IR 05000327/2005006
| ML051040184 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/13/2005 |
| From: | Ogle C NRC/RGN-II/DRS/EB |
| To: | Singer K Tennessee Valley Authority |
| References | |
| IR-05-006 | |
| Download: ML051040184 (40) | |
Text
April 13, 2005
SUBJECT:
SEQUOYAH NUCLEAR PLANT - NRC SAFETY SYSTEM DESIGN AND PERFORMANCE CAPABILITY INSPECTION REPORT NOS.
05000327/2005006 AND 05000328/2005006
Dear Mr. Singer:
On March 4, 2005, the U.S. Nuclear Regulatory Commission (NRC) completed a safety system design and performance capability team inspection at your Sequoyah Nuclear Plant. The enclosed report documents the inspection findings which were discussed on March 4, 2005, with Mr. Kulisek and other members of your staff.
The inspection examined activities conducted under your licenses as they relate to safety and compliance with the Commissions rules and regulations and with the conditions of your licenses. 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\\\\
Charles R. Ogle, Chief Engineering Branch 1 Division of Reactor Safety
Docket Nos.: 50-327, 50-328 License Nos.: DPR-77, DPR-79
Enclosure:
NRC Inspection Report 05000327/2005006 and 05000328/2005006 w/Attachment: Supplemental Information
REGION II==
Docket Nos.:
50-327, 50-328 License Nos.:
05000327/2005006 and 05000328/2005006 Licensee:
Tennessee Valley Authority Facility:
Sequoyah Nuclear Plant, Units 1 and 2 Location:
Sequoyah Access Road Soddy-Daisy, TN 37379 Dates:
February 14-18 and February 28-March 4, 2005 Inspectors:
L. Mellen, Senior Reactor Inspector (Team Lead)
M. Scott, Senior Reactor Inspector R. Cortes, Reactor Inspector K. Maxey, Reactor Inspector J. Rivera-Ortiz, Reactor Inspector F. Jape, Senior Project Inspector (1st Week Only)
Accompanied by:
K. Harper, Reactor Inspector (Trainee)
Approved by:
Charles R. Ogle, Chief
TVA Enclosure Engineering Branch 1 Division of Reactor Safety
TVA Enclosure
SUMMARY OF FINDINGS
IR 05000327/2005006, 05000328/2005006; 02/14-02/18/2005 and 02/28-03/04/2005;
Sequoyah Nuclear Plant, Units 1 and 2; Safety System Design and Performance Capability Inspection.
This inspection was conducted by a team of inspectors from the NRCs Region II 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
No findings of significance were identified.
Licensee-Identified Violations
None.
REPORT DETAILS
REACTOR SAFETY
Cornerstones: Initiating Events and Mitigating Systems
1R21 Safety System Design and Performance Capability
The team evaluated the risk significant systems, support systems, and components required to ensure successful operation of the component cooling system (CCS). The team reviewed CCS operations, maintenance, and surveillance testing. The team also reviewed electrical and mechanical components. The review was to verify the CCS was capable of performing its design functions. The CCS removes residual and sensible heat from the reactor coolant system (RCS), the spent fuel pit (SFP) water, the letdown flow, and provides cooling for safeguards loads associated with a postulated accident.
.1 System Needs
.11 Process Medium
a. Inspection Scope
The team reviewed the availability and reliability of the CCS to transfer heat to the Essential Raw Cooling Water (ERCW) via the CCS heat exchangers (HXs). The review included design documentation, drawings, Updated Final Safety Analysis Report (UFSAR), Technical Specifications (TS), corrective actions history, foreign material exclusion (FME) history, calculations of system capacity, and the CCS pumps available and required net positive suction head (NPSH).
The team reviewed the CCS NPSH and water source calculations, licensing and design basis information, operating/lineup procedures, spool pieces fit tests, drawings, surveillance procedures, and vendor manuals. The review included the surge tanks and the alternate CCS water supply from the demineralizer system. The team walked down the CCS and compared the installed configuration with approved plant drawings and procedures. The reviews and CCS walkdowns were to verify the system design, TS, and UFSAR assumptions were consistent with the actual capability of the CCS. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.12 Energy Sources
a. Inspection Scope
The team walked down the energy sources of selected components to verify selected system alignments were consistent with the design basis assumptions, performance requirements, and system operating procedures. The team reviewed test and design documents to verify the 480 volt alternating current (VAC) and 125 volt direct current (VDC) power sources were adequate to meet minimum voltage specifications for CCS electrical equipment. Among the reviewed components were the CCS pump motors and the thermal barrier booster (TBB) pump motors. The team also reviewed the power supplies for the thermal barrier cooling isolation valves and the SFP train realignment valves.
