IR 05000352/2005007
| ML053500100 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/16/2005 |
| From: | Doerflein L Engineering Region 1 Branch 2 |
| To: | Crane C Exelon Generation Co, Exelon Nuclear |
| References | |
| IR-05-007 | |
| Download: ML053500100 (20) | |
Text
ber 16, 2005
SUBJECT:
LIMERICK GENERATING STATION - NRC SAFETY SYSTEM DESIGN AND PERFORMANCE CAPABILITY INSPECTION REPORT 05000352/2005007 AND 05000353/2005007
Dear Mr. Crane:
On November 4, 2005, the U.S. Nuclear Regulatory Commission (NRC) completed a safety system design and performance capability team inspection at your Limerick Facility. The enclosed report documents the inspection results that were discussed on November 4, 2005, with Messrs. E. Callan and P. Orphanos, 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 inspection team reviewed selected procedures and records, observed activities, and interviewed personnel.
Based on the results of the 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 and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Lawrence T. Doerflein, Chief Engineering Branch 2 Division of Reactor Safety Docket Nos. 50-352, 50-353 License Nos. NPF-39, NPF-85 Enclosure: NRC Inspection Report 05000352/2005007and 05000353/20005007
Mr. Christopher
SUMMARY OF FINDINGS
IR 05000352/20050007, 05000353/20050007; 10/17/2005 - 11/05/2005; Limerick Generating
Station, Units 1 & 2; Engineering Team Inspection.
This inspection was conducted by a team of six inspectors from the NRCs Region I office. No findings of significance were identified. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 3, dated July 2000.
NRC-Identified and Self-Revealing Findings
None.
Licensee-Identified Violations
None.
ii
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Mitigating Systems and Barrier Integrity
1R21 Safety System Design and Performance Capability (SSD&PC) (IP 71111.21)
1. Inspection Basis
The NRC performed an inspection to verify the selected safety systems would achieve their design and performance capability. The inspection effort included a review of the licensee's programs and methods for monitoring the capability of selected safety systems to perform their current design bases functions. The scope of the teams inspection also included non safety-related structures, systems and components that provided functions required to support the selected systems safety functions. The team inspected the selected systems on both units.
The systems reviewed during this inspection were selected by the inspection team using information from the licensees and NRCs probabilistic risk analysis models. The models were used to identify risk significant systems, structures, and components in the mitigating system and barrier integrity cornerstones. The team also used deterministic criteria in the selection process by considering previous SSD&PC sample selection, recent inspection history, site problem history, and operational experience. The two systems selected for review were:
- High Pressure Coolant Injection System (HPCI)
- Reactor Core Isolation Cooling System (RCIC)
The team assessed the adequacy of calculations, analyses, engineering processes, and engineering and operating practices that were used by the licensee to support the performance of the selected safety systems and associated support systems during normal, abnormal, and accident conditions. The inspection included review and examination of support systems, such as DC electrical power, instrumentation, and related structures and components. Acceptance criteria utilized by the NRC team included verification of compliance with NRC regulations, the Limerick Technical Specifications, and applicable sections of the Updated Final Safety Analysis Report (UFSAR). Additionally, the team reviewed guidance in NRC Generic Communications, industry codes and standards, as well as, industry initiatives implemented by the licensees programs, to assess the ability of the systems to meet their design basis function. The team also assessed the licensees ability to monitor the system for age related degradation that could result in the system failing to fulfill its design requirement.
A complete list of documents reviewed is included in the attachment to this report.
2. System Needs
a. Inspection Scope
The team inspected the following attributes of the two systems and associated support systems: Process Medium, Energy Sources, Controls, Operator Actions, and Heat Removal. The inspectors verified the above attributes met the requirements and design basis specifications identified in the UFSAR, technical specifications, licensee commitments, design bases documents, vendor technical manuals and plant drawings.
A complete list of documents reviewed is included in the attachment. The attributes were verified to meet system requirements as described below:
Process Medium. The team verified that the HPCI and RCIC systems would supply adequate flow rate at design pressures to the reactor vessel following normal transients and design basis events from both the suppression pool and condensate storage tank suction sources. Additionally, the team verified sufficient water was available to meet the design basis assumptions. This included a review of the licensees net positive suction head and vortexing calculations to determine if sufficient margin existed to assure the availability of the two systems.
