IR 05000483/2012005
ML13045A318 | |
Person / Time | |
---|---|
Site: | Callaway ![]() |
Issue date: | 02/14/2013 |
From: | O'Keefe N NRC/RGN-IV/DRP/RPB-B |
To: | Heflin A Union Electric Co |
O'Keefe N | |
References | |
IR-12-005 | |
Download: ML13045A318 (44) | |
Text
UNITE D S TATE S NUC LEAR RE GULATOR Y C OMMI S SI ON ary 13, 2013
SUBJECT:
CALLAWAY PLANT - NRC INTEGRATED INSPECTION REPORT 05000483/2012005
Dear Mr. Heflin:
On December 31, 2012, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Callaway Plant. The enclosed inspection report documents the inspection results which were discussed on December 27, 2012, with Mr. D. Neterer, Senior Director Nuclear Operations, and other members of your staff.
The inspection examined activities conducted under your license as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your license.
The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.
One finding of very low safety significance (Green) was identified during this inspection. This finding was determined to involve a violation of NRC requirements. Additionally, the NRC has determined that a traditional enforcement Severity Level IV violation of NRC requirements occurred. The NRC is treating these violations as non-cited violations consistent with Section 2.3.2 of the Enforcement Policy.
If you contest these 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 the Callaway Plant.
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 (the Public Electronic Reading Room).
Sincerely,
/RA/
Neil O'Keefe, Chief Project Branch B Division of Reactor Projects Docket Number: 50-483 License Number: NPF-30 Enclosure: Inspection Report 05000483/2012005 w/ Attachment: Supplemental Information cc w/ encl: Electronic Distribution
SUMMARY OF FINDINGS
IR 05000483/2012005, 09/26 -12/31/2012; Callaway Plant, Integrated Resident and Regional
Report; Heat Sink Performance and Operability Evaluations and Functionality Assessments The report covered a 3-month period of inspection by resident inspectors and announced baseline inspections by region-based inspectors. One Green non-cited violation and one Severity Level IV non-cited violation 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: Barrier Integrity
- Green.
The inspectors identified a non-cited violation of Technical Specification 3.7.11, "Control Room Air Conditioning System (CRACS)," for failure to perform the surveillance requirements specified for the control room air conditioning system. Surveillance Requirement 3.7.11.1 requires the licensee to verify that each control room air conditioning system train has the capability to remove the assumed heat load once every 18 months. The activities that the licensee was crediting to meet the requirement were not adequate because they did not actually verify heat load removal capability. The licensee entered Surveillance Requirement 3.0.3 for a missed surveillance, performed a risk assessment, and will verify that each control room air conditioning system train has the capability to remove the assumed heat load within 18 months. The licensee entered this issue into the corrective action program as Callaway Action Request 201207859.
The inspectors determined that the failure to perform sufficient testing to satisfy a technical specifications surveillance requirement is a performance deficiency.
The performance deficiency was more than minor because it impacted the structures, systems, and components and barrier performance attribute for the control room and auxiliary building and the Barrier Integrity Cornerstone objective to provide reasonable assurance that the radiological barrier remains functional.
Using Inspection Manual Chapter 0609, Appendix A, Exhibit 3, "Barrier Integrity Screening Questions," the finding was determined to be of very low safety significance (Green) because it did not represent an actual degradation of the barrier function of the control room to protect the operators inside from smoke or a toxic atmosphere. The issue has no cross-cutting aspect associated with it because it is not indicative of current licensee performance. (Section 1R07)
Cornerstone: Miscellaneous
- Severity Level IV. The inspectors identified a non-cited violation for failure to comply with Technical Specification 5.5.14, "Technical Specifications (TS) Bases Control Program." Specifically, the licensee made a change to the technical specification bases that altered the application of Technical Specification 3.6.3,
"Containment Isolation Valves," for the hydrogen monitoring system without receiving prior approval from the NRC. The licensee issued a night order to disregard the statement in the technical specification bases and declare the valves inoperable in accordance with Technical Specification 3.6.3 pending a change to the bases. The licensee entered the issue into their corrective action program as Callaway Action Request 201208045.
The inspectors determined that the violation was more than minor because in order to perform its regulatory function, the NRC relies on licensees to comply with their licensing basis documents and request prior approval for changes that may affect these documents. Because this issue affected the NRC's ability to perform its regulatory function, it was evaluated using the traditional enforcement process. This violation was classified as a Severity Level IV violation because it was not willful and was consistent with the guidance in Section 6.1, Paragraph d.,
of the NRC Enforcement Policy. Cross-cutting aspects are not assigned to traditional enforcement violations. (Section 1R15)
Licensee-Identified Violations
None.
REPORT DETAILS
Summary of Plant Status
Callaway operated at 100 percent power for the duration of the inspection period with the exception of planned power reductions for routine surveillance testing.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
.1 Readiness for Seasonal Extreme Weather Conditions
Inspection Scope The inspectors performed a review of the adverse weather procedures for seasonal extremes (e.g., extreme 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 Final Safety Analysis Report 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:
- November 29, 2012, cold weather walkdown of essential service water pump rooms, ultimate heat sink cooling tower, and condensate storage tank valve room These activities constitute completion of one readiness for seasonal adverse weather sample as defined in Inspection Procedure 71111.01-05.
