IR 05000352/2016002
| ML16214A219 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 08/01/2016 |
| From: | Daniel Schroeder Reactor Projects Region 1 Branch 4 |
| To: | Bryan Hanson Exelon Generation Co |
| Schroeder D | |
| References | |
| IR 2016002 | |
| Download: ML16214A219 (27) | |
Text
B. Hanso UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION I
2100 RENAISSANCE BLVD.
KING OF PRUSSIA, PA 19406-2713 August 1, 2016 Mr. Bryan Senior Vice President, Exelon Generation Company, LLC President and Chief Nuclear Officer, Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555 SUBJECT: LIMERICK GENERATING STATION - INTEGRATED INSPECTION REPORT 05000352/2016002 AND 05000353/2016002
Dear Mr. Hanson:
On June 30, 2016, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Limerick Generating Station (LGS), Units 1 and 2. The enclosed report documents the inspection results, which were discussed on July 27, 2016 with Mr. Rick Libra, Site Vice President, and other members of your staff.
NRC Inspectors 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.
No NRC-identified or self-revealing findings were identified during this inspection.
In accordance with Title 10 of the Code of Federal Regulations (CFR) 2.390 of the NRCs Rules of Practice, a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRCs Public Document Room or from the Publicly Available Records component of the NRCs Agencywide Documents Access and Management System (ADAMS). ADAMS is accessible from the NRCs website at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Docket Nos. 50-352 and 50-353 License Nos. NPF-39 and NPF-85
Enclosure:
Inspection Report 05000352/2016002 and 05000353/2016002 w/Attachment: Supplementary Information
REGION I==
Docket Nos.: 50-352 and 50-353 License Nos.: NPF-39 and NPF-85 Report No.: 05000352/2016002 and 05000353/2016002 Licensee: Exelon Generation Company, LLC Facility: Limerick Generating Station, Units 1 & 2 Location: Sanatoga, PA 19464 Dates: April 1, 2016 through June 30, 2016 Inspectors: S. Rutenkroger, PhD, Senior Resident Inspector M. Fannon, Resident Inspector J. Kulp, Senior Reactor Inspector M. Modes, Senior Reactor Inspector J. Schussler, Project Engineer Approved By: Daniel L. Schroeder, Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure
SUMMARY
IR 05000352/2016002 and 05000353/2016002; 4/1/2016 - 6/30/16; Limerick Generating Station (LGS); Routine Integrated Inspection Report.
This report covered a three-month period of inspection by resident inspectors and announced baseline inspections performed by regional inspectors. No findings were identified. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 5.
REPORT DETAILS
Summary of Plant Status
Unit 1 began the inspection period in Operational Condition 5 (Refueling) with the reactor cavity flooded in refueling outage 1R16. Following the completion of outage activities, operators commenced a reactor startup on April 15 and on April 17, operators synchronized the main generator to the electrical grid. The unit reached 100 percent on April 18, and the unit remained at or near 100 percent for the remainder of the inspection period.
Unit 2 began the inspection period at 100 percent power. On May 20, operators reduced power to approximately 63 percent for a rod pattern adjustment and waterbox cleaning. Operators returned the unit to 100 percent power on May 22. On June 1, operators conducted a rapid plant shutdown and manually scrammed the reactor per procedure following the loss of both reactor recirculation pumps. Operators commenced a normal reactor startup on June 2, and the unit reached 100 percent on June 3. The unit remained at or near 100 percent for the remainder of the inspection period.
REACTOR SAFETY
Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity
1R01 Adverse Weather Protection
.1 Summer Readiness of Offsite and Alternate Alternating Current (AC) Power Systems
a. Inspection Scope
The inspectors performed a review of plant features and procedures for the operation and continued availability of the offsite and alternate AC power system to evaluate readiness of the systems prior to seasonal high grid loading. The inspectors reviewed Exelons procedures affecting these areas and the communications protocols between the transmission system operator and Exelon. This review focused on changes to the established program and material condition of the offsite and alternate AC power equipment. The inspectors assessed whether Exelon established and implemented appropriate procedures and protocols to monitor and maintain availability and reliability of both the offsite AC power system and the onsite alternate AC power system. The inspectors evaluated the material condition of the associated equipment by interviewing the responsible system manager and reviewing condition reports and open work orders.
b. Findings
No findings were identified.
