IR 05000335/2005007
| ML052030547 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 07/22/2005 |
| From: | Ogle C NRC/RGN-II/DRS/EB |
| To: | Stall J Florida Power & Light Co |
| References | |
| IR-05-007 | |
| Download: ML052030547 (28) | |
Text
July 22, 2005
SUBJECT:
ST. LUCIE NUCLEAR PLANT - NRC SAFETY SYSTEM DESIGN AND PERFORMANCE CAPABILITY INSPECTION REPORT 05000335/2005007 AND 05000389/2005007
Dear Mr. Stall:
On June 24, 2005, the U.S. Nuclear Regulatory Commission (NRC) completed a safety system design and performance capability team inspection at your St. Lucie Units 1 and 2. The enclosed report documents the inspection findings which were discussed on June 23, 2005, with Mr. Christopher Costanza 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/
Charles R. Ogle, Chief Engineering Branch 1 Division of Reactor Safety Docket Nos.: 50-335, 50-389 License Nos.: DPR-67, NPF-16 cc w/encl: - (See page 2)
Enclosure:
NRC Inspection Report 05000335/2005007 and 05000389/2005007
w/Attachment: Supplemental Information
REGION II==
Docket Nos.:
50-335, 50-389 License No.:
05000335/2005007, 05000389/2005007 Licensee:
Florida Power & Light Company (FPL)
Facility:
St. Lucie Nuclear Plant, Units 1 & 2 Location:
6351 South Ocean Drive Jensen Beach, FL 34957 Dates:
June 13-17, 2005 June 20-24, 2005 Inspectors:
R. Berryman, Senior Reactor Inspector (Lead Inspector)
L. Mellen, Senior Reactor Inspector C. Smith, Senior Reactor Inspector S. Rose, Senior Operations Engineer N. Staples, Reactor Inspector R. Taylor, Reactor Inspector Accompanied by:
C. Fong, Reactor Inspector (Trainee)
Approved by:
Charles R. Ogle, Chief Engineering Branch 1 Division of Reactor Safety
SUMMARY OF FINDINGS
IR 05000335/2005007 and 05000389/2005007, 06/13-17/2005 and 06/20-24/2005; St. Lucie
Nuclear Plant, Units 1 & 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 capability of installed plant equipment to detect and respond to a loss of offsite power (LOOP) including a station blackout (SBO) event. Procedures which direct the mitigating actions for these events were also evaluated.
A specific list of components and documents reviewed for each section is included in the to this report.
.1 System Needs
.11 Process Medium
a. Inspection Scope
The team reviewed the water sources for components and systems required for the mitigation of the LOOP event. These included the refueling water tank (RWT) and the condensate storage tank (CST) for both Units 1 and 2. The team specifically reviewed the availability, reliability and adequacy of the water sources with respect to the anticipated water source requirements for the LOOP event. This review also included machinery history, inspection and test acceptance criteria for check valves V09151, V09157, V09119, and V09135 which are in the flowpath between the CST and auxiliary feedwater pump (AFW) pump suctions to verify these components will support the system function under accident conditions. In addition, the team reviewed design criteria information, drawings, vendor manuals, and calculations to determine the minimum water levels for pump net positive suction head (NPSH) and tank volume to verify that the design and Updated Final Safety Analysis Report (UFSAR) accident analysis assumptions were consistent with existing system and equipment capability.
b. Findings
No findings of significance were identified.
.12 Energy Sources
a. Inspection Scope
The team reviewed design documentation, drawings, calculations, technical manuals, and test documentation to verify that the capacity of the fuel oil storage tanks and the design of the fuel oil transfer pumps were adequate to provide the fuel required to operate the emergency diesel generators (EDGs) for the period of operation assumed in the accident analysis. In addition, the team reviewed the station acceptance criteria tests results and trending for fuel oil quality to verify these were consistent with the EDG vendor recommendations and applicable industry standards. The team reviewed design documentation, drawings, and installed configuration to verify that the EDG air start system capabilities were consistent with design basis assumptions. In addition, the team reviewed plant work orders (PWO) associated with starting air storage tanks to verify that the tanks have been adequately maintained. The team reviewed design documentation, drawings, installed configuration and maintenance history to verify the steam supply valves to the turbine driven AFW pumps, MV-08-13 and MV-08-14, will be available to perform their intended design functions.