The team reviewed the air quality controls in the instrument air system including the surveillance tests and air compressors maintenance history to verify an adequate supply of air to the surge tank make-up valve 1-LCV-70-63 and vent valve 1-FCV-70-66.
The review also included the vendor recommendations for the valve controllers to verify that the system surveillance has adequate acceptance criteria. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.13 Instrumentation and Controls
a. Inspection Scope
The team reviewed completed calibration and functional test procedures for the degraded voltage relays associated with the 480VAC shutdown boards. The completed calibration procedures were reviewed to verify the relays had been calibrated and tested in accordance with TS limits.
The team reviewed instrumentation availability and usability to support normal and accident missions. The team performed this review to verfy CCS controls were as described in the UFSAR, and that operations training material, scaling documents, set points, and loop calibration documents were both accurate and consistent. The team also reviewed the controls in the simulator to verify they matched those in the main control rooms (MCRs) and to verify any differences in CCS control between units were addressed in training material.
The team selected a sample of the process instruments including temperature indications, pressure indication, and the interlock for the TBB HXs. The last two completed instrument calibration records were reviewed for the selected instruments to verify the instrumentation had been calibrated in accordance with the setpoint
TVA documents and calibration procedures. The calibration records were also reviewed to verify any test deficiencies such as out-of-tolerance conditions were entered into the corrective action program.
The team reviewed the instrumentation used to detect CCS surge tank level and assessed CCS make-up capabilities to verify features were provided for the timely detection and recovery of abnormalities in either level or flow. The team reviewed the set points for alarms and actuations to ensure they were consistent with the design basis and assumptions. The team conducted a CCS walkdown to review the CCS surge tank, supply lines, and valve configuration for consistency with design drawings and to assess CCS material condition. Additionally, the team reviewed the CCS make-up water capacity. The team reviewed CCS water quality maintenance and corrosion inhibition chemistry procedures. A specific list of documents reviewed is included in the to this report.
b. Findings
No findings of significance were identified.
.14 Operator Actions
a. Inspection Scope
The team reviewed plant operating instructions, including emergency operating instructions (EOIs), abnormal operating instructions (AOIs), and alarm response procedures (ARPs) that would be used to identify and mitigate a loss of CCS. The team also reviewed the operating instructions (OIs) used to initiate or verify initiation of CCS flow. The team focused on installed equipment and operator actions that could be used to mitigate a loss of CCS. The review was to verify the instructions were consistent with the UFSAR description of the CCS and the accident analysis. Additionally, the team compared the CCS actions in the EOIs with the Westinghouse Owners Group Emergency Procedure Guidelines (EPGs), to verify any step deviations were justified and reasonable, the instructions were written clearly and followed the EOI writers guide.
The team held discussions with licensed operators and training instructors, reviewed job performance measures and training lesson plans pertaining to CCS normal and abnormal operation to confirm that training was consistent with the applicable OIs.
In addition, the team observed the installed instrumentation on the plant simulator and walked down portions of MCRs and applicable instructions to verify that operator training and instrumentation were adequate to identify CCS response during an accident or normal operation. The team reviewed manual operator actions for abnormal CCS operations to verify consistency with accident analyses, EPGs, and operator training. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.15 Heat Removal
a. Inspection Scope
The team reviewed the heat load calculations, vendor manuals, drawings, DBDs, maintenance history, and surveillance test documentation to assess the design and performance capability of the CCS HXs to remove the required load during normal operation and accident conditions. The team reviewed the manufacturers specifications for the CCS pump motors and HXs to verify plant procedures were adequate, proper maintenance had been provided, and operability limits had not been exceeded.
The team also reviewed heat load calculations, surveillance records, maintenance history, and performance history of the CCS pump room fan coolers. The team reviewed the the fan coolers to verify they were capable of removing the required heat loads during normal conditions and all postulated accidents. The team also reviewed the calculated peak temperature during high-energy line breaks (HELB) in the RHR rooms to verify CCS room area fan coolers are properly sized and have adequate ERCW cooling medium flow. A specific list of documents reviewed is included in the to this report.
b. Findings
No findings of significance were identified.