Findings No findings were identified.
.2 Readiness to Cope with External Flooding
a. Inspection Scope
On October 2, 2012, the inspectors evaluated the design, material condition, and procedures for coping with the design basis probable maximum flood. The evaluation included a review to check for deviations from the descriptions provided in the Final Safety Analysis Report for features intended to mitigate the potential for flooding from external factors. As part of this evaluation, the inspectors checked for obstructions that could prevent draining, checked that the roofs did not contain obvious loose items that could clog drains in the event of heavy precipitation, and determined that barriers required to mitigate the flood were in place and operable. Additionally, the inspectors performed an inspection of the protected area to identify any modification to the site that would inhibit site drainage during a probable maximum precipitation event or allow water ingress past a barrier. The inspectors also reviewed the abnormal operating procedure for mitigating the design basis flood to ensure it could be implemented as written.
Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of one external flooding 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:
- October 17, 2012, auxiliary feedwater train A
- October 23, 2012, essential service water train A while essential service water train B was out of service
- October 31, 2012, control room ventilation train B 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, Final Safety Analysis Report, 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 November 11, 2012, the inspectors performed a complete system alignment inspection of the Class 1E 125V DC 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 electrical equipment line ups, electrical power availability, system temperature indications, as appropriate, component labeling, component and equipment cooling, 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
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:
- October 23, 2012, access control and electrical equipment air conditioning units room 1, fire area C-13
- October 24, 2012, DC switchboard rooms 1 and 4, non-vital switchgear and transformer room number 1, fire area C-15
- December 2, 2012, essential service water pump house and ultimate heat sink cooling tower electrical rooms, fire zones S-10A and S-10B
- December 2, 2012, auxiliary feedwater pump rooms, fire areas A-13, A-14, and A-15 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.
1R06 Flood Protection Measures
a. Inspection Scope
The inspectors reviewed the Final Safety Analysis Report, the flooding analysis, and plant procedures to assess susceptibilities involving internal flooding; reviewed the corrective action program to determine if licensee personnel identified and corrected flooding problems; verified the adequacy of sump pumps, level alarm circuits, cable splices subject to submergence; and verified that operator actions for coping with flooding can reasonably achieve the desired outcomes. The inspectors also inspected the areas listed below to verify the adequacy of equipment seals located below the flood line, floor and wall penetration seals, watertight door seals, common drain lines and sumps, sump pumps, level alarms, and control circuits, and temporary or removable flood barriers. Specific documents reviewed during this inspection are listed in the attachment.
- October 12, 2012, auxiliary building auxiliary feedwater pump rooms These activities constitute completion of one flood protection measures inspection sample as defined in Inspection Procedure 71111.06-05.
b. Findings
No findings were identified.
1R07 Heat Sink Performance
a. Inspection Scope
The inspectors reviewed licensee programs, verified performance against industry standards, and reviewed critical operating parameters and maintenance records for the control room air conditioning heat exchanger train A. 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 heat sink inspection sample as defined in Inspection Procedure 71111.07-05.
b. Findings
Introduction.
The inspectors identified a Green non-cited violation of Technical Specification 3.7.11, "Control Room Air Conditioning System (CRACS)," for failure to perform the surveillance requirements specified for the control room air conditioning system. The activities the licensee was crediting to meet the requirement to verify heat removal capability were not adequate to satisfy the requirement.
Description.
The inspectors identified an issue where the licensee failed to perform heat removal capability testing as specified in Surveillance Requirement 3.7.11.1.
Surveillance Requirement 3.7.11.1 requires, Verify each Control Room Air Conditioning System train has the capability to remove the assumed heat load, once every 18 months. The inspectors determined the proper testing had only been performed once, in 1979. The inspectors discussed this concern with operations and engineering personnel, who provided the four station test procedures that were being credited to meet Surveillance Requirement 3.7.11.1. Procedure ESP-GK-0004A/B, Condenser Inspection for SGK04A/B, was an inspection to check for blocked and plugged heat exchanger tubes inside control room air conditioning units SGK04A and SGK04B.
Procedure ESP-EF-0002A/B, Essential Service Water Train A/B Flow Verification, tests for adequate flow through the essential service water system, which cools the control room air conditioners. Procedure ETP-ZZ-03001, GL 89-13 Heat Exchanger Inspection, directs the cleaning and inspection of heat exchanger tubes. This procedure was intended to satisfy the Generic Letter 89-13 heat exchanger reliability program requirements and was specifically credited as heat removal verification by the licensees surveillance testing database. Procedure MSE-GK-0004A/B, Refrigeration Cycle and Air Flow for SGK04A/B, was an operability test for SGK04A and SGK04B compressors, control circuits, evaporator coils, and fans. Upon review of these procedures, the inspectors found no measurement of heat removal capability specified in the wording of Surveillance Requirement 3.7.11.1. The inspectors brought this concern to the attention of the shift manager and operations management. On November 7, 2012, Callaway entered Surveillance Requirement 3.0.3 for missing this requirement on each train, and performed the required risk assessment. The licensee must verify that each control room air conditioning system train has the capability to remove the assumed heat load no later than May 7, 2014.
