IR 05000352/2013005

IR 05000352-13-005, 05000353-13-005; 10/1/2013 - 12/31/2013; Limerick Generating Station (Lgs), Units 1 and 2; Followup of Events and Notices of Enforcement Discretion

ML14037A370
Person / Time
Site:	Limerick
Issue date:	02/06/2014
From:	Fred Bower Reactor Projects Region 1 Branch 4
To:	Pacilio M Exelon Generation Co, Exelon Nuclear
BOWER, FL
References
IR-13-005
Download: ML14037A370 (43)

Text

February 6, 2014

SUBJECT:

LIMERICK GENERATING STATION - NRC INTEGRATED INSPECTION REPORT 05000352/2013005 AND 05000353/2013005

Dear Mr. Pacilio:

On December 31, 2013, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at your Limerick Generating Station (LGS), Units 1 and 2. The enclosed inspection report documents the inspection results, which were discussed on January 10, 2014, with Mr. T. Dougherty, Site Vice President, 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.

NRC inspectors identified one self-revealing finding of very low safety significance (Green)

during this inspection. The finding did not involve a violation of NRC requirements. If you disagree with the cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the Regional Administrator, Region I; and the NRC Resident Inspector at the LGS.

As a result of the Safety Culture Common Language Initiative, the terminology and coding of cross-cutting aspects were revised beginning in calendar year 2014. New cross-cutting aspects identified in calendar year 2014 will be coded under the latest revision to Inspection Manual Chapter (IMC) 0310. Cross-cutting aspects identified in the last six months of 2013 using the previous terminology will be converted to the latest revision in accordance with the cross-reference in IMC 0310. The revised cross-cutting aspects will be evaluated for cross-cutting themes and potential substantive cross-cutting issues in accordance with IMC 0305 starting with the calendar year 2014 mid-cycle assessment review.

In accordance with 10 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 NRC Public Document Room or from the Publicly Available Records component of the NRCs Agencywide Documents Access System (ADAMS).

ADAMS is accessible from the NRC website at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

Fred L. Bower, III, Chief Reactor Projects Branch 4 Division of Reactor Projects

Docket Nos.: 50-352, 50-353 License Nos.: NPF-39, NPF-85

Enclosure:

Inspection Report 05000352/2013005 and 05000353/2013005

w/Attachment: Supplemental Information

REGION I==

Docket Nos.:

50-352, 50-353

License Nos.:

NPF-39, NPF-85

Report No.:

05000352/2013005 and 05000353/2013005

Licensee:

Exelon Generation Company, LLC

Facility:

Limerick Generating Station, Units 1 & 2

Location:

Sanatoga, PA 19464

Dates:

October 1, 2013 through December 31, 2013

Inspectors:

E. DiPaolo, Senior Resident Inspector

J. Hawkins, Resident Inspector

J. Ayala, Resident Inspector (Acting)

R. Nimitz, Senior Health Physicist

K. Mangan, Senior Reactor Inspector

T. Burns, Reactor Inspector

J. DAntonio, Senior Operations Engineer

B. Fuller, Senior Operations Engineer

S. Chaudhary, Reactor Inspector

Approved By:

Fred Bower, Chief

Reactor Projects Branch 4

Division of Reactor Projects

Enclosure

SUMMARY

IR 05000352/2013005, 05000353/2013005; 10/1/2013-12/31/2013; Limerick Generating Station (LGS), Units 1 and 2; Followup of Events and Notices of Enforcement Discretion.

This report covered a three month period of inspection by resident inspectors and announced inspections performed by regional inspectors. Inspectors identified one finding of very low safety significance (Green). The significance of most findings is indicated by their color (i.e., greater than Green, or Green, White, Yellow, Red) and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process, dated June 2, 2011. Cross-cutting aspects are determined using IMC 0310, Components Within Cross-Cutting Areas, dated October 28, 2011. All violations of Nuclear Regulatory Commission (NRC) requirements are dispositioned in accordance with the NRCs Enforcement Policy, dated January 28. 2013. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NRC Technical Report Designation (NUREG)-1649, Reactor Oversight Process,

Revision 4.

Cornerstone: Barrier Integrity

Green.

The inspectors identified a self-revealing finding (FIN) of very low safety significance (Green) for Exelons failure to appropriately prioritize work activities associated with a degraded Unit 2 magnetic switch for a secondary containment airlock door in accordance with Exelon procedure WC-AA-106, Work Screening and Processing. This resulted in both airlock doors being opened simultaneously due to equipment degradation and resulted in a momentary loss of reactor enclosure secondary containment integrity.

The failure of the station to properly prioritize the work order for the defective magnetic switch for the Unit 2 313 elevation reactor building-to-reactor building air supply room access airlock doors was a performance deficiency that was reasonably within Exelons ability to foresee and correct and could have been prevented. This was caused by not performing a site impact review of reportability clarifications made by NUREG 1022, Event Report Guidelines 10 CFR 50.72 and 50.73, Revision 3. The performance deficiency was also contrary to Exelons procedure for work screening and processing. The finding was determined to be more than minor because it was associated with the Barrier Integrity cornerstone attribute of structures, systems, and components (SSC) and Barrier Performance (doors and instrumentation) and affected the cornerstone objective of providing reasonable assurance that physical design barriers (secondary containment)protect the public from radionuclide releases caused by accidents or events. Specifically, opening two reactor building airlock doors at the same time did not maintain reasonable assurance that the secondary containment would be capable of performing its safety function in the event of a reactor accident. The finding was determined to be self-revealing because it was revealed through the receipt of an alarm in the main control room which required no active and deliberate observation by Exelon personnel. The finding was determined to be of very low safety significance (Green) in accordance with Appendix A of IMC 0609, "Significance Determination Process for Findings At-Power." Specifically, the finding only represents a degradation of the radiological barrier function provided by the secondary containment airlock doors. Exelon entered the issue into the corrective action program (CAP) as Issue Report (IR) 1553563. Corrective actions performed or planned included repairing the magnetic switch, verifying that the corrective maintenance backlog did not contain any other issues involving the airlock door indicating lights, developing a periodic routine test of the airlock door indicating circuits, and performing a site impact review of the changes in NUREG 1022, Revision 3.