.2 System Condition and Capability
.21 Installed Configuration
a. Inspection Scope
The team performed field walkdowns of the mechanical and electrical portions of CCS equipment to observe the current condition and configuration. During this walkdown, the team compared valve positions with the expected system configuration and with the configuration listed on the approved system drawings. The team performed this review to verify the material condition of the CCS would be adequate to support all required operator actions.
The team reviewed portions of available CCS operating logs, and instrument operation history to determine reliability, readability, and adequacy of temperature and flow monitoring instruments. The team performed this review to verify the environmental conditions, assumed under accident conditions, such as expected room temperatures and required emergency lighting, were adequate for remote equipment operation.
TVA The team performed field walkdowns of accessible portions of the CCS and the associated support systems. Equipment examined included the CCS pumps, CCS HXs, CCS pump room fan coolers, surge tanks, TBB pumps, CCS pump seal leakage collection tank and pumps, valves, and piping. The walkdowns also included several components cooled by CCS; these included the RHR pump seal coolers, safety injection (SI) pump seal coolers, charging pump seal coolers, and containment spray pump oil and seal coolers. The field inspections were performed to verfy equipment alignment and labeling were consistent with design drawings and operating procedures.
The team reviewed the surveillance test results for the CCS pump motors emergency power loading during a Loss of Offsite Power (LOOP). The team walked down portions of the 125VDC and 480VAC systems to verify the installed configuration was consistent with design basis information. Also, the team reviewed the 125VDC vital batteries, along with their respective chargers, inverters and DC distribution panels to evaluate material condition. The team also reviewed surveillances and plant procedures to verify they were consistent with actual breaker alignment. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.22 Operation
a. Inspection Scope
The team walked down selected portions of CCS OIs, EOIs, and AOIs to verify inclusion of appropriate human factor engineering practices in the procedures and in the installed plant equipment. This review included labeling accuracy, lighting, noise level, communications, and accessibility. The team also reviewed CCS alignments to verify consistency with design and licensing basis assumptions, approved drawings and the TS. These reviews included the walkdown of the surveillance procedures, selected ARPs, and operator rounds procedures. The team performed this review to verify the equipment needed for emergency operations was labeled and accessible. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.23 Design
a. Inspection Scope
Mechanical Design Review The team reviewed design calculations, specifications, and the UFSAR to verify system and equipment design functions were appropriately maintained. Surveillance test procedures and equipment monitoring activities were reviewed to verify the design criteria was appropriately translated into the acceptance criteria on the tests. The team reviewed DBDs, selected TSs, PERs, and corrective maintenance history for the CCS to assess the CCS design basis implementation and maintenance.
The team reviewed the flow balancing procedures to verify proper throttle valve positioning to achieve adequate CCS flow throughout all CCS components. The review included a field walkdown of throttle valve positions and to verify the valves were in the as-left positions as recorded in the last completed flow balance. The team also conducted an independent verification of the actual heat removal capability of the CCS.
The team compared existing CCS parameters indicated in the MCRs with values established in the design documents.
The team reviewed calculations that assessed the NPSH available from the surge tanks to the CCS pumps to verify the capability of the system to meet the minimum specified flow and head requirements. A specific list of documents reviewed is included in the to this report.
Electrical, Instrumentation, and Controls Design Review The team reviewed CCS flow diagrams, mechanical control drawings, electrical elementary and schematic diagrams, instrument setpoint calculations, instrument scaling documents, as well as calibration procedures and calibration test records. The reviews were performed to verify the installed CCS instrumentation and controls were in accordance with the DBDs. Specifically, the team reviewed setpoint calculations for selected process instruments including the surge tank, reactor coolant pump thermal barrier cooling, and SI pump cooling parameters to verify the calculations included appropriate instrument uncertainties. The last two completed calibration test records were reviewed to confirm that instrument setpoints were established consistent with setpoint calculations. Modifications and component replacements were reviewed to assess potential impact on CCS design function and capability.
In addition, the team reviewed MOVATs test results for selected CCS valves to verify that motor in-rush currents were consistent with those used in the calculations. The team also reviewed a selected sample of calculations for sizing of thermal overloads and compared the methodology to industry standards to prevent an inadvertent trip that would defeat the design basis function of the MOV.
