IR 05000461/2003007
| ML033490317 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 12/10/2003 |
| From: | Julio Lara Division of Reactor Safety III |
| To: | Skolds J Exelon Generation Co, Exelon Nuclear |
| References | |
| IR-03-007 | |
| Download: ML033490317 (40) | |
Text
ber 10, 2003
SUBJECT:
CLINTON POWER STATION NRC SAFETY SYSTEM DESIGN AND PERFORMANCE CAPABILITY INSPECTION REPORT 05000461/2003007(DRS)
Dear Mr. Skolds:
On November 7, 2003, the U.S. Nuclear Regulatory Commission (NRC) completed a biennial baseline engineering inspection at the Clinton Power Station. The enclosed report documents the inspection findings which were discussed on November 7, 2003, with Mr. Bement and other members of your staff.
The inspection examined activities conducted under your license as they related 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.
The inspection focused on the safety system design and performance capability of the Shutdown Service Water and the 4160V electrical systems to assure that the selected systems were capable of performing required safety related functions.
Based on the results of this inspection, no findings of significance were identified.
In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be made available electronically for public inspection in the NRC Public Document Room or from the Publically 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/
Julio F. Lara, Chief Electrical Engineering Branch
SUBJECT:
CLINTON NUCLEAR POWER STATION NRC SAFETY SYSTEM DESIGN AND PERFORMANCE CAPABILITY INSPECTION REPORT 05000461/2003007(DRS)
Dear Mr. Skolds:
On November 7, 2003, the U.S. Nuclear Regulatory Commission (NRC) completed a biennial baseline engineering inspection at the Clinton Nuclear Power Station. The enclosed report documents the inspection findings which were discussed on November 7, 2003, with Mr.
Bement and other members of your staff.
The inspection examined activities conducted under your license as they related 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.
The inspection focused on the safety system design and performance capability of the Shutdown Service Water and the 4160V electrical systems to assure that the selected systems were capable of performing required safety related functions.
Based on the results of this inspection, no findings of significance were identified.
In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be made available electronically for public inspection in the NRC Public Document Room or from the Publically 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/
Julio F. Lara, Chief Electrical Engineering Branch Division of Reactor Safety See Attached Distribution DOCUMENT NAME: ML033490317.wpd To receive a copy of this document, indicate in the box: "C" = Copy without attachment/enclosure "E" = Copy with attachment/enclosure "N" = No copy OFFICE RIII RIII RIII NAME AWalker:tr AStone JLara DATE 12/04/03 12/10/03 12/04/03 OFFICIAL RECORD COPY Docket No. 50-461 License No. NPF-62
Enclosure:
Inspection Report 05000461/2003007(DRS)
w/Attachment: Supplemental Information
REGION III==
Docket No: 50-461 License No: NPF-62 Report No: 05000461/2003007(DRS)
Licensee: Exelon Generation Company, LLC Facility: Clinton Power Station Location: Route 54 West Clinton, IL 61727 Dates: October 20 through November 7, 2003 Inspectors: H. Walker, Lead Inspector S. Sheldon, Engineering Inspector N. Valos, Engineering Inspector H. Anderson, Contract Inspector, Mechanical G. Skinner, Contract Inspector, Electrical Observer B. Jose, Engineering Inspector Approved by: Julio F. Lara, Chief Electrical Engineering Branch Division of Reactor Safety
SUMMARY OF FINDINGS
IR 05000461/2003007(DRS); 10/20/03 - 11/07/03; Clinton Power Station; Safety Systems
Design and Performance Capability.
This report covered a three week period of an engineering inspection by regional engineering specialists with both electrical and mechanical consultant assistance. The inspection focused on the safety system design and performance capability of selected important systems. The inspection was performed in accordance with NRC baseline inspection procedure 71111.21,
Safety System Design and Performance Capability.
The significance of most findings are indicated by their color (Green, White, Yellow, Red) using Inspection Manual Chapter (IMC) 0609, Significance Determination Process (SDP). Findings for which the SDP does not apply may be Green or be assigned a severity level after NRC management review. The NRCs program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 3, dated July 2000.
A. Inspector-Identified and Self-Revealed Findings
Cornerstone: Mitigating Systems
No findings of significance were identified.
Licensee-Identified Violations
No findings of significance were identified.
REPORT DETAILS
Summary of Plant Status
Clinton was at or near full power throughout the inspection period.
REACTOR SAFETY
Cornerstone: Mitigating Systems
1R21 Safety System Design and Performance Capability
Introduction:
Inspection of safety system design and performance capability verifies the initial design and subsequent modifications and provides monitoring of the ability of the selected systems to perform design bases functions. As plants age, the design bases may be lost and important design features may be altered or disabled. The plants risk assessment model was based on the capability of the as-built safety system to perform the intended safety functions successfully. This inspectable area verifies aspects of the mitigating systems cornerstone for which there are no indicators to measure performance.