This finding had a cross-cutting aspect in the area of Human Performance, Resources, because Exelon did not ensure that resources were available to minimize preventative maintenance deferrals and ensure maintenance and engineering backlogs were low enough to ensure that safety is maintained H.2(a). Specifically, Exelon deferred implementation of the work order several times over a three year period which resulted in secondary containment becoming inoperable on September 3, 2013. (Section 4OA3)

Other Findings

None.

REPORT DETAILS

Summary of Plant Status

Unit 1 began the inspection period at 100 percent power. On December 12, 2013, operators conducted a planned power reduction to approximately 60 percent to facilitate main steam valve testing, main turbine valve testing, control rod scram time testing, fuel channel distortion testing, and to repair a cooling water leak on the A main condensate pump. Operators returned the unit to 100 percent power on December 16, 2013, and Unit 1 remained at or near 100 percent power for the remainder of the inspection period.

Unit 2 began the inspection period at 100 percent power. On December 7, 2013, operators conducted a planned power reduction to approximately 92 percent to facilitate main turbine valve testing. Operators returned the unit to 100 percent power on December 8, 2013, and Unit 2 remained at or near 100 percent power for the remainder of the inspection period.

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

1R01 Adverse Weather Protection

.1 Readiness for Seasonal Extreme Weather Conditions

a. Inspection Scope

On December 11, 2013, the inspectors performed a review of Exelons readiness for the onset of seasonal cold weather. The review focused on the sites emergency diesel generators (EDGs) and equipment located in the sites Spray Pond Pump House (ie.,

emergency service water and residual heat removal service water pumps). The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR), Technical Specifications (TS), control room logs, and the corrective action program to determine what temperatures or other seasonal weather could challenge these systems, and to ensure Exelon personnel had adequately prepared for these challenges. The inspectors reviewed station procedures, including Exelons seasonal weather preparation procedure and applicable operating procedures. The inspectors performed walkdowns of the selected systems to ensure station personnel identified issues that could challenge the operability of the systems during cold weather conditions. Documents reviewed for each section of this inspection report are listed in the Attachment.

b. Findings

No findings were identified.

.2 Readiness for Impending Adverse Weather Conditions

a. Inspection Scope

On October 7, 2013, the inspectors reviewed Exelon staffs preparations in advance of and during a Tornado Watch issued by the National Weather Service for Montgomery County, Pennsylvania. The inspectors performed walkdowns of equipment that could be effected by high winds including the main transformer areas and the EDGs to verify that potential missile objects were secure. The inspectors verified that Exelon personnel performed preparations in accordance with severe weather procedures.

b. Findings

No findings were identified.

==1R04 Equipment Alignment

Partial System Walkdowns (71111.04 - 5 samples)

a. Inspection Scope

==

The inspectors performed partial walkdowns of the following systems:

Unit 2 high pressure coolant injection (HPCI) system (risk significant system)following the discovery of a degraded system flexible conduit (IR 1564080) on October 2, 2013

10 bus and 101 offsite power source when the 20 bus and 201 offsite source were out-of-service for planned maintenance on October 7, 2013

Unit 2 reactor core isolation cooling (RCIC) system when Unit 2 HPCI system was unavailable due to a flow controller issue (IR 1572132) on October 21, 2013

Unit 1 RCIC system (risk significant system) following return to service following RCIC vacuum breaker testing on November 26, 2013

Unit 2 HPCI system (risk significant system) following return to service following HPCI system simulated automatic actuation testing on December 19, 2013

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 UFSAR, TS, work orders, issue reports (IR), and the impact of ongoing work activities on redundant trains of equipment in order to identify conditions that could have impacted system performance of their 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.

Unit 1 Fire Area 45 - Control Rod Drive (CRD) Hydraulic Equipment Area and Neutron Monitoring System Area (Elevation 253) the week of October 7, 2013

Unit 2 Fire Area 45 - CRD Hydraulic Equipment Area and Neutron Monitoring System Area (Elevation 253) the week of October 7, 2013

Unit 1 Fire Area 13 - D11 4kV Room (Elevation 239) the week of October 21, 2013

Unit 1 Fire Area 22 - Unit 1 Cable Spreading Room (Elevation 254) on November 22, 2013

Common Fire Area 25 - Auxiliary Equipment Room 542 (Elevation 289) on November 26, 2013

b. Findings

No findings were identified.

.2 Fire Protection - Drill Observation

a. Inspection Scope

On November 14, 2013, the inspectors observed multiple fire drills for plant fire brigade members at the Philadelphia Electric Company Fire Training Facility in Conshohocken, Pennsylvania. The inspectors observed pre-job briefs, fire brigade assembly and donning of protective equipment, fire brigade performance, and communications between the fire brigade leader and simulated control room. The inspectors observed instructor critiques and assessed whether appropriate feedback was provided to the fire brigade.

b. Findings

No findings were identified.

1R06 Flood Protection Measures

Internal Flooding Review

a. Inspection Scope

The inspectors reviewed the UFSAR, the site flooding analysis, and plant procedures to assess susceptibilities involving internal flooding. The inspectors also reviewed the corrective action program to determine if Exelon identified and corrected flooding problems and whether operator actions for coping with flooding were adequate. The inspectors performed walkdowns of the areas listed below to verify the adequacy of equipment seals located below the flood line, floor and water penetration seals, watertight door seals, common drain lines and sumps, sump pumps, level alarms, control circuits, and temporary or removable flood barriers.

Units 1 and 2 reactor enclosure Elevation 217 including review of IR 1515259 involving degraded silicone hatch sealant October 25, 2013

Units 1 and 2 HPCI and RCIC rooms on November 20, 2013

b. Findings

No findings were identified.

==1R07 Heat Sink Performance (711111.07A - 1 sample)

a. Inspection Scope

==

During the week of October 21, 2013, the inspectors reviewed the Unit 2 B residual heat removal heat exchanger testing to determine its 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. The inspectors reviewed IR 1569110 which documented an issue involving abandoned heat exchanged vent valves. 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.

