IR 05000482/2013002: Difference between revisions
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==REACTOR SAFETY== | ==REACTOR SAFETY== | ||
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity | Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity {{a|1R01}} | ||
{{a|1R01}} | |||
==1R01 Adverse Weather Protection== | ==1R01 Adverse Weather Protection== | ||
{{IP sample|IP=IP 71111.01}} | {{IP sample|IP=IP 71111.01}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R04}} | ||
{{a|1R04}} | |||
==1R04 Equipment Alignment== | ==1R04 Equipment Alignment== | ||
{{IP sample|IP=IP 71111.04}} | {{IP sample|IP=IP 71111.04}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R05}} | ||
{{a|1R05}} | |||
==1R05 Fire Protection== | ==1R05 Fire Protection== | ||
{{IP sample|IP=IP 71111.05}} | {{IP sample|IP=IP 71111.05}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R07}} | ||
{{a|1R07}} | |||
==1R07 Heat Sink Performance - Annual== | ==1R07 Heat Sink Performance - Annual== | ||
{{IP sample|IP=IP 71111.07}} | {{IP sample|IP=IP 71111.07}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R11}} | ||
{{a|1R11}} | |||
==1R11 Licensed Operator Requalification Program and Licensed Operator Performance== | ==1R11 Licensed Operator Requalification Program and Licensed Operator Performance== | ||
{{IP sample|IP=IP 71111.11}} | {{IP sample|IP=IP 71111.11}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R13}} | ||
{{a|1R13}} | |||
==1R13 Maintenance Risk Assessments and Emergent Work Control== | ==1R13 Maintenance Risk Assessments and Emergent Work Control== | ||
{{IP sample|IP=IP 71111.13}} | {{IP sample|IP=IP 71111.13}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R15}} | ||
{{a|1R15}} | |||
==1R15 Operability Evaluations and Functionality Assessments== | ==1R15 Operability Evaluations and Functionality Assessments== | ||
{{IP sample|IP=IP 71111.15}} | {{IP sample|IP=IP 71111.15}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R18}} | ||
{{a|1R18}} | |||
==1R18 Plant Modifications== | ==1R18 Plant Modifications== | ||
{{IP sample|IP=IP 71111.18}} | {{IP sample|IP=IP 71111.18}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R19}} | ||
{{a|1R19}} | |||
==1R19 Post-Maintenance Testing== | ==1R19 Post-Maintenance Testing== | ||
{{IP sample|IP=IP 71111.19}} | {{IP sample|IP=IP 71111.19}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R20}} | ||
{{a|1R20}} | |||
==1R20 Refueling and Other Outage Activities== | ==1R20 Refueling and Other Outage Activities== | ||
{{IP sample|IP=IP 71111.20}} | {{IP sample|IP=IP 71111.20}} | ||
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====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|1R22}} | ||
{{a|1R22}} | |||
==1R22 Surveillance Testing== | ==1R22 Surveillance Testing== | ||
{{IP sample|IP=IP 71111.22}} | {{IP sample|IP=IP 71111.22}} | ||
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==RADIATION SAFETY== | ==RADIATION SAFETY== | ||
Cornerstones: Public Radiation Safety and Occupational Radiation Safety | Cornerstones: Public Radiation Safety and Occupational Radiation Safety {{a|2RS1}} | ||
{{a|2RS1}} | |||
==2RS1 Radiological Hazard Assessment and Exposure Controls== | ==2RS1 Radiological Hazard Assessment and Exposure Controls== | ||
{{IP sample|IP=IP 71124.01}} | {{IP sample|IP=IP 71124.01}} | ||
Line 338: | Line 326: | ||
====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|2RS3}} | ||
{{a|2RS3}} | |||
==2RS3 In-plant Airborne Radioactivity Control and Mitigation== | ==2RS3 In-plant Airborne Radioactivity Control and Mitigation== | ||
{{IP sample|IP=IP 71124.03}} | {{IP sample|IP=IP 71124.03}} | ||
Line 428: | Line 415: | ||
====b. Findings==== | ====b. Findings==== | ||
No findings or violations were identified. | No findings or violations were identified. {{a|4OA2}} | ||
{{a|4OA2}} | |||
==4OA2 Problem Identification and Resolution== | ==4OA2 Problem Identification and Resolution== | ||
{{IP sample|IP=IP 71152}} | {{IP sample|IP=IP 71152}} | ||
Line 450: | Line 436: | ||
====b. Findings==== | ====b. Findings==== | ||
No findings were identified. | No findings were identified. {{a|4OA3}} | ||
{{a|4OA3}} | |||
==4OA3 Follow-up of Events and Notices of Enforcement Discretion== | ==4OA3 Follow-up of Events and Notices of Enforcement Discretion== | ||
{{IP sample|IP=IP 71153}} | {{IP sample|IP=IP 71153}} | ||
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====b. Findings==== | ====b. Findings==== | ||
A licensee identified finding associated with this event is documented in Section 4OA7 of this inspection report. | A licensee identified finding associated with this event is documented in Section 4OA7 of this inspection report. | ||
===.4 Notice of Unusual Event for Two Diesel Generators Out of Service due to B Train Diesel=== | ===.4 Notice of Unusual Event for Two Diesel Generators Out of Service due to B Train Diesel=== |
Latest revision as of 17:18, 20 December 2019
ML13126A250 | |
Person / Time | |
---|---|
Site: | Wolf Creek ![]() |
Issue date: | 05/06/2013 |
From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
To: | Matthew Sunseri Wolf Creek |
References | |
EA-10-020 IR-13-002 | |
Download: ML13126A250 (49) | |
Text
UNITE D S TATE S NUC LEAR RE GULATOR Y C OMMI S SI ON May 6, 2013
SUBJECT:
WOLF CREEK GENERATING STATION - NRC INTEGRATED INSPECTION REPORT 05000482/2013002
Dear Mr. Sunseri:
On March 30, 2013, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Wolf Creek Generating Station. The enclosed inspection report documents the inspection results which were discussed on April 10, 2013, with Mr. R. Smith, Site Vice President, and other members of your staff.
The inspections examined activities conducted under your license as they relate to safety and compliance with the Commission's rules and regulations and with the conditions of your license.
The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.
Two NRC identified and one self-revealing findings of very low safety significance (Green) were identified during this inspection.
Both of these findings were determined to involve violations of NRC requirements. Further, a licensee-identified violation which was determined to be of very low safety significance is listed in this report. The NRC is treating these violations as non-cited violations consistent with Section 2.3.2a of the Enforcement Policy.
If you contest these non-cited violations, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington DC 20555-0001; with copies to the Regional Administrator, Region IV; the Director, Office of Enforcement, United States Nuclear Regulatory Commission, Washington, DC 20555-0001; 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 Regional Administrator, Region IV; and the NRC Resident Inspector at Wolf Creek Generating Station. In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's Agencywide Document Access and Management System (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Neil O'Keefe, Chief Project Branch B Division of Reactor Projects Docket No.: 50-482 License No.: NPF-42 Enclosure: Inspection Report 05000482/2013002 w/ Attachment: Supplemental Information cc w/ encl: Electronic Distribution
SUMMARY OF FINDINGS
IR 05000482/2013002, 01/01/2013 - 03/30/2013, Wolf Creek Generating Station, Integrated
Resident and Regional Report; Follow-up of Events and Notices of Enforcement Discretion The report covered a 3-month period of inspection by resident inspectors and announced baseline inspections by region-based inspectors. Two Green non-cited violations (NCV) of significance were identified. The significance of most findings is indicated by their color (Green,
White, Yellow, or Red) using Inspection Manual Chapter 0609, Significance Determination Process. The cross-cutting aspect is determined using Inspection Manual Chapter 0310,
Components Within the Cross-Cutting Areas. Findings for which the significance determination process does not apply may be Green or be assigned a severity level after NRC management review. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 4, dated December 2006.