TVA The team reviewed electrical elementary and schematic diagrams, calibration procedures, and calibration test records to verify that the controls for the pumps were in accordance with design basis documents. Also, the team reviewed voltage analysis calculations to verify the CCS pump motors and valves would have adequate voltage during an event. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.24 Testing and Inspection
a. Inspection Scope
The team reviewed performance and post-maintenance testing of CCS pumps and valves to verify the tests and inspections were appropriately validating the licensing and design bases assumptions. The team performed this review to verify the tests would identify any performance degradation. The team reviewed service and performance testing and electrical preventive maintenance procedures for the DC batteries. The review was performed in order to verify that specified acceptance criteria were met and that the equipment operation was consistent with the CCS design bases.
The team reviewed selected full-flow surveillance test data to ensure system injection flow rates remained within system design calculation assumptions. The team reviewed documentation of completed surveillance tests, and pump head curves to verify equipment performance was appropriately monitored and remained consistent with the design and licensing bases. The component tests reviewed included the TBB pumps, CCS pumps, select instrumentation, and the HXs serviced by the CCS.
The team reviewed valve stroke time testing, thrust and torque testing, differential pressure testing, and corrective maintenance records for selected CCS risk-significant MOVs, including the SFP train realignment valves, RHR HXs supply, and thermal barrier supply isolation valves. The team performed this review to verify the availability of the selected valves, adequacy of surveillance testing acceptance criteria, and the monitoring of these valves for degradation. The team reviewed test records to verify that permissives and interlocks not normally tested during pump testing were verified during periodic surveillance testing.
The team reviewed the 125VDC vital batteries surveillance test records to verify that the batteries were capable of meeting design basis load requirements. The team also reviewed calibrations for the CCS TBB pump protective relays.
The team reviewed surveillance instructions which verified the operability of diesel generator 1A-A, 1B-B, 2A-A, and 2B-B start logic, SI signals, and proper operation of Engineered Safety Features (ESF) equipment during a LOOP. A specific list of
TVA documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.3 Selected Components
.31 Component Degradation
a. Inspection Scope
The team reviewed maintenance records, testing documentation, modifications records, operator logs, performance trending data, and equipment history to verify the safety function, reliability and availability of selected components were maintained. In addition, the team reviewed the CCS maintenance rule performance criteria, selected CCS PERs, and system health reports to determine system reliability and availability. The team performed CCS field walkdowns to assess material condition and identify degraded equipment.
The team also reviewed three years of CCS pump and selected MOVs maintenance history data to determine whether adequate preventive maintenance activities were being performed and to verify corrective maintenance activities adequately corrected identified problems. Specifically, the team reviewed applicable motor vendor manuals, and completed work order packages in order to determine if preventive maintenance activities were adequate to prevent and/or identify pump performance problems. To determine if there were any negative trends, the team conducted interviews with the system engineer responsible for motor and pump performance monitoring, reviewed on-line vibrations tests, and verified oil sampling test results. Using the licensees scaling documents, set point documents, and site instrument procedures, the team reviewed CCS instrument calibration, maintenance, and testing. The team also reviewed selected CCS instruments from the system drawings, master equipment list, operations training material, and UFSAR to verify technical consistency with design calculations and scaling documents.
In addition, the team performed a review to verify the CCS motors are replaced based on the number of motor cycles. The team also reviewed oil change work orders, vendor manual information, and maintenance procedures to identify any potential for common cause failures. Additionally, the team reviewed selected components in-service trending data to verify the performance was within the limits specified by the manufacturer and design basis. A specific list of documents reviewed is included in the to this report.
b. Findings
No findings of significance were identified.
.32 Equipment/Environmental Qualification
a. Inspection Scope
The team reviewed work orders, corrective action documents, and interviewed licensee personnel to verify CCS instrumentation availability and usability for both normal and accident operations. The team also reviewed the guidance provided by Regulatory Guide 1.97, Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident, to verify the licensee incorporated the guidance into instrumentation design. Additionally, the team reviewed 10 CFR 50.49, Environmental Qualification of Electric Equipment for Important to Safety for Nuclear Power Plants, to verify requirements had been appropriately incorporated in CCS instrumentation.
The team reviewed environmental qualification test data associated with the components used to mitigate a postulated accident such as the CCS pump motors. The test data was reviewed to confirm these components were qualified for all postulated accident environmental conditions. The team also reviewed seismic test data on instruments to verify appropriate performance during and after a seismic event.