==1R11 Licensed Operator Requalification Program

==

.1 Quarterly Review of Licensed Operator Requalification Testing and Training (71111.11Q

- 1 sample)

a. Inspection Scope

The inspectors observed two licensed operator annual simulator examination scenarios on October 29, 2013. One scenario included an unisolable steam leak outside of containment and other equipment malfunction. The other scenario included a loss of safety-related bus power, a scram due to plant equipment failure, safety-related mitigating equipment failures, and a small break loss of coolant accident. The inspectors evaluated operator performance during the simulated event 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 classification made by the shift manager and the TS action statements entered by the operating crew. 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

(71111.11Q - 1 sample)

a. Inspection Scope

The inspectors observed and reviewed licensed operator performance in the main control room during a planned Unit 1 downpower to 60 percent power on December 14, 2013. The downpower was performed to facilitate main steam and main turbine valve testing, control rod scram time testing, fuel channel distortion testing, and to repair a cooling water leak on the A main condensate pump. The inspectors observed the pre-evolution briefing for the planned downpower and reactivity control briefings to verify that the briefings met established plant practices. The inspectors observed operator performance during the downpower to verify that procedure use, alarm response card response, TS usage, crew communications and coordination of activities were in accordance with established expectations and standards.

b. Findings

No findings were identified.

.3 Limited Senior Reactor Operator Requalification Examination Results (71111.11A - 1

sample)

a. Inspection Scope

On December 9, 2013 one NRC region-based inspector conducted an in-office review of results of licensee-administered requalification examination results for Senior Reactor Operator Limited to Fuel Handling license holders. The inspection assessed whether pass rates were consistent with the guidance of NRC Inspection Manual Chapter 0609, Appendix I, and Operator Requalification Human Performance Significance Determination Process. The inspectors verified that:

Overall pass rate among individuals for all portions of the exam was greater than or equal to 80%. (Overall pass rate was 100%)

b. Findings

No findings were identified.

.4 Licensed Operator Requalification Examination Results

a. Inspection Scope

On December 18, 2013, one NRC region-based inspector conducted an in-office review of results of licensee-administered annual operating tests for 2013, for Limerick Units 1 and 2 licensed operators. Comprehensive written exams were administered in the last quarter of 2013 and will be reviewed during the next requalification program inspection in November 2014. The inspection assessed whether pass rates were consistent with the guidance of NRC Manual Chapter 0609, Appendix I, and Operator Requalification Human Performance Significance Determination Process. The inspector verified that:

Individual pass rate on the dynamic simulator test was greater than 80 percent.

(Pass rate was 100 percent)

Individual pass rate on the job performance measures of the operating exam was greater than 80 percent. (Pass rate was 100 percent)

More than 80 percent of the individuals passed all portions of the requalification exam. (Pass rate was 100 percent)

Crew pass rate was greater than 80 percent. (Pass rate was 100 percent)

b. Findings

No findings were identified.

1R12 Maintenance Effectiveness

a. Inspection Scope

The inspectors reviewed the samples listed below to assess the effectiveness of maintenance activities on SSC 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 SSC 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 SSCs classified as (a)(1), the inspectors assessed the adequacy of goals and corrective actions to return these SSCs 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.

IR 1568795, containment vent motor-operated valve (HV-060-111/112/114)preventive maintenance and performance criteria issues on October 8, 2013 through October 11, 2013

IR 1569198, abnormal noise from a Unit 1 HPCI system instrumentation power supply on October 4, 2013 through October 18, 2013 IR 1573005, Unit 2 redundant reactivity control system Maintenance Rule (a)(1)determination on October 21, 2013 through October 25, 2013

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.

IR 1542786, Abnormal Unit 1 HPCI system stop valve movement during pump startup on October 2, 2013

Unit 1 and Unit 2 elevated online risk (Yellow) due to the 20 bus and 201 offsite source being out-of-service on October 7, 2013

IR 1572412, Unit 1 oscillation power range monitor/average power range monitor #3 non-critical self-test fault (risk assessment, operability, and troubleshooting) on October 21, 2013

Unit 2 on-line risk during one-half reactor protection system scram testing with EDG D24, HPCI system, and A control room emergency fresh air system out-of-service on December 9, 2013

Unit 2, on-line risk during HPCI system automatic actuation testing on December 18, 2013

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:

IR 1564080 and 1561625, Unit 2 HPCI system testing aborted following discovery of a broken conduit supporting the system oil system on October 2, 2013

IR 1569198, Unit 1 HPCI system power supply abnormal noise on October 9, 2013

IR 1588352, Void discover in Unit 1 Cable Spread Room cable penetration fire seal on November 25, 2013

IR 1597676 and 1597369, Unit 1 control rods 02-27 and 34-59 high friction due to fuel channel distortion on December 19, 2013

The inspectors selected these issues based on the risk significance of the associated components and systems. 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.

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. The inspectors determined, where appropriate, compliance with bounding limitations associated with the evaluations.

b. Findings

No findings were identified.

==1R18 Plant Modifications

Permanent Modifications (71111.18 - 1 sample)

a. Inspection Scope

==

The inspectors evaluated the permanent plant modification associated with the Unit 2 A low pressure turbine exhaust hood (Engineering Change Request 12-00482) to determine whether the modification adversely affected the safety-related structures at LGS. These structures include the reactor buildings, diesel generator buildings, the control structure, and the spray pond pump house. Adverse effects to these structures from changes in turbine missile protection could result in a loss of the capability to function in a manner necessary to meet 10 CFR 100 requirements. The inspectors verified that the design bases, licensing bases, and performance capability of the affected components or safety-related structures were not degraded by the modification.

The inspectors reviewed the UFSAR, the safety evaluation of the turbine hood replacement modification, the design analysis included in the licensees engineering change package, and the design specification for the replacement of the main turbine exhaust hood with a modified design, and the work orders for the installation of the new turbine exhaust hood.

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 ensured system operability and functional capability. The inspectors reviewed the test procedure to verify that the procedure adequately tested the safety functions that may have been affected by the maintenance activity, that the acceptance criteria in the procedure was consistent with the information in the applicable licensing basis and/or design basis documents, and that the procedure had been properly reviewed and approved. The inspectors also witnessed the test or reviewed test data to verify that the test results adequately demonstrated restoration of the affected safety functions.

IR 1572132, Unit 2 HPCI system flow controller repair on October 15, 2013

C0249338, Unit 1 A standby liquid control pump rebuild on October 16, 2013

C0250043, Troubleshoot and repair Unit 1 oscillation power range/average power range monitor channel trouble alarm on October 30, 2013

C0250544, Repair Unit 1 Cable Spread Room Cable penetration fire seal (0457-E003E) on November 26, 2013

Unit 2 RCIC system post maintenance testing following system outage window from December 4 until December 6, 2013

IR 1583879, Replace Unit 2 residual heat removal system injection valve low delta-pressure permissive relay on November 13, 2013

IR 1576428, Troubleshoot and repair B control room emergency fresh air system due to flow oscillations

b. Findings

No findings were identified.