1R04 Equipment Alignment
.1 Partial System Walkdowns
a. Inspection Scope
The inspectors performed partial walkdowns of the following systems:
- Unit 1 A residual heat removal (RHR) while in alternate decay heat removal mode on April 6, 2016
- Unit common A control enclosure chiller during B control enclosure chiller maintenance on May 10, 2016
- Unit common A standby gas treatment system (SGTS) during the B SGTS system outage window on May 17, 2016 The inspectors selected these systems based on their risk-significance relative to the reactor safety cornerstones at the time they were inspected. The inspectors reviewed applicable operating procedures, system diagrams, the updated final safety analysis report (UFSAR), technical specifications, work orders, condition reports, and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted the systems performance of its intended safety functions. The inspectors also performed field walkdowns of accessible portions of the systems to verify system components and support equipment were aligned correctly and were operable.
The inspectors examined the material condition of the components and observed operating parameters of equipment to verify that there were no deficiencies. The inspectors also reviewed whether Exelon staff had properly identified equipment issues and entered them into the corrective action program for resolution with the appropriate significance characterization.
b. Findings
No findings were identified.
1R05 Fire Protection
.1 Resident Inspector Quarterly Walkdowns
a. Inspection Scope
The inspectors conducted tours of the areas listed below to assess the material condition and operational status of fire protection features. The inspectors verified that Exelon controlled combustible materials and ignition sources in accordance with administrative procedures. The inspectors verified that fire protection and suppression equipment was available for use as specified in the area pre-fire plan, and passive fire barriers were maintained in good material condition. The inspectors also verified that station personnel implemented compensatory measures for out of service, degraded, or inoperable fire protection equipment, as applicable, in accordance with procedures.
- Fire area 30, Unit 1 drywell, elevation 253, on April 11, 2016
- Fire area 31, Unit 1 B and D RHR heat exchanger and pump rooms, elevation 177 and 201, on April 12, 2016
- Fire area 89 and 102, Unit 1 and Unit 2 control rod drive pump areas, elevation 200, on May 4, 2016
- Fire area 58, Unit 2 B core spray pump room, elevation 177, on May 18, 2016
- Fire areas 1, 22, 23, 25, 26, 27, and 28, Unit common control enclosure, on June 21, 2016
b. Findings
No findings were identified.
1R07 Heat Sink Performance (711111.07A - 1 sample)
a. Inspection Scope
The inspectors reviewed the Unit 1 reactor core isolation cooling (RCIC) lube oil cooler heat exchanger readiness and availability to perform its safety functions. The inspectors reviewed the design basis for the component and verified Exelons commitments to NRC Generic Letter 89-13, Service Water System Requirements Affecting Safety-Related Equipment. The inspectors observed actual performance tests for the heat exchangers and/or reviewed the results of previous inspections of the Unit 1 RCIC lube oil cooler.
The inspectors discussed the results of the most recent inspection with engineering staff and reviewed pictures of the as-found and as-left conditions. The inspectors verified that Exelon initiated appropriate corrective actions for identified deficiencies. The inspectors also verified that the number of tubes plugged within the heat exchanger did not exceed the maximum amount allowed.
b. Findings
No findings were identified.
1R08 In-Service Inspection
a. Inspection Scope
From March 28 - 31, and April 6, 2016, the inspectors conducted an inspection and review of in-service inspection program activities in order to assess the effectiveness of Exelons program at Limerick Generating Station, Unit 1 for monitoring degradation of the reactor coolant system boundary, risk-significant piping system boundaries, and the containment boundary.