The objective of the safety system design and performance capability inspection is to assess the adequacy of calculations, analyses, other engineering documents, and operational and testing practices that were used to support the performance of the selected systems during normal, abnormal, and accident conditions.
The systems and components selected for the inspection were the Shutdown Service Water (SSW) system and the 4160V electrical system. These systems were selected for review based upon:
- having a high probabilistic risk analysis ranking;
- having had recent significant issues;
- not having received recent NRC review; and
- being interacting systems.
The criteria used to determine the acceptability of the systems performance was found in documents such as:
- applicable technical specifications;
- applicable updated safety analysis report (USAR) sections; and
- the systems' design documents.
The following system and component attributes were reviewed in detail:
System Requirements
- Process Medium - water, air, electrical signal;
- Energy Source - electrical power, steam, air;
- Control Systems - initiation, control, and shutdown actions;
- Operator Actions - initiation, monitoring, control, and shutdown; and
- Heat Removal - cooling water and ventilation.
System Condition and Capability Installed Configuration - elevation and flow path operation; Operation - system alignments and operator actions; Design - calculations and procedures; and Testing - level, flow rate, pressure, temperature, voltage, and current.
Component Level Equipment/Environmental Qualification - temperature and radiation; Equipment Protection - fire, flood, missile, high energy line breaks, freezing, heating, ventilation and air conditioning.
.1 System Requirements
a. Inspection Scope
The inspectors reviewed the USAR, technical specifications, system descriptions, drawings and available design basis information to determine the performance requirements of the SSW and the 4160V electrical systems. The reviewed system attributes included process medium, energy sources, control systems, operator actions and heat removal. The rationale for reviewing each of the attributes was:
Process Medium: This attribute required review to ensure that the selected systems flow paths would be available and unimpeded during/following design basis events. To achieve this function, the inspectors verified that the systems would be aligned and maintained in an operable condition as described in the plants USAR, technical specifications and design bases.
Energy Sources: This attribute required review to ensure that the selected systems motive/electrical source would be available/adequate and unimpeded during/following design basis events, that appropriate valves and system control functions would have sufficient power to change state when required. To achieve this function, the inspectors verified that the interactions between the systems and their support systems were appropriate such that all components would operate properly when required.
Controls: This attribute required review to ensure that the automatic controls for operating the systems and associated systems were properly established and maintained. Additionally, review of alarms and indicators was necessary to ensure that operator actions would be accomplished in accordance with design requirements.
Operations: This attribute was reviewed because the operators perform a number of actions during normal, abnormal and emergency operating conditions that have the potential to affect the selected systems operation. In addition, the emergency operating procedures (EOPs) require the operators to manually realign the systems flow paths during and following design basis events. Therefore, operator actions play an important role in the ability of the selected systems to achieve their safety-related functions.
Heat Removal: This attribute was reviewed to ensure that there was adequate and sufficient heat removal capability for the selected systems.
b. Findings
Improperly Secured 4160V Equipment Doors
Introduction:
The inspectors identified an unresolved item having potential safety significance greater than minor. The finding resulted from the licensees failure to properly close the 4160V equipment doors and maintain the safety related 4160V system components in their analyzed configuration.
Description:
During a field walkdown of the safety related 4160V system, the inspectors observed that the Bus 1C1 Reserve Feed Potential Transformer (PT) drawer was misaligned and not fully closed. The inspectors also observed that the panel doors for the Division 1 Diesel Generator CT/PT cabinet (1DG01JA) were fully closed and were not latched at the bottom.
During an examination of the Bus 1C1 Reserve Feed PT drawer licensee personnel determined that the latch rod for the cubicle drawer was resting on top of the latching mechanism instead of being behind the angle latching mechanism. As a result, this configuration could cause the drawer to become displaced during a seismic event.
Opening the drawer would disable the voltage sensors for the Division 3 feed from the Emergency Reserve Auxiliary Transformer (ERAT), which would in turn disconnect the ERAT source from Bus 1C1 if it was connected, or would prevent transfer to the ERAT source in the event of loss of the Reserve Auxiliary Transformer (RAT) source. In addition, displacement of the drawer could adversely affect the seismic qualification of the entire Division 3 switchgear. The Division 3 switchgear supplies power to the High Pressure Core Spray (HPCS) components. Failure of the switchgear would make the HPCS system inoperable.
Licensee personnel initiated condition report (CR) 00182734 to document this issue and to evaluate the past operability of the Division 3 switchgear. Work Order No. 629059 was written on the problem and the drawer was promptly closed and properly latched.
Examination of the Division 1 Diesel Generator CT/PT cabinet by licensee personnel revealed that the finger bolts on two panel doors were not tight. The bolts on one door were subsequently tightened by hand, but station personnel were not able to fully tighten the bolts on the other door, due to apparent damage to either the bolts or the door.