1R22 Surveillance Testing (71111.22 - 3 Routine, 1 In-Service Test and 1 Reactor Coolant

System Leak Test)

a. Inspection Scope

The inspectors observed performance of surveillance tests and/or reviewed test data of selected risk-significant SSCs 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-2-052-802-1, LOOP B Core Spray System Response Time Test on October 31, 2013

ST-6-048-231-1, SLC Pump, Comprehensive Test on November 19, 2013 (In-service Test)

ST-6-092-316-2, D22 Diesel Generator Fast Start Operability Test Run on November 25, 2013

ST-6-107-590-1, Daily Surveillance Log/Operational Conditions 1,2, and 3 (including reactor coolant system leak rate measurement) for week of December 8, 2013

ST-2-055-100-2, HPCI Logic System Functional Simulated Automatic Actuation on December 18, 2013

Findings

No findings were identified.

2RS1 Radiological Hazard Assessment and Exposure Controls

During the period November 18-21, 2013, the inspectors reviewed and assessed Exelons performance in assessing and controlling radiological hazards in the workplace.

The review considered criteria contained in 10 CFR Part 20, TSs, applicable Regulatory Guides, and Exelon procedures for determining compliance.

a. Inspection Scope

Inspection Planning

The inspectors reviewed 2013 performance indicators for the occupational exposure cornerstone, radiation protection (RP) program audits, corrective action documents, and reports of operational occurrences in occupational radiation safety since the last inspection.

Radiological Hazard Assessment The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed changes in radiological hazards for onsite workers or members of the public and potential impact of the changes.

Conducted walk-downs and made independent radiation measurements and reviewed survey documentation to determine thoroughness and frequency of the surveys.

Reviewed risk-significant work activities including radiological surveys performed to identify and quantify the radiological hazard and to establish adequate protective measures.

Instructions to Workers The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed labeling of non-exempt licensed radioactive materials containers.

Contamination and Radioactive Material Control

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Observed various locations where potentially contaminated material were monitored and released from the radiological control area and inspected methods used for control, survey, and release.

Observed the performance of personnel surveying and releasing material for unrestricted use and evaluated whether the work was performed in accordance with plant procedures.

Assessed whether the radiation monitoring instrumentation used for equipment release and personnel contamination surveys had appropriate detection sensitivity.

Reviewed sealed source inventory audits and assessed whether the sources were accounted for and were tested for loose surface contamination.

Reviewed recent transactions involving nationally tracked sources.

Radiological Hazards Control and Work Coverage The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Evaluated radiological conditions and performed independent radiation measurements during walk-downs of the facility.

Reviewed the application of dosimetry to monitor personnel working in significant dose rate gradients.

Reviewed posting and physical controls for high radiation areas (HRAs), locked high radiation areas and very high radiation areas (VHRA).

Risk-Significant HRA and VHRA Controls The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Discussed with the radiation protection manager and supervisors controls and procedures for high-risk HRAs and VHRAs including any changes to relevant procedures.

Radiation Worker Performance and RP Technician Proficiency The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Observed the performance of radiation workers and RP technicians with respect to procedure requirements and awareness of radiological conditions.

Reviewed available radiological problem reports since the last inspection.

Problem Identification and Resolution The inspectors evaluated whether problems associated with radiation monitoring and exposure control were being identified at an appropriate threshold and placed in the corrective action program.

b. Findings

No findings were identified.

2RS2 Occupational As Low As is Reasonably Achievable (ALARA) Planning and Controls

During the period November 18-21, 2013, the inspectors assessed performance with respect to maintaining occupational individual and collective radiation exposures ALARA.

The inspectors used the criteria in 10 CFR 20, applicable Regulatory Guides, TSs, and Exelon procedures for determining compliance.

a. Inspection Scope

Inspection Planning

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed pertinent information regarding collective dose history, current exposure trends, ongoing and planned activities, and the plants three year rolling average collective exposure.

Reviewed any changes in the radioactive source term, and reviewed site-specific procedures associated with maintaining occupational exposures ALARA.

Radiological Work Planning The inspectors conducted inspection and reviewed the following ALARA aspects and associated documentation:

Compared the results achieved for completed work with the intended dose in ALARA planning for these work activities, reviewed work-in-progress and post job reviews and compared the planned person-hour estimates versus actual person-hours, evaluated the accuracy of these estimates, assessed the reasons for any inconsistencies.

Determined whether post-job reviews were conducted to identify lessons learned.

Source Term Reduction and Control The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Discussed source term reduction and reviewed records to determine the historical trends and current status of plant source term.

Reviewed and discussed the current 10 CFR 61 waste stream source term data.

Problem Identification and Resolution The inspectors evaluated whether problems associated with ALARA planning and controls were being identified at an appropriate threshold and were placed in the corrective action program.

b. Findings

No findings were identified.

2RS3 In-Plant Airborne Radioactivity Control and Mitigation

During the period November 18-21, 2013, the inspectors selectively reviewed controls for work in airborne radioactivity areas and the use of respiratory protection devices.

The inspectors used the criteria in 10 CFR Part 20, the guidance in applicable Regulatory Guides, TSs, and Exelon procedures for determining compliance.

a. Inspection Scope

Inspection Planning

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed use of the respiratory protection program and a description of the types of devices used including location and adequacy of storage facility and quantity of respiratory protection devices stored.

Reviewed selected procedures for maintenance, inspection, storage, and use of respiratory protection equipment including self-contained breathing apparatus (SCBA).

Reviewed reported performance indicators to identify any related to unintended dose resulting from intakes of radioactive material including during use of respiratory protective devices.

Engineering Controls The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Assessed whether the Exelon had established threshold criteria for evaluating levels of airborne beta-emitting and alpha-emitting radionuclides.

Use of Respiratory Protection Devices The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Chose various respiratory protection devices staged and ready for use in the plant and assessed the storage and physical condition of the device components and reviewed records of equipment inspection for each type of equipment.

Reviewed equipment storage, maintenance, and quality assurance including training of onsite personnel conducting maintenance and repair of such equipment.

SCBA for Emergency Use The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Inspected and reviewed procedures for surveillance of SCBAs staged in-plant for use during emergencies.