Nondestructive Examination and Welding Activities (IMC Section 02.01)
The inspectors reviewed the nondestructive evaluation of five risk-significant welds in the residual heat removal system. The welds reviewed were ISI-51RM400 UT-E RHA-001, 004, 005 and 009, and weld DW295 UT-E RHA-005A. The inspectors review entailed direct observation and record reviews. The inspectors verified the risk-significant welds were chosen for examination by Limerick staff based on EPRI TR-112657 Revised Risk-Informed Inservice Inspection Evaluation Procedure, Revision B-A (ADAMS Accession No. ML013470102) with Code Case N-578-1, or Code Case N-716-1.
For each evaluation the inspectors verified that that nondestructive evaluation activities were performed in accordance with the 2001 Edition, Addenda 2003 with errata, of the American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel Code requirements. The inspectors verified the nondestructive test met the requirements contained in ASME Section XI, Mandatory Appendix VIII, Article VIII-2000 and the examination personnel were qualified in accordance with ASME Section XI, Mandatory Appendix VII. The inspectors verified that indications and defects, if present, were dispositioned in accordance with the ASME Code and verified that relevant indications were compared to previous examinations to determine if any changes had occurred.
No relevant indications were accepted, by table or analysis, during the prior outage and returned to service.
Welding on Pressure Boundary Systems The inspectors reviewed the pressure boundary risk significant welding activity, including associated nondestructive examination, of the replacement of a section of leaking 3/4 inch schedule 160 pressure boundary equalizing pipe attached to check valve HV-051-1F050A. The inspectors verified that the welding, nondestructive evaluation, and acceptance were performed in accordance with 2001 Edition, Addenda 2003 with errata of the ASME Boiler and Pressure Vessel Code requirements, where applicable, as part of the Exelon Repair and Replacement program. The inspectors verified the following features of the welding evolution:
1. The Welding Procedure Specification contained the essential, and where applicable the supplemental essential variables, in conformance with ASME Section IX, QW-200.
2. The Welding Procedure Specification essential and supplemental essential weld variables were within the range qualified by the supporting Procedure Qualification Record as required by ASME Code Section IX, QW-250.
3. Reviewed weld records to determine if they were performed with the base and weld filler materials listed in the Welding Procedure Specification.
4. Reviewed the records of final acceptance Nondestructive Evaluation to determine if the ASME Section XI repair and replacement program were applied.
Identification and Resolution of Problems (IMC 02.05)
The inspectors verified that Limerick staff were identifying inservice inspection problems at an appropriate threshold and entering them in the corrective action program. The inspectors selected a sample of problems associated with inservice inspection documented by Limerick staff and verified the appropriateness of the corrective actions.
The inspectors used the guidance in NRC inspection procedure 71152, Identification and Resolution of Problems, to evaluate the corrective actions. The inspector also determined if Limerick staff was assessing the applicability of operating experience in this area to their plant.
b. Findings
No findings were identified.
1R11 Licensed Operator Requalification Program and Licensed Operator Performance
.1 Quarterly Review of Licensed Operator Requalification Testing and Training
a. Inspection Scope
The inspectors observed licensed operator simulator training scenarios on June 20, 2016. The scenarios included loss of turbine enclosure cooling water, loss of the A recirculation pump adjustable speed drive, and a reactor coolant system leak.
The scenarios were complicated by a loss of the A narrow range reactor vessel level instrumentation, failure of the C reactor feed pump discharge valve, and failure of the K safety relief valve to open. The inspectors evaluated operator performance during the simulated events and verified completion of risk significant operator actions, including the use of abnormal and emergency operating procedures. The inspectors assessed the clarity and effectiveness of communications, implementation of actions in response to alarms and degrading plant conditions, and the oversight and direction provided by the control room supervisor. The inspectors verified the accuracy and timeliness of the emergency classifications made by the shift manager and the TS action statements entered by the shift technical advisor. Additionally, the inspectors assessed the ability of the crew and training staff to identify and document crew performance problems.
b. Findings
No findings were identified.