Energy Sources. The team verified that the batteries used to supply DC electric power to the HPCI and RCIC systems were adequately sized to meet system demands and that the DC distribution system was designed to assure functionality at reduced voltages anticipated during a design basis event (DBE). Additionally, the team verified that the steam supply to the systems turbines would be available and sufficient to operate the turbines during all design basis events. Finally, the team evaluated the availability of control power to energize/actuate required equipment including motor operated valves (MOV) and governor control circuits during a DBE.
Controls. The team reviewed the automatic and manual controls for the HPCI and RCIC systems to assure that the automatic and manual control functions would be available for initiation, control and shutdown actions including operations at the remote shutdown panel. Additionally, a review of alarms and indicators was performed to ensure that operator actions could be accomplished in accordance with the design assumptions.
The team observed operation of the systems during several accident scenarios in the licensees simulator, reviewed functional testing results, and check electrical prints to assess the ability of the system to both warn operators of problems and allow operators to control the systems.
Operation Actions. The team reviewed normal, abnormal and emergency operating procedures to verify that operator actions for the HPCI and RCIC systems assumed in the design bases could be completed. The team verified this by comparing actions prescribed in the procedure with design basis calculation assumptions, and observing accident scenarios in the licensees simulator. The review included an assessment of battery loading and discharge rates, controlling maximum room temperatures and process temperature limits. Additionally, the team verified that operators were able to manually initiate the system, monitor components and system indications, automatically or manually control system functions and shutdown the system during postulated events, such as Small Break Loss of Cooling Accidents (SBLOCA), Station Blackout (SBO), and Anticipated Transient Without Scram (ATWS). Additionally, the team confirmed that operator actions to prevent isolation of the systems during events could be performed via walkdown of the associated procedure and by review of circuit prints.
Heat Removal. The team verified that the licensees calculations for room heatup and maximum room temperatures during design basis events were adequate to support the design basis documents, which credited no room cooling systems to maintain acceptable environmental conditions in the RCIC and HPCI system rooms. Additionally, the team verified temperature rise on system components due to heat generated by the system was limited such that component temperature qualifications were not exceeded.
b. Findings
No findings of significance were identified.
3. System Condition and Capability
a. Inspection Scope
The team inspected the following attributes of the HPCI and RCIC systems and associated support systems: Installed Configuration, Operation, Design, and Testing.
The inspectors verified the above attributes met the requirements and design bases specifications identified in the UFSAR, technical specifications, licensee commitments, design basis documents, vendor technical manuals, calculations and plant drawings. A complete list of documents reviewed is included in the attachment to this report. The attributes were verified to meet system requirements as described below:
Installed Configuration. The team confirmed that the installed configuration of the HPCI and RCIC systems were in agreement with design basis assumptions by performing detailed system walkdowns of accessible portions of both systems. The walkdowns focused on the installation and configuration of piping and instruments; component material condition; licensee identified deficiencies; the placement of protective barriers; the susceptibility to flooding, fire, or other environmental concerns such as temperature and humidity levels in the room; physical separation of redundant trains; and provisions for seismic and other pressure transient concerns. The team compared their observations of the current installed configuration of the systems with the design and licensing bases to assure that the system would be capable of functioning during plant transients or accident conditions.
Operation. The team performed a procedure walk-through of selected manual operator actions to confirm that the operators had the capability to complete the actions. Actions reviewed included establishing room cooling, cross-tying vital AC power supplies and removing isolation logic during an SBO event. The walk down was conducted to ensure that operators had access and tools necessary to accomplish actions credited and they could perform the actions in the time frame described in the design basis. Additionally, the team verified that the performance of operations procedures was consistent with the design and licensing bases.
Design. The team reviewed the mechanical, electrical, and instrumentation design of the HPCI and RCIC systems to verify that the systems and subsystems would function as required under design conditions. This included a review of the design basis, design changes, design assumptions, calculations, boundary conditions, and models as well as a review of selected modification packages. Instrumentation was reviewed to verify appropriateness of applications and set points based on the required equipment function. Additionally, the inspectors performed independent calculations and analyses in several areas, such as room heat-up and operating the pumps with no minimum flow valve, to verify the appropriateness of the design values.