Problem Identification and Resolution The inspectors evaluated whether problems associated with the control and mitigation of in-plant airborne radioactivity were being identified at an appropriate threshold and were placed in the corrective action program.

b. Findings

No findings were identified.

2RS4 Occupational Dose Assessment

During the periods November 18-21, 2013, the inspectors reviewed the monitoring, assessment, and reporting of occupational dose. The inspectors used the criteria in 10 CFR 20, applicable Regulatory Guides, TSs, and Exelon procedures for determining compliance.

a. Inspection Scope

Inspection Planning

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Radiation protection program audits.

Procedures associated with dosimetry operations, including issuance/use of external dosimetry, and assessments of dose for radiological incidents.

Available dosimetry occurrence reports and corrective action program documents for adverse trends related to electronic personal dosimeters.

Internal Dosimetry Routine Bioassay (In-Vivo)

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed procedures to assess dose from internally deposited radionuclides including the release of contaminated individuals.

Reviewed available worker dose assessments.

Internal Dose Assessment - Whole Body Count Analyses The inspectors conducted inspection and reviewed dose assessments performed using the results of whole body count analyses.

Special Dosimetric Situations The inspectors conducted inspection and reviewed training on the risks of radiation exposure, regulatory aspects of declaring a pregnancy, exposure controls, and the specific process to be used for voluntarily declaring a pregnancy.

Shallow Dose Equivalent

The inspectors conducted inspection and reviewed dose assessments for shallow dose equivalent, including associated documentation.

Problem Identification and Resolution The inspectors assessed whether problems associated with occupational dose assessment were being identified an appropriate threshold and were placed in the corrective action program.

b. Findings

No findings were identified.

2RS5 Radiation Monitoring Instrumentation

During the period November 18-21, 2013, the inspectors reviewed the accuracy and operability of radiation monitoring instruments that were used to protect occupational workers and members of the public. The review considered criteria contained in 10 CFR Part 20, 10 CFR Part 50, 40 CFR 190, applicable Regulatory Guides and industry standards, TSs/Offsite Dose Calculation Manual (ODCM), and Exelon station procedures for determining compliance.

a. Inspection Scope

Inspection Planning

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed procedures that govern instrument source checks and calibrations.

Reviewed effluent monitor alarm set-points and the calculation methods provided in the ODCM.

Walkdowns and Observations The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Selected various portable survey instruments in use and assessed calibration and source check stickers for currency, as well as, instrument material condition and operability.

Compared monitor response (via local readout or remote control room indications)with actual area radiological conditions for consistency.

Selected various personnel contamination monitors, portal monitors, Small Article Monitors, and bag monitor to evaluate whether the periodic source checks and calibrations were performed in accordance with requirements.

Calibration and Testing Program

Portal Monitors, Personnel Contamination Monitors, and Small Article Monitors

The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Selected various types of instruments in use (e.g. radioactivity analysis and quantification instrumentation) and verified that the alarm set-point values were reasonable to ensure that licensed material is not released from the site.

Reviewed calibration documentation for each instrument selected and reviewed the calibration methods with respect to requirements.

Calibration and Check Sources

The inspectors reviewed the Exelons source term or waste stream characterization per 10 CFR Part 61, Licensing Requirements for Land Disposal of Radioactive Waste, to assess whether calibration sources used were representative of the types and energies of radiation encountered in the plant.

Problem Identification and Resolution The inspectors evaluated whether problems associated with radiation monitoring instrumentation were being identified by the Exelon at an appropriate threshold and were placed in the corrective action program.

b. Findings

No findings were identified.

2RS6 Radioactive Gaseous and Liquid Effluent Treatment

During the period November 18-21, 2013, the inspectors reviewed monitoring and evaluation of gaseous and liquid effluents. The review considered criteria contained in 10 CFR Part 20, 10 CFR Part 50, 40 CFR 190, applicable Regulatory Guides and industry standards, TSs/ODCM, and Exelon station procedures for determining compliance.

a. Inspection Scope

Inspection Planning and Program Reviews Event Report and Effluent Report Reviews The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed the 2012 Radioactive Effluent Release Report to determine if the reports were submitted as required including anomalous results, unexpected trends, and abnormal releases that were identified.

Determined if abnormal effluent results were evaluated, were entered in the corrective action program, and were adequately resolved.

ODCM and Final Safety Analysis Report Review The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed changes to the ODCM made since the last inspection.

Reviewed the technical basis or evaluations of any changes and determined whether they were technically justified and maintained effluent releases ALARA.

Walk-downs and Observations The inspectors walked-down the standby gas treatment ventilation trains and Reactor Building Recirculation air cleaning systems to review material conditions for Unit 1 and Unit 2.

Procedures, Special Reports, and Other Documents The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed Exelon event reports and/or special reports related to the effluent program issued since the previous inspection.

Sampling and Analyses The inspectors reviewed and discussed inter-laboratory and intra-laboratory comparison program to verify the quality of the radioactive effluent sample analyses.

Dose Calculations The inspectors conducted inspection and reviewed the following aspects and associated documentation:

Reviewed significant changes in reported dose values compared to the previous radioactive effluent release report to evaluate the factors which may have resulted in the change.

Reviewed changes in methodology for offsite dose calculations since the last inspection. The inspectors reviewed and discussed meteorological dispersion and deposition factors used in the ODCM and effluent dose calculations.

Reviewed the latest Land Use Census to verify changes have been incorporated into the effluent release and environmental programs.

Problem Identification and Resolution Inspectors assessed whether problems associated with the effluent monitoring and control program were being identified by the Exelon at an appropriate threshold and placed in the corrective action program.

b. Findings

No findings were identified.

4OA1 Performance Indicator (PI) Verification

.1 Occupational Exposure Control Effectiveness

a. Inspection Scope

During the period November 18-21, 2013, the inspectors reviewed various corrective action documents covering the past four quarters to determine if issues met the report threshold for the occupational exposure control effectiveness PI or the threshold for the public exposure control effectiveness PI. The inspectors used PI definitions and guidance contained in the Nuclear Energy Institute (NEI) Document 99-02, Regulatory Assessment Performance Indicator Guideline, Revision 7, dated August 31, 2013, to determine the accuracy of the PI data reported.