Opening of the doors during a seismic event could affect the seismic qualification of the panel but a preliminary evaluation by licensee personnel concluded that it was unlikely that opening of the doors would have adverse consequences. Work Order No. 628564 was issued for the repair of the panel and CR 00182327 was written for a more thorough evaluation of the past operability of the Division 1 Diesel Generator.
Analysis:
The inspectors determined that the failure to maintain 4160V equipment panels in a qualified configuration was a performance deficiency warranting a significance evaluation in accordance with IMC 0612, Power Reactor Inspection Reports, Appendix B, Issue Disposition Screening, issued on June 20, 2003. The inspectors determined that the finding was greater than minor because it affected the mitigating systems cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, Bus 1C1 Reserve PT drawer configuration could result in inoperable Division 3 switchgear. However, since licensee personnel had not completed their evaluation of past operability of the affected components, the significance determination of this issue could not be completed. As a result, this item will tracked as Unresolved Item (05000461/2003007-01), Improperly Secured 4160V Equipment Doors, pending further evaluation by licensee personnel and the NRC.
Enforcement:
Although the equipment problem was promptly corrected and does not present an immediate safety concern, the failure to maintain safety related 4160V system components in their design and analyzed configuration is a violation of 10 CFR Part 50 Appendix B, Criterion III, Design Control. A thorough evaluation of the past operability of the Division 1 Diesel Generator is to be completed and enforcement actions to be taken as a result of this issue (if any) will be determined after review of the above evaluation results.
.2 System Condition and Capability
a. Inspection Scope
The inspectors reviewed design basis documents and plant drawings, abnormal and emergency operating procedures, requirements, and commitments identified in the USAR and technical specifications. Information in these documents was compared to applicable electrical, instrumentation and control, and mechanical calculations, setpoint changes, and plant modifications. The inspectors also reviewed operational procedures to verify that instructions to operators were consistent with design assumptions.
Information was reviewed to verify that the actual system condition and tested capability was consistent with the identified design bases. Specifically, the inspectors reviewed the installed configuration, the system operation, the detailed design, and the system testing, as described below.
Installed Configuration: The inspectors confirmed that the installed configuration of the SSW and the 4160V electrical systems met the design basis by performing detailed system walkdowns. The walkdowns focused on the installation and configuration of piping, components, and instruments; the placement of protective barriers and systems; the susceptibility to flooding, fire, or other environmental concerns; physical separation; provisions for seismic and other pressure transient concerns; and the conformance of the currently installed configuration of the systems with the design and licensing bases.
Operation: The inspectors performed a procedure walk through of selected manual operator actions to confirm that the operators had the knowledge and tools necessary to accomplish actions credited in the design basis.
Design: The inspectors reviewed the mechanical, electrical and instrumentation design of the SSW and the 4160V electrical systems to verify that the systems and subsystems would function as required under accident conditions. The review 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 limited analyses in several areas to verify the appropriateness of the design values.
Testing: The inspectors reviewed records of selected periodic testing and calibration procedures and results to verify that the design requirements of calculations, drawings, and procedures were incorporated in the system and were adequately demonstrated by test results. 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.
OTHER ACTIVITIES (OA)
4OA2 Identification and Resolution of Problems
Routine Review of Identification and Resolution of Problems
a. Inspection Scope
The inspectors reviewed a sample of problems associated with the SSW and the 4160V electrical systems that were identified and entered into the corrective action program by licensee personnel. The inspectors reviewed these issues to verify an appropriate threshold for identifying issues and to evaluate the effectiveness of corrective actions related to design issues. In addition, CRs 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
.1 Exit Meeting
An exit meeting was conducted for:
- Safety Systems Design and Performance Capability, to Mr. R. Bement and other members of licensee management at the conclusion of the inspection on November 7, 2003. One document supplied to the inspectors was identified as being proprietary and was returned. The inspectors asked licensee personnel to identify any additional proprietary information discussed during the exit meeting.
No additional proprietary information was identified.
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee
- R. Bement, Site Vice President
- M. Baetz, Operations Support/Services Manager
- K. Baker, Senior Manager Design Engineering
- R. Chear, Auxiliary Power Systems Engineer
- T. Danley, NSED - Design
- R. Frantz, Regulatory Assurance
- D. Lillyman, Shutdown Service Water Systems Engineer
- J. Madden, Nuclear Oversight Manager
- R. Peak, Senior Manager Plant Engineering
- M. Stickney, NSED Design
- J. Williams, Site Engineering Director
Nuclear Regulatory Commission
- B. Dickson, Senior Resident Inspector
- C. Brown, Resident Inspector
- J. Lara, Chief, Electrical Engineering Branch
LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED
Opened
50-461/03007-01 URI Improperly Secured 4160V Equipment Doors (Section 1R21.1b.)
Closed
None
Discussed
None Attachment