.2 Quarterly Review of Licensed Operator Performance in the Main Control Room
a. Inspection Scope
The inspectors observed and reviewed licensed operator performance in the main control room during the performance of the Unit 1 startup on April 15, 2016 and Unit 2 startup on June 2, 2016. The inspectors observed infrequently performed test or evolution briefings and reactivity control briefings to verify that the briefings met the criteria specified in Exelons Operations and Administrative Procedures. Additionally, the inspectors observed test performance to verify that procedure use, crew communications, and coordination of activities between work groups similarly met established expectations and standards.
b. Findings
No findings were identified.
1R12 Maintenance Effectiveness
a. Inspection Scope
The inspectors reviewed the sample listed below to assess the effectiveness of maintenance activities on structure, system, and component performance and reliability.
The inspectors reviewed system health reports, corrective action program documents, maintenance work orders, and maintenance rule basis documents to ensure that Exelon was identifying and properly evaluating performance problems within the scope of the maintenance rule. For each sample selected, the inspectors verified that the structure, system, or component was properly scoped into the maintenance rule in accordance with 10 CFR 50.65 and verified that the (a)(2) performance criteria established by Exelon staff was reasonable. As applicable, for structures, systems, and components classified as (a)(1), the inspectors assessed the adequacy of goals and corrective actions to return these structures, systems, and components to (a)(2). Additionally, the inspectors ensured that Exelon staff was identifying and addressing common cause failures that occurred within and across maintenance rule system boundaries.
- Unit 2 D23 emergency diesel generator (EDG) maintenance outage quality control review on June 30, 2016
b. Findings
No findings were identified.
1R13 Maintenance Risk Assessments and Emergent Work Control
a. Inspection Scope
The inspectors reviewed station evaluation and management of plant risk for the maintenance and emergent work activities listed below to verify that Exelon performed the appropriate risk assessments prior to removing equipment for work. 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 Exelon personnel performed risk assessments as required by 10 CFR 50.65(a)(4) and that the assessments were accurate and complete. When Exelon performed emergent work, the inspectors verified that operations personnel promptly assessed and managed plant risk.
The inspectors reviewed the scope of maintenance work and discussed the results of the assessment with the stations probabilistic risk analyst to verify 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.
- Unit 1 RCIC functional testing and calibration of steam supply pressure low trip, division 3, channel C, on April 27, 2016
- Unit 1 B RHR maintenance outage on May 3, 2016
- Unit common B SGTS maintenance outage on May 17, 2016
b. Findings
No findings were identified.
1R15 Operability Determinations and Functionality Assessments
a. Inspection Scope
The inspectors reviewed operability determinations for the following degraded or non-conforming conditions based on the risk significance of the associated components and systems:
- Unit 1 RHR low pressure coolant injection header high point vent valve leakby on April 13, 2016
- Unit 1 D outboard main steam isolation valve (MSIV) slow stroke time on April 6, 2016
- Unit 1 Snubber DLA-108-H012 found with high drag values on April 6, 2016
- Unit 2 A standby liquid control pump did not produce the required flow rate on April 27, 2016
- Unit 1 D12 and Unit 2 D23 EDGs heat exchanger outlet expansion joint alignments on June 27, 2016
- Unit 2 D23 EDG heat exchanger inlet expansion joint bulge on June 29, 2016
- Unit 2 main steam drain isolation, primary containment isolation valve, HV-041-2F019, pressure seal leak on June 29, 2016 The inspectors evaluated the technical adequacy of the operability determinations to assess whether technical specification operability was properly justified and 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 UFSAR to Exelons evaluations to determine whether the components or systems were operable. The inspectors confirmed, where appropriate, compliance with bounding limitations associated with the evaluations.
Where compensatory measures were required to maintain operability, the inspectors determined whether the measures in place would function as intended and were properly controlled by Exelon.
b. Findings
No findings were identified.