Occupational Exposure Control Effectiveness (1 sample)

During the period November 18-21, 2013, the inspectors reviewed the scope and breadth of the Exelon data review and the results of those reviews. The inspectors reviewed electronic personal dosimeter dose alarms, dose reports, and dose assignments for any intakes that occurred during the past four quarters to determine if there were any potentially unrecognized PI occurrences. The inspector also conducted walk-downs of accessible locked high and very high radiation area entrances to determine the adequacy of the controls in place for these areas.

RETS/ODCM Radiological Effluent Occurrences (1 sample)

During the period November 18-21, 2013, the inspectors reviewed the corrective action report database and selected individual reports covering the past four quarters to identify any potential occurrences such as unmonitored, uncontrolled, or improperly calculated effluent releases that may have impacted offsite dose. The inspectors reviewed gaseous and liquid effluent summary data and the results of associated offsite dose calculations to determine if indicator results were accurately reported. The inspectors also reviewed methods for quantifying gaseous and liquid effluents and determining effluent dose.

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 October 1, 2012 through September 30, 2013:

Unit 1 Cooling Water (MS10)

Unit 2 Cooling Water (MS10)

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.

.3 Reactor Coolant System (RCS) Specific Activity and RCS Leak Rate (4 samples)

a. Inspection Scope

The inspectors reviewed Exelons submittal for the RCS specific activity and RCS leak rate performance indicators for both Unit 1 and Unit 2 for the period of October 1, 2012 through September 30, 2013. 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 RCS sample analysis and control room logs of daily measurements of RCS leakage, and compared that information to the data reported by the performance indicator.

b. Inspection 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 that 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 and management review committee meetings.

b. Findings

No findings were identified.

.2 Semi-Annual Trend Review

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 third and fourth quarters of 2013 to assess IRs 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 Exelon quarterly trend meeting information report for the third quarter of 2013, conducted under LS-AA-125-1005, Coding and Analysis Manual, Revision 8, 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 assessed that Exelon personnel were identifying issues at a low threshold and entering issues into the CAP for resolution. The inspectors continued to monitor a previously identified negative trend associated with plant issues related to preventive maintenance of plant equipment discussed in NRC Inspection Report

===05000352, 353/2013003. During this period, the inspectors did not identify any plant events, transients, or major plant issues related to preventive maintenance.

.3 Annual Sample:

Emergency Diesel Generator D24 Lubricating Oil Pipe Failure

a. Inspection Scope

The inspectors performed an in-depth review of Exelons evaluation and corrective actions associated with failures of the D24 EDG lubricating oil pipe on November 13, 2012 and April 27, 2013. In both cases the EDG was declared inoperable and Exelon remained in the Action Statement of Technical Specification 3.8.1.1 until the pipe was replaced. After the second failure Exelon completed an engineering assessment of the event and determined that the probable cause of the pipe failure was due to vibration induced high cycle fatigue. Exelon identified a defective support bracket and concluded that the missing support allowed the excessive vibration to occur.

The inspectors assessed Exelons engineering evaluation, extent-of-condition review, completed and proposed corrective actions, and the prioritization and timeliness of actions to evaluate whether the corrective actions were appropriate. The inspectors interviewed engineers and reviewed Exelons evaluation of the issue and corrective actions taken to ensure they met the requirements of the corrective action program.

Specifically, the inspectors reviewed Exelons actions to evaluate whether support bracket inspections were incorporated into the preventative maintenance (PM) program and deficiencies identified by Exelon during walkdowns of the EDGs had been adequately addressed in the corrective action program. The inspectors reviewed the results of vibration data, collected at the location of the piping failure for several of the EDGs, to assess whether corrective actions had sufficiently reduced vibrations so that displacement due to vibration were below cyclic failure limits. Finally, the inspectors walked down the EDGs to evaluate the material condition of the supports for the EDG auxiliary systems.

b. Findings and Observations

No findings were identified.

The inspectors determined that Exelons apparent cause evaluation and extent-of-condition review were thorough, and the probable and contributing causes were appropriately identified. However, vibration data was not taken at the piping prior to correcting the deficient hanger, therefore, conclusive proof of a high vibration condition could not be verified. The inspectors also determined that the corrective actions were reasonable and addressed the probable and contributing causes. Exelons engineering evaluation identified that the pipe failures in 2012 and in 2013 were caused by high vibration fatigue failure due to a missing grommet used to support the piping.

Additionally, Exelons extent-of-condition review of all the EDGs found other instances of missing grommets and loose clamps that were installed to support EDG auxiliary piping. Immediate corrective actions for these deficiencies included installing grommets and tightening clamps to ensure that the rigidity of the piping was adequate to minimize vibration amplitudes. Additionally, Exelon revised PMs to include inspection and replacement of grommets and clamps. Finally, Exelon determined that the installed configuration of the EDG auxiliary systems was not uniform and has long term corrective actions in place to determine and correct the configurations of the piping supports for each EDG. Following the repair Exelon compared the vibration data for the piping on each of the EDGs and determined that the vibration readings on the D24 EDG were in line with the other EDGs installed at Limerick. The inspectors concluded that Exelons evaluation and corrective action efforts associated with this event were appropriate and thorough.

.4 Residual Heat Removal Service Water Reduced Flow Rate

a. Inspection Scope

The inspectors performed an in-depth review of Exelons evaluation and corrective actions performed to correct a reduction in the flow below design limits of cooling water to components in the residual heat removal service water (RHRSW) and emergency service water (ESW) systems. Exelon identified during flow balance testing of the RHRSW and ESW B loop on November 18, 2011 that ESW design flow rates to two EDGs could not be met. Exelon declared the two EDGs inoperable and entered the Action Statement for Technical Specification 3.8.1.1. Additionally, during trouble-shooting on November 19, 2011, Exelon determined that the design flow rate for RHRSW to the residual heat removal (RHR) heat exchangers could not be met in certain system configurations. Exelon performed an operability assessment and following an evaluation of the actual system conditions of the RHR heat exchanger, ESW system loads and spray pond spray network determined that the ESW, RHRSW, and EDGs were operable but both service water systems were degraded.

Subsequently, Exelon completed an apparent cause analysis and determined that the probable cause of the flow degradation was a result of increased corrosion in the RHRSW/ESW common return piping and spray pond spray network piping. Exelon concluded that corrosion on the interior of the systems carbon steel piping created smaller pipe diameters and increased flow resistance which resulted in lower flow rates to RHR and ESW system components. Exelons corrective actions included cleaning the interior piping and nozzles in the spray network, reanalyzing the spray pond flow requirements, reanalyzing the RHR heat exchanger flow requirements and revising operating procedures to limit the RHRSW flow rates to the RHR heat exchanger.