NRC-Identified Findings and Self-Revealing Findings
Cornerstone: Initiating Events
- Green.
The inspectors reviewed a self-revealing NCV of 10 CFR 50, Appendix B,
Criterion XVI, "Corrective Actions," for the failure to promptly identify and correct the source of a reactor coolant system pressure boundary leak from about August, 2012, through February 5, 2013. On February 4, 2013, Wolf Creek was performing a routine boric acid walkdown of containment as part of Refueling Outage 19. A cracked weld spraying reactor coolant pump seal water was observed on the upstream side of valve BBV130, reactor coolant pump A seal water supply line drain valve. The licensee had attributed increased leakage to reactor coolant system leakage identified in early June 2012, past emergency core cooling system check valves, without conducting inspections to rule out pressure boundary leakage. This issue was entered into the Corrective Action Program (CAP) as Condition Report (CR) 62946.
Wolf Creek's failure to promptly identify and correct the cause of reactor coolant system pressure boundary leakage is a performance deficiency. The issue is more than minor because, if left uncorrected, it would have the potential to lead to a more significant safety concern in that leakage could increase over time.
The inspectors assessed the significance of the issue using IMC 609, Appendix A, Significance Determination Process for Findings at Power, Exhibit 1,
Initiating Events Screening Questions, Section A , Loss of Coolant Accident Initiators. The inspectors determined that the finding was of very low safety significance (Green) because after a reasonable assessment of degradation, the finding could not result in exceeding the reactor coolant system leak rate for a small loss of coolant accident and the finding would not have affected other systems used to mitigate a loss of coolant accident resulting in a total loss of their function (e.g., Interfacing System LOCA). The inspectors determined that this issue had a cross-cutting aspect in the human performance cross-cutting area because Wolf Creek did not maintain long term plant safety by minimization of long-standing equipment issues to support safety. Specifically, the pressure boundary leakage was more difficult to identify because of concurrent check valve leakage into emergency core cooling systems, an intermittent but long-standing issue H.2(a) (Section 4OA3.2).
Cornerstone: Mitigating Systems
- Green.
The inspectors identified a NCV of 10 CFR 50 Appendix B, Criterion XVI,
Corrective Actions. The licensee did not initiate a CR for a hardware failure of an emergency diesel generator structural component identified in October 2006.
On October 15, 2006, while performing planned maintenance on the emergency diesel generator B, a broken cylinder head stud was discovered while disassembling the number four cylinder. None of the other seven studs on that cylinder showed any visible damage, so maintenance and engineering personnel assumed a surface nick was the cause of the failure and simply replaced the bolt under Work Order WO 06-288926-000. No CR was written so there was no formal cause evaluation, no hardware failure analysis to specify the mode of degradation, or any consideration of extent of condition for potential common cause failures. On January 7, 2013, a broken cylinder head stud was found during maintenance on emergency diesel generator B. An independent laboratory determined that the stud had failed due to high cycle fatigue.
Subsequent analysis of the stud that failed in 2006 confirmed the same failure cause. This issue was entered into the CAP as CR 65912.
Failure to identify, determine the cause and take actions to prevent recurrence for a broken emergency diesel generator cylinder head stud, a significant condition adverse to quality, is a performance deficiency. The performance deficiency is more than minor and therefore a finding because, if left uncorrected, would have the potential to lead to a more significant safety concern because the failure to determine the cause, evaluate the extent of condition, and take action to preclude repetition was later confirmed to have left an additional degraded or failed studs undetected for over six years. The inspectors screened the finding using Inspection Manual Chapter 0609, Appendix A, "Significance Determination Process for Findings at Power," Exhibit 2, "Mitigating Systems Screening Questions," Section A. The finding screened as Green because it was a design or qualification issue where affected system, structures, or components maintain their operability or functionality. No cross-cutting aspect was assigned associated with the 2006 events because the primary causes of this finding were not indicative of current licensee performance (Section 4OA3.1).
Licensee-Identified Violations
A violation of very low safety significance that was identified by the licensee has been reviewed by the inspectors. Corrective actions taken or planned by the licensee have been entered into the licensees corrective action program. This violation and associated corrective action tracking numbers are listed in Section 4OA7 of this report.
REPORT DETAILS
Summary of Plant Status
Wolf Creek began the inspection period at 100% power. On February 3, 2012, Wolf Creek shut down for Refueling Outage 19, and remained offline for the remainder of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
.1 Readiness for Seasonal Extreme Weather Conditions
a. Inspection Scope
The inspectors performed a review of the adverse weather procedures for seasonal extremes (low temperatures). The inspectors verified that weather-related equipment deficiencies identified during the previous year were corrected prior to the onset of seasonal extremes and evaluated the implementation of the adverse weather preparation procedures and compensatory measures for the affected conditions before the onset of, and during, the adverse weather conditions.
During the inspection, the inspectors focused on plant-specific design features and the procedures used by plant personnel to mitigate or respond to adverse weather conditions. Additionally, the inspectors reviewed the Updated Safety Analysis Report (USAR) and performance requirements for systems selected for inspection, and verified that operator actions were appropriate as specified by plant-specific procedures.
Specific documents reviewed during this inspection are listed in the attachment. The inspectors also reviewed corrective action program items to verify that plant personnel were identifying adverse weather issues at an appropriate threshold and entering them into their corrective action program in accordance with station corrective action procedures. The inspectors reviews focused specifically on the following plant systems:
- January 7, 2013, essential service water warming (essential service water, component cooling water)
These activities constitute completion of one readiness for seasonal adverse weather sample as defined in Inspection Procedure 71111.01-05.
b. Findings
No findings were identified.
1R04 Equipment Alignment
.1 Partial Walkdown
a. Inspection Scope
The inspectors performed partial system walkdowns of the following risk-significant systems:
- February 4, 2013, A train residual heat removal system
- March 26, 2013, B train Class 1E 480Vac electrical distribution system
- March 26, 2013, A train Class 1E 480Vac electrical distribution system The inspectors selected these systems based on their risk significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors attempted to identify any discrepancies that could affect the function of the system, and, therefore, potentially increase risk. The inspectors reviewed applicable operating procedures, system diagrams, USAR, technical specification requirements, administrative technical specifications, outstanding work orders, condition reports, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have rendered the systems incapable of performing their intended functions. The inspectors also inspected accessible portions of the systems to verify system components and support equipment were aligned correctly and operable. The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no obvious deficiencies. The inspectors also verified that the licensee had properly identified and resolved equipment alignment problems that could cause initiating events or impact the capability of mitigating systems or barriers and entered them into the corrective action program with the appropriate significance characterization. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of three partial system walkdown samples as defined in Inspection Procedure 71111.04-05.
b. Findings
No findings were identified.