The inspectors reviewed the design and licensing basis history for air conditioning units SGK04A and SGK04B. Callaways original technical specifications did not specify any heat removal verification surveillance requirements for the control room air conditioning units. The heat removal capability was initially tested in 1979. In response to Generic Letter 89-13, the licensee committed to clean and inspect the condensers for SGK04A and SGK04B in order to ensure that fouling remained within design basis assumptions. The control room air conditioners were added to the technical specifications upon Callaways conversion to improved standard technical specifications in 2000, when the standard Westinghouse pressurized water reactor improved technical specification wording was adopted. In the technical specification bases, the licensee stated that heat removal capability would be verified by either heat exchanger performance testing or regular cleaning and inspection. The inspectors acknowledge that verifying the absence of heat exchanger fouling does provide added assurance that it is functioning properly, and the justification in the prompt operability determination reflected that. However, since this is only one of several variables affecting heat removal capability, the inspectors concluded that although it was specified in the basis, this action alone would not satisfy the surveillance requirement because it did not measure heat removal capability.
Analysis.
Failure to perform sufficient testing to satisfy a technical specifications surveillance requirement is a performance deficiency. Specifically, the licensee did not measure heat removal capability to verify that the control room air conditioning units have the capability to remove the assumed heat load since the surveillance requirement was added to technical specifications in 2000. The performance deficiency was more than minor because it impacted the structures, systems, and components and barrier performance attribute of the control room and auxiliary building, and the Barrier Integrity Cornerstone objective to provide reasonable assurance the radiological barrier remains functional. Specifically, surveillance instructions did not meet licensing basis requirement to verify heat removal capability. Using Inspection Manual Chapter 0609 Appendix A, Exhibit 3, "Barrier Integrity Screening Questions," the inspectors determined that the finding screened as Green because it did not represent an actual degradation of the barrier function of the control room to protect the operators inside from smoke or a toxic atmosphere. The inspectors did not assign a cross-cutting aspect because the performance deficiency occurred in 2000 and is not a reflection of current licensee performance.
Enforcement.
Callaway Technical Specification Surveillance Requirement 3.7.11.1 requires the licensee verify that each control room air conditioning system train has the capability to remove the assumed heat load once every 18 months. Contrary to the above, from April 1, 2000, through November 7, 2012, Callaway failed to verify that each control room air conditioning system train has the capability to remove the assumed heat load. This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy, because it was of very low safety significance and was entered into the licensees corrective action program as Callaway Action Request 201207859: NCV 05000483/2012005-01, Failure to Perform Technical Specification Surveillance Requirements on the Control Room Air Conditioning System."
1R11 Licensed Operator Requalification Program and Licensed Operator
Performance (71111.11)
.1 Quarterly Review of Licensed Operator Requalification Program
a. Inspection Scope
On October 16, 2012, the inspectors observed a crew of licensed operators in the plants simulator during training. The inspectors assessed the following areas:
- Licensed operator performance
- The ability of the licensee to administer and the quality of the training provided
- The modeling and performance of the control room simulator
- The quality of post-scenario critiques
- Follow-up actions taken by the licensee for identified discrepancies These activities constitute completion of one quarterly licensed operator requalification program sample as defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
.2 Quarterly Observation of Licensed Operator Performance
a. Inspection Scope
On November 11 and 13, 2012, 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 the evolutions listed below. The inspectors observed the operators performance of the following activities:
- November 11, 2012, reactivity manipulation and technical support center diesel generator run
- November 13, 2012, reactivity manipulation and testing of atmospheric steam dump D In addition, the inspectors assessed the operators adherence to plant procedures, including Procedure ODP-ZZ-00001, "Operations Department - Code of Conduct," and other operations department policies.
Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of two quarterly licensed-operator performance samples as defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
.3 Annual Inspection
a. Inspection Scope
The inspectors reviewed the annual operating examination test results for 2012. Since this was the first half of the biennial requalification cycle, the licensee was not required to administer a written examination. These results were assessed to determine if they were consistent with NUREG 1021, "Operator Licensing Examination Standards for Power Reactors," guidance and Inspection Manual Chapter 0609, Appendix I, "Operator Requalification Human Performance Significance Determination Process," requirements.
This review included the test results for a total of nine crews composed of 49 licensed operators, which included: 26 senior operators and 23 reactor operators. There was one crew failure during the scenario test. They were remediated and passed a retake scenario test prior to returning to shift. Two senior operators failed emergency action level classifications, and they were remediated and retested satisfactorily using static job performance measures.
This activity constitutes completion of one annual requalification examination results review sample as defined in Inspection Procedure 71111.11.
b. Findings
No findings were identified.