1R19 Post-Maintenance Testing
a. Inspection Scope
The inspectors reviewed the post-maintenance tests for the maintenance activities listed below to verify that procedures and test activities adequately tested the safety functions that may have been affected by the maintenance activity, that the acceptance criteria in the procedure were consistent with the information in the applicable licensing basis and/or design basis documents, and that the test results were properly reviewed and accepted and problems were appropriately documented.
The inspectors also walked down the affected job site, observed the pre-job brief and post-job critique where possible, confirmed work site cleanliness was maintained, and witnessed the test or reviewed test data to verify quality control hold point were performed and checked, and that results adequately demonstrated restoration of the affected safety functions.
- Unit 1 electrical panel 10Y-163 feeder breaker replacement due to a loosened connection causing overheating on April 4, 2016
- Unit common B emergency service water discharge piping return to A residual heat removal service water blank flange plate removal on April 7, 2016
- Unit 1 control rod scram time testing following maintenance during 1R16 on April 10, 2016
- Unit 1 high pressure coolant injection following maintenance during 1R16 on April 16, 17, and 18, 2016
- Unit 1 RCIC comprehensive test following maintenance outage on April 16, 2016
- Unit 2 D14 blower inspection plate bolting replacement on April 28, 2016
- Unit 2 RCIC remote shutdown instrumentation inverter replacement on June 1, 2016
- Unit 2 turbine control valve R-line valve positioner circuit card replacement on June 14, 2016
b. Findings
No findings were identified.
1R20 Refueling and Other Outage Activities
a. Inspection Scope
The inspectors reviewed the stations work schedule and outage risk plan for the Unit 1 maintenance and refueling outage 1R16, conducted March 20 through April 17, 2016.
The inspectors reviewed Exelons development and implementation of outage plans and schedules to verify that risk, industry experience, previous site-specific problems, and defense-in-depth were considered. During the outage, the inspectors observed portions of the shutdown and cooldown processes and monitored controls associated with the following outage activities:
- Configuration management, including maintenance of defense-in-depth, commensurate with the outage plan for the key safety functions and compliance with the applicable technical specifications when taking equipment out of service
- Implementation of clearance activities and confirmation that tags were properly hung and that equipment was appropriately configured to safely support the associated work or testing
- Installation and configuration of reactor coolant pressure, level, and temperature instruments to provide accurate indication and instrument error accounting
- Status and configuration of electrical systems and switchyard activities to ensure that technical specifications were met
- Monitoring of decay heat removal operations
- Impact of outage work on the ability of the operators to operate the spent fuel pool cooling system
- Reactor water inventory controls, including flow paths, configurations, alternative means for inventory additions, and controls to prevent inventory loss
- Activities that could affect reactivity
- Maintenance of secondary containment as required by technical specifications
- Refueling activities, including fuel handling and fuel receipt inspections
- Fatigue management
- Tracking of startup prerequisites, walkdown of the drywell (primary containment) to verify that debris had not been left which could block the emergency core cooling system suction strainers, and startup and ascension to full power operation
- Identification and resolution of problems related to refueling outage activities
b. Findings
No findings were identified.
1R22 Surveillance Testing
a. Inspection Scope
The inspectors observed performance of surveillance tests and/or reviewed test data of selected risk-significant structures, systems, and components to assess whether test results satisfied technical specifications, the UFSAR, and Exelon procedure requirements. The inspectors verified that test acceptance criteria were clear, tests demonstrated operational readiness and were consistent with design documentation, test instrumentation had current calibrations and the range and accuracy for the application, tests were performed as written, and applicable test prerequisites were satisfied. Upon test completion, the inspectors considered whether the test results supported that equipment was capable of performing the required safety functions.