.2 Complete Walkdown
a. Inspection Scope
On February 14, 2013, the inspectors performed a complete system alignment inspection of the spent fuel pool cooling system to verify the functional capability of the system. The inspectors selected this system because it was considered both safety significant and risk significant in the licensees probabilistic risk assessment. The inspectors inspected the system to review mechanical and electrical equipment line ups, electrical power availability, system pressure and temperature indications, as appropriate, component labeling, component lubrication, component and equipment cooling, hangers and supports, operability of support systems, and to ensure that ancillary equipment or debris did not interfere with equipment operation. The inspectors reviewed a sample of past and outstanding work orders to determine whether any deficiencies significantly affected the system function. In addition, the inspectors reviewed the corrective action program database to ensure that system equipment-alignment problems were being identified and appropriately resolved. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of one complete system walkdown sample as defined in Inspection Procedure 71111.04-05.
b. Findings
No findings were identified.
1R05 Fire Protection
.1 Quarterly Fire Inspection Tours
a. Inspection Scope
The inspectors conducted fire protection walkdowns that were focused on availability, accessibility, and the condition of firefighting equipment in the following risk-significant plant areas:
- February 14, 2013, Fuel Building 2047 elevation
- February 14, 2013, Fuel Building 2026 elevation
- February 14, 2013, Fuel Building 2000 elevation
- March 28, 2013, Turbine Building 2065 elevation The inspectors reviewed areas to assess if licensee personnel had implemented a fire protection program that adequately controlled combustibles and ignition sources within the plant; effectively maintained fire detection and suppression capability; maintained passive fire protection features in good material condition; and had implemented adequate compensatory measures for out of service, degraded or inoperable fire protection equipment, systems, or features, in accordance with the licensees fire plan.
The inspectors selected fire areas based on their overall contribution to internal fire risk as documented in the plants Individual Plant Examination of External Events with later additional insights, their potential to affect equipment that could initiate or mitigate a plant transient, or their impact on the plants ability to respond to a security event. Using the documents listed in the attachment, the inspectors verified that fire hoses and extinguishers were in their designated locations and available for immediate use; that fire detectors and sprinklers were unobstructed; that transient material loading was within the analyzed limits; and fire doors, dampers, and penetration seals appeared to be in satisfactory condition. The inspectors also verified that minor issues identified during the inspection were entered into the licensees corrective action program.
Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of four quarterly fire-protection inspection samples as defined in Inspection Procedure 71111.05-05.
b. Findings
No findings were identified.
1R07 Heat Sink Performance - Annual
a. Inspection Scope
The inspectors reviewed licensee programs, verified performance against industry standards, and reviewed critical operating parameters and maintenance records for the B train essential service water to component cooling water heat exchanger. The inspectors verified that performance tests were satisfactorily conducted for heat exchangers/heat sinks and reviewed for problems or errors; the licensee utilized the periodic maintenance method outlined in EPRI Report NP 7552, Heat Exchanger Performance Monitoring Guidelines; the licensee properly utilized biofouling controls; the licensees heat exchanger inspections adequately assessed the state of cleanliness of their tubes; and the heat exchanger was correctly categorized under 10 CFR 50.65, Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of one annual heat sink inspection sample as defined in Inspection Procedure 71111.07-05.
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification Program and Licensed Operator Performance
.1 Quarterly Observation of Licensed Operator Performance
a. Inspection Scope
On February 3-4, 2013, the inspectors observed the performance of on-shift licensed operators in the plants main control room. At the time of the observations, the plant was in a period of heightened activity due to unit shutdown for refueling. The inspectors observed the operators performance of the following activities:
- Primary reactivity changes: control rod manipulations and borations
- Secondary plant load changes: automatic and manual load set changes
- Securing of main feed pump
- Securing of condensate pump
- Swap over from main feed regulating valves to bypass feed regulating valves
- Swap over of plant electrical loads from unit auxiliary transformer to the start-up transformer
- Main generator output breaker opening and turbine trip
- Mode changes to Mode 2 and 3
- Verification of sub-criticality and shutdown margin
- Insertion of all control and shutdown rod banks In addition, the inspectors assessed the operators adherence to plant procedures, including AP 21-001, Conduct of Operations, and other operations department policies.
These activities constitute completion of one quarterly licensed-operator performance sample as defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
1R13 Maintenance Risk Assessments and Emergent Work Control
a. Inspection Scope
The inspectors reviewed licensee personnel's evaluation and management of plant risk for the maintenance and emergent work activities affecting risk-significant and safety-related equipment listed below to verify that the appropriate risk assessments were performed prior to removing equipment for work:
- January 7, 2013, broken B emergency diesel generator cylinder head bolt
- January 20, 2013, A emergency diesel generator maintenance outage
- February 10, 2013, planned Orange risk for reduced reactor coolant system inventory
- March 13, 2013, Red electrical power shutdown risk indicator for loss of both onsite electrical power sources The inspectors selected these activities based on potential risk significance relative to the reactor safety cornerstones. As applicable for each activity, the inspectors verified that licensee personnel performed risk assessments as required by 10 CFR 50.65(a)(4)and that the assessments were accurate and complete. When licensee personnel performed emergent work, the inspectors verified that the licensee personnel promptly assessed and managed plant risk. The inspectors reviewed the scope of maintenance work, discussed the results of the assessment with the licensee's probabilistic risk analyst or shift technical advisor, and verified plant conditions were consistent with the risk assessment. The inspectors also reviewed the technical specification requirements and inspected portions of redundant safety systems, when applicable, to verify risk analysis assumptions were valid and applicable requirements were met. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of four maintenance risk assessments and emergent work control inspection samples as defined in Inspection Procedure 71111.13-05.
b. Findings
No findings were identified.
1R15 Operability Evaluations and Functionality Assessments
a. Inspection Scope
The inspectors reviewed the following assessments:
- January 21, 2013, unit vent radiation monitor GTRE-21B iodine and particulate sampler failure
- March 8, 2013, turbine driven auxiliary feedwater pump stuffing box extension through wall leak
- March 11, 2013, train B residual heat removal pump diffuser vane damage
- January 7, 2013, train B emergency diesel generator broken cylinder head stud The inspectors selected these operability and functionality assessments based on the risk significance of the associated components and systems. The inspectors evaluated the technical adequacy of the evaluations to ensure technical specification operability was properly justified and to verify the subject component or system remained available such that no unrecognized increase in risk occurred. The inspectors compared the operability and design criteria in the appropriate sections of the technical specifications and USAR to the licensees evaluations to determine whether the components or systems were operable. Where compensatory measures were required to maintain operability, the inspectors determined whether the measures in place would function as intended and were properly controlled. Additionally, the inspectors reviewed a sampling of corrective action documents to verify that the licensee was identifying and correcting any deficiencies associated with operability evaluations. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of three operability evaluations inspection samples as defined in Inspection Procedure 71111.15-05.
b. Findings
No findings were identified.
1R18 Plant Modifications
Permanent Modifications
a. Inspection Scope
The inspectors reviewed key parameters associated with energy needs, materials, replacement components, timing, control signals, equipment protection from hazards, operations, flow paths, pressure boundary, structural, licensing basis, and failure modes for the permanent modification identified as non-safety auxiliary feedwater pump installation.