1R12 Maintenance Effectiveness
a. Inspection Scope
The inspectors evaluated degraded performance issues involving the following risk significant systems:
- November 14, 2012, centrifugal charging pumps trains A and B
- December 18, 2012, closed cooling water system The inspectors reviewed events such as where ineffective equipment maintenance has resulted in valid or invalid automatic actuations of engineered safeguards systems and independently verified the licensee's actions to address system performance or condition problems in terms of the following:
- Implementing appropriate work practices
- Identifying and addressing common cause failures
- Scoping of systems in accordance with 10 CFR 50.65(b)
- Characterizing system reliability issues for performance monitoring
- Charging unavailability for performance monitoring
- Trending key parameters for condition monitoring
- Ensuring proper classification in accordance with 10 CFR 50.65(a)(1) or -(a)(2)
- Verifying appropriate performance criteria for structures, systems, and components classified as having an adequate demonstration of performance through preventive maintenance, as described in 10 CFR 50.65(a)(2), or as requiring the establishment of appropriate and adequate goals and corrective actions for systems classified as not having adequate performance, as described in 10 CFR 50.65(a)(1)
The inspectors assessed performance issues with respect to the reliability, availability, and condition monitoring of the system. In addition, the inspectors verified maintenance effectiveness issues were entered 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 two quarterly maintenance effectiveness samples as defined in Inspection Procedure 71111.12-05.
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:
- October 5, 2012, door DSK13291 repairs, Job 12005177
- October 23-25, 2012, risk and risk management actions for essential service water train A, emergency diesel generator train A, and ultimate heat sink train A out of service, Jobs 12501073, 10502293, and 11507106
- November 28, 2012, repair of pressurizer pressure channel 3 transmitter, Job 12005994
- December 18, 2012, risk management actions and repair of Class 1E switchgear cooler SGK05A freon leak, Job 12511902 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:
- November 6, 2012, control room air conditioning system surveillances not performed, Callaway Action Request 201207889
- November 14, 2012, Technical Specification 3.6.3 bases may be non-conservative, Callaway Action Request 201208045
- November 26, 2012, past operability determination for train A centrifugal charging pump, Callaway Action Request 201207677
- November 30, 2012, pressurizer pressure channel 3 transmitter replacement following adverse trend, Callaway Action Request 201208203
- December 5, 2012, essential switchgear ventilation capability with one train inoperable, Callaway Action Request 201208908 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 Final Safety Analysis Report 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 five operability evaluations inspection samples as defined in Inspection Procedure 71111.15-05.
b. Findings
Inappropriate Technical Specification Bases Change
1.
Introduction.
The inspectors identified a Severity Level IV non-cited violation for failure to comply with Technical Specifications 5.5.14, "Technical Specifications (TS) Bases Control Program." Specifically, the licensee changed the technical specification bases, which altered the application of Technical Specification 3.6.3, "Containment Isolation Valves," for the hydrogen monitoring system without receiving prior approval from the NRC.
Description.
On November 11, 2012, during a tour of the control room, the inspectors observed the licensee open the containment isolation valves for the hydrogen monitoring system to support containment atmospheric sampling for a planned containment entry.
The licensee stationed a dedicated operator to close the valves if necessary, because when sampling in this manner, these containment isolation valves may not close under certain conditions. The inspectors questioned whether the valves were considered inoperable. The licensee stated the valves were operable, but only if they established administrative controls (i.e., a dedicated operator). Discussions with the licensee identified the technical specification bases had a statement that these specific valves were operable as long as administrative controls were in place.
In 2002, the licensee changed the technical specification bases for Technical Specification 3.6.3 to include a statement that the containment isolation valves for the hydrogen monitoring system are considered operable when opened under administrative controls. The licensee processed this change as an administrative change and did not consider it as affecting the requirements of Technical Specification 3.6.3.
Technical Specification 3.6.3 actions are modified by a note that states, Penetration flow path(s) except for containment shutdown purge valve flow paths may be unisolated intermittently under administrative controls. This note allows the licensee to open these containment isolation valves and suspend entering Condition B and the Required Actions listed. However, this note is only applicable if the licensee had already declared the valves inoperable and entered the limiting condition for operations action statement.
The inspectors discussed this issue with members of the Containment Systems Branch and Technical Specification Branch in the Office of Nuclear Reactor Regulation. The staff concluded that when the licensee opens the hydrogen sample valves and additional valves needed to sample containment atmosphere, this renders the containment isolation function inoperable. The licensee is required to declare that penetration inoperable and enter Technical Specification 3.6.3 Actions. Associated Action Note 1 then allows intermittent opening of the containment isolation valves under administrative controls.
The inspectors determined that Technical Specification 5.5.14 requires in part, "Licensees may make changes to Bases without prior NRC approval provided the changes do not require . . . a change in the TS incorporated in the license. It goes on to state, Proposed changes that meet the criteria of Specification 5.5.14b above shall be reviewed and approved by the NRC prior to implementation. As initial corrective action, the licensee issued a standing order to disregard the statement in the technical specification bases and declare these valves inoperable in accordance with Technical Specification 3.6.3 pending a change to the bases.
This violation was identified in connection with a review of Operating Experience Smart Sample 2012/02, Technical Specification Interpretation and Operability Determination.
Analysis.
Failure to obtain NRC approval prior to making a technical specification bases change that also required a technical specification change constituted a violation of Technical Specification 5.5.14, "Technical Specifications (TS) Bases Control Program."
