IR 05000482/2020002

Integrated Inspection Report 05000482/2020002 and Independent Spent Fuel Storage Installation Inspection Report 07200079/2020001

ML20224A354
Person / Time
Site:	Peach Bottom, Wolf Creek
Issue date:	08/12/2020
From:	O'Keefe N NRC/RGN-IV/DRP/RPB-B
To:	Reasoner C Wolf Creek
References
EA 20-0089 IR 2020001, IR 2020002
Download: ML20224A354 (31)

Text

August 12, 2020

SUBJECT:

WOLF CREEK GENERATING STATION - INTEGRATED INSPECTION REPORT 05000482/2020002 AND INDEPENDENT SPENT FUEL STORAGE INSTALLATION INSPECTION REPORT 07200079/2020001

Dear Mr. Reasoner:

On June 30, 2020, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Wolf Creek Generating Station. On July 14, 2020, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.

Two findings of very low safety significance (Green) are documented in this report. Both of these findings involved violations of NRC requirements. We are treating these violations as non-cited violations (NCVs) consistent with Section 2.3.2 of the Enforcement Policy.

A licensee-identified violation that was determined to be Severity Level IV is documented in this report. We are treating this violation as an NCV consistent with Section 2.3.2 of the Enforcement Policy.

If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN:

Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; the Director, Office of Enforcement; and the NRC Resident Inspector at Wolf Creek Generating Station.

If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region IV; and the NRC Resident Inspector at Wolf Creek Generating Station. III 2 In the 2017 and 2018 Annual Assessment Letters for Wolf Creek Generating Station (Reports 05000482/2017006, Agencywide Documents Access and Management System (ADAMS) ML18052A345 and 05000482/2018006, ADAMS ML19058A195, respectively), the NRC identified a cross-cutting theme in the safety conscious work environment area. No additional inputs to the theme have been identified in the last 18 months.

Therefore, there is no longer a cross-cutting theme in the safety conscious work environment area.

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,

/RA/

Neil F. O'Keefe, Chief Reactor Projects Branch B Division of Reactor Projects Docket Nos. 05000482 and 07200079 License No. NPF-42

Enclosure:

As stated

Inspection Report

Docket Numbers: 05000482 and 07200079 License Number: NPF-42 Report Numbers: 05000482/2020002 and 07200079/2020001 Enterprise Identifiers: I-2020-002-0008, L-2020-LLD-0000, and I-2020-001-0130 Licensee: Wolf Creek Nuclear Operating Corporation Facility: Wolf Creek Generating Station and Independent Spent Fuel Storage Installation Location: Burlington, KS 66839 Inspection Dates: April 1, 2020, to June 30, 2020 Inspectors: D. Dodson, Senior Resident Inspector J. Vera, Resident Inspector R. Alexander, Senior Emergency Preparedness Inspector L. Brookhart, Senior Spent Fuel Storage Inspector D. Proulx, Senior Project Engineer C. Smith, Health Physicist Approved By: Neil F. O'Keefe, Chief Reactor Projects Branch B Division of Reactor Projects Enclosure

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection and an independent spent fuel storage installation inspection at Wolf Creek Generating Station, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information. A licensee-identified non-cited violation is documented in report section 7115

List of Findings and Violations

Operations Supervision Failed to Control and Direct Activities of All Members of the Operating Staff Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.2] - Field 71111.12 Systems NCV 05000482/2020002-01 Presence Open/Closed The NRC inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for the licensees failure to implement procedure use and adherence requirements. Specifically, senior reactor operators failed to adequately control and direct the activities of all members of the operating staff to assure coordination of safety-related activities when a Class 1E air conditioning unit was identified as inoperable. The uncoordinated actions of non-licensed operators rendered safety-related batteries in both trains inoperable, a condition prohibited by technical specifications, while attempting to implement mitigating actions to restore cooling to the affected train.

Failure to Properly Pre-Plan Maintenance Associated with Containment Purge Isolation Valves Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.14] - 71152 NCV 05000482/2020002-02 Conservative Open/Closed Bias A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a was identified when the licensee failed to properly preplan and perform maintenance that can affect the performance of safety-related equipment. Specifically, the station failed to include in work instructions appropriate vendor manual guidance for establishing proper 36-inch containment purge isolation valve seat leak tightness and performing subsequent checks to verify sealing, which led to both 36-inch containment purge isolation valves exceeding their allowed leakage values and an unplanned plant shutdown to correct excessive leakage.

Additional Tracking Items

Type Issue Number Title Report Section Status URI 05000482/2020002-03 Train B Emergency Diesel 71153 Open Generator Supply Fan Motor Failure (EA-20-0089)

LER 05000482/2017-003-00 [Atmospheric Relief Valve] 71153 Closed and [Main Steam Safety Valve] Tornado Missile Vulnerabilities Result in Unanalyzed Condition LER 05000482/2020-001-00 Plant Shutdown Due to 71153 Closed Inoperable Containment Purge Isolation Valves

PLANT STATUS

Wolf Creek Generating Station began the inspection period at rated thermal power. On May 26, 2020, power was reduced to 62 percent at the request of the transmission system operator due to a loss of the Waverly/LaCygne 345 kV offsite power line to the switchyard. The unit was returned to rated thermal power later on May 26, 2020, and remained at or near rated thermal power for the remainder of the inspection period.

INSPECTION SCOPES

Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors 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), resident inspectors were directed to begin telework and to remotely access licensee information using available technology. During this time, the resident inspectors performed periodic site visits each week, and during that time conducted plant status activities, as described in IMC 2515, Appendix D; observed risk-significant activities, and completed on site portions of IPs. In addition, resident and 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 onsite. The inspections documented below met the objectives and requirements for completion of the IP.

71111.01 - Adverse Weather Protection

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

(1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal hot temperatures for the following systems and areas:

• offsite alternating current (AC) power systems

• onsite alternate AC power systems

• emergency core cooling pump rooms

• essential service water vertical loop pipe chase

71111.04 - Equipment Alignment

Partial Walkdown Sample (IP Section 03.01) (3 Samples)

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

(1) Turbine-driven auxiliary feedwater on May 22, 2020

(2) Component cooling water train B on June 1, 2020

(3) Containment spray train B on June 15, 2020

Complete Walkdown Sample (IP Section 03.02) (1 Sample)

(1) The inspectors evaluated system configurations during a complete walkdown of emergency diesel generator systems from June 16 through June 30, 2020.

71111.05 - Fire Protection

Fire Area Walkdown and Inspection Sample (IP Section 03.01) (8 Samples)

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

(1) Control building, elevation 2,000 feet, fire area C-9, on April 2, 2020

(2) Auxiliary building, elevation 2,047 feet, fire areas A-21 and A-22, on April 7, 2020

(3) Control building, elevation 1,974 feet, fire area C-1, on April 10, 2020

(4) Control building, elevation 2,016 feet, fire area C-35, on April 17, 2020

(5) Control building, elevation 2,032 feet, fire area C-21, on April 29, 2020

(6) Auxiliary building, all elevations, fire area A-6, on May 5, 2020

(7) Control building, elevation 1,984 feet, fire area C-5, on May 7, 2020

(8) Control building, elevation 1,984 feet, fire area C-6, on May 7, 2020

71111.06 - Flood Protection Measures

Inspection Activities - Internal Flooding (IP Section 03.01) (2 Samples)

The inspectors evaluated internal flooding mitigation protections in the:

(1) Auxiliary building, elevation 2,000 feet, south pipe penetration room on May 8, 2020

(2) Auxiliary Building, elevation 1,974 feet, main corridor from May 30-June 15, 2020

71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance

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

(1 Sample)

(1) The inspectors observed and evaluated licensed operator performance in the control room during a train A containment spray pump test and steam generator blowdown system operations on May 14, 2020.