The team reviewed instrument uncertainty calculations for a selection of risk-significant degraded voltage relays which initiate logic for separation from the grid, automatic start of the EDGs, sequential loading of risk significant equipment required to mitigate a LOOP and provide alarm functions for protection of risk significant equipment from the effects of a degraded voltage condition. Based on the minimum bus voltages at the class 1E switchgear under the worst degraded grid voltage conditions, the team evaluated the degraded voltage analysis which demonstrated the adequacy of protection provided to risk significant equipment by the degraded voltage relays. The team also evaluated transient voltage protection provided by the loss of voltage relays installed in a selection of Class 1E switchgear for risk significant equipment.
Additionally, the team reviewed and evaluated completed calibration procedures of these relays which were performed in accordance with the requirements of Technical Specifications (TS) 4.3.2.1.1.
Reviews of the undervoltage relay uncertainty calculations were performed in order to verify that the undervoltage relays were sufficiently accurate to comply with the trip values and allowed values delineated in TS Table 3.3-4, Functional Unit 6, Loss of Voltage. Additionally, reviews of completed undervoltage relay calibration procedures were performed in order to verify that the instruments were performing in accordance with the accuracies established in the uncertainty analyses, and that the Class 1E electrical distribution system was meeting the requirements of the plants licensing and design bases.
The team also reviewed the loading and power supplies of equipment in the technical support center (TSC) to verify that the TSC could conduct required functions during a LOOP.
b. Findings
No findings of significance were identified.
.13 Controls
a. Inspection Scope
The team reviewed the pump start logic for the 1A and 1C AFW pumps and 1A high pressure safety injection (HPSI) pump to verify that the pumps would be functional and provide desired control during accident/event conditions. The team reviewed the EDG load sequencer logic to verify that the permissives and starting circuits for EDGs and EDG load sequencers were appropriate for degraded or loss of voltage conditions on the 4160 volts alternating current (VAC) safety-related buses. The team also reviewed control wiring diagrams (CWDs) depicting the logic initiated by the loss of voltage relays to separate the 4160 VAC safety-related buses from offsite power sources.
The team reviewed logic and control diagrams for automatic makeup to EDG day tanks to verify that the fuel supplies to the EDGs would be maintained automatically. The team also reviewed the instrument functional, logic, and elementary drawings for a selection of risk significant motor operated valve (MOV) motors to verify that the valves could perform their critical functions during a design basis event.
b. Findings
No findings of significance were identified.
.14 Operator Actions
a. Inspection Scope
The team reviewed plant operating procedures, including emergency operating procedures (EOPs), abnormal operating procedures, alarm response procedures, and normal operating procedures that would be used in the identification and mitigation of a LOOP. The team focused on installed equipment and operator actions that could be used to mitigate LOOPs. The review was done to verify that the procedures were consistent with the UFSAR description of a LOOP and with the Combustion Engineering emergency procedure guidelines (CENs), any step deviations were justified and reasonable, and the procedures were written clearly. The team reviewed job performance measures, simulator exercise guides and training lesson plans pertaining to identification and mitigation of LOOPs to confirm that training was consistent with the applicable operating procedures.
In addition, the team reviewed simulation of various LOOP scenarios on the plant simulator and walked down portions of applicable procedures to verify that operator training, procedure guidance, and instrumentation were adequate to identify a LOOP and implement post-LOOP mitigation strategies. The manual operator action times for performance of LOOP mitigation activities were reviewed to verify consistency with accident analyses, CENs, and operator training.
b. Findings
No findings of significance were identified.
.15 Heat Removal
a. Inspection Scope
The team reviewed design documentation, drawings, calculations and test records to verify that EDG cooling systems were capable of removing the heat load and maintaining the EDGs within design requirements at maximum ambient temperatures during EDG standby conditions and during design basis operating conditions. The team also reviewed design documentation and calculations to verify that the AFW pumps received adequate cooling and would not exceed design temperature limitations during design basis loading at maximum assumed ambient temperature based upon their configuration. Additionally, the team walked down portions of the ventilation system supplying the battery rooms and reviewed logs to verify that air flow was steady and unobstructed and that battery room ambient temperatures were not excessive.
