IR 05000443/1992027
| ML20127N275 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 01/12/1993 |
| From: | Rogge J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20127N274 | List: |
| References | |
| 50-443-92-27, NUDOCS 9301290160 | |
| Download: ML20127N275 (16) | |
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U. S. NUCLEAR REGULATORY COMMISSION
REGION I
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Report Number:
92-27 Docket No:
50.WJ W License No:
NPF-368 6 Licensee:
North Atlantic Energy Service Corporation Post Office Box 300 Seabrook, New Hampshire 03874 Facility:
Seabrook Station Dates:
November 17 - December 21,1992 Inspector:
Noel Dudley, Senior Resident Inspector Richard Laura, Resident Inspector
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//// 23 Approved By:
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p6hn F. Rogg'e, CliidU
' Dat6 Reactor Projects Section 4B OVERVIEW Operators maintained excellent control of plant activities during three reactor startups and following two reactor trips. The identification of a small steam leak inside containment and the identification of increased vibration on the 'C' service water pump indicated auxiliary operator rounds were effective in identifying equipment problems.
Maintenance workers properly conducted routine maintenance and surveillance tests.
Maintenance supervisors provided proper eversight of contract maintenance workers.
The inspector identified an unresolved itcm concerning repetitive failures of the emergency diesel generator fuel delivery springs. North Atlantic has not yet identified long term corrective actions to address the spring failures.
Several modifications made to steam plant equipment during the second refuel outage improved plant performance and reflected a proactive attitude by station management.
Inspector review of the instrument air system identified instances where equipment problems
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were not aggressively pursued and resolved.
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I North Atlantic complied with the special license requirement contained in license amendment
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No.10 for reporting significant p! ant, organizational, or budgetary changes to the NRC.
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l-I 9301290160 930112 i-PDR ADOCK 05000443 G,
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TAllLE OF CONTENTS O V E R V I EW..............................................
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TA llLE OF CONTENTS...............................
....... ii 1.0 SUMM ARY OF ACTIVITIES (71707)..................
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1.1 N R C Activities....................................
I 1.2 Plant Activities....................................
2.0 PLANT OPERATIONS (71707, 92701, 93702).....................
2.1 Routine Plant Operations..............................
2.2 R eac to r Tri p......................................
2.3 Reactor Trip Due to Seaweed...........................
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3.0 R ADI ATION CONTROLS /CilEMISTRY (71707)..............,....
4.0 M AINTENANCE/ SURVEILLANCE (61726, 62703)
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4.1 Fuel Storage Building Exhaust Fan
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4.2 Radiation Monitor Modification..........................
4.3 Overtemperatore Delta T Surveillance Test
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4.5 Emergency Diesel Generator lH Operability Test
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5.0 lim ERG ENCY PLANNING (71707)........................,
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L 6.0 SECURITY (71707)
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7.0 ENGINEERING /TECilNICAL SUPPORT (71707, 37055).............,
7.1 Instrument Air System
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7.2 Emergency _ Diesel Generator Fuel Delivery Spring Failures (Open, URI 92-27-01)
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7.3 Steam Plant Enhancements.............................
I1 8.0 SAFETY ASSESSMENT / QUALITY VERIFICATION (71707,92701)
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8.1 Special License Requirements........................... 12 8.2 Service Water Pump Evaluation..........................
13-9.0 M EETI N G S (30702)..................................... 14 --
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DETAILS
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1.0 SUMMARY OF ACTIVITIES (71707)
1.1 NRC Activities Two resident inspectors were assigned throughout the period. The in'.pectors conducted
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backshift inspections on December 15 and deep backshift inspections on November 21,28, 29, and December 6.
NRC regional management held a meeting with North Atlantic senior managers on
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December 3,1992, to discuss licensing of three operators whose operator licenses were terminated due to inaccurate auxiliary opcrator logs. Neither the NRC nor North Atlantic reached any decisions or made any commitments.
On December 15, the present section chief, Division of Reactor Projects, Region I,
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responsible for Seabrook and the branch and section chiefs who will become responsible for Seabrook on January 3,1993, toured the site and met with North Atlantic management.