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

(1) The inspectors observed and evaluated licensed operator simulator requalification and training activities that included instrument and equipment malfunctions, a failure to trip the reactor by use of a manual hand switch, and a main steam line break on May 12, 2020.

71111.12 - Maintenance Effectiveness

Maintenance Effectiveness (IP Section 03.01) (2 Samples)

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

(1) Class 1E electrical equipment air conditioning unit SGK05A fan trip on October 30, 2019

(2) Class 1E electrical equipment air conditioning unit SGK05B refrigerant leak on April 10, 2020

71111.13 - Maintenance Risk Assessments and Emergent Work Control

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

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

(1) Unplanned power reduction to approximately 62 percent power due to the loss of the Waverly/LaCygne 345 kV offsite feed to the switchyard and extended turbine-driven auxiliary feedwater out-of-service time for governor position testing and overspeed trip indication troubleshooting during the week of May 25, 2020

(2) Planned weekly risk assessment for work week 0213, June 22-28, 2020

(3) Unplanned inoperability of the train B emergency diesel generator following discovery of a tripped supply fan breaker on June 25, 2020

(4) Unplanned rigging, lifting, and installation of the train B emergency diesel generator cooling fan motor on June 27, 2020

71111.15 - Operability Determinations and Functionality Assessments

Operability Determination or Functionality Assessment (IP Section 03.01) (2 Samples)

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

(1) Spray additive tank to train B containment spray isolation valve (ENHV0016)overthrust condition identified as not evaluated on April 21, 2020

(2) Class 1E inverter (NN012) indicating light relays not holding contact on May 1, 2020

71111.18 - Plant Modifications

Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)

(1 Sample)

The inspectors evaluated the following permanent modification:

(1) Change Package 12513, "[Engineered Safety Feature] XNB02 Transformer Replacement"

71111.19 - Post-Maintenance Testing

Post-Maintenance Test Sample (IP Section 03.01) (3 Samples)

The inspectors evaluated the following post maintenance test activities to verify system operability and functionality:

(1) Emergency diesel generator train A following planned maintenance on May 19, 2020

(2) Containment spray pump train B room cooler following planned maintenance on June 10, 2020

(3) Emergency diesel generator train B supply fan motor following unplanned maintenance on June 29, 2020

71111.22 - Surveillance Testing

The inspectors evaluated the following surveillance tests:

Surveillance Tests (other) (IP Section 03.01)

(1) STS IC-208B, "4KV Loss Of Voltage & Degraded Voltage [Testing Actuation Device Operational Testing] NB02 BUS - Separation Group 4," on April 27, 2020

(2) STS IC-260, "Channel Operational Test Auxiliary Feedwater Pump Suction Pressure Low Transfer to [Essential Service Water]," on April 27, 2020

FLEX Testing (IP Section 03.02) (1 Sample)

(1) SYS FP-290, "Temporary Diesel Fire Pump Operations," on June 23, 2020

71114.04 - Emergency Action Level and Emergency Plan Changes

Inspection Review (IP Section 02.01-02.03) (1 Sample)

(1) The inspectors evaluated the following risk-significant, emergency plan implementing procedure change, which was submitted to the NRC within 30 days of implementation in accordance with 10 CFR 50.54(q)(5) and 10 CFR 50.4:

• EPP 06-012, Dose Assessment, Revision 17 This evaluation does not constitute NRC approval.

OTHER ACTIVITIES - BASELINE

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

MS07: High Pressure Injection Systems (IP Section 02.06) ===

(1) July 1, 2019-June 30, 2020

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

(1) July 1, 2019-June 30, 2020 BI01: Reactor Coolant System (RCS) Specific Activity Sample (IP Section 02.10) (1 Sample)

(1) July 1, 2019-June 30, 2020

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

(1) July 1, 2019-June 30, 2020

71152 - Problem Identification and Resolution

Semiannual Trend Review (IP Section 02.02) (1 Sample)

(1) The inspectors reviewed the licensees corrective action program for potential adverse trends in work order implementation, procedure use, and adherence issues that might be indicative of a more significant safety issue.

The inspection conclusions associated with this review are documented in this report under Inspection Results, Section 71152.

Annual Follow-up of Selected Issues (IP Section 02.03) (1 Sample)

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

(1) Containment purge valve GTHZ0007 test failure on February 1, 2020 The inspection conclusions associated with this review are documented in this report under Inspection Results, Section 71152.

71153 - Follow-up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)

The inspectors evaluated the following licensee event reports (LERs):

(1) LER 05000482/2017-003-00, "ARV and MSSV Tornado Missile Vulnerabilities Result in Unanalyzed Condition" (ADAMS Accession No. ML17317A462). This LER was closed using the Very Low Safety Significance Issue Resolution Process. The inspection conclusions associated with this LER are documented in this report under Inspection Results, Section 71153.

(2) LER 05000482/2020-001-00, "Plant Shutdown Due to Inoperable Containment Purge Isolation Valves" (ADAMS Accession No. ML20092N985). The inspection conclusions associated with this LER are documented in this report under Inspection Results, Section 71152.

Notice of Enforcement Discretion (NOED) (IP Section 03.04) (1 Sample)

(1) The inspectors evaluated the licensee actions surrounding Notice of Enforcement Discretion for Wolf Creek Operating Corporation [EA-20-0089], which can be accessed at:

https://www.nrc.gov/reading-rm/doc-collections/enforcement/notices/noedreactor.html

OTHER ACTIVITIES

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

===60853 - On-Site Fabrication of Components and Construction On An ISFSI The inspection procedures objectives include determining whether Independent Spent Fuel Storage Installation (ISFSI) dry cask storage components were designed and fabricated in accordance with license requirements. This sample included a review of Wolf Creek Generating Station's ISFSI pad.

On-Site Fabrication of Components and Construction On An ISFSI ===

(1) On April 7-8, 2020, the NRC conducted an inspection of Wolf Creek Generating Station's planning and construction of their ISFSI concrete pad. Wolf Creek Generating Station has elected to become a 10 CFR Part 72 general licensee in accordance with 10 CFR 72.210. The licensee has selected the Transnuclear Americas LLC (TN) Nutech Horizontal Modular Storage (NUHOMS) Extended Optimized Storage (EOS) system. The licensee designed the ISFSI pad and started construction of the pad, in accordance with TN's NUHOMS EOS Certificate of Compliance 72-1042, Amendment 1, and FSAR, Revision 3. Additionally, the licensee plans to load fuel in accordance with the same Certificate of Compliance and FSAR revisions.

During the inspection quarter, Wolf Creek Generating Station constructed two ISFSI concrete pads. The pads were each 25 feet x 201 feet x 3 feet in dimension. Each pad was designed to hold 32 canisters inside the Matrix Horizontal Storage Modules (HSM-MX). The HSM-MX is an overpack construction that has canisters stacked in two rows on top of each other in a horizontal array. Each of the ISFSI concrete pads were split into eight sections for concrete pad placement activities. The inspectors observed the second concrete pad placement activity at the facility. By the end of the quarter (June 30th) the licensee had completed all 16 pours and finished the construction of the site's two ISFSI pads. Currently the licensee is using the vendor, TN, to build the HSM-MX on the ISFSI pads.

