IR 05000220/1992011
| ML17056B877 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/15/1992 |
| From: | Larry Nicholson NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17056B876 | List: |
| References | |
| 50-220-92-11, 50-410-92-13, NUDOCS 9206020122 | |
| Download: ML17056B877 (40) | |
Text
Report Nos.:
Docket Nos.:
License Nos.:
U.S. NUCLEAR REGULATORY COMMISSION
REGION I
92-11; 92-13 50-220; 50-410 DPR-63; NPF-69 Licensee:
Niagara Mohawk Power Corporation 301 Plainfield Road Syracuse, New York 13212 Facility:
Nine Mile Point, Units 1 and 2 Location:
Dates:
Scriba, New York April 1, 1992 - April 28, 1992 Inspectors:
R. A. Laura, Acting Senior Resident Inspector W. F. Mattingly, Resident Inspector (in training)
C. D. Beardslee, Reactor Engineer, Intern Approved by Cj'. 4 Reactor Projects S tion No. 1A Division of Reactor Projects s
is 'z.
Date Ins ection Summar:
This inspection report documents routine and reactive inspections of plant operations, radiological controls, maintenance, surveillance, security, and safety assessment/quality verification activities.
Results:
See Executive Summary.
920b020i22 920522 PDR ADOCK 05000220
EXECUTIVESUMMARY Nine Mile Point Units 1 and 2 NRC Region I Inspection Report Nos. 50-220/92-11 & 50-410/92-13 April 1, 1992 - April28, 1992 Pl n era i n NMPC operated Unit 1 and conducted refueling activities at Unit 2 safely over the period.
On April 18, Unit 1 operators responded well to an automatic high neutron flux reactor scram, caused by reactor pressure fluctuations due to a malfunction of the turbine control system.
The safety system walkdown performed on the emergency cooling system verified operability of the system and positive configuration control.
Unit 2 operators exhibited a good safety perspective while performing refuel outage activities, The safety system walkdown of the spent fuel pool cooling system proved system operability and generally good configuration control; one instrument ball valve was found throttled vice full open as required.
Two inadvertent isolations of the normal reactor building ventilation system occurred.
Ra dipl ical ontrols
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Effective radiation protection controls over high radiation and contaminated areas minimized personnel exposure and the spread of contamination.
The Unit 2 radiation protection department responded well to control the spread of contamination in the reactor building following the release of particulate material from a system being vented.
Maintenance A
AtUnit 1, mechanical maintenance personnel minimized outage time by promptly and effectively repairing the 102 emergency diesel generator lube oil circulating pump.
A non-cited violation was identified where troubleshooting was performed without the use of a work request.
The maintenance activities observed at Unit 2 were performed properly and with good supervisory oversight in the field.
An unresolved item (410/91-17-01) on the unauthorized operation of equipment under a red markup was close The surveillance activities observed at Unit 2 were conducted properly and in a professional manner.
Generally good performance was observed during a containment isolation valve leak-rate test and low pressure core spray channel functional test, En ine rin nd Technical u
rt An unresolved item (220/92-07-02) at Unit 1 concerning secondary containment leak rate testing was updated based on further NMPC review and was left open pending inspector review of the corrective actions taken.
NMPC inspection of the Unit 2 high pressure core spray nozzle indicated that the previously identified flaw in the weld had not propagated.
An unresolved item was opened (410/92-13-01) concerning NMPC identification that a design deficiency could result in cooling water being isolated from the Unit 2 Division IIIemergency diesel generator.
ecurit Good control of vital areas by the security force was evident.
Precautions in handling safeguards information were properly followed. No concerns were identified by the inspector.
f A
ment ualit Verific i n A configuration control issue concerning the vents on the containment spray heat exchangers was identified and properly dispositioned by NMPC. The submittal of a Unit 1 license amendment to delete the requirement to perform redundant operability testing was an example of NMPC being proactive.
A Unit 1 management meeting was assessed to be effective in evaluating the secondary containment integrity operability issues.
A Unit 1 licensee event report was reviewed and found to be well writte TABLE OF CONTENT 1.0 SUMMARYOF FACILITYACTIVITIES 1.1 Niagara Mohawk Power Corporation Activities.................
1 ~2 NRC Activities
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2.0 PLANT OPERATIONS (71707,71710,93702)......................
2.1 Routine Observations of Plant Operations - Unit 1...............
2.2 Routine Observation of Plant Operations - Unit2................
3.0 RADIOLOGICALAND CHEMISTRY CONTROLS (71707).............
3.1 Routine Observations - Unit 1 and Unit 2....................
3.2 Contamination Event - Unit2....,..... ~.................
4.0 MAINTENANCE(62703)
4.1 Routine Observation of Maintenance Activities - Unit 1.'....,....
4.2 Routine Observation of Maintenance Activities - Unit2..........
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5.0 6.2 6.3 SURVEILLANCE (61726)
5.1 Routine Observation of Surveillance Activities - Unit 2 6.1 (Open) Unresolved Item 220/92-07-02:
Secondary Containment Leak T
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estlilg - Uillt 1 High Pressure Core Spray Nozzle Inspection - Unit 2 High Pressure Core Spray Emergency Diesel Generator Cooling Water Design Deficiency.................................