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.r 1.2 Plant Activities At the beginning of the period, the reactor was at 30% power. On November 16, the.
operator completed raising power to 100%. On November 23, the operators reduced power to 92% in response to the loss of the heater drain pumps. The operators returned power to
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-100% the same day.
On November 27, an automatic reactor trip occurred due to a spurious overpower delta temperature (OPDT) trip signal. The operators brought the reactor critical and raised power to 100% on November 28.
On December 13, operatars manually tripped the reactor when seaweed clogged the circulating water screens causing the circulating water pumps to trip. The operators brought -
the reactor critical on December 14, placed the generator on the grid on December 15, and reached full power on December 17 2.0 PLANT OPERATIONS (71707, 92701, 93702)
2.1 Routine Plant Operations The inspector conducted daily control room tours, observed shift turnovers, attended the morning station manager's meeting, and monitored plan-of-the-day meetings. The inspector reviewed plant staffing, safety system valve lineups, and compliance with Technical Specification requirements. Tours were conducted in the primary auxiliary building, the emergency diesel generator rooms, the residual heat removal vaults, the turbine building, the condensate storage tank building, and the circulating. water pumphouse. During the tours and i
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attendance at the various meetings, the inspector noted overall good performance by the operations staff.
At the beginning of this period, the second refueling cutage had been completed and the unit was at 30% power in the process of power ascension. The inspector observed portions of reactor physics testing and flux mapping, and noted that the reactor engineers performed well and maintained good communications with the operators. Reactor engineers evaluated difficulties with the operation of the incore instrument drives and initiated corrective actions.
After reaching full power, operators reduced power to mitigate the effects of the unexpected tripping of both heater drain pumps.
The inspector reviewed the unit journal and noted several entrics which did not adequately document pertinent information such that an independent reader could review plant activities, in each case, the operations staff took all the proper actions, but did not provide sufficient information in the unit journal. The inspector discussed unit journal entries with the operations manager who initiated a review to detennine if enhancements were necessary.
During a weekly containment entry, an operator heard and eventually located a packing leak on instrument root valve MS-V-47, for the steam flow detector on steam generator 'D'. The technical support department evaluated the leak and an operator placed the valve on its backseat, stopping the leak.
The inspector observed a reactor operator perform the Technical Specifications required shift check surveillance. Plant operating data was obtained from meter readings, annunciator status, bistable light status, and the plant process computer. The inspector assessed the reactor operator was experienced and properly evaluated operational data.
2.2 Reactor Trip On November 27, the reactor tripped from 100% power. Instrument and Control (l&C)
technicians had placed reactor protection system (RPS) logic cabinet I in test to adjust temperature setpoints using recent incore llux mapping data. With the channel in test, the reactor trip coincidence logic changed from two out of four to one out of three channel actuation signals needed to open the reactor trip breaker. A spurious loop four overpower delta temperature (OPDT) reactor trip signal caused the reactor to trip.
The inspector reviewed the event evaluation, the alarm logger printout, the control room logs, the charts generated during the troubleshooting activitics, and the completed post trip review procedure; observed portions of the trip recovery, troubleshooting efforts, and plant startup; held discussions with maintenance, technical support, and operations personnel; and attended the management meeting which reviewed the event evaluation and approved the plant startup.
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3-The plant response to the trip was normal. ~ A modiGcation, installed during the first refueling outage to the time delay circuit for the steam generator high-high water level actuation signal -
prevented the steam line pressure transients from generating a feedwater isolation actuation
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signal. A modiGcation installed during the second refueling outage, opened the herter drain tank high level dump valve and transferred the stored energy in the feedwater system to the condenser As a result, the response of the secondary system was less severe than that for -
previous plant trips. The emergency feedwater system automatically started on the steam ~
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generator low. low water level signal caused by the shrink in the steam generators.
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The operators followed the emergency operating procedures, stabilized plant conditions, and supported troubleshooting activities. The I&C technicians identified the source of the spurious OPDT trip signal as a fluctuating reactor trip setpoint caused by a faulty biasing -
resistor on the output of an operational amplifier on the bistable (NAL) card for OPDT channel IV. The setpoint dropped below the value for OPDT calculated from measured plant parameters. The RPS cabinet IV door was closed and locked at the time of the trip.