During the concrete pad placement activities, the inspectors reviewed the following samples:

• Reviewed documentation and observed construction activities to ensure the Wolf Creek ISFSI pad was designed and fabricated to meet the EOS NUHOMS FSAR and license requirements.

• Concrete was cured in accordance with American Concrete Institute (ACI)318, "Building Code Requirements for Structural Concrete."

• Batch plant and concrete delivery trucks met American Society for Testing and Materials (ASTM) C 94, "Standard Specification for Ready-Mixed Concrete,"

with respect to maximum mix time, maximum/minimum drum revolutions, addition of admixtures on the job site, and calibration of scales at the batch plant.

• Concrete forms met ACI 318 with respect to wetting prior to concrete placement, removal of debris, controlling leaks, controlling form deflection, applying release agents, and removal of standing water.

• Concrete mix design for all ingredients met the ACI code requirements and ASTM standards for water-reducing admixtures, retarding admixtures, aggregates, cement, air-entrainment admixtures, and potable water.

• Rebar placement and construction was consistent with ACI 318 requirements for rebar size, bend diameters, tensile strength test records, and minimum concrete cover requirements to protect the rebar from corrosion.

• Concrete testing and sampling met the ACI and ASTM standards with respect to sampling locations, methods, number of samples, and methods for molding and curing strength test cylinders.

• Concrete placement met design specifications for air entrainment, slump, and water/cement ratio.

• Concrete placement issues that arose during the activities were placed and addressed in the licensee's corrective action program for resolution.

===60854 - Preoperational Testing Of An ISFSI The inspection procedures objectives include determining by direct observation and independent evaluation whether the licensee had developed, implemented, and evaluated preoperational testing activities to safely load spent fuel from the site's spent fuel pool to the ISFSI. Additionally, the inspection determines whether the licensee had developed, implemented, and evaluated preoperational testing activities to safely retrieve spent fuel from the ISFSI and transfer it back to the licensee's spent fuel pool.

Preoperational Testing Of An ISFSI ===

(1) On June 16-18, 2020, inspectors traveled to TN's training facility in Aiken, South Carolina to observe and evaluate Wolf Creek Generating Station's pre-operational testing and training exercise. These operations are required to be performed by a general licensee prior to the use of the system to store spent fuel assemblies. The TN NUHOMS EOS Certificate of Compliance 72-1042, Amendment 1, Condition 9, lists a number of dry run training exercises each general licensee must complete.

During the inspection period, inspectors specifically observed the following demonstrations that were successfully completed by the licensee:

• Dry Storage Canister (DSC) sealing, drying and backfilling operation (Condition 9.b.)

• Opening of the DSC (Condition 9.f.)

These dry run operations included: welding of the canister inner and outer lids, welding of the vent and drain ports, non-destructive examination (NDE) liquid penetrant testing of the welds, helium leak testing of the welds, vacuum drying, pneumatic testing of the canister, helium backfill of the canister, cutting of the lid from the canister shell, cutting of the vent/drain port openings, and flooding the DSC. The remaining dry run demonstrations listed in Condition 9, are planned to take place at Wolf Creek Generating Station in 2021.

In addition, the inspectors reviewed the following documents to support the demonstrations listed above:

• Reviewed welder qualification program, welder performance qualifications, weld procedure specifications, and weld procedure qualification records

• Reviewed NDE program procedure, NDE personnel certification records, the qualification program for liquid penetrant exams, liquid penetrant procedure, and helium leak testing procedure

• Reviewed Certified Material test reports for the liquid penetrant chemical and welder filler metals

• Reviewed the vacuum drying, backfill, pneumatic testing, weld cutting, and re-flood procedures The inspectors identified a number of procedure discrepancies through the course of the demonstrations that the licensee placed into their corrective action program for resolution (Condition Report 143652).

The areas identified that will be addressed prior to any loading operations in 2021 include:

• The pneumatic testing portion of the licensee's procedure did not include various requirements from ASME NB-6000 (e.g. 14-day calibration requirement for pressure gauges, over-pressure devices, witness of testing by a quality assurance individual).

• After the welding of the canister lid to the shell, the procedure directed installation of the vent and drain port valves that isolated the canister with fuel and water. This created the possibility of an over-pressurization accident not analyzed in the EOS FSAR.

• The re-flood procedure contained numerous sequence errors and missing steps and it was identified that the EOS FSAR procedural steps required a revision to allow the canister to be re-flooded in the correct sequence.

INSPECTION RESULTS

Operations Supervision Failed to Control and Direct Activities of All Members of the Operating Staff Cornerstone Significance Cross-Cutting Report Aspect Section Mitigating Green [H.2] - Field 71111.12 Systems NCV 05000482/2020002-01 Presence Open/Closed The NRC inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for the licensees failure to implement procedure use and adherence requirements. Specifically, senior reactor operators failed to adequately control and direct the activities of all members of the operating staff to assure coordination of safety-related activities when a Class 1E air conditioning unit was identified as inoperable. The uncoordinated actions of non-licensed operators rendered safety-related batteries in both trains inoperable, a condition prohibited by technical specifications, while attempting to implement mitigating actions to restore cooling to the affected train.

Description:

On April 10, 2020, Wolf Creek personnel identified a refrigerant leak associated with Class 1E air conditioning unit SGK05B. In response, the SGK05B unit was declared inoperable. The licensee began taking actions to implement required mitigating actions with SGK05B inoperable. Technical Specification 3.7.20, Class 1E Electrical Equipment Air Conditioning (A/C) System, requires, in part, that the licensee immediately implement mitigating actions when one Class 1E electrical equipment A/C train is inoperable and verify room temperatures are less than or equal to 90 degrees Fahrenheit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. These actions establish a plant configuration that allows the remaining train to provide adequate cooling to both trains of the Class 1E power distribution system. This includes turning on circulation fans to allow rooms without cooling to receive cooling and shifting battery chargers so that room heat loads are distributed more advantageously.

The inspectors noted that Procedure SYS GK-201, Mitigating Actions for Inoperable SGK05 Train, Revision 0, provides all the necessary mitigating actions required by Technical Specification 3.7.20. However, there were various issues associated with implementing these mitigating actions:

• The shift engineer/shift technical advisor, a senior reactor operator, initially dispatched non-licensed operators to shift inverters to the swing inverters, which was not necessary and delayed the implementation of the mitigating actions. After non-licensed operators were sent out, the licensee recognized the error and the non-licensed operators were recalled.

• The non-licensed operators were then provided with Procedures SYS GK-201 (the correct procedure) and SYS NK-131, Energizing NK Buses, Revision 23, which was not needed and not appropriate considering the plant configuration. The licensee later concluded that an informal and inadequate pre-job briefing was conducted by the shift engineer when he directed that these procedures be implemented. Specifically, critical steps were not identified, the process and sequence of activities were not understood, and the operators did not identify that SYS NK-131 would not be applicable based on the current plant configuration. The shift engineer later indicated to the inspector that the shift engineer was unfamiliar with the latter portions of the task and unsure whether both procedures would be needed.

• Non-licensed operators were unclear about how to coordinate the two procedures and discussed how to perform the task, but decided to continue without seeking additional guidance. At this point, the operators did not follow continuous use procedure steps in order in several instances, but did not discuss this with their supervisors.