The inspectors verified that modification preparation, staging, and implementation did not impair emergency/abnormal operating procedure actions, key safety functions, or operator response to loss of key safety functions; post-modification testing will maintain the plant in a safe configuration during testing by verifying that unintended system interactions will not occur; systems, structures and components performance characteristics still meet the design basis; the modification design assumptions were appropriate; the modification test acceptance criteria will be met; and licensee personnel identified and implemented appropriate corrective actions associated with permanent plant modifications. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of one sample for plant modifications as defined in Inspection Procedure 71111.18-05.
b. Findings
No findings were identified.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors reviewed the following post-maintenance activities to verify that procedures and test activities were adequate to ensure system operability and functional capability:
- February 27, 2013, train B emergency service water pipe replacement leak checks
- February 22, 2013, NK012 125Vdc vital battery duty cycle testing
- February 21, 2013, NK014 125Vdc vital battery duty cycle testing
- February 28, 2013, emergency diesel generator B run following maintenance outage
- March 13, 2013, emergency diesel generator B jacket water pressure switch replacement
- March 19, 2013, train A emergency service water pipe replacement leak checks The inspectors selected these activities based upon the structure, system, or component's ability to affect risk. The inspectors evaluated these activities for the following (as applicable):
- The effect of testing on the plant had been adequately addressed; testing was adequate for the maintenance performed
- Acceptance criteria were clear and demonstrated operational readiness; test instrumentation was appropriate The inspectors evaluated the activities against the technical specifications, the USAR, 10 CFR Part 50 requirements, licensee procedures, and various NRC generic communications to ensure that the test results adequately ensured that the equipment met the licensing basis and design requirements. In addition, the inspectors reviewed corrective action documents associated with post-maintenance tests to determine whether the licensee was identifying problems and entering them in the corrective action program, and that the problems were being corrected commensurate with their importance to safety. Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of six post-maintenance testing inspection samples as defined in Inspection Procedure 71111.19-05.
b. Findings
No findings were identified.
1R20 Refueling and Other Outage Activities
a. Inspection Scope
The inspectors reviewed the outage safety plan and contingency plans for the refueling outage, conducted on December 20, 2012, to confirm that licensee personnel had appropriately considered risk, industry experience, and previous site-specific problems in developing and implementing a plan that assured maintenance of defense in depth.
During the refueling outage, the inspectors observed portions of the shutdown and cooldown processes and monitored licensee controls over the outage activities listed below.
- Configuration management, including maintenance of defense in depth, is commensurate with the outage safety plan for key safety functions and compliance with the applicable technical specifications when taking equipment out of service.
- Clearance activities, including confirmation that tags were properly hung and equipment appropriately configured to safely support the work or testing.
- Installation and configuration of reactor coolant pressure, level, and temperature instruments to provide accurate indication, accounting for instrument error.
- Status and configuration of electrical systems to ensure that technical specifications and outage safety-plan requirements were met, and controls over switchyard activities.
- Monitoring of decay heat removal processes, systems, and components.
- Verification that outage work was not impacting the ability of the operators to operate the spent fuel pool cooling system.
- Reactor water inventory controls, including flow paths, configurations, and alternative means for inventory addition, and controls to prevent inventory loss.
- Controls over activities that could affect reactivity.
- Refueling activities, including fuel handling and sipping to detect fuel assembly leakage.
- Licensee identification and resolution of problems related to refueling outage activities.
Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of one refueling outage and other outage inspection sample as defined in Inspection Procedure 71111.20-05.
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors reviewed the Updated Safety Analysis Report, procedure requirements, and technical specifications to ensure that the surveillance activities listed below demonstrated that the systems, structures, and/or components tested were capable of performing their intended safety functions. The inspectors either witnessed or reviewed test data to verify that the significant surveillance test attributes were adequate to address the following:
- Preconditioning
- Evaluation of testing impact on the plant
- Acceptance criteria
- Test equipment
- Procedures
- Jumper/lifted lead controls
- Test data
- Testing frequency and method demonstrated technical specification operability
- Test equipment removal
- Restoration of plant systems
- Fulfillment of ASME Code requirements
- Updating of performance indicator data
- Engineering evaluations, root causes, and bases for returning tested systems, structures, and components not meeting the test acceptance criteria were correct
- Reference setting data
- Annunciators and alarms setpoints The inspectors also verified that licensee personnel identified and implemented any needed corrective actions associated with the surveillance testing.
- January 21, 2013, diesel generator A 24-hour run
- February 24, 2013, train B Class 1E switchgear air conditioning system flow rate verification
- March 13, 2013, train A emergency service water pump comprehensive flow test (IST)
- March 30, 2013, residual heat removal pump A reference pump curve determination (IST)
Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of four surveillance testing inspection samples as defined in Inspection Procedure 71111.22-05.
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP4 Emergency Action Level and Emergency Plan Changes
a. Inspection Scope
The NSIR headquarters staff performed an in-office review of the latest revisions of various Emergency Plan Implementing Procedures (EPIPs) and the Emergency Plan located under ADAMS accession numbers ML13025A085 and ML130020566 as listed in the Attachment.
The licensee determined that in accordance with 10 CFR 50.54(q), the changes made in the revisions resulted in no reduction in the effectiveness of the Plan, and that the revised Plan continued to meet the requirements of 10 CFR 50.47(b) and Appendix E to 10 CFR Part 50. The NRC review was not documented in a safety evaluation report and did not constitute approval of licensee-generated changes; therefore, this revision is subject to future inspection. The specific documents reviewed during this inspection are listed in the Attachment.
These activities constitute completion of two samples as defined in Inspection Procedure 71114.04-05.
b. Findings
No findings were identified.
RADIATION SAFETY
Cornerstones: Public Radiation Safety and Occupational Radiation Safety
2RS1 Radiological Hazard Assessment and Exposure Controls
a. Inspection Scope
This area was inspected to:
- (1) review and assess licensees performance in assessing the radiological hazards in the workplace associated with licensed activities and the implementation of appropriate radiation monitoring and exposure control measures for both individual and collective exposures,
- (2) verify the licensee is properly identifying and reporting Occupational Radiation Safety Cornerstone performance indicators, and
- (3) identify those performance deficiencies that were reportable as a performance indicator and which may have represented a substantial potential for overexposure of the worker.
The inspectors used the requirements in 10 CFR Part 20, the technical specifications, and the licensees procedures required by technical specifications as criteria for determining compliance. During the inspection, the inspectors interviewed the radiation protection manager, radiation protection supervisors, and radiation workers. The inspectors performed walkdowns of various portions of the plant, performed independent radiation dose rate measurements and reviewed the following items:
- Performance indicator events and associated documentation reported by the licensee in the Occupational Radiation Safety Cornerstone
- The hazard assessment program, including a review of the licensees evaluations of changes in plant operations and radiological surveys to detect dose rates, airborne radioactivity, and surface contamination levels
- Instructions and notices to workers, including labeling or marking containers of radioactive material, radiation work permits, actions for electronic dosimeter alarms, and changes to radiological conditions
- Programs and processes for control of sealed sources and release of potentially contaminated material from the radiologically controlled area, including survey performance, instrument sensitivity, release criteria, procedural guidance, and sealed source accountability
- Radiological hazards control and work coverage, including the adequacy of surveys, radiation protection job coverage, and contamination controls; the use of electronic dosimeters in high noise areas; dosimetry placement; airborne radioactivity monitoring; controls for highly activated or contaminated materials (non-fuel) stored within spent fuel and other storage pools; and posting and physical controls for high radiation areas and very high radiation areas
- Radiation worker and radiation protection technician performance with respect to radiation protection work requirements
- Audits, self-assessments, and corrective action documents related to radiological hazard assessment and exposure controls since the last inspection Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of the one required sample as defined in Inspection Procedure 71124.01-05.
b. Findings
No findings were identified.