The event evaluation team determined that the operators and the I&C technicians' actions were appropriate. The team determined the root cause of the trip was equipment failure.
The management review of the event evaluation report and approval of the mode change
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checklist _were well directed. Management decided not to test the OPDT setpoint signals generated by the other NAL channel cards based on the last successful performance of calibrations, surveillances, and setpoint adjustments. The operators restarted the reactor, maintained good communications while controlling steam generator level during low power conditions, and synchronized the main generator onto the electrical grid.
The inspector concluded that the event evaluation team conducted a thorough review o_f the plant response to the trip and reached well supported t.onclusions. The inspector noted that the unit journal contained equipment status but did not include a narrative discussion of the-basis for restarting the plant.
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2.3 Reactor Trip Due to Seaweed
On December 13, the operators tripped the reactor after two circulating water pumps tripped due to high differential pressure across the traveling screens. Due to a winter storm _which began on December 11, the auxiliary operators had been continually washing seaweed off of -
the circulating water pump traveling screens. The seaweed stirred up by the storm traveled three miles through the intake tunnel, up the 260-foot tall intake structure, into the circMig water pumphouse forebay, and collected on the traveling screens. - During the screen washing -
operations, the traveling screens moved at slow speed (5 fpm) or fast speed (20 fpm)_
depending on the differential pressure across the screens. On December 13, the 'C' train screen drive motor stopped moving after cycling between slow and fast speeds; The screen differential pressures rapidly increased to the point that tripped the circulating water pumps.
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The plant responded as designed. The operators stabilized plant conditions, started a circulating water pump, and verified seaweed could be washed off of the screens prior to restarting the reactor, The technical support department developed and I&C technicians installed a temporary modification on the speed control circuit of the traveling screen motor -
which allowed operators to select either slow or fast speed. The operations department began evaluating the need for administrative procedures for screen washing operations during severe.
weather conditions.
The auxiliary operator efforts to remove seaweed from the traveling screens allowed the plant to remain on line through the worst part of the winter storm. The operations staff identified more effective methods for operation of the screen wash system, which included single speed operation of the screen drive motor. The operators believed these methods would mitigate the effects of future seaweed incursions.
The inspector observed the main control room operators stabilize plant conditions and the auxiliary operators perform screen wash operations; reviewed the event evaluation and the temporary modification package for the screen wash motor _ control circuit; held discussions with technical support and operations personnel; and attended management meetings which reviewed the event evaluation and rccovery activities.
The inspector concluded that the reactor trip was caused by a massive seaweed meursion mto -
the circulating water system. The inspector determined that operator response was excellent, that the event evaluation was thorough, that the ternporary modification package was complete, and that the management decision to delay reactor startup was conservative and indicated a good safety perspective.
3.0 RADIATION CONTROLS /CIIEMISTRY (71707)
H The inspector toured the primary auxiliary building and the residual heat removal vaults. The-inspector reviewed radiation postings, area surveys, monitoring' equipment calibration, and
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locked high radiation area doors. The inspector discussed minor discrepancies with health physics supervisors who aggressively resolved the discrepancies. Health physics technicians-
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effectively controlled radiation exposure and contained radioactive contamination.
The inspector toured the primary chemistry lab, reviewed the grab sample logs and associated procedures, and held a discussion with a chemistry technician. The inspector noted the lab was clean, organized, spacious, and setup in a way to avoid sample contaminations. Several random pieces of equipment were verified to be calibrated. Chemistry technicians followed-the posted exit instructions which required a check for radioactive contamination.1The inspector assessed that activities conducted in the lab were properly performed.
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4.0 M AINTENANCE/SUltVEILLANCE (61726, 62703)
4.1 Fuel Storage llullding Exhnust Fan The inspector observed the replacement of a flexible duct in the ductwork for fuel storage building exhaust fan FAH-FN ll A. A contractor maintenance worker performed the -
replacement under work request 92-WR-03679. The inspector reviewed tagout 92-259 and raoiation work pern.it 92R518, and found them to be complete and properly implemented.