• The non-licensed operators implementing Procedure SYS GK-201 indicated that they felt time pressure following a telephone discussion with the shift manager approximately 45 minutes into the evolution. The shift manager called to get a progress report and emphasized they had 15 minutes remaining to complete the activity.

• Interviews with the shift engineer and non-licensed operators revealed that no senior reactor operators performed any observation of non-licensed operators in the field during the performance of Procedures SYS GK-201 or SYS NK-131.

• While shifting battery chargers, the non-licensed operators were inappropriately working simultaneously on chargers that affected both trains. In doing so, operators reduced charger outputs effectively to zero.

The control room then received trouble alarms for safety-related 125 Vdc bus NK01 and NK04 and recognized that the two affected batteries were discharging to power the associated direct current loads, which rendered the batteries inoperable. Having one inoperable safety-related battery in each of two DC trains is a condition prohibited by technical specifications, so Technical Specification 3.0.3, which requires an orderly shutdown, was entered. Nine minutes later operators restored the systems to operable when the swing chargers were properly placed into service.

The licensee determined that the probable cause for this error was field operators failing to stop when unsure because field operators expressed confusion to each other, but proceeded ahead and performed sections of continuous use procedures concurrently, which was neither expected, nor allowed, by procedure use and adherence procedures. The licensees evaluation determined that this occurred because operators felt time pressure, which contributed to the operator making the decision to perform Sections 6.2 and 6.11 of SYS NK-131 concurrently with performance of SYS GK-201.

After reviewing the licensees evaluation of the event, the inspectors were concerned with the lack of supervisory involvement in the chain of events. Specifically:

• Non-licensed operators were directed to perform an infrequent task and were not proficient. Specifically, operator training on Procedure SYS GK-201 did not include latter portions of the procedure, which is the part where operators swap battery chargers.

• This evolution was an unplanned task necessitated by an emergent equipment failure that did not allow sufficient time to prepare a good pre-job briefing.

• The task involved completing a complex set of tasks in multiple locations, which affected both trains and needed to be completed in a coordinated manner to be successful.

• The activities were performed under technical specification required time constraints.

The inspectors concluded that individually and collectively, these considerations point to an increased need for supervision in the field.

The inspectors performed interviews with non-licensed operators, a senior reactor operator, and others. One non-licensed operator noted that it was very hectic when direction was being provided to the non-licensed operators. The non-licensed operator stated that he/she was trying to figure out how the SYS NK-131 and SYS GK-201 procedures fit together. The non-licensed operator also noted that the informal briefing with the senior reactor operator neither included specific identification of steps or sections that would be performed within the procedures nor included identification of critical steps; this was further supported in senior reactor operator interviews. Additionally, neither a pre-job briefing checklist, nor a procedure briefing sheet, were used.

The inspectors identified that the only corrective action to address the inadequate pre-job briefing was to update the SYS GK-201 briefing sheet, which was not used, so this action appeared to have limited value. Additionally, the inspectors determined that one non-licensed operator had a procedure use and adherence requirement knowledge gap, even following remediation. The licensee entered the proposed violation into its corrective action program as Condition Report 143775.

Corrective Actions: The licensee updated the briefing sheet for SYS GK-201, initiated a training request associated with SYS GK-201, removed qualifications from and remediated one of the non-licensed operators, administered the discipline process for senior reactor operators, and planned to review previously provided training on mitigating actions for a failed SGK05 unit.

Corrective Action References: Condition Reports 141893 and 143775

Performance Assessment:

Performance Deficiency: Senior reactor operators failed to control and direct the activities of all members of the operating staff to assure integrated direction of safety-related activities during emergent, complex activities being performed under time constraints. Specifically, while attempting to implement 1-hour actions to provide alternate cooling to the train B safety-related power distribution system, the operations shift supervisory personnel assigned a complex set of infrequently performed tasks that required coordination under technical specification-required time limitations to non-licensed operators without providing adequate oversight. As a result, the field operators inappropriately rendered safety-related batteries in both trains inoperable at the same time.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the human performance attribute of the Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, failure to follow procedure use and adherence requirements led to simultaneous inoperability of safety-related NK01 and NK04 125 Vdc buses.

Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power, issued December 13, 2019, and determined this finding is not a deficiency affecting the design or qualification of a mitigating SSC; the finding does not represent a loss of the probabilistic risk assessment function of a single train technical specification system or a multi-train technical specification system; the finding does not represent a loss of the probabilistic risk assessment function of two separate technical specification systems for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or a probabilistic risk assessment system and/or function for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; and the finding does not represent a loss of the probabilistic risk assessment function of one or more nontechnical specification trains of equipment designated as risk-significant in accordance with the licensees maintenance rule program for greater than 3 days. Specifically, while two safety-related batteries were technically inoperable, they had a small discharge for 9 minutes and were still capable of filling their probabilistic risk assessment functions.

Therefore, the inspectors determined the finding was of very low safety significance (Green).

Cross-Cutting Aspect: H.2 - Field Presence: Leaders are commonly seen in the work areas of the plant observing, coaching, and reinforcing standards and expectations. Deviations from standards and expectations are corrected promptly. Senior managers ensure supervisory and management oversight of work activities, including contractors and supplemental personnel. This was similar to NUREG 2165 example

(3) for Field Presence: Managers and supervisors practice visible leadership in the field and during safety-significant evolutions by placing eyes on the problem, coaching, mentoring, reinforcing standards, and reinforcing positive decision-making practices and behaviors. Specifically, the inspectors determined that senior reactor operators did not adequately control and direct the activities of all members of the operating staff because they were not in the field observing the work and reinforcing standards and positive decision making practices.

Enforcement:

Violation: Title 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, requires, in part, that activities affecting quality shall be accomplished in accordance with documented instructions, procedures, or drawings of a type appropriate to the circumstances.

Licensee Procedure AP 17C-018, Shift Engineer Qualifications and Responsibilities, Revision 14, an Appendix B quality related procedure, provides responsibilities for the shift technical advisor, shift engineer and work control senior reactor operator. Step 5.2, states, The [Shift Technical Advisor] will stay actively involved in shift activities by performing duties of [the Shift Manager, Control Room Supervisor], or Work Control [Senior Reactor Operator].

Licensee Procedure AP 17C-005, Shift Manager Qualifications and Responsibilities, an Appendix B quality related procedure, provides responsibilities for the shift manager.

Specifically, Step 5.2.7 of Procedure AP 17C-005, states, in part, that the shift manager should control and direct the activities of all members of the operating staff to assure integrated direction of safety-related activities.

Contrary to the above, on April 10, 2020, the shift engineer/shift technical advisor did not adequately stay actively involved in shift activities, and the shift engineer/shift technical advisor did not control and direct the activities of all members of the operating staff to assure integrated direction of safety-related activities. Specifically, operations supervision directed non-licensed operators to perform an infrequent task that involved a complex set of tasks in multiple locations, under time constraints, without providing an adequate pre-job briefing to specify the procedure sections to be completed or how to coordinate actions affecting both trains, and assigned these tasks to operators who had not been provided appropriate training on all portions of the procedure. This action resulted in the non-licensed operators failing to understand the process and sequence of implementing mitigating actions when the SGK05B chiller became inoperable and two safety-related 125 Vdc batteries were simultaneously rendered inoperable for approximately 9 minutes. Immediate corrective actions included restoring the safety-related batteries to operable status.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Failure to Properly Pre-Plan Maintenance Associated with Containment Purge Isolation Valves Cornerstone Significance Cross-Cutting Report Aspect Section Barrier Integrity Green [H.14] - 71152 NCV 05000482/2020002-02 Conservative Open/Closed Bias A self-revealed Green finding and associated non-cited violation of Technical Specification 5.4.1.a was identified when the licensee failed to properly preplan and perform maintenance that can affect the performance of safety-related equipment. Specifically, the station failed to include in work instructions appropriate vendor manual guidance for establishing proper 36-inch containment purge isolation valve seat leak tightness and for performing subsequent checks to verify sealing, which led to both 36-inch containment purge isolation valves exceeding their allowed leakage values and an unplanned plant shutdown to correct excessive leakage.