2RS3 In-plant Airborne Radioactivity Control and Mitigation
a. Inspection Scope
This area was inspected to verify in-plant airborne concentrations are being controlled consistent with ALARA principles and the use of respiratory protection devices on-site do not pose an undue risk to the wearer. The inspectors used the requirements in 10 CFR Part 20, the technical specifications, and the licensees procedures required by technical specifications as criteria for determining compliance. During the inspection, the inspectors interviewed licensee personnel, performed walkdowns of various portions of the plant, and reviewed the following items items:
- The licensees use, when applicable, of ventilation systems as part of its engineering controls
- The licensees respiratory protection program for use, storage, maintenance, and quality assurance of NIOSH certified equipment, qualification and training of personnel, and user performance
- The licensees capability for refilling and transporting SCBA air bottles to and from the control room and operations support center during emergency conditions, status of SCBA staged and ready for use in the plant and associated surveillance records, and personnel qualification and training
- Audits, self-assessments, and corrective action documents related to in-plant airborne radioactivity control and mitigation since the last inspection Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of the one sample as defined in Inspection Procedure 71124.03-05.
b. Findings
No findings were identified.
OTHER ACTIVITIES
Cornerstones: Initiating Events, Mitigating Systems, Barrier Integrity, Emergency Preparedness, Public Radiation Safety, Occupational Radiation Safety, and Security
4OA1 Performance Indicator Verification
.1 Data Submission Issue
a. Inspection Scope
The inspectors performed a review of the performance indicator data submitted by the licensee for the 4th Quarter 2012 performance indicators for any obvious inconsistencies prior to its public release in accordance with Inspection Manual Chapter 0608, Performance Indicator Program.
This review was performed as part of the inspectors normal plant status activities and, as such, did not constitute a separate inspection sample.
b. Findings
No findings were identified.
.2 Unplanned Scrams per 7000 Critical Hours (IE01)
a. Inspection Scope
The inspectors sampled licensee submittals for the unplanned scrams per 7,000 critical hours performance indicator for the period from the first quarter 2012 through the fourth quarter 2012. To determine the accuracy of the performance indicator data reported during those periods, the inspectors used definitions and guidance contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6.
The inspectors reviewed the licensees operator narrative logs, issue reports, event reports, and NRC integrated inspection reports for the period of January 2012 through December 2012, to validate the accuracy of the submittals. The inspectors also reviewed the licensees issue report database to determine if any problems had been identified with the performance indicator data collected or transmitted for this indicator and none were identified. Specific documents reviewed are described in the attachment to this report.
These activities constitute completion of one unplanned scrams per 7,000 critical hours sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings were identified.
.3 Unplanned Power Changes per 7000 Critical Hours (IE03)
a. Inspection Scope
The inspectors sampled licensee submittals for the unplanned power changes per 7,000 critical hours performance indicator for the period from the first quarter 2012 through the fourth quarter 2012. To determine the accuracy of the performance indicator data reported during those periods, the inspectors used definitions and guidance contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6. The inspectors reviewed the licensees operator narrative logs, issue reports, maintenance rule records, event reports, and NRC integrated inspection reports for the period of January 2012 through December 2012, to validate the accuracy of the submittals. The inspectors also reviewed the licensees issue report database to determine if any problems had been identified with the performance indicator data collected or transmitted for this indicator and none were identified. Specific documents reviewed are described in the attachment to this report.
These activities constitute completion of one unplanned transients per 7,000 critical hours sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings were identified.
.4 Unplanned Scrams with Complications (IE04)
a. Inspection Scope
The inspectors sampled licensee submittals for the unplanned scrams with complications performance indicator for the period from the first quarter 2012 through the fourth quarter 2012. To determine the accuracy of the performance indicator data reported during those periods, the inspectors used definitions and guidance contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6. The inspectors reviewed the licensees operator narrative logs, issue reports, event reports, and NRC integrated inspection reports for the period of January 2012 through December 2012, to validate the accuracy of the submittals. The inspectors also reviewed the licensees issue report database to determine if any problems had been identified with the performance indicator data collected or transmitted for this indicator and none were identified. Specific documents reviewed are described in the attachment to this report.
These activities constitute completion of one unplanned scrams with complications sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings were identified.
.5 Occupational Exposure Control Effectiveness (OR01)
a. Inspection Scope
The inspectors reviewed performance indicator data for the fourth quarter of 2012. The objective of the inspection was to determine the accuracy and completeness of the performance indicator data reported during these periods. The inspectors used the definitions and clarifying notes contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6, as criteria for determining whether the licensee was in compliance.
The inspectors reviewed corrective action program records associated with high radiation area (greater than 1 rem/hr) and very high radiation area non-conformances.
The inspectors reviewed radiological, controlled area exit transactions greater than 100 mrem. The inspectors also conducted walkdowns of high radiation areas (greater than 1 rem/hr) and very high radiation area entrances to determine the adequacy of the controls of these areas.
These activities constitute completion of the occupational exposure control effectiveness sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings were identified.
.6 Radiological Effluent Technical Specifications/Offsite Dose Calculation Manual
Radiological Effluent Occurrences (PR01)
a. Inspection Scope
The inspectors reviewed performance indicator data for the fourth quarter of 2012. The objective of the inspection was to determine the accuracy and completeness of the performance indicator data reported during these periods. The inspectors used the definitions and clarifying notes contained in NEI Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 6, as criteria for determining whether the licensee was in compliance.
The inspectors reviewed the licensees corrective action program records and selected individual annual or special reports to identify potential occurrences such as unmonitored, uncontrolled, or improperly calculated effluent releases that may have impacted offsite dose.
These activities constitute completion of the radiological effluent technical specifications/offsite dose calculation manual radiological effluent occurrences sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings or violations were identified.
4OA2 Problem Identification and Resolution
.1 Routine Review of Identification and Resolution of Problems
a. Inspection Scope
As part of the various baseline inspection procedures discussed in previous sections of this report, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify that they were being entered into the licensees corrective action program at an appropriate threshold, that adequate attention was being given to timely corrective actions, and that adverse trends were identified and addressed. The inspectors reviewed attributes that included the complete and accurate identification of the problem; the timely correction, commensurate with the safety significance; the evaluation and disposition of performance issues, generic implications, common causes, contributing factors, root causes, extent of condition reviews, and previous occurrences reviews; and the classification, prioritization, focus, and timeliness of corrective actions. Minor issues entered into the licensees corrective action program because of the inspectors observations are included in the attached list of documents reviewed.
These routine reviews for the identification and resolution of problems did not constitute any additional inspection samples. Instead, by procedure, they were considered an integral part of the inspections performed during the quarter and documented in Section 1 of this report.
b. Findings
No findings were identified.
.2 Daily Corrective Action Program Reviews
a. Inspection Scope
In order to assist with the identification of repetitive equipment failures and specific human performance issues for follow-up, the inspectors performed a daily screening of items entered into the licensees CAP. The inspectors accomplished this through review of the stations daily corrective action documents.