The inspectors reviewed the following surveillance tests:
- ST-6-092-117-1, D13 EDG loss of offsite power and loss of coolant accident logic system functional test on April 1, 2016
- ST-2-042-932-2, Unit 2 reactor vessel water level low - level 3; division 1A, channel A response time test on April 26, 2016
- ST-6-052-232-2,Unit 2 B loop core spray pump, valve, and flow test on April 26, 2016
- ST-6-107-790-2, Unit 2 control rod scram timing on June 1, 2016
- ST-6-051-231-1, Unit 1 A RHR pump, valve, and flow test on June 28, 2016
b. Findings
No findings were identified.
Cornerstone: Emergency Preparedness
1EP6 Drill Evaluation
.1 Emergency Preparedness Drill Observation
a. Inspection Scope
The inspectors evaluated the conduct of a routine Exelon emergency drill on June 27, 2016, to identify any weaknesses and deficiencies in the classification, notification, and protective action recommendation development activities. The inspectors observed emergency response operations in the simulator and technical support center to determine whether the event classification, notifications, and protective action recommendations were performed in accordance with procedures. The inspectors also attended the station drill critique to compare inspector observations with those identified by Exelon staff in order to evaluate Exelons critique and to verify whether the Exelon staff was properly identifying weaknesses and entering them into the corrective action program.
b. Findings
No findings were identified.
OTHER ACTIVITIES
4OA1 Performance Indicator Verification
.1 Safety System Functional Failures (2 samples)
a. Inspection Scope
The inspectors sampled Exelons submittals for the Safety System Functional Failures performance indicator for both Unit 1 and Unit 2 for the period of April 1, 2015, through March 31, 2016. To determine the accuracy of the performance indicator data reported during those periods, inspectors used definitions and guidance contained in Nuclear Energy Institute (NEI) Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 7, and NUREG-1022, Event Reporting Guidelines 10 CFR 50.72 and 10 CFR 50.73." The inspectors reviewed Exelons operator narrative logs, operability assessments, maintenance rule records, maintenance work orders, condition reports, event reports and NRC integrated inspection reports to validate the accuracy of the submittals.
b. Findings
No findings were identified.
.2 Mitigating Systems Performance Index (2 samples)
a. Inspection Scope
The inspectors reviewed Exelons submittal of the Mitigating Systems Performance Index for the following systems for the period of April 1, 2015, through March 31, 2016:
- Unit 1 Emergency AC Power System
- Unit 2 Emergency AC Power System 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 7. The inspectors also reviewed Exelons operator narrative logs, condition reports, mitigating systems performance index derivation reports, event reports, and NRC integrated inspection reports to validate the accuracy of the submittals.
b. Findings
No findings were identified.
4OA2 Problem Identification and Resolution
.1 Routine Review of Problem Identification and Resolution Activities
a. Inspection Scope
As required by Inspection Procedure 71152, Problem Identification and Resolution, the inspectors routinely reviewed issues during baseline inspection activities and plant status reviews to verify Exelon entered issues into the corrective action program at an appropriate threshold, gave adequate attention to timely corrective actions, and identified and addressed adverse trends. 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 corrective action program and periodically attended condition report screening meetings. The inspectors also confirmed, on a sampling basis, that, as applicable, for identified defects and non-conformances, Exelon performed an evaluation in accordance with 10 CFR Part 21.
b. Findings
No findings were identified.
.2 Semi-Annual Trend Review (1 sample)
a. Inspection Scope
The inspectors performed a semi-annual review of site issues, as required by Inspection Procedure 71152, Problem Identification and Resolution, to identify trends that might indicate the existence of more significant safety issues. In this review, the inspectors included repetitive or closely-related issues that may have been documented by Exelon outside of the corrective action program, such as trend reports, performance indicators, major equipment problem lists, system health reports, maintenance rule assessments, and maintenance or corrective action program backlogs. The inspectors also reviewed Exelons corrective action program database for the first and second quarters of 2016 to assess condition reports written in various subject areas (equipment problems, human performance issues, etc.), as well as individual issues identified during the NRCs daily condition report review (Section 4OA2.1). The inspectors reviewed Exelons trending information conducted under PI-AA-1001 to verify that Exelon personnel were appropriately evaluating and trending adverse conditions in accordance with applicable procedures.
b. Findings and Observations
No findings were identified.