Procedure MS0517.ll contained the work instructions which provided generic instructions on the fabrication and installation of flexible ducting. The old flex duct, composed of thick rubber, had hardened and cracked over time. The new flex duct material was more durable and flexible.
The worker performed a quality job installing the rew flex duct. The gasket and scaler material were specified by the procedure and had the proper material usage tags. All fasteners were properly secured. The inspector assessed the contractor worker performed a good job in replacing the nex duct.-
4.2 Radiation Monitor Modification The inspector observed portions of the implementation of modification 91-0642 which recon 0gured the location and piping arrangement for the turbine building sump discharge radiation element IRM-RM-6521. The purpose of the modification was to increase the reliability and accuracy of the radiation monitor readings.
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Contractor workers performed the work with North Atlantic oversight provided by the construction supervisor. The turbine building sump pump was inoperable during the modification work. A temporary sump pump and hose, which discharged to the storm drain, was installed per the instructions of procedure WN0598.039, Rev.00,_" Installation of Temporary Pumps." Chemistry technicians performed the requirement of Technical-Specincations Table 3.3-12, Action Statement 30, by taking and analyzing samples for -
radioactivity every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The inspector reviewed the chemistry sample data and frequency, and found the sampling process was properly controlled.
The modification work consisted of installing a new piping arrangement. The. work included two bimetallic welds which connected stainless steel to carbon steel piping. The inspector -
reviewed the weld traveler, weld filler material, and the welder qualifications. The welder qualified to weld carbon steel per procedure YA-WP-3S and stainless steel per procedure YA WP-2S. However, the welder did not qualify to weld carbon steel to stainless steel per procedure YA-WP-6S. Training and engineering personnel stated that the general welder
- performance qualification procedure, YA-WP-IS, allowed a welder qualified in one welding procedure to weld using other procedures provided the same weld process was used and there were no different essential welding variables. The inspector verified the essentid welding variables for procedure YA-WP-6S were the same as for procedures YA-WP-25 and YA-WP-
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25. The inspector concluded that the welder met the requirements of Section IX of the -
ASME boiler and pressure vessel code for welding carbon steel to stainless steel.
Maintenance workers properly condu,ted post maintenance tests to verify the operability of the radiation monitor. Qualified contractor personnel effectively installed the radiation element. The inspector assessed that this modification was a positive initiative to improve the reliability and accuracy of the turbine building sump discharge line radiation monitor.
4.3 Overtemperature Delta T Sunelliance Test l
The inspector observed instrument and control (I&C) technicians perform Procedure
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IX1662.410, "T-411 A Loop i Delta T/TAVG Protection Channel 1 Calibration." The inspector verified that operations personnel properly entered the applicable Technical Speci6 cations action statements. Before the I&C technicians by-passed the reactor protective system (RPS) instruments, an I&C supervisor verified the-technicians were working in the connect RPS cabinet.
The technicians performed the calibration in a controlled manner using good procedural adherence. The inspector verified proper calibration of the Duke meter, switch box, and power supplies used for the calibration. The I&C technicians and the operations staff '
l displayed good communications and teamwork. The I&C technicians adjusted the setpoints to the middle of the setpoint band for optimum performance. The inspector assessed that the I&C technicians were experienced and very knowledgeable of the calibration process and the use of test equipment.
4.5 Emergency Diesel Generator 111 Operability Test The inspector observed the performance of Procedure OX1426.05, "D/G 1B Monthly Operability Surveillance " Operators started the emergency diesel generator (EDG) which responded properly by coming up to speed and voltage within 10 seconds. Operators loaded the EDG to 6000 KW for one hour then ran the diesel at reduced load for an additional threc
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hours. The inspector reviewed the test data and verined that all the acceptance criteria were
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met.
During the operability run, the 'B' EDG vibmtion annunciator alarmed in the control room.
