IR 05000352/2007004

IR 05000352-07-004, 05000353-07-004; on 07/01/07-09/30/07; Limerick Generating Station, Units 1 and 2; Routine Integrated Report

ML073180045
Person / Time
Site:	Limerick
Issue date:	11/13/2007
From:	Paul Krohn Reactor Projects Region 1 Branch 4
To:	Pardee C Exelon Generation Co, Exelon Nuclear
KROHN, PG
References
IR-07-004
Download: ML073180045 (25)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I475 ALLENDALE ROADKING OF PRUSSIA, PENNSYLVANIA 19406-1415 November 13, 2007Mr. Charles G. PardeePresident and CNO Exelon Nuclear Exelon Generation Company, LLC 200 Exelon Way Kennett Square, PA 19348SUBJECT:LIMERICK GENERATING STATION - NRC INTEGRATED INSPECTIONREPORT 05000352/2007004 AND 05000353/2007004

Dear Mr. Pardee:

On September 30, 2007, the U. S. Nuclear Regulatory Commission (NRC) completed aninspection at your Limerick Generating Station Units 1 and 2. The enclosed integrated inspection report documents the inspection results which were discussed on October 15, 2007, with Mr. E. Callan and other members of your staff.The inspection examined activities conducted under your license as they relate to safety andcompliance with the Commission's rules and regulations and with the conditions of your license.

The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.Based on the results of this inspection, no findings of significance were identified.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter, itsenclosure, and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of the NRC's document 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/Paul G. Krohn, ChiefProjects Branch 4 Division of Reactor ProjectsDocket Nos: 50-352, 50-353License Nos: NPF-39, NPF-85Enclosure:Inspection Report 05000352/2007004 and 05000353/2007004w/Attachment: Supplemental Information

SUMMARY OF FINDINGS

IR 05000352/2007-004, 05000353/2007-004; 07/01/2007 - 09/30/2007; Limerick GeneratingStation, Units 1 and 2; Routine Integrated Report.The report covered a three-month period of inspection by resident inspectors and announcedinspections by reactor inspectors. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, "Reactor Oversight," Revision 4, dated December 2006.A.

NRC-Identified and Self-Revealing Findings

No findings of significance were identified.

B. Licensee-Identified Violations

None.

REPORT DETAILS

Summary of Plant StatusUnit 1 began this inspection period operating at full rated thermal power. On August 16, 2007,reactor power was reduced to 20 percent and the main generator was removed from service to repair the generator output number 11 disconnect switch. On August 17, 2007, the disconnect switch repairs were completed and the main generator was returned to service. Unit 1 returned to 100 percent power on August 18, 2007. With the exception of a planned end of summer load drop to 85 percent power on September 8, 2007, Unit 1 remained at full power for the remainder of the period.

Unit 2 began this inspection period operating at full rated thermal power. On August 6, 2007, reactor power decreased to 75 percent due to an unplanned speed reduction on the 2B reactor recirculation pump. The pump speed change was due to a recirculation motor generator electronic card failure. The card was replaced and Unit 2 was returned to 100 percent power later in the day. With the exception of a planned end of summer load drop to 60 percent power on September 15, 2007, Unit 2 remained at full power for the remainder of the period.

REACTOR SAFETY

Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity1R01Adverse Weather Protection (71111.01 - 1 system sample)

a. Inspection Scope

The inspectors evaluated Exelon's preparations and protection for summer weather. OnJuly 10, 2007, the inspectors walked down Unit 1 and Unit 2 main generators and main transformers during hot weather and a grid heavy load voltage condition. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified.

1R04 Equipment Alignment (71111.04)

.1 Partial Walkdown

a. Inspection Scope

The inspectors performed four partial walkdowns of plant systems to verify the operabilityof redundant or diverse trains and components when safety equipment in the opposite train was either inoperable, undergoing surveillance testing, or potentially degraded. The inspectors used plant Technical Specifications (TS), Exelon operating procedures, plantpiping and instrumentation drawings (P&IDs), and the Updated Final Safety Analysis Report (USFAR) as guidance for conducting partial system walkdowns. The inspectors reviewed the alignment of system valves and electrical breakers to ensure proper in-service or standby configurations as described in plant procedures and drawings.