Description:

On February 1, 2020, during surveillance testing in accordance with Procedure STS PE-015, Containment Purge Valve Leakage Test, Revision 22, leakage for the V-161 penetration exceeded allowable limits for the containment pressure boundary. The plant completed an unplanned plant shutdown on February 1, 2020, to comply with Technical Specification 3.6.3, Containment Isolation Valves, Condition E, and 3.6.1, Containment, Condition B.

Containment penetration V-161 includes two 36-inch shutdown purge supply butterfly valves with an elastomer (T-ring) installed on the valve disc. In order to seal properly when the valve is shut, the cap screw fasteners must be correctly tightened so the elastomer is slightly extruded. The outside containment shutdown purge supply valve, GTHZ0006, had its T-ring replaced in April 2019, and subsequently passed surveillance testing in May 2019 and August 2019. The valve was known to be exceeding its surveillance leakage limits prior to the end of the fall 2019 outage. Rather than repairing the valve to restore it to be within the allowable leak rate, the licensee decided to isolate the penetration and start up with GTHZ0006 inoperable and a blind flange installeda configuration allowed by Technical Specification 3.6.6 if the other valves in the penetration remained operable. However, as a consequence, technical specifications required increased testing of the associated containment penetration.

The inside containment shutdown purge supply isolation valve, GTHZ0007, had its T-ring replaced during the fall 2019 outage. Later in the outage the valve was found to be leaking. The T-ring fasteners were re-tightened and the penetration passed with a leak rate of 10,500 standard cubic centimeters per minute (SCCM) on November 2, 2020, prior to the unit going from Mode 5 to Mode 4. During the first performance of the increased frequency testing of penetration V-161 on February 1, 2020, GTHZ0007 leakage exceeded the allowable leak rate, but was too large to be measured. The outside and inside containment mini-purge supply valves, GTHZ0004 and GTHZ0005, respectively, which are also associated with the V-161 penetration, were ruled out as the valves contributing to the penetrations leakage. To comply with Technical Specification 3.6.3, the licensee shut the unit down and conducted testing and repairs.

The licensees root cause evaluation associated with Condition Report 140210 determined that the root cause of the event was, Wolf Creek personnel did not fully institutionalize the information regarding the relaxation of the T-ring on the 36-inch Fisher 9200 series valves following initial installation. Additionally, the licensee determined that the most reasonable explanation for leak rate failure of both GTHZ0006 and GTHZ0007 was T-ring elastomer relaxation.

The inspectors reviewed the licensees cause evaluation, vendor manual, and other materials and noted that the Vendor Technical Manual M-237-00168, 5151, Instruction Manual 9200 Series Adjustable Elastomer T-Ring Control Valve Contract Issue, Revision 05-80, states, The T-ring will require adjustment after some of the maintenance procedures. It may also need readjustment after being in operation for some time to compensate for wear and retain satisfactory shutoff. Additionally, Nuclear Maintenance Applications Center (NMAC) and Electric Power Research Institute (EPRI) manuals/reports on good bolting practices note that it may be necessary to compensate for the creep of gaskets with this type of design by retightening (at rated torque) 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after initial assembly and sometimes again after 48 and 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The station neither had, nor created, maintenance work packages to monitor or check T-ring elastomer relaxation following T-ring replacement or on a periodic basis. The inspectors determined that this information had not been incorporated into the maintenance procedures associated with T-ring replacements.

Corrective Actions: The licensee completed T-ring adjustments for GTHZ0006 and GTHZ0007 and performed increased frequency testing to monitor penetration V-161.

Licensee planned actions include developing core work instructions for T-ring replacements on applicable valves, and revising the Vendor Technical Manual to include additional monitoring, communicating changes to mechanical maintenance and planning personnel.

Corrective Action References: Condition Reports 140210 and 143776

Performance Assessment:

Performance Deficiency: The licensees failure to appropriately pre-plan maintenance associated with containment purge supply isolation valve T-ring replacement activities and ensure that maintenance instructions appropriately readjusted T-ring fastener tightness after recent maintenance on the T-rings was a performance deficiency. Specifically, the licensee failed to include in work instructions appropriate vendor manual guidance for establishing proper 36-inch containment purge isolation valve seat leak tightness and perform subsequent checks to verify proper sealing to verify the elastomer was not relaxing.

Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the SSC and barrier performance attribute of the Barrier Integrity Cornerstone and adversely affected the cornerstone objective to provide reasonable assurance that physical design barriers protect the public from radionuclide releases caused by accidents or events. Specifically, the licensee failed to assure SSC reliability through the maintenance and decision-making process, which led to a containment penetration becoming inoperable and an unplanned technical specification required shutdown.

Significance: The inspectors assessed the significance of the finding using Appendix A, The Significance Determination Process (SDP) for Findings At-Power, issued December 13, 2019, and determined this finding did not represent an actual open pathway in the physical integrity of reactor containment, failure of containment system, failure of pressure control equipment, or failure of containment heat removal components, and the finding did not involve an actual reduction in function of hydrogen igniters in the reactor containment. Therefore, the inspectors determined the finding was of very low safety significance (Green).

Cross-Cutting Aspect: H.14 - Conservative Bias: 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, leaders did not take a conservative approach to decision-making by collecting relevant information needed to make an informed decision, including the cause of the failure of GTHZ0006, the work performed on the valves in containment penetration V-161, and the failure history of the affected valves. As a result, the licensee decided to leave the GTHZ0006 valve inoperable and start up when the other valve in the penetration (GTHZ0007) was susceptible to the same failure as a result of the work performed without verifying the elastomers were not relaxing.

Enforcement:

Violation: Technical Specification 5.4.1.a, requires, in part, that procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Appendix A of Regulatory Guide 1.33, Revision 2. Section 9.a of Appendix A to Regulatory Guide 1.33, Revision 2, requires, in part, that maintenance that can affect the performance of safety-related equipment should be properly pre-planned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances.

Contrary to the above, from plant construction until February 2, 2020, maintenance that could affect the performance of safety-related equipment was not properly pre-planned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances. Specifically, T-ring replacement activities that could affect the containment isolation performance of the 36-inch containment purge isolation valves were not properly pre-planned and performed in accordance with procedures, documented instructions, or drawings appropriate to the circumstances in that work instructions did not include vendor technical manual instructions on T-ring maintenance to ensure a proper seal and how to perform subsequent checks to verify the elastomers were not relaxing. As a result, penetration V-161 was inoperable and an unplanned shutdown was completed.

Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Observation: Semi-Annual Trend Review 71152 The inspectors reviewed the licensees corrective action program for trends in work order documentation and procedure use and adherence issues that might be indicative of more significant safety issues.