The inspectors assessed Exelons apparent cause evaluation, extent-of-condition review, completed and proposed corrective actions, and the prioritization and timeliness of actions to evaluate whether the corrective actions were appropriate (IRs1292570 and 1346780). The inspectors interviewed engineers and reviewed Exelons evaluation of the issue and corrective actions taken to ensure they met the requirements of their corrective action program and addressed the degraded conditions. Specifically, the inspectors reviewed Exelons actions to evaluate whether the actions taken to clean the pipe were effective; reanalysis of the spray network and spray pond was in accordance with the UFSAR; and testing and operating procedures had been correctly revised to ensure the systems were operated within the new design assumptions.

b. Findings and Observations

No findings were identified.

The inspectors determined that Exelons apparent cause evaluation and extent of condition review were thorough and that the probable and contributing causes were appropriately identified. The inspectors also determined that the corrective actions were reasonable and addressed the probable and contributing causes for the degraded condition. The inspectors noted Exelon had identified corrosion in the piping; however, the corrective actions to monitor the impact of the corrosion had focused on the nozzles in the spray pond spray network.

In response to the degraded flow Exelon created a recurring PM program to clean all of the spray pond piping and monitor the effect corrosion had on RHRSW and ESW system flow. The inspectors found that following the initial cleaning of the piping network flow was restored to system components. The inspectors also noted that procedure modifications made to the system operating and testing procedures were adequate such that RHRSW and ESW system flows were controlled to assure flow to all system components was maintained. Finally, the inspectors found that the actions taken to reevaluate the design requirements of the system maintained the systems design and licensing basis requirements and additional margin to design limits had been realized.

The inspectors concluded that Exelons evaluation and corrective action efforts associated with this event were appropriate and thorough.

4OA3 Follow-Up of Events and Notices of Enforcement Discretion

.1 (Closed) Licensee Event Report (LER) 05000353/2013-002-00:

Inoperable Reactor Secondary Containment Integrity Due to Open Airlock

Introduction.

The inspectors identified a self-revealing finding (FIN) of very low safety significance (Green) for Exelons failure to appropriately prioritize work activities associated with a degraded Unit 2 magnetic switch for a secondary containment airlock door in accordance with Exelon procedure WC-AA-106, Work Screening and Processing. This contributed to both airlock doors being opened simultaneously and resulted in a loss of reactor enclosure secondary containment integrity.

Description.

On Tuesday, September 3, 2013, the main control room received an alarm for reactor enclosure low differential pressure when Exelon personnel were moving equipment through the 313 elevation reactor building-to-reactor building air supply room access airlock doors. Both airlock doors were inadvertently opened causing the reactor enclosure pressure to drop to 0.18 inch of vacuum water gauge which is below the Technical Specification minimum value of 0.25 inch of vacuum water gauge. An indicating light is located at each entrance door leading to the airlock; one on the reactor building side and one on the turbine building side. When either door is open (e.g.,

turbine building side), the indicating lights illuminate warning those personnel that are potentially attempting to enter the airlock from the opposite side (e.g., reactor building side), that the opposite side airlock door is open. Plant workers are expected to not proceed through an airlock door when the indicating light is on so as to not create a loss of secondary containment integrity. On September 3, after verifying that the indicating light was not illuminated, workers proceeded to open the airlock door. Upon opening the door they discovered that the opposite side airlock door was already open and proceeded to close both doors. Once both airlock doors were closed, secondary containment pressure was restored to its normal pressure of 0.33 inch of vacuum water gauge.

The failure of the indicating light to warn the maintenance workers that the airlock door (Door 559) was open was due to a defective magnetic position switch. Exelon had identified that the switch was defective on October 12, 2010, and entered the issue into the CAP under IR 1125544. The inoperable magnetic switch caused the indication feature to be non-functional. At the time, Exelon personnel did not consider the simultaneous opening of two airlock doors to be a loss of safety function. As a result, the work order to repair the magnetic switch was given a routine (Priority 5) work priority that should be worked following the normal scheduling process. Because of the low priority, four times in 2013 Exelon staff deferred the work order once in 2010, three times in 2012, and four times in 2013.

In January 2013, the NRC made a revision (Revision 3) to the guidance provided in NUREG-1022, Event Report Guidelines 10 CFR 50.72 and 50.73, that clarified that licensees were required to make a 10 CFR 50.72 and 50.73 notification for an SSC being declared inoperable when required by a specific TS defined operating mode.

Following the guidance of Revision 3, a loss of secondary containment integrity as a result of both airlock doors being opened at the same time would be reportable. The NUREG was revised and issued in January 2013 with an effective date of July 1, 2013.

On July 1, 2013, Exelon issued Revision 19 to procedure LS-AA-1110, Exelon Reportability Reference Manual, which implemented the requirements of NUREG 1022, Revision 3. Operations personnel (Operations Support, Operations Manage-ment, and licensed operators) were informed of the changes. The procedure change checklist did not specify a site impact review. The work order to replace the magnetic switch was deferred twice after the issuance of the new guidance and two additional times after the effective date of NUREG-1022, Revision 3 and LS-AA-1110, Revision 19 on July 1, 2013.

Exelon subsequently reported the degraded condition via the NRCs Emergency Notification. System. Exelons investigation concluded that the sites implementation of the revision to LS-AA-1110 contributed to the event because no site impact review was performed for the change. A site impact review should have performed a review of degraded equipment potentially affected by the change and identified that the indicating light was inoperable. As a result, the work order to repair the magnetic switch would have been given a higher priority in the work scheduling process. The inspectors reviewed Exelon procedure WC-AA-106, Work Screening and Processing, Revision 13 and concluded that the work order would have been given a Priority 4. This is because it satisfied the criteria that the loss of equipment causes or will cause, if additional redundant equipment degrades, a reduction in generation or loss of function. Issues given priority 4 should be scheduled and started within five weeks

Analysis.

The failure of the station to properly prioritize the work order for the defective magnetic switch for the Unit 2 313 elevation reactor building-to-reactor building air supply room access airlock doors was a performance deficiency that was reasonably within Exelons ability to foresee and correct and could have been prevented. This was caused by not performing a site impact review of reportability clarifications made by NUREG 1022, Event Report Guidelines 10 CFR 50.72 and 50.73, Revision 3. The performance deficiency was also contrary to Exelons procedure for work screening and processing. The finding was determined to be more than minor because it was associated with the Barrier Integrity cornerstone attribute of SSC and Barrier Performance (doors and instrumentation) and affected the cornerstone objective of providing reasonable assurance that physical design barriers (secondary containment)protect the public from radionuclide releases caused by accidents or events.