2Enclosure During the walkdown, the inspectors evaluated material condition and generalhousekeeping of the system and adjacent spaces. The documents reviewed are listed in the Attachment. The inspectors performed walkdowns of the following systems:*Unit 1 High Pressure Coolant Injection (HPCI) system;*Unit 1 D-13 Emergency Diesel Generator (EDG);

• Unit 1 Standby Liquid Control System; and

• Unit 1 Reactor Core Isolation Cooling (RCIC)..2Complete System Walkdown (71111.04S - 1 sample)The inspectors conducted one complete walkdown of the Unit 1 and Unit 2 Control RodDrive (CRD) systems to verify functional capability of the system. The inspectors used plant TS, Exelon operating procedures, P&IDs, the UFSAR, and past surveillance tests as guidance for conducting the complete system walkdown. The inspectors reviewed the alignment of system valves, position of electrical breakers and settings of the system flow controller to ensure proper system configuration as described in plant procedures and drawings. During the walkdown, the inspectors evaluated the material condition and general housekeeping of the system and open issue reports associated with the system.

The walkdown also included an evaluation of system piping, supports, and component foundations to ensure they were not degraded. The documents reviewed are listed in the

.

b. Findings

No findings of significance were identified.

1R05 Fire Protection.1Fire Protection - Tours

(71111.05Q - 8 samples)

a. Inspection Scope

The inspectors conducted a tour of the eight areas listed below to assess the materialcondition and operational status of fire protection features. The inspectors verified that combustibles and ignition sources were controlled in accordance with Exelon's administrative procedures, fire detection and suppression equipment was available for use, and that 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 in accordance with Exelon's fire plan. The documents reviewed are listed in the Attachment. The inspectors performed the following samples:*Main Control Room and peripheral rooms;*Unit 1 Refuel Floor;

• Unit 2 Refuel Floor;

• Unit 1 220 KV Switchyard;

• Unit 1 and Unit 2 Static Inverter compartments;

• Unit 1 and Unit 2 Standby Gas Treatment system filter compartments and accessarea; 3Enclosure *Control Room Structure fan room, Elevation 304; and*Unit 1 D14 Diesel Generator Room..2Fire Protection - Drill Observation (71111.05A - 1 sample)

a. Inspection Scope

The inspectors observed one unannounced fire drill conducted in the Unit 1 aircompressor, electro-hydraulic control (EHC) power unit, and turbine lubricating oil storage tank area on September 26, 2007. The inspectors observed the drill to evaluate the readiness of the plant fire brigade to fight fires. The documents reviewed are listed in the Attachment. Specific attributes evaluated were:*Proper donning of fire fighting turnout gear and self-contained breathingapparatus (SCBA); *Proper use and layout of fire hoses;

• Employment of appropriate fire fighting techniques;

• Sufficient fire fighting equipment brought to the scene;

• Effectiveness of fire brigade leader communications, command, and control;

• Search for victims and propagation of fire into other plant areas;

• Smoke removal operations;

• Utilization of pre-planned strategies;

• Adherence to the pre-planned drill scenario; and

• Drill objectives.

b. Findings

No findings of significance were identified.

1R06 Flood Protection Measures

(71111.06 - 1 sample)Internal Flooding

a. Inspection Scope

The inspectors reviewed documents and inspected structures, systems, and components(SSCs) relative to the adequacy of internal flood protection measures for the Unit 1 HPCI room. The inspectors performed walkdowns of the relevant areas to verify the adequacy of flood mitigation doors and barriers, drainage systems, and other flood protection features. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified.

1R11 Licensed Operator Requalification Program (71111.11Q - 1 sample)Resident Inspector Quarterly Review (1 sample)

a. Inspection Scope

4Enclosure On August 28, 2007, the inspectors observed a licensed operator requalificationsimulator scenario. The scenario included a simulated spurious Division 1 Loss of Coolant Accident (LOCA) signal with failure of the D11 EDG to start and an unisolablereactor water cleanup leak, which resulted in a manual scram and emergency blowdown.

The inspectors observed the performance of two operating crews responding to the same scenario. The inspectors assessed licensed operator performance, including operator critical tasks that measure operator actions required to ensure the safe operation of the reactor and protection of the nuclear fuel and primary containment barriers. The inspectors observed the training evaluators' critiques at the conclusion of each simulation. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified.