Specifically, the licensee made a change to the technical specification bases that altered the application of Technical Specification 3.6.3 without prior NRC approval. This change affected the licensees determination of operability of the hydrogen monitoring system containment isolation valves and resulted in the licensee failing to enter the conditions and associated required actions when not meeting Technical Specification 3.6.3 requirements. The inspectors determined that the violation was more than minor and assessed using traditional enforcement because in order to perform its regulatory function, the NRC relies on licensees to comply with their licensing basis documents and request prior approval for changes that may affect these documents. The inspectors reviewed this issue in accordance with Inspection Manual Chapter 0612, Appendix B, and the discussion for Figure 1, Block TE2, Paragraph 1, and determined that failure to receive prior NRC approval for changes in licensed activities was an example of a violation that impacted the regulatory process and was subject to traditional enforcement. Consistent with the guidance in Section 6.1, Paragraph d, of the NRC Enforcement Policy, this performance deficiency was determined to be a Severity Level IV non-cited violation. No cross-cutting aspects are assigned for traditional enforcement violations.
Enforcement.
Technical Specification 5.5.14, "Technical Specifications (TS) Bases Control Program," requires in part, "Licensees may make changes to Bases without prior NRC approval provided the changes do not require . . . a change in the TS incorporated in the license. It goes on to state, Proposed changes that meet the criteria of Specification 5.5.14b above shall be reviewed and approved by the NRC prior to implementation. Contrary to the above, on November 27, 2002, the licensee made a change to the Technical Specification 3.6.3 bases that altered the application of Technical Specification 3.6.3 and failed to obtain NRC review and approval prior to implementation. Specifically, the licensee added a statement into the bases that allowed the licensee to consider the hydrogen monitoring system containment isolation valves operable with administrative controls established even though the technical specifications would require first declaring the penetration inoperable. The licensee processed this change as an administrative change instead of one that affected the bases of TS 3.6.3, which would require NRC review and approval in accordance with TS 5.5.14b.
This violation was classified as a Severity Level IV violation because it was not willful and was consistent with Section 6.1, Paragraph d, of the NRC Enforcement Policy. This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy because it was Severity Level IV and was entered into the licensees corrective action program as Callaway Action Request 201208045:
NCV 5000483/2012005-02, "Failure to Comply with Technical Specification 5.5.14, Technical Specifications (TS) Bases Control Program."
Capacity Needed to Cross-Tie Switchgear Cooling
2.
Introduction.
The inspectors identified an unresolved item involving the licensing basis and cooling capability of the safety-related air conditioning units and the ability to cool both trains of safety-related switchgear, batteries, battery chargers, and inverters with a single train of cooling.
Description.
On December 5, 2012, the inspectors identified an issue with the licensees plan to cope with / mitigate an inoperable vital switchgear Class 1E air conditioning unit.
This system has two trains, each comprised of a chiller, fans and ductwork to cool the rooms containing its associated safety-related switchgear, battery, battery charger, and inverters. This system and its cooling function are not explicitly covered by technical specifications, while the supported systems are covered by technical specifications.
In 2004, in an attempt to address the fact that these cooling trains are not covered by technical specifications, and therefore have no allowed outage time, the licensee created Final Safety Analysis Report Administrative Technical Specification 16.7.13. This specification states that if one of the trains of cooling is inoperable, the ESF switchgear and vital batteries/chargers may be considered operable for up to 7 days provided the following conditions are met:
- (1) all doors between trains are open;
- (2) safety-related transformers XNN05 and XNN06 for 120VAC are de-energized;
- (3) thermostats on the operable cooling unit are set below 80F; and
- (4) at least one Class 1E air conditioning unit is operable and capable of operating at full capacity.
As described in Callaway Action Request 201009024, if one train of cooling were inoperable, operators would declare the associated switchgear, battery, charger, and inverters inoperable and enter associated technical specification action statements, then implement/verify the compensatory measures, then exit the action statements for up to 7 days.
The inspectors questioned the technical basis for how the equipment that was cooled by this air conditioning unit would be able to function without cooling. Specifically, the inspectors questioned the adequacy of the single unit to cool both trains.
On December 6, 2012, while the licensee was reviewing the inspectors concerns, they identified that heat load calculations GK-10, DC SWBD, Battery and ESF SWGR Room Temperatures with One 1E A/C Unit Inoperable, and GK-22, Eval. Inverter Loads, 92-1014, did not account for both trains of control building pressurization heaters being energized. This increases the heat load assumed in the calculation and required additional compensatory actions beyond the Final Safety Analysis Report 16.7.13 actions. The licensee revised a standing order to direct operations to secure the control room emergency ventilation system associated with the affected Class 1E air conditioning unit. This is achieved by placing three fans in pull-to-lock when using one cooling train to cool both electrical trains. The licensee initiated Callaway Action Request 201208550 to address this issue.
The inspectors have the following concerns:
- (1) Callaway relies on compensatory measures to open all doors between trains of batteries and switchgear, posting fire watches, and de-energizing plant equipment (which is safety-related). The inspectors questioned the appropriateness and cooling capability of these measures, which were used as a basis for assuring the operability of the supported safety-related systems.
Specifically:
a. the temporary air flow paths did not appear to ensure adequate air flow between trains b. portions of the temporary air flow path went through a corridor that was not cooled, allowing unaccounted-for heat, as well as loss of cooled air, since there was no way to efficiently move all the cooled air to the other trains room with a corridor between the individual train rooms c. one safety-related control room ventilation system is rendered inoperable by implementing the compensatory measures d. the heat loads and cooling capacity were not adequately accounted for (see below)
- (2) The licensees creation of Final Safety Analysis Report Administrative Technical Specification 16.7.13, appeared to conflict with existing technical specifications that covered the situation. Specifically, cooling was required to support the safety functions of the associated safety-related batteries, battery chargers, inverters, and switchgear. The definition of operable in technical specifications stated that for a system to be considered operable, all necessary cooling systems must also be capable of performing their related support functions.