Operators followed the alarm response procedure which directed that temporary vibration monitoring equipment be installed on.'B' EDG. The vibration data revealed a cyclic vibration of two to six mils in the generator bearings. Engineering personnel determined that the vibration resulted from misfiring in the engine Mechanical maintenance technicians installed a temporary pressure gauge and recorded engine cylinder data. The cylinder -
l pressure and temperature in the number 13 cylinder were notably lower than the other cylinders. After completion of the operability run, the EDG was secured and work request 92-WR-05485 was initiated to inspect and repair the number 13 cylinder fuel injection pump
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After disassembly of the fuel pump, mechanical maintenance technicians found that the delivery valve spring was broken. The spring maintained the delivery valve shut until the fuel pump piston stroked upward and delivered fuel to the injector. Mechanics replaced the broken spring with a spring from a unit two EDG fuel pump. As a preventative measure, mechanics replaced the number 13 cylinder injector with a new injector that had successfully passed a leak test. The torque wrenches used in the repairs were properly calibrated and were the correct size. The inspector observed that the mechanics conducted the work in a safe, controlled, and experienced manner.
The inspector determined the work package was complete and well prepared. The work package contained several different marked up EDG preventative maintenance procedures that provided the necessary work instructions. The po~ maintenance test sheet required an operability run at the completion of the maintenante. The inspector noted effective use of quality control holdpoints such as verification of 'O' rings and proper torque values.
During the maintenance run of the emergency diesel generator, the temperature and pressure in the number 13 cylinder were still much lower than the other cylinders. The machine was secured and the fuel pump assembly was replaced and timing adjustments were made. The EDG successfully passed a maintenance run and then the operability test, in summary, the inspector assessed that deficiencies identified during the performance of the surveillance test were properly resolved.
5.0 EMERGENCY PI,ANNING (71707)
On December 8, North Atlantic conducted a drill of their ability to activate the technical support center (TSC) and emergency operating facility (EOF) within one hour. A paging system notified the primary responders. The emergency response organization notification system (ERONS) notified the secondary responders.
The inspector reviewed and discussed the results of the drill with the emergency planning drill group supervisor. Response times were determined by the combination of notification time and estimated mobilization time provided by each responder. The response to the drill was satisfactory, in that the TSC and EOF could have been activated within one hour. The inspector assessed that the drill was effective in verifying the ability to properly activate the TSC and EOF.
6.0 SECURITY (71707)
The inspector toured the protected area, observed security guards on patrol, evaluated protected area lighting, and monitored activities in the central and secondary alarm stations.
While observing activities in the secondary alarm stations, the inspector noted a security area supervisor providing oversight. An instrument and control technician performed corrective maintenance on a security camera which indicated the security staff was sensitive to I
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equipment problems. The inspector observed properly performed testing of the vital area motion detectors. The security of0cers in the central alarm station closely monitored work performed in a manway which was located in the exclusion area adjacent to the protec!cd area fence. The inspector concluded security activities were performed in a professional manner.
Security management's presence at the morning management meeting was assessed to be a strength.
7.0 ENGINEERING /TECIINICAL SUPPORT (71707, 37055)
7.1 Instrument Air System To verify that the instrument air system supplied clean dry air to safety related components, the inspectar walked down the system, held discussions with technical support engineers, and reviewed the Updated Final Safety Analysis Report, system procedures, and maintenance history. The instrument air system is non-safety rehted and is not relied upon for accident mitigation.
System Description The instrument air and service air systems are supplied by one centrifugal and three reciprocating air compressors. Air discharged from each compressor is routed to two air receivers through a common discharge manifold.130th receivers are connected in parallel to a second manifold that supplies the instrument air and service air systems. Two valves on the second manifold isolate the senice air system in case of low pressure in the instrument air system, thus ensuring all available air is reserved for the instrument air system. Branch lines off the common manifold direct air to two independent air dryers before being routed to two independent instrument air ring headers.
Nitrogen bottles provide a backup to the normal instrument air supply for the steam supply valves to the turbine driven emergency feedwater pump, the atmospheric steam dump valves, the primary component cooling water (PCCW) temperature control valves, and the PCCW temperature control bypass valves. One-inch spring actuated Kerotest soft seat check valves separate the nitrogen bottles from the instrument air header.
Two diesel driven instrument air compressors are available on site to provide a back up source of instrument air in the event all the installed instrument air compressors failed.
Two separate trains of air compressors, receivers, and air driers provide instrument air in the containment. During the second refueling outage, construction workers installed a normally closed cross-connect line between the instrument air and containment instrument air systems.