Specifically, opening two reactor building airlock doors at the same time did not maintain reasonable assurance that the secondary containment would be capable of performing its safety function in the event of a reactor accident. The finding was determined to be self-revealing because it was revealed through the receipt of an alarm in the main control room which required no active and deliberate observation by Exelon personnel.

The finding was determined to be of very low safety significance (Green) in accordance with Appendix A of IMC 0609, "Significance Determination Process for Findings At-Power." Specifically, the finding only represents a degradation of the radiological barrier function provided by the secondary containment airlock doors. Exelon entered the issue into the CAP as IR 1553563. Corrective actions performed or planned included repairing the magnetic switch, verifying that the corrective maintenance backlog did not contain any other issues involving the airlock door indicating lights, developing a periodic routine test of the airlock door indicating circuits, and performing a site impact review of the changes make by NUREG 1022, Revision 3.

This finding had a cross-cutting aspect in the area of Human Performance, Resources, because Exelon did not ensure that resources were available to minimize preventative maintenance deferrals and ensure maintenance and engineering backlogs were low enough to ensure that safety is maintained H.2(a). Specifically, Exelon deferred implementation of the work order several times over a three year period which resulted in secondary containment becoming inoperable on September 3, 2013.

Enforcement.

This finding does not involve enforcement action because no regulatory requirement violation was identified. Exelon entered this issue into their corrective action program as IR 1553563. Because this finding does not involve a violation and has very low safety significance, it was identified as a finding. (FIN 05000353/2013005-01, Failure to Properly Plan Work for Failed Airlock Door Magnetic Switch)

.2 (Closed) LER 05000352, 353/2013-002-00:

Condition that could have Prevented Fulfillment of the Offsite Power Safety Function

On August 5, 2013, 201-D23 bus source undervoltage relay calibration/functional testing was being performed in conjunction with monthly D23 EDG testing. During EDG monthly testing, the D23 EDG is declared inoperable per the surveillance test. The associated safeguard transformers tap changer that the EDG is paralleled with during the test was placed in manual which renders that offsite power source inoperable.

During the undervoltage test, EDG D23 was paralleled with safeguard bus transformer 101. As-found testing revealed that 201-D23 bus undervoltage relay was inoperable due to exceeding the reset setpoint upper acceptance limit. Technicians were not able to recalibrate the relay within TS Limiting Condition for Operation 3.3.3, Emergency Core Cooling System Actuation Instrumentation, action requirement of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. As a result, the 201-D23 breaker was racked out to comply with TS requirements. This resulted in Unit 2 entering Limiting Condition for Operation 3.0.3 due to the EDG D23, the 101 Offsite source, and the 201 offsite source being inoperable. This condition was exited 17 minutes later when EDG testing was aborted which restored EDG D23 and the 101 offsite source to operable status.

The cause of the undervoltage relay inoperability was setpoint drift. The relay was recalibrated successfully. Exelon revised the EDG operating procedures to add specific guidance to place the offsite safeguard transformer tap changer to automatic if under-voltage testing is being performed in conjunction with the EDG being run in parallel with the offsite source. The inspectors did not identify any performance deficiency as a result of reviewing the issue. This LER is closed.

4OA5 Other Activities

Temporary Instruction (TI) 2515/182, Phase 2, Buried Piping===

a. Inspection Scope

The licensees buried piping and underground piping and tanks program was inspected in accordance with paragraph 03.02.a of the TI 2515/182. The inspectors confirmed that activities completed subsequent to the Phase 1 inspection were completed by the program specified completion dates.

The licensees buried piping and underground piping and tanks program was inspected in accordance with paragraph 03.02.b of the TI and responses to specific questions found in http:www.nrc.gov/reactors/operating/ops-experience/buried-pipe-ti-phase-2-insp-req-2011-11-16.pdf were submitted to NRC headquarters staff.

b. Findings

No findings were identified

4OA6 Meetings, Including Exit

On January 10, 2013, the inspectors presented the inspection results to Mr. Tom Dougherty, Site Vice President, and other members of the LGS 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

T. Dougherty, Site Vice President

D. Lewis, Plant Manager

R. Kreider, Director of Operations

D. Doran, Director of Engineering

F. Sturniolo, Director of Maintenance

J. Hunter, Director of Work Management

K. Kemper, Security Manager

R. Dickinson, Manager, Regulatory Assurance

J. Karkoska, Manager, Nuclear Oversight

R. Ruffe, Training Director

M. Gillin, Shift Operations Superintendent. Manager, Engineering Systems

M. Bonifanti, Manager, ECCS Systems

G. Budock, Regulatory Assurance Engineer

D. Molteni, Licensed Operator Requalification Training Supervisor

M. DiRado, Manager, Engineering Programs

D. Merchant, Radiation Protection Manager

C. Gerdes, Chemistry Manager

A. Varghese, System Manager, Radiation Instruments

T. Kan, License Coordinator

J. Risteter, Radiological Technical Manager

L. Birkmire, Manager, Environmental

S. Gamble, Regulatory Assurance Engineer

K. Nicely, Exelon Corporate Regulatory Assurance

N. Harmon, Senior Technical Specialist

R. Woolverton, System Manager

M. McGill, Senior Engineer

C. Boyle, Instrument Chemist

P. Imm, Radiological Engineering Manager

T. Fritz, Engineer, Rad Monitors

M. Strawn, Training Manager

B. Nealis, Senior Effluent and Environmental Specialist

J. Zellmer, LSRO Requal Coordinator

LIST OF ITEMS OPENED, CLOSED, DISCUSSED, AND UPDATED

Opened/Closed

05000353/2013-005-01 FIN Failure to Properly Plan Work for Failed Airlock Door Magnetic Switch (Section 4OA3.1)

Opened

None.

Closed

05000353/2013-002-00 LER Inoperable Reactor Enclosure Secondary Containment Integrity Due to Open Airlock (Section 4OA3.1)

05000352,353/2013-002-00 LER Condition That Could Have Prevented Fulfillment of the Offsite Power Safety Function (Section 4OA3.2)