The team reviewed drawings and calculations to verify that the reactor auxiliary building (RAB), electrical equipment room, EDG building room, and safeguards pump room ventilation systems were adequately sized for heat removal under accident conditions.
Additionally, the team reviewed drawings and calculations to verify that the control room air conditioning system (CRACS) was capable of maintaining the air temperature within the limits specified by the UFSAR.
b. Findings
No findings of significance were identified.
.2 System Condition and Capability
.21 Installed Configuration
a. Inspection Scope
The team performed field inspections of the EDGs and selected portions of the Class 1E electrical switchgear that are required to perform their design function to mitigate a LOOP. A field inspection of the 125 VDC Class 1E train A and B batteries and associated chargers and distribution panels was also performed. Additionally, inspections were performed of the AFW pump motors and selected AFW MOVs.
The field inspections were performed to verify that the material conditions of the installed equipment was acceptable as demonstrated by the absence of unusual odors; damaged insulation as shown by discoloration and/or embrittlement; electric arc damage; fluctuating changes in motor drive currents; broken or missing lights/lenses; and missing ground straps or poor ground connections. Additionally, during the walk down, the team verified the as built configuration of the Class 1E electrical distribution system against approved design output drawings and protective relays setting calculations.
The team also performed field walkdowns of selected portions of systems which identify and mitigate LOOPs to observe the present condition and configuration. The team walked down portions of the AFW systems on Units 1 and 2 as well as portions of the CST suction sources on Units 1 and 2 to verify that they were aligned so that they would be available for operators to mitigate a design basis accident (DBA). The team walked down portions of the emergency diesel generators to verify that fuel supplies were aligned properly and cooling systems were aligned and available. The team walked down portions of the HPSI and shutdown cooling system (SDC) as well as portions of the RWT suction source to verify that they were aligned so that they would be available to the operators to mitigate a DBA. The team compared valve positions with those specified in the system operating procedure line-ups and drawings, and observed the material condition of the plant to verify it would be adequate to support operator actions.
The team reviewed maintenance records to verify that the steam supply to the 1C turbine-driven auxiliary feedwater pump was not obstructed.
The team also performed a field inspection of the diesel fuel oil tank level instruments to verify that the instruments were installed in accordance with the instrument installation drawing. Additionally, the team observed the material conditions of the field mounted instruments to verify that they were acceptable, freeze protection was provided where necessary, and that redundant instrument sensing lines were routed and protected to prevent common cause failure of the instruments.
b. Findings
No findings of significance were identified.
.22 Operation
a. Inspection Scope
The team reviewed selected portions of procedures used to mitigate LOOPs to verify the licensee had included appropriate human factors considerations in the procedures and in the plant. This review included verification of labeling, lighting, noise, communications, and accessibility. The team also checked system alignments, conducted field walkdowns and observed surveillance tests of selected components specified in the LOOP EOP for which local operation or main control room operation was required. These reviews were conducted to verify consistency with design and licensing basis assumptions, and the TS.
b. Findings
No findings of significance were identified.
.23 Design
a. Inspection Scope
.1 Mechanical Design Review
The team reviewed mechanical design calculations, specifications, and system design basis documentation to identify design criteria which defined the required capacity and capability of LOOP mitigation mechanical equipment. Surveillance test procedures and equipment monitoring activities were also reviewed to verify the design criteria were appropriately translated into acceptance criteria. The team reviewed NPSH calculations for the AFW, HPSI, and SDC pumps to verify that adequate NPSH was available from each of the applicable water sources. Design changes were reviewed to verify that system and equipment design functions were appropriately evaluated and maintained.
The team also reviewed design calculations to verify adequate minimum flow and pump run-out protection for the AFW, HPSI, and SDC pumps.
