miscellaneous

Diablo Canyon Simulator Post Event Simulator Test (PEST) Full Load Rejection and OTDT Reactor Trip on Unit 2; SAPN: 51006288; Simulator Change Request (SCR): 2018-154

Diablo Canyon 500kV Special Protection Scheme 04/30/2008 Unit 2 Control room Logs from 7/28-30/2017

# 2020-IA-05 Pacific Gas & Electric Company, Diablo Canyon Nuclear Power Plant, 2020 Procurement Audit

4/16/2020

2006-004 Diablo Canyon Special Protection Scheme (DCSPS) Operations Handbook

03/14/2006

50980823 Clearance Events Action Plan 5/8/2018 ANSI/ANS 3.5 Nuclear Power Plant Simulators for Use in Operator Training

and Examination 2009

DCL-15-023 LAR 15-01

License Amendment Request 15-01, Incorporation into Licensing Basis of Pressurizer Filling Analysis for Major Rupture of a Main Feedwater Pipe Accident

02/25/2015

DCL-20-005 Docket No. 50-323, OL-DPR-82; Diablo Canyon Power Plant, Unit 2; Unit 2 Licensee Event Report 2019-001-00, Containment Spray Inoperable in Mode 4

1/29/2020

DCL-98-109 License Amendment Request 98-05

Revision of Technical Specifications 3/4.3.2, Engineered Safety Features Actuation System Instrumentation, and Technical Specification 3/4.7.1.7, Main Feedwater Regulating, Bypass and Isolation Valves

08/10/1998

DCM S-3C Main Feedwater System and Steam Dump Control System 17 DCM S-4 Turbine Steam Supply System 36 FileNet # 180360003

Pacific Gas & Electric Company, Diablo Canyon Nuclear Power Plant, 2018 Procurement Audit

4/30/2018

FileNet # 180940011

Pacific Gas & Electric Company, Diablo Canyon Nuclear Power Plant, 2018 Operations and Technical Specifications Audit

6/26/2018

FileNet # 181550006

Pacific Gas & Electric Company, Diablo Canyon Nuclear Power Plant, 2018 Training and Qualifications Audit

9/17/2018

FileNet # Pacific Gas & Electric Company, Diablo Canyon Nuclear 10/1/2019

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191330004 Power Plant, 2019 Problem Prevention and Corrective Action Program Audit

IERL2-13-53 INPO Loss of Off-Site Power LOOP Analysis 0 IIERL4-11-45 INPO Industry Lessons in Achieving Transformer Switchyard

and Grid Excellence 0

INPO 04-004 INPO 04-004 Data Element Manual 17 INPO 04-004 Data Element Manual 18 INPO 09-008 INPO Achieving Excellence in Transformer Switchyard and

Grid Reliability 0

INPO 18-001 Leveraging Operating Experience, Learning from the Most Relevant Legacy IERs and SOER

08/2018

INPO 19-002 Industry Reporting and Information System 07/2019 INPO 19-002 Industry Reporting and Information System 12/2019 Lesson Number: LC-2B

Lesson: Steam Dump System 15

RCE 50652094 Unit 2 EDG 2-2 Broken/ EDG 2-3 Cracked Capscrews 2 RCE 50870357 Undetected ECCS Interlock Failure 3 RCE 50934855 Response to Nitrogen Leak 0.D RCE 51006788 Unit 2 Reactor Trip_ DC-SPS 2 RCE 51026389 Degradation of MFP 1-1 Oil System 3b SAPN 50957978 Diablo Canyon 2018 Mid Cycle Assessment, September 4-

20, 2018 11/8/2018

SAPN 51006788 Diablo Canyon Power Plant Root Cause Evaluation Report, Unit 2 Reactor Trip; DC-SPS

2

Simulator Change Request (SCR)

2018-080, 2018-081, 2018-095, 2018-123, 2018-146, 2018-154, 2020-044

T36714 MFWP Trip Reliability Commitments 04/21/2011 WCAP-16638-P Diablo Canyon Units 1 and 2 Replacement Steam Generator

Program NSSS Licensing Report 1

WEC CN-TA-11-56

Feedline Break Analysis with Operator Actions for PORV Cycling

12/14/2014

Procedures AD7.ID2 Daily Notification Review Team (DRT) and Standard Plant Priority Assignment Scheme

22, 23, 24, 35

AD7ID15 On-Line Maintenance Outage Window Execution 04, 6

9



AD7ID2 Daily Notification Review Team & Standard Plant Priority Assignment Scheme