1R12 Maintenance Effectiveness

(71111.12 - 3 samples)

a. Inspection Scope

The inspectors evaluated Exelon's work practices and follow-up corrective actions forSSCs and identified issues to assess the effectiveness of Exelon's maintenance activities. The inspectors reviewed the performance history of risk significant SSCs and assessed Exelon's extent-of-condition determinations for those issues with potential common cause or generic implications to evaluate the adequacy of the station's corrective actions. The inspectors assessed Exelon's problem identification and resolution actions for these issues to evaluate whether Exelon had appropriately monitored, evaluated, and dispositioned the issues in accordance with Exelon procedures and the requirements of 10 CFR 50.65, "Requirements for Monitoring the Effectiveness of Maintenance." In addition, the inspectors reviewed selected SSC classifications, performance criteria and goals, and Exelon's corrective actions that were taken or planned, to evaluate whether the actions were reasonable and appropriate. The documents reviewed are listed in the Attachment. The inspectors performed the following samples:*1A post LOCA recombiner maintenance rule (a)(1) determination;*2B Turbine Enclosure Cooling Water heat exchanger system outage window; and

• Unit 2 High Pressure Coolant Injection maintenance rule (a)(1) determination.

1R13 Maintenance Risk Assessments and Emergent Work Control (71111.13 - 8 samples)

a. Inspection Scope

The inspectors evaluated the effectiveness of Exelon's maintenance risk assessmentsrequired by 10 CFR 50.65 (a)(4). This inspection included discussion with control room operators and risk analysis personnel regarding the use of Exelon's on-line risk monitoring software. The inspectors reviewed equipment tracking documentation, daily work schedules, and performed plant tours to gain assurance that the actual plant configuration matched the assessed configuration. Additionally, the inspectors verified that Exelon's risk management actions, for both planned and emergent work, were 5Enclosure consistent with those described in Exelon procedure, ER-AA-600-1042, "On-Line RiskManagement." The documents reviewed are listed in the Attachment. Inspectors reviewed risk assessments for the following issues:*Incorrect interpretation of ASME Code Case N-435-1;*Unit 1 HPCI room temperature high;

• Unit 2 Reactor Recirculation Motor Generator runback to minimum speed;

• Unit 1 Main Generator Disconnect high temperatures;

• Unit 1 Main Generator Disconnect phases A and C jumper installation;

• Large VAR (Volt-Ampere Reactive) swings during EDG run;

• Unit 2 placing alternate steam jet air ejector in service; and

• Unit 1 "D" Safety Relief Valve position indicator converter module replacement.

b. Findings

No findings of significance were identified.

1R15 Operability Evaluations

(71111.15 - 5 samples)

a. Inspection Scope

For the five operability evaluations described below, the inspectors assessed thetechnical adequacy of the evaluations to ensure that Exelon properly justified TS operability and verified that the subject component or system remained available such that no unrecognized increase in risk occurred. The inspectors reviewed the UFSAR to verify that the system or component remained available to perform its intended safety function. In addition, the inspectors reviewed compensatory measures implemented to ensure that the measures worked and were adequately controlled. The inspectors also reviewed a sample of issue reports (IRs) to verify that Exelon identified and corrected deficiencies associated with operability evaluations. The documents reviewed are listed in the Attachment. The inspectors reviewed operability evaluations for the following components:*Unit 2 HPCI HV-055-2F006;*Unit 1 HPCI Room Cooler;

• Unit 2 Reactor Core Isolation Cooling Pump Suction High Pressure Alarm;

• Unit 2 HPCI Oil Pressure; and

• Unit 2B Reactor Circulation Pump mechanical seal.

b. Findings

No findings of significance were identified.

1R19 Post-Maintenance Testing (71111.19 - 8 samples)

a. Inspection Scope

The inspectors reviewed the eight post-maintenance tests (PMTs) listed below to verifythat procedures and test activities ensured system operability and functional capability.

The inspectors reviewed Exelon's test procedures to verify that the procedures 6Enclosure adequately tested the safety functions that may have been affected by the maintenanceactivity, and that the applicable criteria in the procedures were consistent with information in the licensing and design basis documents. The inspectors also witnessed the test or reviewed test data to verify that the results adequately demonstrated restoration of the affected safety functions. The documents reviewed are listed in the Attachment. The inspectors reviewed post-maintenance tests for the following systems and components:*"C" Residual Heat Removal Service Water pump;*"2A" RHR Suppression Pool Cooling Valve;

• "D" Emergency Diesel Generator;

• D21 Diesel Generator;

• Unit 1 "A" Standby Liquid Control Squib Valve;

• Unit 1 Reactor Core Isolation Cooling Flow Controller;

• Unit 2 Reactor Core Isolation Cooling Outboard Steam Isolation Valve; and

• Unit 2 Redundant Reactivity Control System (RRCS).

b. Findings

No findings of significance were identified.