The inspectors performed these daily reviews as part of their daily plant status monitoring activities and, as such, did not constitute any separate inspection samples.
b. Findings
No findings were identified.
4OA3 Follow-up of Events and Notices of Enforcement Discretion
.1 (Closed) Licensee Event Report (LER) 2013-001-00 and Notice of Enforcement
Discretion 2013-4-001, Broken Cylinder Head Stud Causes Inoperable Diesel Generator Longer than Technical Specification Completion Time Event Description On January 8, 2013, while performing planned maintenance on emergency diesel generator B a broken cylinder head stud on the number 7 cylinder was found to be broken. Engineering ordered a hardware failure analysis to determine the failure mode.
When reviewing internal operating experience, the licensee noted a work request documenting a similar failure in 2006. The remains of that stud were located and sent off for a similar analysis. All 108 train B diesel generator cylinder head studs were ping tested and ultrasonically tested to confirm no additional bolt failures existed. All remaining number 7 cylinder head studs were removed and visually inspected; the two adjacent bolts were replaced, but returned to the warehouse for future use following a satisfactory non-destructive examination. All of this work was expected to take longer than the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> completion time allowed by Technical Specification 3.8.1; therefore Wolf Creek requested and was granted enforcement discretion (NOED 2013-4-001) by the Nuclear Regulatory Commission on January 10, 2013, to allow an additional 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> to restore the diesel generator. The repairs and postmaintenance testing were satisfactorily completed within the enforcement discretion window on January 12, 2013.
Extent of condition ping and ultrasonic testing for emergency diesel generator A was completed on January 20, 2013. No additional failed bolts were identified.
On January 15, 2013, Fairbanks Morse provided Wolf Creek with a computer modeled engine analysis verifying the ability of the engine to complete its seven day mission time with one of 108 cylinder head studs broken. On January 31, 2013, Exelon Power Labs provided the hardware failure analysis of the number 4 and number 7 cylinder bolts. The conclusions were identical for each bolt. The failure was low stress high cycle fatigue, with a contributing cause of outer diameter fretting corrosion.
On March 11, 2013, Wolf Creek submitted Licensee Event Report (LER) 2013-001-00 to document the details and cause of this event. The inspectors reviewed this LER.
LER 2013-001-00 and NOED 2013-4-001 are closed.
b. Findings
Introduction.
The inspectors identified a Green, NCV of 10 CFR 50 Appendix B, Criterion XVI, Corrective Actions. The licensee did not initiate a CR for a hardware failure of an emergency diesel generator structural component identified in October 2006, determine the cause, and take actions to prevent recurrence for a broken emergency diesel generator cylinder head stud. A similar failure with the same cause was identified in January of 2013.
Description.
On October 15, 2006, while performing planned maintenance on the emergency diesel generator B, a broken cylinder head stud was discovered while disassembling the number 4 cylinder. None of the other seven studs on that cylinder showed any visible damage, so maintenance and engineering personnel assumed a surface nick was the cause of the failure and replaced the stud under Work Order 06-288926-000. No CR was written, so there was no formal cause evaluation, no hardware failure analysis to specify the mode of degradation, or any other consideration of extent of condition for potential common cause failures was implemented.
The inspectors concluded that the licensee failed to recognize that the failure represented a significant condition adverse to quality because they did not attempted to verify their failure theory with a hardware failure analysis. If they had done this then the licensee would have been aware of a potential common cause failure mechanism at work, and established a monitoring program that would have identified the failed bolt on the number seven cylinder much sooner, possibly even before it failed.
Analysis.
Failure to identify, determine the cause and take actions to prevent recurrence for a broken emergency diesel generator cylinder head stud, a significant condition adverse to quality, is a performance deficiency. The performance deficiency is more than minor and therefore a finding because, if left uncorrected, would lead to a more significant safety concern; specifically, because the failure to evaluate extent of condition was later confirmed to have left additional degraded or failed studs undetected for over six years. The inspectors screened the finding using Inspection Manual Chapter 0609, Appendix A, "Significance Determination Process for Findings at Power," Exhibit 2, "Mitigating Systems Screening Questions," Section A. The finding screened as Green because it was a design or qualification issue where affected system, structures, or components maintain their operability or functionality. No cross-cutting aspect associated with the 2006 events was assigned because the primary causal factor contributing to this finding was not indicative of current licensee performance.
Specifically the inspectors observed that the proactive decision making by engineering management in the 2013 bolt failure including the condition reporting, hardware failure analyses, and extent of condition testing missing from the 2006 event were promptly carried out with no impetus from government or industry regulators.
Enforcement.
Title 10 CFR 50, Appendix B, Quality Assurance Criteria for Nuclear Power Plants, Criterion XVI, Corrective Action, states, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition. The identification of the significant condition adverse to quality, the cause of the condition, and the corrective action taken shall be documented and reported to appropriate levels of management. Contrary to the above, from October 15, 2006, through January 20, 2013, a significant condition adverse to quality was not entered into the CAP and the extent of condition was indeterminate.
Specifically, the failure of a number 4 emergency diesel generator B cylinder head stud was not entered into the CAP, no cause evaluation was performed, and no corrective actions to preclude repetition were taken. An identical failure was identified on a cylinder head stud for cylinder number 7 on January 8, 2013, and was properly evaluated with all repairs and the extent of condition testing to preclude further repetition was completed on January 20, 2013. Because the finding is of very low safety significance and has been entered into the licensees CAP as CR 65912, this violation is being treated as a NCV consistent with Section 2.3.2 of the NRC Enforcement Policy:
NCV 05000482/2013002-01, Failure to Initiate a Condition Report and Determine Extent of Condition for Emergency Diesel Generator Head Stud Failure.
.2 (Closed) Licensee Event Report 2013-002-00, Pressure Boundary Leakage on a Seal
Water Injection Drain Line due to Low Stress High Cycle Fatigue a. Event Description On February 4, 2013, Wolf Creek was performing a routine boric acid walkdown of containment as part of Refueling Outage 19. A cracked weld spraying reactor coolant pump seal injection water was observed on the upstream side of valve BBV130, reactor coolant pump A seal water supply line drain valve. This line was spraying an estimated 0.03-0.04 gpm stream of borated reactor coolant water at 160 degrees Fahrenheit (F)and 2235 psi. This leakage was coming from a Class 1 weld on a 3/4-inch austenitic stainless pipe stub inside the bioshield wall, an area not accessible with the reactor critical. The pipe stub was cut out and replaced prior to plant restart. LER 2013-002-00 was submitted on April 2, 2013. The inspectors reviewed the LER and the corrective action evaluations and analyses to verify that the licensee had appropriately considered the cause of the event and taken actions to prevent recurrence. The inspectors also reviewed the reactor coolant system leak rate data from cycle 19 to determine if any opportunities to identify and correct leakage were missed.
LER 2013-002-00 is closed.
b. Findings
Introduction:
The inspectors reviewed a self-revealing Green NCV of 10 CFR 50, Appendix B, Criterion XVI, "Corrective Actions," for failure to promptly identify and correct the source of an reactor coolant system (RCS) pressure boundary leak from about July 27, 2012, through February 5, 2013.