Testing. The team reviewed records of selected periodic testing including technical specification surveillance tests, In-Service Testing (IST) for pumps and valves, post maintenance tests and calibration procedures. The team verified that the results obtained by system and component testing adequately demonstrated that the systems met operability requirements. The test results were compared against system calculations, drawings, and procedures. Test results were also reviewed to ensure automatic initiations occurred within required times and that testing was consistent with design basis information.
b. Findings
No findings of significance were identified.
4. System Components
a. Inspection Scope
The inspectors selected several risk significant components in the HPCI and RCIC systems to ensure equipment at the component level met design requirements. The components selected for detailed review included:
- Division I Safeguard Batteries
- RCIC electrical control system
- RCIC pump
- RCIC minimum flow valve
- Division II Safeguard Batteries
- Division II Battery Chargers
- HPCI Auxiliary Oil Pump
- HPCI Main and Booster Pump
Component Degradation, Environmental Qualification, Equipment Protection, Input/Output, and Operating Experience. The inspectors verified the above attributes met the requirements and design basis specifications identified in the UFSAR, technical specifications, licensee commitments, design basis documents, vendor technical manuals, calculations and plant drawings. A complete list of documents reviewed is included in the attachment to this report. The attributes were verified to meet system requirements as described below:
Component Degradation. The team reviewed selected maintenance and operations procedures to determine how potential age related degradation of the selected components was monitored and corrected. The team verified that component and/or component materials replacement were scheduled prior to exceeding its expected qualified life or allowed number of cycles.
Environmental Qualification. The team verified that the equipment was qualified to operate under the environment in which it expected to be subjected to under normal and accident conditions. These included a review of the temperatures, pressures, and humidity levels the components are exposed to during standby operation, normal operations, and events such as SBO, SBLOCA, and ATWS. The team reviewed design information, specifications, and documentation to evaluate the component qualification under the expected environment.
Protection. The team verified that the selected components were adequately protected from natural phenomenon and other hazards, such as high energy line breaks, fire, floods or missiles. The team reviewed design information, specifications, and documentation to ensure that system components were adequately protected from those hazards identified in the UFSAR which could impact their ability to perform their safety function. The team walked down the system to assess if potential interactions identified were accounted for in the design basis.
Input/Output. The team verified that the HPCI and RCIC system components input and output was adequate to provide the required signal strength to the receiving component during event or accident conditions. The team reviewed design information, specifications, and documentation to ensure component status information required to enable operators to make decisions and signals used for control of equipment operations as described in the UFSAR would be present during events.
Operating Experience. The team verified that insights from operating experience of similar systems had been reviewed and adequately evaluated by the licensee for the HPCI and RCIC components.
b. Findings
No findings of significance were identified.
OTHER ACTIVITIES (OA)
4OA2 Problem Identification and Resolution
a. Inspection Scope
The team reviewed a sample of HPCI and RCIC system problems that were identified by the licensee and entered into the corrective action program. The team reviewed these issues to verify the licensee established an appropriate threshold for identifying issues and to evaluate the effectiveness of corrective actions related to design or qualification issues. In addition, condition reports written on issues identified during the inspection were reviewed to verify adequate problem identification and incorporation of the problem into the corrective action system. The specific corrective action documents that were sampled and reviewed by the team are listed in the attachment to this report.
b. Findings
No findings of significance were identified.
4OA6 Meetings, Including Exit
The lead inspector presented the inspection results on November 4, 2005, to Messrs. E. Callan and P. Orphanos, and other members of the licensees staff. The inspection team verified that this inspection report does not contain proprietary information.
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
- R. DeGregorio, VP Limerick Generating Station (LGS)
- C. Mudrick, Plant Manager LGS
- P. Orphanos, Director Operations
- J. White, Director Training
- R. Harding, Regulatory Assurance
- T. Basso, Senior Manager Engineering
- R. George, Manager Electric Design
LIST OF ITEMS
OPENED, CLOSED AND DISCUSSED
None.