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Technical Support / Engineering North Atlantic responded to NRC Generic Letter (GL) 8814, " Instrument Air Supply Problems Affecting Safety-Related Equipment," in a letter (NYN-89018) dated February 21, 1989. The letter discussed an Air System Task Force. The Task Force developed recommendations which where never formally documented nor reviewed by station management. The Task Force has since become inactive. Technical support and engineering personnel recently met and reviewed and prioritized the list of task force recommendations.
Technical support engineers plan to implement document coordination report (DCR) 91-31 during the third refueling outage. DCR 91-31 provided directions for modifying the station and instrument air headers to improve train separation, increase available air storage capacity, and increase reliability. The DCR would climinate the nitrogen bottles which are presently needed to open the service air isolation valves after a loss of instrument air header pressure.
Technical support personnel monitored the air flow through the service and instrument air headers to determine the size of compressors needed to replace the reciprocating air compressors. North Atlantic had not developed a schedule for purchase and installation of
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the new air compressors.
The inspector cencluded that engineering efforts were in progress to enhance the reliability of the instrument air system, even though management had not formally reviewed the Air System Task Force recommendations.
Procedures The inspector verified that existing procedures provided guidance for the normal and off normal operation of instrument, station, and containment air systems. Procedure ON 1242.01, " Loss of Instrument Air," provided guidance for restoring instrument air and included a listing of time dependent actions required to he taken by the operators, Procedure ON 1042.01, " Operation of Containment Compressed Air System," included a recent revision.
that provided steps for cross-connecting the containment instrument air system with the-instrument air header.
Both procedures contained information that equated the ability to open PCCW containment isolation valves with an instrument air pressure of 60 psig. The inspector questioned whether the 60 psig was the pressure at the regulator to the valve actuator or the indicated instrument -
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air header pressure. NRC Inspection Report 50-443/91-16 discussed a similar situation that resulted in the opeations departmen' revising an emergency operating procedure.
The operations procedure writer determined the pressure values were not important and initiated procedural changes to remove the values from the procedures.
The inspector concluded that a complete set of clear procedures allowed for the safe and reliable operation of the instrument air system.
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The inspector reviewed the last two annual air samples taken per procedure IS 1649.999,
- Instrument Air System Quality Veri 0 cation Procedure." Workers collected samples from ten sample points throughout the plant and containment. All samples were within acceptance criteria.
The inspector observed the performance of a portion of proceduie OX 1436, Turbine Driven Emergency Feedwater Pumr Monthly, Quarteriv, and 18 Month Surveillance Test," which exercised the instrument air check valves assocle d with the 'B' steam generator steam supply valve, MS V-394. The auxiliary operato
..ectly performed the surveillance. The check valves performed satisfactorily. The inspector noted no evidence of moisture in the
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instrument air lines..
The dew point monitors are the only instruments to provide indication of the moisture content of air provided to the instrument air header. The instrument and control (l&C) technicians had not performed calibration surveillances on the dew point monitors since March 1988 when construction workers installed the monitors. The 1&C supervisor stated that he would develop a routine calibration procedure for the dew point monitors. The inspector concluded that the lack of testing the dew imint monitors was a weakness.
Maintenance On July 20,1992, instrument air header pressure decreased over several hours. During that time, nitrogen pressure in the backup nitrogen bottles to the 'A' train PCCW temperature control valves decreased. A technical support engineer issued a woik request to trouble shoot and repair check valves IA-V-8030 and 8031 that separated the nitregen bottles from the instrument air header. I&C technicians initially tested the check valves in accordance with surveillance procedure OX 1412.11, "PC'JW System Cold Shutdown Valve Test." The check valves performed satisfactorily.
Based on previous experience, a program suppoli engineer suspected that the spring actuated Kerotest check valves would provide isolation on a rapid depressuri7.ation of the instrument air header but might not provide isolation on a slow depressurization of the header. The
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manufacturer indicated that the check valves should provide isolation with a 3 to 5 psid pressure but had not been tested below a 45 psid pressure. On November 18,1992, the technical support engineer generated a request for engineering services to evaluate the potentially unacceptable performance of the Kerotest check valves. The inspector noted that four months had elapsed between the occurrence of a failure and the issuance of a request for an engineering evaluation.