Safety Conscious Work Environment (SCWE)

The NRCs semi-annual review of the licensees progress in addressing the SCWE theme, as discussed in the 2017 Annual Assessment Letter for Wolf Creek Generating Station (Report 05000482/2017006, ADAMS ML18052A345), was accomplished within the scope of the biennial problem identification and resolution inspection, which was completed on June 25, 2020. NRC Inspection Report 05000482/2020010 (ADAMS ML20199M385), dated August 3, 2020, discusses the results of this inspection, which concluded that the licensee continued to make progress in addressing the cross-cutting theme. As of the end of June 2020, there are no longer any current SCWE cross-cutting theme inputs.

Work Order Implementation and Procedure Use and Adherence The inspectors reviewed condition reports and a licensee self-assessment on work order documentation quality issues for trends associated with work order implementation, procedure use and adherence, and corrective action program effectiveness.

Wolf Creek conducted a self-assessment to satisfy a confirmatory order commitment, which states, in part, "Within 6 months of the completion of Refueling Outage 23, Wolf Creek will perform a self-assessment on work order documentation quality by sampling 40 quality-related sub-work order packages performed during the refueling outage. As part of the licensees self-assessment, station personnel looked specifically at the following areas: procedure use and adherence, work order implementation, and records. The station reviewed 48 sub-work orders and identified issues with 42 of them. As a result, the station documented 22 condition reports to capture the identified issues.

The self-assessment concluded that there were a substantial number of instances of incomplete documentation or incomplete records that were not isolated to any one work group. Specifically, the self-assessment documented less than adequate behaviors related to incomplete documentation, incomplete records, inconsistent use of place-keeping, and inappropriate marking of procedure steps as not applicable or otherwise failing to follow related procedure standards. The self-assessment recommended additional reinforcement of standards for complete and accurate documentation, monitoring, and expanding the scope of the assessment to work orders performed during non-outage timeframes and work performed outside the work order process.

Assessment The inspectors concluded that the licensees self-assessment was thorough and appropriately identified problems with procedure use and adherence, documentation of work, and work order implementation. The problems identified by the self-assessment were concerning because the work documents reviewed were completed after the majority of related corrective actions in the Confirmatory Order had been completed, indicating that these actions had not been fully effective.

The inspectors noted that additional action is warranted to continue to correct the behaviors leading to these types of issues. Specifically, the inspectors noted licensee plans to expand the scope of the self-assessment and determine the causes for procedure use and adherence and work order implementation issues. Specifically, the licensee initiated Condition Report 141957 and others for weaknesses identified during Self-Assessment (SA)-2020-0156. As part of the actions, the licensee planned to assign a cross-disciplinary team to perform an audit on work order documentation quality by sampling an additional 40 quality-related sub-work order packages. The audit is intended to compare the completed quality records against the requirements contained in Procedures AI 16C-008, Work Order Implementation, and AP 15C-002, Procedure Use and Adherence.

Additionally, the licensee planned to perform an Organizational and Programmatic Evaluation at the conclusion of the audit to determine organizational or programmatic weakness that caused the identified deficiencies.

The inspectors concluded that the licensees response to the weaknesses identified in SA-2020-0156 was appropriate to assess the problem scope and could be used to develop appropriate cause evaluations and additional corrective action in order to address the intent of the associated action in the Confirmatory Order.

Unresolved Item Train B Emergency Diesel Generator Supply Fan Motor 71153 (Open) Failure (EA-20-0089)

URI 05000482/2020002-03

Description:

At 1:48 p.m. on June 25, 2020, control room operators noticed no indicating lights were lit for the train B emergency diesel generator supply fan. The licensee investigated the condition and found the supply breaker for the supply fan open and tripped. The train B emergency diesel generator and supply fan were declared inoperable at 2:00 p.m. Subsequently, the licensee performed troubleshooting and determined that the breaker trip was most likely the result of a fault in the fan motor.

During a June 28, 2020, teleconference, the licensee requested the NRC to exercise enforcement discretion for an unanticipated temporary noncompliance with Technical Specification 3.8.1 in order to avoid an unnecessary plant transient. The licensee presented the timeline to complete repairs and testing of the fan motor to restore the emergency diesel generator to operable status, demonstrating that the necessary work and testing could not be completed within the 72-hour completion time of Required Action B.4.1 of Technical Specification 3.8.1, which would otherwise have expired at 2:00 p.m. on June 28, 2020.

On Sunday, June 28, 2020, the staff verbally approved a request by the licensee to allow an additional 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> to complete repairs and testing for the faulted supply fan motor and restore the train B emergency diesel generator to operable status by 12:00 p.m. on June 29, 2020. The train B emergency diesel generator and supply fan were declared operable at 4:25 a.m. on June 29, 2020. Subsequently, the licensee submitted its written request for enforcement discretion in Letter WO 20-0048, Request for Notice of Enforcement Discretion for Technical Specifications 3.8.1, AC Sources - Operating, dated June 30, 2020 (ADAMS Accession Number ML20182A428). The Notice of Enforcement Discretion letter from the NRC staff was sent to the licensee on July 1, 2020 (ADAMS Accession Number ML20183A431).

Planned Closure Actions: In accordance with the NRC Enforcement Manual, Appendix F, an unresolved item is being issued to review the cause of the need for enforcement discretion to determine if there is a violation associated with that cause. The inspectors plan to review the licensees hardware failure analysis and cause evaluation associated with the failure of the train B emergency diesel generator supply fan motor.

Licensee Actions: The licensee tested the train A emergency diesel generator to verify no common cause failure existed, verified the train A supply fan was operating, replaced the train B emergency diesel generator supply fan motor, and declared the train B emergency diesel generator and supply fan operable at 4:25 a.m. on Sunday, June 29, 2020.

Corrective Action References: Condition Report 143388 Licensee-Identified Non-Cited Violation 71153 This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.

Violation: Title 10 CFR 50.54(p)(2) requires, in part, that when a licensee makes security plan changes, it shall submit a report to the NRC containing a description of each change within 2 months after the change is made. Contrary to the above, between January 8, 2019, and June 25, 2020, the licensee did not submit a report containing a description of each security plan change within 2 months after the change was made on November 8, 2019. Specifically, the licensee failed to submit the required report to the NRC containing a description of each change to the NRC.

Significance/Severity: Severity Level IV. This violation was assessed using traditional enforcement because it had the potential for impacting the NRCs ability to perform its regulatory function. It is necessary to address this violation using traditional enforcement to adequately deter noncompliance. The inspectors determined the significance of this violation was a Severity Level IV violation in accordance with Section 6.9.c and 6.9.d of the NRCs Enforcement Policy because the failure to report security plan changes to the NRC did not prevent the NRC from undertaking a substantial further inquiry.

Corrective Action References: Condition Reports 143185 and 143777 Very Low Safety Significance Issue Resolution Process: Atmospheric Relief 71153 Valve and Main Steam Safety Valve Tornado Missile Vulnerabilities Result in Unanalyzed Condition This issue involved a current licensing basis question and inspection effort is being discontinued in accordance with the Very Low Safety Significance Issue Resolution process.

No further evaluation is required.