The team also reviewed the component cooling water (CCW) and SDC heat exchangers to verify that the heat exchangers would provide the nessesary heat transfer to support the SDC system under accident conditions. This review included the maintenance procedures associated with the inspection of the CCW heat exchangers to verify that conditions inside of the heat exchangers are maintained such that the heat transfer requirements may be met.
The team reviewed head curves and calculations that assessed the NPSH available to the SDC pumps to verify the capability of the system to meet the minimum specified flow and head requirements during DBA conditions. The review included a verification that adequate NPSH would be available at the predicted sump temperature during recirculation, if required to mitigate a LOOP.
.2 Instrumentation and Controls
The team reviewed and evaluated condition report (CR) 00-1069 which described actions completed by the licensee in response to Information Notice (IN) 2000-06. The scope of the review included actions completed by the licensee for the establishment of interfaces between FPL Power Supply and Transmission Station Operations and the St.
Lucie plant to ensure that the plant is informed by the load dispatcher or system operators of emerging conditions that could affect offsite power reliability. The team also reviewed and evaluated actions required by the interface agreement to inform the plant of forecasted conditions that may result in the grid exceeding voltage limits. The reviews were performed to verify that the concerns addressed in NRC IN 2000-06 were reviewed by the licensee and appropriate responses were developed and implemented.
Additionally, the review was performed to verify that plant activities such as maintenance which could impact the capability of the plants to respond to the emerging conditions would be controlled.
The team also reviewed the design basis documents; TS; functional, logic, and elementary drawings; and surveillance data associated with the control circuits for HPSI Pump 1A, AFW Pumps 1A/1C, and selected MOVs for the AFW system. The team also reviewed control circuits for MOV actuation and control for the auxiliary feedwater actuation signal (AFAS). These reviews were conducted to verify that equipment performance was appropriately monitored and maintained consistent with the design and licensing basis and to confi.rm that the control circuits implemented the functional requirements stated in the design and licensing basis.
b. Findings
No findings of significance were identified.
.24 Testing and Inspection
a. Inspection Scope
The team reviewed surveillance testing and inspection documentation for the EDGs to verify performance monitoring was adequate to assure that design capability was maintained and equipment degradation would be identified. The team also reviewed the surveillance test procedures which control testing of the 1C AFW pump to verify testing requirements specified in the procedures were adequate. Additionally, completed test and inspection results were reviewed to assess the licensees actions to verify and maintain the safety function, reliability, and availability of the 1C AFW pump. The team reviewed MOV test results for AFW injection MOVs to verify test results satisfied the criteria for MOV testing. Test and inspection results were reviewed to verify that the results were consistent with design specifications, that test acceptance criteria and test results appropriately considered differences between testing conditions and design requirements during accident conditions, and that test and inspection results met established acceptance criteria.
The team reviewed and evaluated surveilance test results for the periodic test of train A engineered safety features and 1A/1B EDGs. The team also reviewed and evaluated test results of the 1A battery capacity test. The reviews were performed to verify that the requirements of the plants licensing and design bases were being met as demonstrated by the test results.
The team reviewed surveillance procedures of Unit 1 process instrument channels LT-9013A, SG narrow range level, PT-8013A SG pressure, and FT-09-2A AFW pump flow to verify that the prescribed tests were consistent with the instrument design including uncertainty calculations, setpoint documents, and TS. The team verified that the calculations included appropriate uncertainties for normal and accident parameters.
The team also reviewed procedures and records of completed surveillance tests, performance tests, inspections, and walked down selected components of the AFW and main steam systems to verify that the tests and inspections appropriately verified that licensing and design bases assumptions were being maintained. The team reviewed the design for EDG Fuel Oil Transfer Pump 1A and to verify that testing performed validated integrated system operation for event conditions. The team also reviewed control circuit test results for valve MV-09-9 and valve MV-09-10 to verify that components were adequately tested to verify component operability.
b. Findings
No findings of significance were identified.
.3 Selected Components
.31 Component Degradation
a. Inspection Scope
The team reviewed inservice test program trending data, maintenance and testing documentation, calibration records, work orders, and condition reports to assess the licensees actions to verify and maintain the safety function, reliability and availability of selected components. Additionally, the team reviewed potential common cause failure mechanisms due to flooding, maintenance, parts replacement, and modifications.
b. Findings
No findings of significance were identified.