Mechanics inspected and replaced the instrument air in line duplex filters for the nrst time in 1991. The technical support engineer stated that the removed Glters were in good shape and that there was no indication of desiceant carryover. The maintenance department rescheduled
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the yearly inspection of the air filters, which resulted in exceeding the planned periodicity specified in the program described in North Atlantic's response to GL-88-14. The inspector noted that there was no engineering basis for extending the preventive maintenance periodicity since only one data point existed for trending the performance of the Olters.
Conclusion The inspector concluded the operations, maintenance, and surveillance of the instrument air system were adequate and that engineering efforts were in progress to enhance the reliability of the system. The inspecter noted instances where surveillance activities were not performed on a routine basis and where identified component problems were not aggressively pursued and resolved.
7.2 Emergency Diesel Generntor Fuel Delivery Spring Fntlures (Open, URI 92-27-01)
The inspector held discussions with maintenance and technical support personnel, and reviewed the maintenance history of the fuel delivery valve spring performance. The insivetor viewed the broken spring that was identified during tbc monthly surveillance test (see Section 3.2). The spring was approximately one-inch-long and the tips of the spring, at both ends, had broken off. Improper performance of the spring and unusual wear of the seating surfaces interfered with close tolerance components inside the fuel pumps and caused misfiring in cylinders, liased on discussions and review of the maintenance files, the inspector identified that there had been 12 spring failures in the last three years. Each failed spring was replaced with one of the same design. The technical support staff and management stated that they were evaluating extending the periodicity of the teardown inspection presently performed each refueling outage. This would reduce the number of required diesel starts and minimize fuel delivery valve spring wear.
The inspector assessed that North Atlantic was slow in addressing the spring failures. North Atlantic had not identified or taken any long-term corrective actions which specifically address the failures. Engineering had not performed a part 21 evaluation of the failures.
This concern will remain as an unresolved item pending inspector review of the North Atlantic disposition of the repetitive spring failures (Ult! 92-27-01).
7.3 Steam Plant Enhancements During the second refueling outage several modifications enhanced the operation and reliability of major steam plant equipment. Workers installed modi 6 cations to the moisture separator reheaters (MSR), heater drain tank level control system, and feedwater heaters.
The inspector reviewed the associated design change paperwork, reviewed performance data, and held discussions with operations and technical support personnel to determine the effectiveness of the changes.
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A new MSR digital control system installed per design coordination report (DCR) 92-0004 improved operation of the MSRs at low turbine loads and allowed for reliable automated loading. The DCR installed a new control panel on the turbine deck and an operator console in the control room. The new system performed very well during the three startups subsequent to the second refueling outage.
DCR 91040 made enhancements to the heater drain tank level control system including new level columns and switches on the heater drain tank. North Atlantic experienced some difficulties with the performance of the new heater drain tank level columns which required replacing the columns. Notwithstanding these difficulties, '.he enhancements improved overall i
performance of the level control in the heater drah, tank.
DCR 914)049 made enhancements to the feedwater, condensate, and heater drain systems to minimirc the effects of pressure excursions following a rapid closure of the feedwater regulating valves.
Collectively, these steam plant enhancements indicated a significant effort by North Atlantic to improve plant operating performance, minimize the occurrence of reactor trips, and mitigate the effects of reactor trips. During plant operations following the second refuelmg
outage, including three startups and two reactor trips, there was substantial improvement in steam plant operation. The inspector assessed that these modifications reflected a proactive approach by North Atlantic in improving plant operations.
8,0 sal'ETY ASSESSMl?NT/ QUAL.lTY YEltil'ICATION (71707,92701)
8,1 Special 1,1 cense Requirements On May 29,1992, the NRC issued license amendment No.10 which approved transfer of the Seabrook operating license from New Hampshire Yankee, a division of Public Service Company of New Hampshire, to North Atlantic Energy Service Corporation (North Atlantic),
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a wholly owned subsidiary of Northeast Utilities Company. The inspector held discussions with the North Atlantic Senior Vice President and Chief Nuclear Officer to verify compliance with special requirements contained in license amendment No.10.