Part 9900 guidance for assessing operability further states that, in order to be considered operable, structures, systems and components must be capable of performing the safety functions specified by its design within the range of specified physical conditions, which would include room temperature, and accident loading Creating a Final Safety Analysis Report specification and limiting condition for operation allowing the support system to be out of service would not alleviate the need to consider the impact to the operability of the supported systems.
- (3) The inspectors found that the electrical equipment heat load evaluated in calculation GK-10 did not appear to adequately account for all heat sources, and may not have provided an adequate technical basis for credited heat removal.
a. Sensible and latent heat added to the switchgear rooms by outside air from the control building pressurization fans were not included in calculations. During accidents, the control building pressurization fans add outside air to raise the pressure in the control building to minimize in-leakage, but would add sensible and latent heat that was not included in heat removal calculations.
b. The DC switchgear and battery rooms are located directly above the AC switchgear rooms. An assumption for the DC switchgear and battery rooms stated that heat will be removed through the floor, while another assumption for the AC switchgear room stated that heat will be removed through the ceiling.
- (4) The inspectors questioned whether both trains of supported equipment would satisfy the design and licensing basis of the plant with a single train of cooling.
Specifically, loss of the single operable cooling train would lead to failure of both trains of supported equipment such that the plant would no longer be able to withstand a single failure without prior NRC approval.
The inspectors noted that the licensee has actually implemented the compensatory measures described above and declared the supported systems operable by relying on one train of cooling, including December 17- 18, 2012, when train A chiller had a refrigerant leak and again on December 22, 2012, through January 5, 2013, when train B chiller had a refrigerant leak.
The above concerns must be addressed before an evaluation of the combined effect of these concerns can be performed. In response, the licensee created Callaway Action Request 201208908 to re-evaluate their current practice and the basis for using a single cooling unit.
Analysis.
The inspectors were concerned that the licensee implemented a Final Safety Analysis Report change that conflicted with existing requirements in technical specifications and created a condition where the plant would be subject to loss of both trains with a single failure of the operating train of cooling without prior NRC approval. In addition, the technical basis for this Final Safety Analysis Report change may not have adequately accounted for the maximum expected heat loads, and may not have demonstrated air flows to remove heat loads from both trains simultaneously.
Enforcement.
Additional information was needed to determine whether the concerns discussed above involve one or more violations of 10 CFR Part 50, Appendix B, Criterion III, Design Control, 10 CFR 50.59,Changes, Tests and Experiments, Technical Specification 3.8.1, AC Sources - Operating, Technical Specification 3.8.4, DC Sources - Operating, Technical Specification 3.8.7, Inverters - Operating, and Technical Specification 3.8.9, Distribution Systems - Operating.
Pending further evaluation of the above issues by the licensee and subsequent review by inspectors, this issue will be tracked as unresolved item (URI)05000483/2012004-03, Determine Licensing Basis and Capability of One Vital Air Conditioning Unit to Cool Both Trains of Class 1E Electrical Equipment.
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:
- October 18, 2012, motor-driven auxiliary feedwater pump train B and valve inservice test after pump bearing oil change, Job 11506380
- October 24, 2012, ultimate heat sink fan D vibration after fan blade inspection, Job 12507969
- November 7, 2012, residual heat removal pump train A and valve inservice test after pump bearing oil change, Job 11504619
- November 13, 2012, atmospheric steam dump D after diagnostic testing, Job 11501714 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:
- 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 Final Safety Analysis Report, 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 four post-maintenance testing inspection samples as defined in Inspection Procedure 71111.19-05.
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors reviewed the Final 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
- Test data
- Testing frequency and method demonstrated technical specification operability
- Test equipment removal
- Restoration of plant systems
- Annunciator and alarm setpoints The inspectors also verified that licensee personnel identified and implemented any needed corrective actions associated with the surveillance testing.
- October 2, 2012, containment spray pump A routine test, Job 12507427
- October 31, 2012, centrifugal charging pump A routine test, Job 12508555
- December 2, 2012, normal charging pump check valves closure routine test, Job 12509942 Specific documents reviewed during this inspection are listed in the attachment.
These activities constitute completion of three routine 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 inspectors performed an in-office review to verify that no changes to the site Emergency Plan or Emergency Plan Implementing Procedures were submitted to the NRC in calendar year 2012 that required a detailed review according to the requirements of Inspection Procedure 71114.04.
These activities constitute completion of one sample as defined in Inspection Procedure 71114.04-05.
b. Findings
No findings were identified.
1EP6 Drill Evaluation
Training Observations
a. Inspection Scope
The inspectors observed a simulator training evolution for licensed operators on October 16, 2012, which required emergency plan implementation by a licensee operations crew. This evolution was planned to be evaluated and included in performance indicator data regarding drill and exercise performance. The inspectors observed event classification and notification activities performed by the crew. The inspectors also attended the post-evolution critique for the scenario. The focus of the inspectors activities was to note any weaknesses and deficiencies in the crews performance and ensure that the licensee evaluators noted the same issues and entered them into the corrective action program. As part of the inspection, the inspectors reviewed the scenario package and other documents listed in the attachment.