Description:

On September 7, 2017, during evaluation of protection for safety-related equipment from the damaging effects of tornados, the licensee determined that the 44 atmospheric relief valve (ARV) and main steam safety valve (MSSV) exhaust lines that route exhaust from these valves to outside the auxiliary building could be crimped by tornado generated missiles. The licensee postulated that, if enough of these 44 exhaust pipes are crimped completely, the associated ARVs and MSSVs may be unable to perform their safety functions. The ARVs and MSSVs were declared inoperable and Enforcement Guidance Memorandum (EGM) 15-002, "Enforcement Discretion for Tornado Generated Missile Protection Noncompliance," Revision 1, was applied. Immediate compensatory measures consistent with EGM 15-002 were implemented within the time allowed by the applicable technical specification limiting condition(s) for operation. The ARVs and MSSVs were subsequently declared operable but nonconforming. These tornado missile vulnerabilities had existed since original plant construction.

On November 2, 2017, the licensee submitted Licensee Event Report 2017-003-00, ARV and MSSV Tornado Missile Vulnerabilities Result in Unanalyzed Condition, in accordance with 10 CFR 50.73. The licensee stated that actions would be taken to establish compliance for these components either by a plant modification or employing a methodology for addressing tornado missile non-conformances.

The licensee requested and received an extension to resolve these vulnerabilities by June 10, 2020. The licensee elected to verify (with calculations) that the current plant remained within the current licensing basis.

Licensing Basis: The FSAR, Section 3.2 states, The safety-related structures, systems, and components are designed either to withstand the effects of natural phenomena without loss of the capability to perform their safety functions, or to fail in a safe condition. The FSAR Section 3.3 states, in part, All seismic Category I structures which are required for post-accident safe shutdown, contain equipment required for post-accident safe shutdown, are required to protect reactor coolant system integrity, or which protect stored fuel assemblies are designed to withstand the effects of a tornado.

Regulatory Guide 1.117, Protection Against Extreme Wind Events and Missiles for Nuclear Power Plants, Revision 2, states, The physical separation of redundant or alternative structures or components required for the safe shutdown of the plant is generally not considered acceptable by itself for protecting against tornado effects, including tornado-generated missiles. This is because of the large number and random direction of potential missiles that could result from a tornado as well as the need to consider the single failure criterion. The FSAR, Appendix 3A, Conformance with NRC Regulatory Guides, states the recommendations of this regulatory guide are met and does not take exception to any of the statements.

Licensee Position: The licensee performed a review of their current licensing basis. The Wolf Creek steam system consists of four ARVs (one per steam generator) and a total of 20 MSSVs (five per steam generator). In review of the above references, the licensee determined that the statement, without a loss of their safety functions, implied that effects of a tornado need protection only if the tornado missile could cause a total loss of safety function. The licensee provided calculations demonstrating that a single missile could damage the exhaust pipe of only one of four ARVs, or one of 20 MSSVs. Thus, with three ARVs or 19 total MSSVs available, the overall safety function to place and maintain the plant in a safe shutdown condition would be preserved. The Wolf Creek safety analysis demonstrated that two steam generators and associated ARVs/MSSVs are needed to achieve and maintain safe shutdown. Since a single missile would only affect one steam generator, the safety function would be maintained. The licensee used the industry position in a Nuclear Energy Institute letter, dated February 28, 2018, to demonstrate that only a single missile need be considered. The licensee modified the UFSAR to explicitly explain their tornado missile strategy as stated above and performed a 10 CFR 50.59 screen. Thus, the licensees review concluded that the plant was within its current licensing basis and no further action was required.

The inspectors determined, in view of the commitment made to Regulatory Guide 1.117, it was not clear that the current licensing basis was to preserve the overall safety function, rather than protecting the individual safety-related components/subsystems against tornado generated missiles. That the licensee modified the FSAR to explicitly explain their tornado missile strategy as stated above and performed a 10 CFR 50.59 screen to make the change, further demonstrated that the current licensing basis was not clear.

Significance: In response to this issue, the licensee provided an analysis demonstrating that a single tornado missile would likely only affect one ARV or MSSV component. A tornado with multiple missiles with the potential for crimping all sufficient MSSVs or ARVs to impact the safety function is considered a very low probability event. Thus, the most likely significance of this issue, if valid, would be very low safety significance, or Green.

For the purpose of the Very Low Safety Significance Issue Resolution Process, the inspectors screened the issue of concern through Inspection Manual Chapter 0609, Appendix A, and determined the issue of concern would likely be Green had a performance deficiency been identified. The staff concluded that further inspection effort should be discontinued in accordance with the Very Low Safety Significance Issue Resolution Process because this issue involves a current licensing basis question that cannot be resolved without a significant level of effort, and the agency has chosen not to expend the resources because the issue is expected to be of very low safety significance if found to be valid.

EXIT MEETINGS AND DEBRIEFS

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

• On June 18, 2020, the inspectors presented the emergency plan/procedure change inspection results to M. Dekat, Manager, Emergency Preparedness, and other members of the licensee staff.

• On July 13, 2020, the inspectors presented the ISFSI Pad Construction and Dry Run Exercises inspection results to Mr. S. Smith, Vice President Engineering, and other members of the licensee staff.

• On July 14, 2020, the inspectors presented the integrated inspection results to Mr. C. Reasoner, Chief Executive Officer and Chief Nuclear Officer, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection Type Designation Description or Title Revision or

Procedure Date

60853 Calculations Burns & Wolf Creek Nuclear Operating Corporation ISFSI Project 0

McDonnel Project

No. 108093

Drawings CS003 ISFSI Heavy Haul Path 3

CS004 ISFSI Heavy Haul Path Pipe Alignment 1

SB-100 WCNOC ISFSI Standard Details 0

SB-102 WCNOC ISFSI Details 0

SB-110 WCNOC-ISFSI Foundation Plan 1

SB-111 WCNOC ISFSI Foundation Sections 1

Miscellaneous Slab 5000 Wolf Creek NUHOMS Slab 5000 Mix Design 03/10/2020

60854 Corrective Action Condition Reports 143652

Documents

Resulting from

Inspection

Procedures 1PMP-DC-70.4R EOS DSC Processing 4

HTPT-DSC- High Temperature Liquid Penetrant Examination Using the 0

Orano Wolf Creek Color Contrast Solvent-Removable Method

MSLT-DSC- Helium Mass Spectrometer Leak Test Procedure 1

Orano Wolf Creek

SPM 9.8 NUHOMS EOS-37PTH DSC Closure Procedure 2

71111.01 Corrective Action Condition Reports 142996, 142997, 142998, 142999, 143000

Documents

Procedures AI 14-006 Severe Weather 17

SYS OPS-009 Hot Weather Operations 3

71111.04 Drawings M-12KJ05 Piping & Instrumentation Diagram Standby Diesel Generator 17

B Intake Exhaust, F.O. & Start Air System

M-12KJ06 Piping & Instrumentation Diagram Standby Diesel Generator 22

B Lube Oil System

Miscellaneous M-018-00309 Vendor Technical Manual - Emergency Diesel Generator W139