The Joint Owners have made no change to either the Joint Owner Agreement or the Managing Agent Operating Agreement since the license transfer occurred. The senior management changes announced for Northeast Utilities Company have no effect on the principle duties of the Senior Vice President and Chief Nuclear Officer of North Atlantic.
From routine inspection findings the inspector noted no plant design, equipment, or personnel performance trends that could have potentially adverse effects on facility safety. The employee concerns program continued to be effective. North Atlantic continually reminded their supervisors of federal regulations concerning employee discrimination and North Atlantic's high regard for employee rights.
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Following the license transfer, some craft employees voted to be represented by the Utility Workers' Union of America. Union contract negotiations were planned to begin in January 1993. North Atlantic modined the benefits plan for non-bargaining unit employees. The inspector noted no adverse effects on facility safe'y or worker attitudes resulting from either the creation of a union or the modification of the benefits plan.
The inspector reviewed the Seabrook Oversight Committee report prepared for the Seabrook Nonoperating Participants Committee. The joint Owner Executive Committee created the Oversight Committee to review the performance of North Atlantic. The report identified no significant safety concerns at Seabrook and presented twelve recommendations. The recommendations identified areas for improvement such as the use of computer networks for planning and procurement activities.
The inspector reviewed North Atlantic letter (NYN 92169) to the NRC dated December 17, 1992. The letter stated the Joint Owner Executive Committee reviewed the Oversight Committee's report and concluded that no report was required under the license conditions of amendment No.10.
The inspector held discussions with the New llampshire Public Utilities Commission site representative concerning annual operating and maintenance (O&ht) and capital expenditure budgets. The 1993 O&ht budget did not include the additional cost of a refueling outage since North Atlantic extended the refueling cycle to 18 months. As a result, the 1993 O&ht budget was numerically lower than the 1992 O&ht budget. North Atlantic reduced the capital expenditure budget for 1993 due to a claims settlement for work performed during construction. Overall, the planned 1993 and actual 1992 capital improvements were equivalent. The inspector concluded the level of funding of Seabrook operations has not changed signincantly.
The inspector concluded that North Atlantic complied with special license requirements contained in license amendment No.10.
8.2 Service Water Pump Evaluntion During a routine tour of the service water pumphouse, an auxiliary operator noted an unusually high vibration on the 'C' service water pump motor. A technical support engineer measured and evaluated the pump vibrations and determined the amplitude of some frequency -
peaks exceeded administratively established limits. The shift superintendent declared the pump inoperable and entered Technical Specification 3.7.4, " Service Water System," which required restoring the operability of the pump in seven days or shutting down the reactor.
The technical support department contracted divers to inspect the suction to the 'C' service water pump, which was 60 feet below the water level in the sersice water pumphouse forebay. hianagement decided that all service water pumps in the service water pumphouse must be pulled to lock with their supply breakers open prior to allowing divers in the water.
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The licensing department developed an engineering evaluation that concluded that the sen' ice water pumps could be considered operable if a procedure was implemented which allowed transfer of service water from the cooling tower to the crean within 74 minutes.
The inspector reviewed the engineering evaluation and the special procedure, and attended several management meetings. The evaluation was ihorough and supported the conclusion by using the design basis for the cooling tower and the intake structures and the fact that transfer from the cooling tower to intake structure required operator actions. The procedure provided directions for controlling the service water pump breakers and for establishing continual communications between the main control room, service water pumphouse, and vital switch gear rooms. The management meetings were focused on ensuring personnel safety, complying with regulatory requirements, and managing the corrective maintenance activities.
The inspector concluded that North Atlantic identified a significant equipment problem, declared the equipment inoperable, and established sound engineering and regulatory basis for conducting repairs.
9.0 MEETINGS (30702)
The scope and findings of the inspection were discussed periodically throughout the inspection period. An oral summary of the inspection findings was provided to the station manager and his staff at the conclusion of the inspection period.
Region-based inspectors conducted the following exit meetings during this time period.
JhgE SlH}lliCT IEPORT NO.
INSPECTOR Dec.15 License 92-28 J. D' Antonio Examination