These activities constitute completion of one sample as defined in Inspection Procedure 71114.06-05.
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 third 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 Mitigating Systems Performance Index - High Pressure Injection Systems (MS07)
a. Inspection Scope
The inspectors sampled licensee submittals for the mitigating systems performance index - high pressure injection systems performance for the period from the fourth quarter 2011 through the third 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, mitigating systems performance index derivation reports, event reports, and NRC integrated inspection reports for the period of October 2011 through September 2012 to validate the accuracy of the submittals. The inspectors reviewed the mitigating systems performance index component risk coefficient to determine if it had changed by more than 25 percent in value since the previous inspection, and if so, that the change was in accordance with applicable NEI guidance.
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 mitigating systems performance index -
high pressure injection system sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings were identified.
.3 Mitigating Systems Performance Index - Residual Heat Removal System (MS09)
a. Inspection Scope
The inspectors sampled licensee submittals for the mitigating systems performance index - residual heat removal system performance indicator for the period from the fourth quarter 2011 through the third 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, mitigating systems performance index derivation reports, event reports, and NRC integrated inspection reports for the period October 2011 through September 2012 to validate the accuracy of the submittals. The inspectors reviewed the mitigating systems performance index component risk coefficient to determine if it had changed by more than 25 percent in value since the previous inspection, and if so, that the change was in accordance with applicable NEI guidance.
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 mitigating systems performance index -
residual heat removal system sample as defined in Inspection Procedure 71151-05.
b. Findings
No findings 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 corrective action program. 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.
.3 Semi-Annual Trend Review
a. Inspection Scope
The inspectors performed a review of the licensees corrective action program and associated documents to identify trends that could indicate the existence of a more significant safety issue. The inspectors focused their review on repetitive equipment issues, but also considered the results of daily corrective action item screening discussed in Section 4OA2.2, above, licensee trending efforts, and licensee human performance results. The inspectors nominally considered the 6-month period of June 2012 through November 2012 although some examples expanded beyond those dates where the scope of the trend warranted.
The inspectors also included issues documented outside the normal corrective action program in major equipment problem lists, repetitive and/or rework maintenance lists, departmental problem/challenges lists, system health reports, quality assurance audit/surveillance reports, self-assessment reports, and Maintenance Rule assessments.
The inspectors compared and contrasted their results with the results contained in the licensees corrective action program trending reports. Corrective actions associated with a sample of the issues identified in the licensees trending reports were reviewed for adequacy.
These activities constitute completion of one semi-annual trend inspection sample as defined in Inspection Procedure 71152-05.
b. Findings
No findings were identified.
4OA3 Follow-up of Events and Notices of Enforcement Discretion
(Closed) Licensee Event Report 2012-002-00, Failure of 120-V Vital Instrument System Power Inverter NN14 On August 19, 2012, safety-related inverter NN14 failed. After determining the cause of the failure, the length of time to repair, test, and return to service; the licensee requested enforcement discretion since activities would extend beyond the allowed outage time specified in technical specifications. On October 15, 2012, the licensee reported this failure in Licensee Event Report 2012-002-00, Failure of 120-V Vital Instrument System Power Inverter NN14.
The NRC documented this failure as an unresolved item (URI 05000483/2012004-03, "Review Cause of the Failure of Inverter NN14") in inspection report 05000483/2012004-03. The inspectors follow-up review and any enforcement actions related to this licensee event report and the unresolved item are documented in Section 4OA5 of this report. This license event report is closed.
4OA5 Other Activities
.1 Institute of Nuclear Power Operations Plant Assessment Report Review
a. Inspection Scope
The inspectors reviewed the final report for the Institute of Nuclear Power Operations plant assessment of Callaway Plant conducted in August 2012. The inspectors reviewed the report to ensure that issues identified were consistent with the NRC perspectives of licensee performance and to verify whether any significant safety issues were identified that required further NRC follow-up.
b. Findings
No findings were identified.
.2 (Closed) URI 05000483/2012004-03, Review Cause of the Failure of Inverter NN14
On August 19, 2012, safety-related inverter NN14 failed. After determining the cause of the failure, the length of time to repair, test, and return to service; the licensee requested enforcement discretion since activities would extend beyond the allowed outage time specified in technical specifications. An unresolved item (URI 05000483/2012004-03, Review Cause of the Failure of Inverter NN14) was identified to assess whether the cause for the noncompliance, for which a Notice of Enforcement Discretion was granted, involved a violation.
On July 27 and August 13, 2012, safety related inverter NN14 unexpectedly auto-transferred to the backup source. The licensee entered Technical Specification 3.8.7, Action A.1, which required returning the inverter to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or placing the plant in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. Troubleshooting efforts concluded that the most likely cause for the inadvertent auto-transfer was a degraded card associated with the automatic static transfer switch. This card was replaced along with successful completion of post-maintenance testing.
On August 19, 2012, inverter NN14 failed again. The licensee entered Technical Specification 3.8.7, Action A.1. Troubleshooting revealed that the constant-voltage transformer phase B secondary windings were shorted to ground. The most probable cause of the short was determined to be degradation of the transformer windings/insulation.