System

Procedures CKL AL-120 Auxiliary Feedwater Normal Lineup 44

CKL EG-120 Component Cooling Water System Valve, Switch and 50

Inspection Type Designation Description or Title Revision or

Procedure Date

Breaker Lineup

CKL EN-120 Containment Spray System Lineup 15A

CKL KJ-121 Diesel Generator NE01 and NE02 Valve Checklist 41

STS EG-100B Component Cooling Water Pumps B/D Inservice Pump Test 30

71111.05 Corrective Action Condition Reports 141738, 141739, 142031, 142032, 142033, 142036,

Documents 142255, 142256, 142257, 142259, 142268, 142395

Miscellaneous E-1F9905 Fire Hazard Analysis 10

E-1F9910 Post Fire Safe Shutdown Area Analysis 16

XX-E-013 Post-Fire Safe Shutdown (PFSSD) Analysis 4

XX-X-004 Combustible Fire Loading for Each Room in the Various 4

Areas at WCNOC

Procedures AP 10-106 Fire Preplans 19

71111.06 Calculations FL-01 Flooding of the Auxiliary Building, 1974 elevation 3

FL-11 Flooding of Auxiliary Building Containment Penetration 2

Areas

71111.11Q Corrective Action Condition Reports 142555

Documents

Miscellaneous APF 06-002 EAL Classification Matrix B

LR4640001 Simulator Evaluation 4

Procedures AP 21-001 Conduct of Operations 84

STS BM-205 SGBD System Inservice Valve Test 14

STS EN-100A Containment Spray Pump A Inservice Pump Test 31

71111.12 Corrective Action Condition Reports 27105, 92905, 94112, 95061, 96386, 99903, 99935,

Documents 101867, 103311, 103937, 105802, 106417, 111411,

111895, 117869, 119446, 121792, 123194, 127009,

27109, 129008, 129174, 129488, 129920, 132220,

2263, 132912, 136650, 138017, 139229, 140044,

140135, 141891, 141893, 142106, 143117, 143225,

143227, 143228, 143775

Work Orders 17-421954-000, 17-421954-011, 18-445407-016, 18-

445407-017, 18-445407-020, 19-455924-001, 19-455924-

2

71111.13 Calculations 06-22-F Diesel Generator Building Structural Steel At EL 2047- 2 1

Drawings C-0S5311 Diesel Generator Building Structural Steel Roof Framing at 3

Inspection Type Designation Description or Title Revision or

Procedure Date

EL 2047

Miscellaneous Basic Engineering Disposition - Rigging Evaluation for

Supply Fan Motor (DCGM01B) in Emergency Diesel

Generator Train-B Room

APF 22C-003-01 On-Line Nuclear Safety and Generation Risk Assessment, 05/25/2020 -

Schedule Week 20-0209 05/31/2020

APF 22C-003-01 On-Line Nuclear Safety and Generation Risk Assessment, 06/22/2020 -

Schedule Week 20-0213 06/28/2020

Procedures SYS SY-120 Sharpe Diesel Operation and Alignment to Site 14A

71111.15 Corrective Action Condition Reports 136328, 142230

Documents

Drawings E-025-00003 Limitorque Design Information W13

E-025-00007 Sheet 266, ENHV0016 MOV Design Configuration W13

Document

E-025-00008 Thrust Rating Increase Limitorque Actuators W01

Procedures STS NB-005 Breaker Alignment Verification 34B

Work Orders 17-433434-003, 17-433434-005, 17-433434-014, 20-

2340-000, 20-462446-000, 20-462446-006, 20-462446-

007

71111.18 Corrective Action Condition Reports 141849

Documents

Miscellaneous Design Change ESF XNB02 Transformer Replacement 0

Package 012513

71111.19 Procedures STS EN-100B Containment Spray Pump B Inservice Pump Test 35

STS KJ-005A Manual/Auto Start Sync, & Loading of EDG NE01 69A

STS KJ-005B Manual/Auto Start Sync, & Loading of EDG NE02 65A

Work Orders 20-463704-004

71111.22 Procedures STN FP-209 Fire Pump Performance and Sequential Start Test 33

STS IC-208B 4KV Loss Of Voltage & Degraded Voltage TADOT NB02 5

BUS - Separation Group 4

STS IC-260 Channel Operational Test Auxiliary Feedwater Pump 18

Suction Pressure Low Transfer to ESW

SYS FP-290 Temporary Diesel Fire Pump Operations 26

Work Orders 19-454552-000, 20-462340-000

Inspection Type Designation Description or Title Revision or

Procedure Date

71114.04 Miscellaneous E-Plan Screening - EPP 06-012, Revision 17 02/26/2020

E-Plan Effectiveness Evaluation - EPP 06-012, Rev. 17 02/26/2020

Applicability Determination - EPP 06-012, Dose 02/26/2020

Assessment, Rev 17

Document Revision Request - EPP 06-012, Dose 03/11/2020

Assessment, Rev 17

Procedures AI 26A-003 Regulatory Evaluations (Other than 10 CFR 50.59) 16

EPP 06-012 Dose Assessment 17

71151 Corrective Action Condition Reports 143778

Documents

Miscellaneous MSPI Unavailability for High Pressure Coolant Injection 07/17/2019

System/MSPI HHSI System EM-01 A

MSPI Demand and Run Time Events for Report for HHIS 06/15/2020

Demands 7/19 through 3/20

MSPI Derivation Report: MSPI High Pressure Injection 06/15/2020

System - Unavailability Index (UAI)

MSPI Derivation Report: MSPI Cooling Water System - 06/15/2020

Unavailability Index (UA)

MSPI Unavailability for Essential Service Water/MSPI 12/17/2019

Cooling Water System 2 EF-01 A

MSPI Demand and Run Time Events for ESW Demands 7- 06/15/2020

1-19 through 3-31-20

NEI 99-02 Regulatory Assessment Performance Indicator Guideline 7

Procedures AP 26A-007 NRC Performance Indicators 11

CHS SJ-143B RCS/CVCS/RHR Sampling At The SJ-143 Panel 2A

STS BB-006 RCS Water Inventory Balance using the NPIS Computer 21

STS BB-006 RCS Water Inventory Balance Using the NPIS Computer 21

71152 Corrective Action Condition Reports 125270, 128909, 131147, 134185, 140208, 140210,

Documents 140565, 140899, 141264, 141956, 141957, 141958,

141959, 142361, 143775, 143776, 143777, 143778, 143769

Miscellaneous M-237-00168 Document 5152 05-80

SA-2020-0156

STS PE-015 Containment Purge Valve Leakage Test 11/02/2019

STS PE-015 Containment Purge Valve Leakage Test 02/02/2020

Inspection Type Designation Description or Title Revision or

Procedure Date

Procedures AI 16C-008 Work Order Implementation 28

AI 28A-010 Screening Condition Reports 32

AI 28A-100 Condition Report Resolution 17

AP 15C-002 Procedure Use and Adherence 44

Work Orders 18-442877-058, 18-442877-064, 20-460441-000

71153 Corrective Action Condition Reports 115590, 119047, 140210, 143185, 143388. 143776, 143777

Documents

Miscellaneous Wolf Creek Generating Station RIS 2015-06 Report 11/28/2018

Enforcement Enforcement Discretion for Tornado Generated Missile 1

Guidance Protection Non-Compliance

Memorandum 15-

2

LER 2017-003-00 ARV and MSSV Tornado Missile Vulnerabilities Result in 11/02/2017

Unanalyzed Condition

LER 2020-001-00 Plant Shutdown Due to Inoperable Containment Purge 04/01/2020

Isolation Valves

RA 20-001 Revision 13 to The Wolf Creek Generating Station Security 06/25/2020

Plan, Training and Qualification Plan, and Safeguards

Contingency Plan

WO 20-0048 Request for Notice of Enforcement Discretion for Technical 06/30/2020

Specifications 3.8.1, AC Sources - Operating"

28