35

AD7IDC8u3 Work Planning 53 AD8ID3 Outage Execution 09, 11 AR PK11-17 Diablo Canyon Power Plant Annunciator Response, "SG

Blow Down Hi Rad" 10

CAP A-8 Off-Site Dose Calculations 39 CF2.DC1 Configuration Management Plan for the Operator Training

Simulator 12

CF5.ID2 Control of Material in Storage 15 CY2.ID1 Radioactive Effluents Control Program 15 D-12 Watch Bill And OCC (Outage Control Center) Guidance For

Curtailments And Forced Outages 2

MA1.ID17 Maintenance Rule Monitoring Program 30 MA1IDC62u3 Welding Program 0 MA3IDC1u3 Weld Planning and Inspection 12 MP E-42.POL.1 Prepare Polar Crane for Operation and Install Variable

Frequency Drives (VFD) 8

MP M-51.11 Contromatic Pneumatic Spring Return Actuator Maintenance 12, 13 OM10.ID6 EAL Equipment and Compensatory Measures 7 OM15.ID10 Performance Monitoring Program 3 OM4 Nuclear Oversight Program 7B OM4.ID13 Nuclear Generation Internal Auditing 30 OM4.ID14 Notification Review Team (NRT) 31, 32, 33 OM4.ID15 Corrective Action Review Boards (CARB) 28 OM5 Quality Assurance Program 13 OM7 Corrective Action Program 7A OM7.DC3 Engineering Decision Making 1 OM7.ID1 Problem Identification and Resolution 51, 52, 53,

54, 55 OM7.ID11 10 CFR 21 Reporting Review Process 4 OM7.ID12 Operability Determination 41 OM7.ID12 Operability Determination 37

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OM7.ID13 Technical Evaluations 7 OM7.ID3 Root Cause Evaluation 49 OM7.ID4 Cause Evaluations 39 OM7.ID6 Supplier Quality Programs 3 OM7.ID7 Emerging Issue and Event Investigation 19 OM8IID1u3 Fire Loss Prevention 30 OP B-8DS3 Insert Shuffle Within the Spent Fuel Pool 27 OP B-8H Spent Fuel Pool Work Instructions 40, 41, 53 OP C-8:III Shutdown and Clearing of a Main Feedwater Pump 29, 30, 31,

32 OP K-11:I Operating the Nitrogen Supply System 28, 29, 30 OP K-20 Miscellaneous Auxiliary Control Board Alarm Response 1, 2 OP L-3 Secondary Plant Startup 53A, 53B OP_J-4A_IIIu1 Generator Stator Cooling Water - Shutdown and Draining 19 OP_J-4A_IIIu2 Generator Stator Cooling Water - Shutdown and Draining 13 OP1.DC10 Conduct of Operations 44A, 57 OP1.DC3 Operator Routine Plant Equipment Inspections 14 OP1.ID2 Timed Critical/Sensitive Operator Action 12 OP1.ID2 Time Critical/Sensitive Operator Action 13 OP1DC10 Conduct of Operations 53, 54, 55,

56, 57, 58, 59, 60, 61

OP1DC40 Operations Equipment Deficiency and Adverse Condition Monitoring

10

OPC3BIIIu1 Lube Oil Distribution System - Shutdown and Clearing 23, 24 OPC3BIu1 Lube Oil Distribution - Make Available and Place In Service 35, 37 OPC8IIIu1 Shutdown and Clearing of a Main Feedwater Pump 29, 32 PEP V-7B Test Of ECCS Valve Interlocks 6, 7, 8, 12 STP M-16A Slave Relay Test of Trains A and B K603 (Safety Injection) 30 STP M-16BA Slave Relay Test of Trains A and B K604 (Safety Injection) 15, 16 STP M-16BB Slave Relay Test Train B K604 (Safety Injection) 16, 17 STP M-16C Operation of Train A Slave Relay K608 (Safety Injection) 36, 42 STP M-16D Operation of Train B Slave Relay K608 (Safety Injection) 38, 39, 40,

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Type Designation Description or Title Revision or Date 41, 43

STP M-16T Slave Relay Test Of K615A/B, K612A, And K614B (Safety Injection And Phase A Isolation)

6

STP V-2D2B Exercising and Position Verification of Valve 8700B 0, 2 STP V-3M4B Exercising RHR Pump 2 Suction Valve 8700B 2A TQ1.DC28 Simulator Testing 5

Self-Assessments 180710010 2018 Quality Assurance Program Audit 05/07/2018 81550006 2018 Training and Qualifications Audit 09/17/2018

Work Orders Orders 68058344, 68058345