In consultation with the vendor, the licensee determined that following replacement of the transformer, post-maintenance testing and temperature/voltage stabilization would exceed the time allowed by technical specifications. Therefore, the licensee contacted the NRC on August 20, 2012, to request enforcement discretion to extend the allowed outage time of Technical Specification 3.8.7, Action A.1, for an additional 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (a total of 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />).
On September 20, 2012, the licensee completed the root cause for inverter NN14 failure.
The failure was attributed to inadequate insulating varnish. This inverter was replaced in 1994 and had an expected life span on forty years. In 1998 the vendor changed to a different type varnish that is considered more robust. Despite the vendor change, there was no expectation that the original varnish would degrade to cause a failure after only eighteen years of service, less than half the life expectancy.
The inspectors noted that the intermittent symptoms that accompanied the eventual failure of the transformer did not appear to indicate a transformer problem. Therefore, it was reasonable for the licensee to pursue possible problems with inverter cards. The inspectors confirmed that the vendor did not recommend periodic transformer replacement, and there was no relevant operating experience that contained symptoms similar to those experiences in this case.
The inspectors reviewed the event, the actions taken prior to inverter NN14 failure, and the corrective actions the licensee is taking to preclude further failures. The inspectors identified no performance deficiency associated with the cause of the failure. This constitutes completion of one occurrence of inspection procedure 71153 and closes unresolved item: URI 05000483/2012004-03, "Review Cause of the Failure of Inverter NN14."
Specific documents reviewed during this inspection are listed in the attachment.
.3 Temporary Instruction 2515/182, Review of the Implementation of the Industry Initiative
to Control Degradation of Underground Piping and Tanks The licensees buried piping and underground piping and tanks program was inspected in accordance with paragraphs 03.01.a through 03.01.c of the temporary instruction and was found to be consistent with the guidance in NEI 09-14, Guidance for the Management of Underground Piping and Tank Integrity, Revision 1, (ADAMS Accession No. ML110700122), as set forth in Table 1 of the temporary instruction.
This inspection effort counts toward the completion of Temporary Instruction 2515/182, which will be closed in a later inspection report. Specific documents reviewed during this inspection are listed in the attachment.
.4 (Closed) Temporary Instruction 2515/177, Managing Gas Accumulation in Emergency
Core Cooling, Decay Heat Removal and Containment Spray Systems (NRC Generic Letter 2008-01)
a. Inspection Scope
As documented in Inspection Reports 05000483/2010003 and 05000483/2011004 the inspectors completed activities associated with Temporary Instruction 2515/177.
b. Findings
No findings were identified.
4OA6 Meetings, Including Exit
Exit Meeting Summary
On November 8, 2012, the inspectors discussed the results of the licensed operator annual requalification examination and conducted a telephonic exit meeting with Mr. L. Wilhelm, Operating Supervisor, Operations Training. The licensee acknowledged the results of the inspection presented in the final exit meeting. The inspectors confirmed that proprietary information was not provided or examined during the inspection.
On December 27, 2012, the inspectors presented the resident inspection results to Mr. D.
Neterer, Senior Director Nuclear Operations, 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 retained.
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- L. Bodenschatz, Engineer, Maintenance Rule
- M. Covey, Assistant Operations Manager
- B. Cox, Senior Director, Nuclear Operations
- F. Diya, Vice President, Nuclear Operations
- L. Eitel, Supervising Engineer Systems, Balance of Plant
- T. Elwood, Supervising Engineer, Regulatory Affairs and Licensing
- L. Graessle, Senior Director, Operations Support
- J. Little, Supervising Engineer, Reactor/Safety Analysis
- S. Maglio, Regulatory Affairs Manager
- P. McKenna, Manager, Emergency Preparedness
- S. Petzel, Engineer, Regulatory Affairs
- C. Reasoner, Vice President, Engineering
NRC Personnel
- J. Bettle, NRR/DSS/SCVB, Reactor Systems Engineer
- K. Bucholtz, NRR/DSS/STSB, Reactor Systems Engineer
- R. Elliott, NRR/DSS/STSB, Branch Chief
- G. Waig, NRR/DSS/STSB, Senior Reactor Systems Engineer
LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Opened
- 05000483/2012005-03 URI Determine Licensing Basis and Capability of One Vital Air Conditioning Unit to Cool Both Trains of Class 1E Electrical Equipment (Section 1R15.b.2)
Opened and Closed
- 05000483/2012005-01 NCV Failure to Perform Technical Specification Surveillance Requirements on the Control Room Air Conditioning System (Section 1R07)
- 05000483/2012005-02 NCV Failure to Comply with Technical Specification 5.5.14, Technical Specifications (TS) Bases Control Program (Section 1R15.b.1)
Attachment
- 05000483/2012-002-00 LER Failure of 120-V Vital Instrument System Power Inverter NN14 (Section 4OA3)
- 05000483/2012004-03 URI Review Cause of the Failure of Inverter NN14 (Section 4OA5)
2515/177 TI Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems (NRC Generic Letter 2008-01) (Section 4OA5)
Discussed
2515/182 TI Review of the Implementation of the Industry Initiative to Control Degradation of Underground Piping and Tanks (Section 4OA5)