1R22 Surveillance Testing (71111.22 - 5 samples)

a. Inspection Scope

The inspectors witnessed the performance and reviewed test data for five surveillancetests that are associated with selected risk-significant SSCs. The review verified that Exelon personnel followed TS requirements and that acceptance criteria were appropriate. The inspectors also verified that the station established proper test conditions, as specified in the procedures, that no equipment preconditioning activities occurred, and that acceptance criteria had been met. The documents reviewed are listed in the Attachment. The inspectors reviewed the surveillance tests for the following systems and components:*Unit 2 D24 EDG;*Unit 2 Division 2 Lower Pressure Coolant Injection;

• Unit 2 Control Rods;

• Unit 1 High Pressure Coolant Injection Pump; and

• Unit 1 High Pressure Coolant Injection.

b. Findings

No findings of significance were identified.

1R23 Temporary Plant Modifications

(71111.23 - 1 sample)

a. Inspection Scope

The inspectors reviewed and compared the temporary modification listed below with theUFSAR and TS to verify that the modification did not affect operability or availability of the Unit 1 reactor recirculation motor generator. The inspectors ensured that station 7Enclosure personnel implemented the modification in accordance with the applicable temporaryconfiguration change process. The inspectors also reviewed the impact on existing procedures to verify appropriate revisions were made to reflect the temporary configuration change. Additionally, the inspectors evaluated the adequacy of proposed testing upon removal of the change. The documents reviewed are listed in the

. The inspectors performed the following sample:*TRT-D7-164, Install 1B Reactor Recirculation Pump Motor Generator TemporaryMechanical Stop.

b. Findings

No findings of significance were identified.

===Cornerstone: Emergency Preparedness (EP)1EP6Drill Evaluation (71114.06 - 2 samples).1General Emergency Classification due to Simulated Fuel Failure Coincident with FailedOpen Main Steam Line Isolation Valves

a. Inspection Scope

On June 19, 2007, the inspectors observed an EP training drill in the control roomsimulator. The inspectors assessed Exelon's emergency response organization's (ERO)===

implementation of the Limerick emergency plan and implementing procedures, and the ERO's response to simulated degraded plant conditions to identify weaknesses and deficiencies in classification, notification, and protective action recommendation (PAR)development activities. In addition, the inspectors assessed licensed operator performance required to ensure the safe operation of the reactor and the protection of the nuclear fuel and primary containment barriers. The inspectors reviewed Exelon's training evaluators' critiques and the formal critique report, dated July 31, 2007, associated with the EP drill, to evaluate Exelon's identification of weaknesses and deficiencies. The inspectors compared inspector observed weaknesses with those identified in Exelon's formal drill critique to verify whether Exelon adequately identified weaknesses and deficiencies at an appropriate threshold. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified..2Site Area Emergency Classification Due to a Simulated Reactor Coolant System Leak inthe Reactor Building

a. Inspection Scope

The inspectors observed a licensed operator requalification simulator exercise evaluationto identify the timing and adequacy of classification, notification, and PAR development activities. During the simulator evaluation, the inspectors reviewed checklists and forms 8Enclosure used for classification and notification activities, and compared them to the criteria inExelon's Emergency Plan, EP-MA-114-100-F-01, "State/Local Event Notification Form,"

and supporting procedures. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified.2.OTHER ACTIVITIES

4OA1 Performance Indicator (PI) Verification

1. Inspection ScopeThe inspector sampled Exelon's submittal of the performance indicators listed below toverify the accuracy of the data recorded from the third quarter of 2006 through the third quarter of 2007. The inspectors utilized performance indicator definitions and guidance contained in Nuclear Energy Institute (NEI) 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 5, to verify the basis in reporting for each data element.

The inspectors reviewed various documents, including portions of main control room logs, issue reports, power history curves, work orders, and system derivation reports.