.32 Equipment/Environmental Qualifications
a. Inspection Scope
The team reviewed the environmental requirements for the AFW pumps and EDG rooms to verify that the equipment is suitable for the environment under postulated accident conditions. This review included verification of adequate space or room cooling by means of outdoor ambient air. The team also reviewed AFW lubricating oil and governor oil systems to verify adequate temperature protection at low temperatures.
b. Findings
No findings of significance were identified.
.33 Equipment Protection
a. Inspection Scope
The team performed field walkdowns of the AFW pump rooms and EDG rooms to verify that the rooms were able to withstand an external flood up to the design basis flood level and to evaluate susceptibility to internal flooding. The team also evaluated both Unit 1 and 2 AFW piping and pump susceptibility to freezing and evaluated freeze protection.
The team also performed field walkdowns of the CSTs to verify that installed missile protection was intact and installed in accordance with the original design configuration.
b. Findings
No findings of significance were identified.
.34 Component Inputs/Outputs
c. Inspection Scope
The team reviewed and evaluated calculations performed for determining the required brake horsepower (BHP) of the 1A and 1B AFW pump motors based on the mechanical load demand. The team also reviewed and evaluated the EDG loading calculations to verify that the BHP rating of the AFW pump motors had been correctly incorporated in the EDG loading analysis. Th-e team inspected the capability of 1A and 1B AFW pumps and critical AFW MOVs to perform their design functions under degraded voltage conditions. The capability of the AFW pumps to perform under degraded voltage conditons was inspected by reviewing the voltage drop calculations that were completed for the motors. The capability of the selected AFW MOVs to perform under degraded voltage conditions was inspected by review and evaluation of the voltage drop calculations that were completed for both 125 VDC and 120 VAC MOV motor operators.
This review was conducted to verify that there was sufficient voltage margin for starting the AFW pump motors and that adequate starting torque was developed by the AFW MOVs under these starting conditions.
The team also reviewed the instrumentation used by operators for mitigation of a LOOP event. The team reviewed appropriate design basis documents, TS, system flow diagrams, instrument uncertainty calculations, instrument setpoint calculations, instrument scaling documents, calibration procedures, and calibration test records to verify that the instruments provided adequate range and accuracy to perform their safety function. The setpoints for the alarms and equipment actuation relays were reviewed to verify that they were established in accordance with setpoint guideline procedures and design output documents. The last two completed calibration test records were reviewed to confirm that instrument setpoints were consistent with setpoint calculations.
b. Findings
No findings of significance were identified.
.35 Operating Experience
a. Inspection Scope
The team reviewed a sample of extent of condition reviews and corrective actions for industry and station operating experience issues related to LOOPs, surveillance tests, loss of grid, auxiliary feedwater and check valve problems to verify that plant specific issues were appropriately identified and addressed. The team also verified the lessons learned from the 2004 hurricanes and LOOP event were incorporated into operator training.
b. Findings
No findings of significance were identified.
.4 Identification and Resolution of Problems
a. Inspection Scope
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 selected pumps and valves. The team reviewed selected system health reports, maintenance records, surveillance test records, and CRs to verify that design and performance problems were identified and entered into the corrective action program.
b. Findings
No findings of significance were identified.
4. OTHER ACTIVITIES
4OA6 Meetings, Including Exit
The lead inspector presented the inspection results on June 23, 2005, to Mr. Costanza 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
- K. Frehafer, Licensing
- E. Sumner, Shift Manager
- J. Cimino, Configuration Control Analyst
- R. Filipek, Design Engineering Configuration Management Supervisor
- V. Rubano, Project Engineer
- M. Rubano, Systems Engineer
- J. Giampietro, Design Engineering Civil Supervisor
- R. Hughes, Site Engineering Manager
- T. Patterson, Licensing Manager
NRC (attended exit meeting)
- C. Ogle, Chief, Engineering Branch One, Division of Reactor Safety
LIST OF ITEMS
OPENED, CLOSED AND DISCUSSED
None.
LIST OF COMPONENTS AND