Description:
On February 4, 2013, Wolf Creek was performing a routine boric acid walkdown of containment as part of Refueling Outage 19. A cracked weld spraying reactor coolant pump seal injection water was observed on the upstream side of valve BBV130, reactor coolant pump A seal water supply line drain valve. Boric acid had covered the surrounding area and the floor below was wet. This valve is inside the bioshield which is not accessible with the reactor critical. The licensee wrote CR 62946 and reported the event to the NRC as Event Notification 48713. A subsequent hardware failure analysis determined the cause of the failure to be low stress, high cycle fatigue.
The weld material, thickness, and form was determined to be acceptable per the design specifications. The leakage flow rate was estimated to be 0.02-0.04 gpm based on the dimensions of the crack. The valve was replaced during the refueling outage.
Wolf Creek last performed a boric acid walkdown inside containment following a loss of offsite power on January 14, 2012. No leakage was noted in the vicinity of this component. The plant computer system recorded an increase of about 0.06 gpm in reactor coolant system leakage in early June 2012. This leakage was also accompanied by pressurization of the residual heat removal system and safety injection accumulator level increases, both are direct indications of emergency core cooling system check valve leakage. Wolf Creek attempted to quantify this leakage on June 28, 2012, but could only identify approximately 0.02-0.03 gpm of leakage using the safety injection system test line. Wolf Creek attributed this to imperfections in the test methodology, and closed the corrective actions under the auspice that the increase in leakage was wholly attributable to the check valve leakage.
Using a computer model and boron recovery estimates, the licensee believes that the leak from the cracked weld originated sometime between June and August, 2012.
A cracked weld leading to a leak in this location constituted reactor coolant pressure boundary leakage, a condition prohibited by Technical Specification 3.4.13. The inspectors noted that the licensee did not adequately consider the potential for RCS pressure boundary leakage, despite the difference between the total RCS leakage measured and the smaller value of leakage into the emergency core cooling system.
The licensees leakage monitoring program did not require consideration of new leakage sources once a leakage source had been identified, so all leakage was attributed to the single source that was identified.
Analysis:
The failure to promptly identify and correct the cause of RCS pressure boundary leakage is a performance deficiency. The issue is more than minor because, if left uncorrected, would lead to a more significant safety concern in that leakage could increase over time. The inspectors assessed the significance of the issue using IMC 609, Appendix A, Significance Determination Process for Findings at Power, Exhibit 1, Initiating Events Screening Questions, Section A, LOCA Initiators. The inspectors determined that the finding was of very low safety significance (Green) because after a reasonable assessment of degradation, the finding result could not result in exceeding the reactor coolant system leak rate for a small loss of coolant accident and the finding would not have likely affected other systems used to mitigate a loss of coolant accident resulting in a total loss of their function (e.g., Interfacing System LOCA). The inspectors determined that this issue had a cross-cutting aspect in the Human Performance cross-cutting area, because Wolf Creek did not maintaining long term plant safety by minimization of long-standing equipment issues to support safety. Specifically, the pressure boundary leakage was more difficult to identify because of concurrent check valve leakage into emergency core cooling systems, an intermittent but long-standing issue H.2(a).
Enforcement:
Title 10 CFR 50, Appendix B, Criterion XVI, "Corrective Actions," states, in part, that, measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. In the case of significant conditions adverse to quality, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition." Contrary to the above, Wolf Creek did not promptly identify and correct RCS pressure boundary leakage, a condition adverse to quality, from about August, 2012, to February 5, 2013.
Because this was of very low safety significance and was entered into the licensee's CAP as CR 62946, this violation is being treated as a NCV, consistent with Section 2.3.2 of the NRC Enforcement Policy:
NCV 05000482/2013002-02, Failure to Promptly Identify and Correct Reactor Coolant System Pressure Boundary Leakage.
.3 Notice of Unusual Event for Two Diesel Generators Out of Service due to B Train Diesel
Generator Governor Oil Level High a. Event Description On March 1, 2013, while Wolf Creek was defueled for a planned refueling outage and diesel generator A was disassembled for planned maintenance, a local operator discovered that the B diesel generator governor oil level was above the top of the sight glass. At 10:35 p.m. the shift manager declared the B diesel generator inoperable. The control room staff dispatched the fix it now team to drain the oil to an acceptable level.
At 10:42 p.m. Wolf Creek declared a Notification of Unusual Event (NOUE) on EAL-6, Loss of Electrical Power/Assessment Capability, because both emergency diesel generators were inoperable. At 11:07 p.m. the oil had been drained to an appropriate level, and the NOUE was terminated at 11:21 p.m.
Wolf Creek initiated CR 64828 to investigate the as-found condition. The evaluation concluded that a procedural inadequacy in the system operability restoration process was the cause, and directed procedure changes to the diesel generators operating logs (alignment checklist), system operating procedures, and preventive maintenance procedures that would ensure that this activity is not overlooked in the future.
The licensee subsequently concluded that the engine had remained capable of performing its intended safety function, as the high oil level in the governor had been present during the postmaintenance testing that had been performed earlier in the day, and the engine had not exhibited any unusual governor response.
b. Findings
A licensee identified finding associated with this event is documented in Section 4OA7 of this inspection report.
.4 Notice of Unusual Event for Two Diesel Generators Out of Service due to B Train Diesel
Generator Jacket Water Pressure Switch Failure On March 13, 2013, the reactor was defueled for a planned refueling outage and the A emergency diesel generator disassembled for planned maintenance. At 1:34 a.m. the control room received the B Diesel Generator Trouble Alarm. The local operator found the shutdown relay in the control cabinet had actuated and would not reset. The engine was declared inoperable and Wolf Creek declared a NOUE for two onsite electrical sources being unavailable. Instrumentation and controls technicians troubleshooting the condition determined that the control circuitry was working properly, but a jacket water pressure switch diaphragm had failed and the water that leaked was shorting out the electrical switch, causing a false positive signal. This signal rendered the engine inoperable because the resulting logic state indicated the engine was running with no lube oil pressure and locked in a protective trip. The pressure switch was repaired and the engine was tested and returned to service on March 14, 2013 at 2:21a.m.,
terminating the NOUE. The inspectors are continuing to review the cause of this event, and any issues of concern identified will be addressed in a future inspection report.
4OA5 Other Activities
.1 (Closed) NRC Temporary Instruction 2515/188, Inspection of (Fukushima Daiichi) Near-
Term Task Force Recommendation 2.3 Seismic Walkdowns The inspectors accompanied Wolf Creek staff and contractors performing the following seismic walkdowns:
- September 18, 2012, main control room
- September 19, 2012, turbine driven auxiliary feedwater pump room The inspectors verified that Wolf Creek staff confirmed the following seismic features associated with the main control room instrumentation and control panels (RL017, RL020, and RL021) and the turbine driven auxiliary feedwater pump (PAL02), its local control panel, were free of potential adverse seismic conditions:
- Anchorage was free of bent, broken, missing or loose hardware
- Anchorage was free of corrosion that is more than mild surface oxidation
- Anchorage was free of visible cracks in the concrete near the anchors
- Anchorage configuration was consistent with plant documentation
- Strucutres, systems and components will not be damaged from impact by nearby equipment or structures
- Overhead equipment, distribution systems, ceiling tiles and lighting, and masonry block walls are secure and not likely to collapse onto the equipment
- Attached lines have adequate flexibility to avoid damage
- The area appears to be free of potentially adverse seismic interactions that could cause flooding or spray in the area
- The area appears to be free of potentially adverse seismic interactions that could cause a fire in the area
- The area appears to be free of potentially adverse seismic interactions associated with housekeeping practices, storage of portable equipment, and temporary installations (e.g. scaffolding, lead shielding)
The inspectors independently performed walkdowns and verified that the following Seismic Walkdown Equipment List Items were appropriately evaluated by the licensee:
- March 12, 2013, centrifugal charging pump B
- March 12, 2013, 4.16kV-480V transformer XNG02 The inspectors observed no unacceptable conditions on the independent walkdown.