In addition, the team reviewed the environmental classification for several other instruments associated with the CCS to determine if the components had been properly evaluated for inclusion in the Environmental Qualification (EQ) Program. The team conducted walkdowns to verify that the observable portion of selected mechanical components were suitable for all expected environmental conditions, including HELBs.
The team reviewed calculations and data for environmental conditions of the CCS pump room. The team reviewed vendor environmental specifications for CCS pumps and CCS pump motors to verify that maximum temperatures during design basis accidents (DBAs) and HELB do not exceed the maximum operational temperature of the CCS components in that area. A specific list of documents reviewed is included in the to this report.
b. Findings
No findings of significance were identified.
.33 Equipment Protection
a. Inspection Scope
The team walked down the CCS and reviewed CCS environmental qualifications of the
TVA CCS temperature switches to verify the equipment was adequately protected against external events and would be able to operate during a HELB. Additionally, the team performed this walkdown to verify there was no observable damage to installations designed to protect components from potential effects of flooding. Additionally, the team walked down areas containing major equipment in the 250 VDC systems to assess the potential for damage from flood, missiles, or HELB.
The team reviewed the licensees chemical addition and sampling program to determine if the program provided adequate protection from both corrosion and bacterial attack.
The team identified system dead legs and reviewed the licensees program for maintaining chemical protection to prevent dead leg corrosion. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.34 Component Inputs/Outputs
a. Inspection Scope
The team reviewed selected MOV actuator requirements calculations and evaluated the capability of the MOVs to perform their design function under degraded voltage and differential pressure conditions. The team reviewed the calculated inputs to verify voltage and pressure drops were provided and properly translated to the torque and thrust MOV test critera. A specific list of documents reviewed is included in the to this report.
b. Findings
No findings of significance were identified.
.35 Operating Experience
a. Inspection Scope
The team reviewed the licensees applicability evaluations, extent of condition reviews, and corrective actions for industry and station operating experience issues related to CCS equipment problems, such as oil cooler plugging, and check valve problems to verify that plant specific issues were appropriately dispositioned. Work orders, procedures, field observations and discussions with engineering staff provided verification that Operating Experience related corrective actions were accomplished.
The team evaluated the licensees review of NRC Information Notice (IN) 04-07, Plugging of Safety Injection Pump Lubrication Oil Coolers with Lakeweed, for applicability to their facility. Actions taken by the licensee in response to their review of
TVA the IN were evaluated by the team to verify their responsiveness to industry experience.
A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
.4 Identification and Resolution of Problems
a. Inspection Scope
The team reviewed selected system health reports, operator logs, work orders, maintenance records, surveillance test records, and PERs to verify that design and performance problems were identified and entered into the corrective action program.
The team assessed the scope of the licensees extent-of-condition reviews and the adequacy of the corrective actions. The team reviewed calibration test records to verify that out-of-tolerance conditions were properly entered into the corrective action program for evaluation and disposition. Additionally, the team reviewed a sample of corrective maintenance work orders on the selected pumps and valves. A specific list of documents reviewed is included in the Attachment to this report.
b. Findings
No findings of significance were identified.
4. OTHER ACTIVITIES
4OA6 Meetings, Including Exit
The lead inspector presented the inspection results on March 4, 2005, to Mr. Kulisek and other members of the licensee staff. The licensee acknowledged the findings presented.
Proprietary information is not included in this inspection report.
SUPPLEMENTAL INFORMATION
KEY POINTS OF CONTACT
Licensee
- D. Kulisek, Plant Manager
- L. Alexander, Inservice Testing Engineer
- R. Bruno, Training Manager
- T. Cosby, Maintenance Support Manager
- R. Gladney, Electrical Design Manager
- J. Hanevich, Mechanical Engineer
- K. Jones, Systems Engineering Manager
- K. Korth, Operations Support Manager
- T. Neissen, Nuclear Assurance Manager
- D. Osborne, Design Engineering Manager
- P. Pace, Licensing and Industry Affairs Manager
- R. Proffitt, Licensing Engineer
- R. Rogers, Engineering Manager
- J. Smith, Licensing Supervisor
- J. Thomas, Mechanical Engineer
- J. Thomas, Mechanical Design Manager
NRC
- S. Freeman, Senior Resident Inspector, Sequoyah Nuclear Station
- C. Ogle, Branch Chief, Division of Reactor Safety, Region II
- attended exit meeting
List of Items Opened, Closed and Discussed
None
LIST OF DOCUMENTS
AND EQUIPMENT REVIEWED