The inspectors also discussed the method for compiling and reporting performance indicators with cognizant engineering personnel and compared graphical representations from the most recent PI report to the raw data to verify that the report correctly reflected the data. The documents reviewed are listed in the Attachment. Cornerstone: Initiating Events (2 samples)*Unit 1 Unplanned Power Changes per 7000 Critical Hours; and*Unit 2 Unplanned Power Changes per 7000 Critical Hours.Cornerstone: Mitigating Systems (6 samples)*Unit 1 High Pressure Coolant Injection system;*Unit 2 High Pressure Coolant Injection system;

• Unit 1 Reactor Core Isolation Cooling system;

• Unit 2 Reactor Core Isolation Cooling system;

• Unit 1 Emergency Diesel Generators; and

• Unit 2 Emergency Diesel Generators.

b. Findings

No findings of significance were identified.4OA2Identification and Resolution of Problems (71152)Review of Items Entered into the Corrective Action Program (CAP)9Enclosure As required by Inspection Procedure 71152, "Identification and Resolution of Problems,"and in order to help identify repetitive equipment failures or specific human performance issues for follow-up, the inspectors performed a screening of all items entered into Limerick's CAP. The inspectors accomplished this by reviewing the description of each new issue report and accessing Exelon's computerized database. The documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified. The inspectors observed that issues selectedfor review were appropriately categorized and prioritized in accordance with Exelon's corrective action process.4OA3Event Followup (71153).1Unit 1 Main Generator Output Switchyard Disconnect Removal from Service due to HighTemperature

a. Inspection Scope

On August 16, 2007, the inspectors responded to the plant due to a high temperature onthe Unit 1 main generator output disconnect. The inspectors discussed the switchyard disconnect problem with operations personnel, engineering personnel, and Exelon management to gain an understanding of Exelon's response and follow-up actions. The inspectors reviewed troubleshooting activities, the disconnect temperature surveillance monitoring, and the planned actions to repair and correct the disconnect high temperature condition. The number 11 disconnect is located on the output of the Unit 1 main transformers and isphysically located in the Unit 1 220 kilovolt (kV) switchyard. The disconnect is comprised of three individual disconnects and associated bus bars. The disconnect "B" phase temperature reached a maximum value of 375 degrees Celsius and resulted in reactor power reductions to lower the temperature. The location of the elevated temperature was at the movable hinged section of the disconnect. The "A" and "C" phase temperatures were 95 to 100 degrees Celsius. The "B" phase high temperature was discovered during ongoing monthly temperature monitoring. In response to the high temperature, operators reduced reactor power from 100 percentdown to 25 percent to reduce the disconnect temperature and support removal of the main generator and disconnect from service to perform repairs. The inspectors observed "just-in-time training" in the simulator that was given to the operators prior to removing the main generator and disconnect from service. The inspectors also observed the operators' removal of the main generator and disconnect from service to support repairs.

After removal from service, the "B" phase disconnect was rebuilt and tested satisfactorily prior to being returned to service. The main generator was placed back in service and the plant was returned to 100 percent power. The documents reviewed are listed in the

.

b. Findings

10Enclosure No findings of significance were identified..2(Closed) LER 05000353/02007-001, Scram Discharge Volume Vent and Drain Valves Failed Open Due to Clearance Tagging ErrorOn March 10, 2007, Limerick Unit 2 was in hot shutdown and depressurized toapproximately 25 psig for the 2R09 refueling outage. A full scram signal was present and the scram discharge volume (SDV) was isolated, as designed. Operators were in the process of applying a clearance in preparation for planned maintenance on the Reactor Protection System and the scram air header. As part of this clearance, operators removed the Reactor Protection System backup scram fuses which ultimately resulted in the SDV vent and drain valves opening unexpectedly. Water from the SDV began to vent through these open valves into the plant drain system. Station personnel discovered the condition and closed the SDV vent and drain valves, stopping the source of the water. Further investigation by the station determined that the inadvertent opening of the SDV vent and drain valves was due to an improperly written clearance. A non-cited violation (NCV) associated with this issue was documented in Section 1R20of NRC integrated inspection report 05000352/2007002 and 05000353/2007002. The inspectors reviewed this LER and did not identify any additional findings of significance.

Exelon documented this event and associated corrective actions in IR 602042. The documents reviewed are listed in the Attachment. This LER is closed..3(Closed) LER 05000353/02007-002, Valid Actuation of Main Condenser Low Vacuum Isolation Logic During OutageOn March 12, 2007, operators were in the process of lowering vacuum on Limerick Unit 2as part of refueling outage activities in accordance with procedure S07.2.A, "Shutdown of the Steam Jet Air Ejector and Breaking Main Condenser Vacuum." During this evolution, the main condenser low vacuum main steam isolation valve (MSIV) isolation logic actuated unexpectedly. Further investigation revealed that due to a procedural execution error, station personnel had only bypassed two of the required four channels of the isolation logic. Even though this resulted in actuation of two channels of logic when vacuum was lowered, no valves actually repositioned since the MSIVs and other affected valves were closed earlier as required by procedure. This failure to comply with procedure S07.2.A constitutes a violation of minor significance that is not subject to enforcement action in accordance with Section IV of the NRC's enforcement policy. The inspectors reviewed this LER and did not identify any additional findings of significance.