Wolf Creek does not have any systems, structures, or components that could allow the spent fuel pool to drain down rapidly.
No NRC-identified or self-revealing findings were identified. Temporary Instruction 2515/188 is closed.
.2 (Open) Temporary Instruction 2515/188 - Review of the Implementation of the Industry
Initiative to Control Degradation of Underground Piping and Tanks (Phase 1 of 2)
The inspectors reviewed Wolf Creeks buried and underground piping and tanks program in accordance with Section 03.01a through 03.01c of this temporary instruction. The attributes of NEI 09-14, Revision 1, Section 3.3 A and B, have been incorporated into the Wolf Creek Buried Piping and Tanks Program as described by station Administrative Procedure 23L-003. Completion dates in the program are in accordance with the NEI guidance and thus far, all have been completed on or ahead of schedule. Wolf Creek meets all applicable aspects of NEI 09-14, Revision 1, as set forth in Table 1 of the temporary instruction. The inspectors also visually observed the material condition of exhumed refueling water storage tank piping during Refuel Outage 19.
Temporary Instruction 2515/188 will remain open pending the completion of remaining licensee inspections, the results of which will be discussed in Phase 2.
.3 (Closed) Notice of Violation 05000482/2009005-11, Failure to Correct Vessel Head Vent
Path (EA 10-020)
On February 11, 2010, Wolf Creek was issued Violation 05000482/2009005-11 (EA 10-020) because from December 2, 2003, to December 31, 2009, Wolf Creek failed to ensure the design basis of the reactor vessel head vent path was correctly translated into specifications, drawings and procedures. Specifically, Wolf Creek designed and installed a reactor vessel head permanent vent piping modification which failed to vent noncondensable gases to the pressurizer during shutdown operations. This resulted in the formation of voids in the reactor vessel head while the plant was shut down and depressurized in successive refueling outages.
In performing corrective actions in response to this violation, Wolf Creek determined that the vent path geometry was too complex for proper venting. In Refuel Outage 18, in the spring of 2011, Wolf Creek determined a suitable location for a more simple vent path to the cavity drains. That design was implemented and confirmed to operate satisfactorily in Refuel Outage 19, in the spring of 2013, when the reactor head was satisfactorily drained in a slow and controlled manner. The success of these actions was documented in CR 63301. The inspectors did not identify any additional concerns.
Violation 05000482/2009005-11 (EA 10-020) is closed.
4OA6 Meetings, Including Exit
Exit Meeting Summary
On February 7, 2013, the inspectors presented the results of the radiation safety inspections to Mr. M. Sunseri, President and Chief Executive Officer, and other members of the licensee staff.
The licensee acknowledged the issues presented. The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified.
On April 10, 2013, the inspectors presented the resident inspector inspection results to Mr. R.
Smith, Site Vice President, and other members of the licensee staff. The licensee acknowledged the issues presented. The inspector asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified.
On May 3, 2013, the inspectors recharacterized one finding in a meeting with Mr, R. Smith, Site Vice President. The licensee acknowledged the issue presented. No proprietary information was identified.
4OA7 Licensee-Identified Violations
The following violation of very low safety significance (Green) was identified by the licensee and is a violation of NRC requirements which meets the criteria of the NRC Enforcement Policy for being dispositioned as a NCV.
.1 Inadequate Procedures Allow Diesel Generator Restoration without Adjusting Governor
Oil Level The licensee identified a Green NCV of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for inadequate procedures to ensure all post-maintenance testing activities are completed prior to restoration. Specifically, the B EDG governor lube oil was not drained to its proper level prior to declaring the diesel generator and taking the opposite train out of service for planned maintenance on February 28, 2013. The violation is more than minor because it affects the procedure quality attribute of the mitigating systems cornerstone objective to ensure the availability and reliability of systems which respond to initiating events to prevent undesirable consequences. The inspectors determined the finding to be Green, or of very low safety significance, using IMC 0609, Appendix A, Significance Determination Process for findings at Power, Exhibit 2, Mitigating Systems Screening Questions, Section A, because the finding did not meet any of the criteria requiring a detailed risk evaluation.
Title 10 CFR 50 Appendix B, Criterion V, states, in part, that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished. Contrary to the above, from 5:49 a.m.
to 11:07 p.m. on March 1, 2013, procedure number, title and revision was inappropriate to the circumstances because it caused the B emergency diesel generator to be inappropriately restored due to inadequate guidance to ensure that the governor oil level was properly adjusted.
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- T. Baban, Manager Systems Engineering
- P. Bedgood, Manager, Radiation Protection
- M. Brinkmeyer, Fire Protection Technician
- J. Broschak, Engineering VP
- A. Camp, Plant Manager
- B. Carlson, Support Engineer
- R. Clemens, Strategic Projects VP
- D. Erbe, Manager Security
- S. Henry, Manager Operations
- J. Hinterweger, Fire Protection Instructor
- R. Hobby, Licensing Engineer
- S. Kubacka, Instructor 2, Radiation Protection
- M. McMullen, Design Engineer
- C. Medenciy, Supervisor, Radiation Protection
- W. Muilenburg, Supervisor Licensing
- G. Pendergrass, Manager Station Recovery
- L. Ratzlaff, Manager Maintenance
- T. Slenker, Operations CAPCO
- R. Smith, Site Vice President
- M. Sunseri, President and CEO
- M. Westman, Manager Regulatory Affairs
- S. Wideman, Licensing Engineer
- J. Yunk, Manager Corrective Actions
NRC Personnel
- C. Peabody, Sr. Resident Inspector
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LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Discussed
NRC TI 2515/188 TI Review of the Implementation of the Industry Initiative to Control Degradation of Underground Piping and Tanks (Phase 1 of 2)
(Section 4OA5)
Opened and Closed
- 05000482/2013-001-00 LER Broken Cylinder Head Stud Causes Inoperable Diesel Generator Longer than Technical Specification Completion Time (Section 4OA3)
- 05000482/2013-002-00 LER Pressure Boundary Leakage on a Seal Water Injection Drain Line due to Low Stress High Cycle Fatigue (Section 4OA3)
- 05000482/2013002-01 NCV Failure to Initiate a Condition Report and Determine Extent of Condition for Emergency Diesel Generator Head Stud Failure (Section 4OA3)
- 05000482/2013002-02 NCV Failure to Promptly Identify and Correct Reactor Coolant System Pressure Boundary Leakage (Section 4OA3)
Closed
NRC TI 2515/188 TI Inspection of (Fukushima Daiichi) Near-Term Task Force Recommendation 2.3 Seismic Walkdowns (Section 4OA5)
- 05000482/2009005-11 VIO Failure to Correct Vessel Head Vent Path (Section 4OA5)
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