The review did not reveal any new trends that could indicate a more significant safety issue. The inspectors determined that Exelon personnel were identifying issues at a low threshold and entering issues into the corrective action program for resolution and appropriately prioritizing investigation reviews. The inspectors specifically evaluated a trend in defective Ametek annunciator cans identified by Exelon and reviewed the applicable condition reports. The inspectors noted six different occurrences where a defective annunciator can resulted in loss of an annunciator panel. The defective cans were identified to be from two manufacturer date batches. These cans were replaced, retested, and returned to service. Exelon initiated corrective actions to assess the current stock of replacement annunciator cans, identify any potential cans from the defective batches, and determine if other batches had similar deficiencies.
The inspectors also noted and evaluated a declining trend in human performance identified by Exelon and reviewed the applicable condition reports. For example, there were human performance issues involving a fuse installed in the incorrect location, a missed step in a chemistry procedure, and a partial MSIV isolation during a relay replacement. These issues in aggregate represent a negative trend in configuration control performance. Exelon performed causal evaluations for the configuration control events and is working to implement a site wide configuration control intervention plan.
The inspectors determined that the issues were of minor safety significance and that Exelons identification of a declining trend was appropriate.
Based on the overall results of the semi-annual trend review, the inspectors determined that Exelon was appropriately identifying and entering issues into the corrective action program, adequately evaluating the issues, and properly identifying adverse trends before they became more safety significant problems.
.3 Annual Sample: Review of the Repair of Steam Leak in EBD-208-2 downstream of
HV-041-2F021 (1 sample)
a. Inspection Scope
The inspectors reviewed corrective actions associated with work order C0257090, describing the repair of the steam leak in EBD-208-2 downstream of HV-041-2F021.
EBD-208-2 is the alternate MSIV drain pathway designed to divert fission products that could leak past the closed MSIVs after a loss of coolant accident as described in the UFSAR at 6.7.2. The possible leakage is diverted to a hold-up volume in the high pressure shell of the main condenser. As a consequence of its alternative function, this line is classified as ASME Boiler and Pressure Vessel Code Section III no-class. This classification gives the licensee wider latitude in designing and implementing a repair for the through-wall leak.
The inspectors determined if the documentation was complete and accurate and entered in timely manner. The corrective action, which involved installation of an engineered welded plate followed by longer term component replacement plans, was reviewed for its evaluation and disposition of operability and reportability issues, consideration of extent of condition and cause, generic implications, common cause, and previous occurrences.
The corrective action was further reviewed to determine if the classification and prioritization of the problems resolution was commensurate with the safety significance.
The inspectors reviewed various related documents and interviewed station personnel.
The derived information was compared with the corrective actions contributing causes of the problem. The comparison focused on the identification of the condition and the corrective action taken. The inspectors ascertained if the documented information was reported to appropriate levels of management. The inspectors reviewed the corrective action to determine if the corrective action was appropriately focused to correct the problem (and to address the root and contributing causes for significant conditions adverse to quality).
The inspectors then determined if the completion of corrective actions was in a timely manner commensurate with the safety significance of the issue. The inspectors considered if any delays in implementation were justified based on the safety significance of the issue. The inspectors considered if any permanent corrective actions required significant time to implement and if interim corrective actions and/or compensatory actions were identified and implemented to minimize the problem and/or mitigate its effects until the permanent action could be implemented.
The inspectors reviewed the actions taken to determine if the actions resulted in the correction of the identified problem. In the case of this significant condition adverse to quality, the inspectors determined if the corrective action taken would preclude repetition. In addition, the inspectors compared the corrective action against related negative trends associated with human or equipment performance to determine if the corrective action can potentially impact nuclear safety.