Exelon documented this event and associated corrective actions in IR 602921. This LER is closed.

.4 (Closed) LER 05000353/02007-003, Automatic Actuation of the Reactor ProtectionSystem at PowerOn April 24, 2007, the Unit 2 Reactor Protection System automatically actuated whenreactor water level decreased from +35 inches to +12.5 inches.

All control rods fullyinserted. When reactor level decreased to the low-low level setpoint of -38 inches, both HPCI and RCIC systems initiated and injected into the vessel. HPCI and RCIC were placed in manual mode when flow oscillations were observed on both systems. Both systems were automatically secured when reactor level increased to +54 inches.

11Enclosure Exelon's investigation determined that a circuit card in Redundant Reactivity ControlSystem (RRCS) Division 1, channel "B" spuriously actuated while channel "A" was in a tripped condition due to planned surveillance testing. This resulted in a feedwater runback. The feedwater runback reduced reactor level as expected.Exelon's investigation determined that HPCI and RCIC flow oscillations were due to flowcontrol loop tuning settings that did not properly account for differences in flow path testing conditions and vessel injection flow conditions. Station personnel replaced and successfully tested the affected RRCS circuit card. In addition the HPCI and RCIC flow controller gain and reset settings were adjusted to be consistent with Unit 1 settings, which are consistent with industry values and similar to previous Unit 2 settings when stable flow was demonstrated during Unit 2 initial startup testing. The procedure for tuning of HPCI and RCIC flow controls was revised to specify the required gain and reset settings.The inspectors reviewed Exelon's apparent cause investigation, Unit 2 TS, andnotification requirements. The apparent cause investigation determined that the HPCI and RCIC gain and reset settings were changed during system tuning in May 1999; therefore, this condition existed for approximately 8 years. This resulted in a condition that could have prevented the safety function of Unit 2 HPCI. A non-cited violation (NCV)associated with this issue was documented in Section IR19 of NRC integrated inspection report 05000352/2007003 and 05000353/2007003. Exelon documented this issue and its corrective actions in IR 620861. The review determined that Unit 1 was not affected.

The inspectors reviewed the corrective actions, including revised procedures, and found no additional findings or unresolved issues. The documents reviewed are listed in the

. This LER is closed.4OA6Meetings, Including ExitExit Meeting SummaryOn October 15, 2007, the resident inspectors presented the inspection results toMr. E. Callan and other members of his staff. The inspectors confirmed that proprietary information was not included in the inspection report. ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Exelon Generation Company

C. Mudrick, Site Vice President

E. Callan, Plant Manager

D. DiCello, Radiation Protection Manager

R. Dickinson, Director Engineering

J. Berg, System Manager, HPCI and RCIC

J. George, System Manager, Remote Shutdown Panel

M. Gift, System Manager, Radiation Monitoring Systems

R. Gosby, Radiation Protection Technician, Instrumentation

R. Harding, Engineer, Regulatory Assurance

R. Kreider, Manager, Regulatory Assurance

D. Malinowski, Simulator Instructor

B. Tracy, System Manager

P. Tarpinian, PRA Engineer

D. Boylan, Summer Readiness Coordinator

R. Newmaster, Manager - Emergency Preparedness, Limerick

J. Broillet, Operations Shift Manager

LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED

Closed

05000353/2007-001-0LERScram Discharge Volume Vent and DrainValves Failed Open due to Clearance

Tagging Error (Section 40A3.2)05000353/2007-002-0LERValid Actuation of Main Condenser LowVacuum Isolation Logic During Outage

(Section 40A3.3)

05000353/2007-003LERAutomatic Actuation of the ReactorProtection System at Power (Section

40A3.4)

Discussed

None

A-2Attachment

Section 1R01:

Adverse Weather ProtectionProceduresOP-AA-108-107-1001, "Station Response to Grid Capacity Conditions," Revision 2S32.3.A, "Main Generator Inspection During Heavy Grid Load," Revision 7Section 1R04: Equipment AlignmentProceduresTechnical Specification 3/4 8.1, "A.C. Sources"S92.9.N, "Routine Inspection of the Diesel Generators," Revision 53