Finally, the inspectors reviewed operating experience to determine if it was adequately evaluated for applicability, and applicable lessons learned were communicated to appropriate organizations and implemented.
b. Findings
No findings were identified.
4OA3 Follow-Up of Events and Notices of Enforcement Discretion
.1 Plant Events
a. Inspection Scope
For the plant events listed below, the inspectors reviewed and/or observed plant parameters, reviewed personnel performance, and evaluated performance of mitigating systems. The inspectors communicated the plant events to appropriate regional personnel, and compared the event details with criteria contained in IMC 0309, Reactive Inspection Decision Basis for Reactors, for consideration of potential reactive inspection activities. As applicable, the inspectors verified that Exelon made appropriate emergency classification assessments and properly reported the event in accordance with 10 CFR Parts 50.72 and 50.73. The inspectors reviewed Exelons follow-up actions related to the events to assure that Exelon implemented appropriate corrective actions commensurate with their safety significance.
- Unit 2 manual scram due to unexpected core flow changes on June 1, 2016 (Event Number 51968)
b. Findings
No findings were identified.
.2 (Closed) Licensee Event Report (LER) 05000352/2016-001-00: Condition That Could Have
Prevented the Fulfillment of the Reactor Enclosure Secondary Containment Integrity Safety Function On January 25, 2016, the main control room was notified that the local airlock open door alarm was activated when a worker in the residual heat removal service water/emergency service water pipe tunnel opened the airlock outboard door. The investigation determined that the worker using the airlock properly verified that the door open blue light indication was not lit and then opened the outboard airlock door which activated the local airlock alarm.
The cause was a degraded inboard door closing mechanism that resulted in the inboard door opening enough to activate the alarm when the outboard door was opened. The door closing mechanism was adjusted. TS 3.6.5.1.1. Reactor Enclosure Secondary Containment Integrity, Surveillance Requirement 4.6.5.1.1.b, requires at least one door in each access to the reactor enclosure be closed. The airlock doors were re-closed within 10 seconds, well within the Limiting Condition of Operation 3.6.5.1.1 action time limit of four hours. As a result, a violation of plant TS did not occur. The inspectors did not identify any new issues during the review of the LER. This LER is closed.
4OA6 Meetings, Including Exit
On July 27, 2016, the inspectors presented the inspection results to Mr. Rick Libra, Site Vice President, and other members of the Exelon staff. The inspectors verified that no proprietary information was retained by the inspectors or documented in this report.
ATTACHMENT:
SUPPLEMENTARY INFORMATION
KEY POINTS OF CONTACT
Licensee Personnel
- R. Libra, Site Vice President
- D. Lewis, Plant Manager
- M. Herr, Director of Operations
- F. Sturniolo, Director of Engineering
- D. Palena, Director of Maintenance
- J. Hunter, Director of Work Management
- K. Kemper, Security Manager
- R. Dickinson, Manager, Regulatory Assurance
- R. Ruffe, Training Director
- H. Weissinger, Shift Operations Superintendent
- A. Hightower, Emergency Preparedness Manager
- G. Budock, Regulatory Assurance Engineer
- D. Molteni, Manager Operations Training
- M. DiRado, Manager, Engineering Programs
- D. Merchant, Radiation Protection Manager
- C. Gerdes, Manager, Chemistry, Environmental and Radioactive Waste
- B. Bielecki, Assistant Director of Engineering
- T. Ryan, Manager Engineering Programs
- C. Hawkins, NDE Level III
- K. Moore, Main Steam Piping, Valves and ADS System Engineer
- M. Karasek, Snubber Program Manager
- L. Cheung, Maintenance Planner
- M. Arnosky, Operations Shift Manger
LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED
Closed
- 05000352/2016-001-00 LER Condition That Could Have Prevented the Fulfillment of the Reactor Enclosure Secondary Containment Integrity Safety Function (Section 4OA3.2)