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7.0 SECURITY AND SAFEGUARDS (71707)........................
7.1 Routine Observations.....,.......,........*...........
8.0 SAFETY ASSESSMENT AND QUALITYVERIFICATION(71707)........
8.1 Proper Resolution of a Configuration Control Issue - Unit 1......,..
8.2 Elimination of Redundant Safety System Testing - Unit 1...........
8.3 Assessment of Meetings - Unit 1 and Unit2,..................
8.4 Routine Review of Licensee Event Reports and Special Reports.......
9.0 MANAGEMENTMEETINGS.............................,,
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- The NRC inspection manual procedure or temporary instruction that was used as inspection guidance is listed for each applicable report section.)
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DETAILS 1.0 SV1VIMARYOF FACILITYACTIVITIES 1.1 ia ara M hawk P wer ration Activities The Niagara Mohawk Power Corporation (NMPC) conducted activities at Nine Mile Point Unit 1 (Unit 1) safely over the period.
At the beginning of the period, operators restarted the unit following the replacement of an intermediate range neutron monitor that had malfunctioned during the previous startup attempt.
Unit 1 reached full power on April 9 and operated there until April 18 when an automatic reactor scram occurred due to a malfunction of the turbine control system.
Major maintenance activities conducted during the subsequent outage included:
repair of the turbine control system, repair of two source range monitors, repair of the No. 11 drywell equipment drain tank pump, and resolution of secondary containment integrity operability issues.
Following the completion of these activities NMPC began plant startup on April28.
modification. At the e 1.2 N~R NMPC conducted refueling outage activities at Nine Mile Point Unit 2 (Unit 2) safely over the period. Major refueling outage work conducted during the period included: Division I, II, and IIIsafety system and electrical bus maintenance, Division I and II emergency diesel generator (EDG) five year preventive maintenance, Division IIIEDG refueling outage maintenance and six year head gasket replacement, and installation of the feedwater system thermal stratification nd of the period, Unit 2 was preparing for core reload.
Over this period resident inspectors conducted inspection activities during normal, backshift and weekend hours. There were 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> ofbackshift (evening shift) and 33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> ofdeep backshift (weekend, holiday, and midnight shift) inspection during this period.
A routine emergency preparedness inspection was conducted during the week ofApril 6.
The findings of this inspection will be documented in Combined Inspection Report 220/92-10 alld 410/92-12.
A followup inspection of the short term corrective actions taken by NMPC following the isolation of Unit 1 from its ultimate heat sink was performed intermittently between March 28 and April 18. The findings ofthis inspection willbe documented in Combined Inspection Report 220/92-81 and 410/92-8 On April 8, an enforcement conference was held with NMPC at Region I to discuss two Unit 1 issues: the isolation from the ultimate heat sink and the inadvertent partial bypass of the turbine generator trip anticipatory reactor scram.
NMPC's presentation material from that meeting and a list of attendees is provided as attachment (1) to this report.
2.0 PLANT OPERATIONS (71707,71710,93702)
R in rvation f Plan in-ni
During the period, control room operators exhibited a good safety perspective during routine plant operations.
Control room activities observed included: shift turnovers and crew briefings, panel manipulations, and response to alarms. Operators responded in a prompt and thorough manner to an alarming area radiation monitor annunciator on April 12.
The station shift supervisors (SSSs)
consistently maintained well written operating logs, containing sufficient information to allow an independent reader to understand plant conditions, ongoing evolutions, and problems encountered by the shift. Operators responded well to the April 18 reactor scram.
The inspector noted no deficiencies during review of two active markups and a walkdown of two safety systems in the control room.
The inspector identified an inconsistent implementation of Technical Specification (TS) 4.6.3.e which required that operability be demonstrated for one EDG immediately after declaring the other EDG inoperable.
Specifically, some SSSs interpreted
"immediately" such that an operability run performed within the last few hours met the testing requirements.
The rationale was that this increased safety by minimizing wear on the EDG.
Other SSSs interpreted
"immediately" as requiring an operability run, even ifit had been tested within the last few hours. The inspector discussed this inconsistency with the NRC Project Manager who concluded that in both cases, the SSS met the intent of TS 4.6.3.e.
The inspector expressed concern that the licensee's internal guidance was not uniformly applied.
The operations manager stated that this issue would be reviewed to ensure consistent implementation of the licensee's internal requirements.
2.1.1 fe tern Walkd wn of h Emer enc lin tern A safety system walkdown of the emergency cooling (EC) system confirmed proper system configuration and the ability to perform its safety function, ifnecessary.
The review consisted of the following: verification that the operating procedure (OP) N1-OP-13 contained sufficient instructions for initiating, operating, and securing the system; review of the piping and instrumentation diagram (P&ID)C-18017-C and OP to ensure consistencies in the normal valve positions; and lastly, a walkdown was conducted to verify the actual in-plant configuration of valves, breakers, switches, annunciators, and indicators.
During the walkdown the inspector assessed the condition of equipment and cleanliness of general equipment area P ~
g4
The OP contained the necessary instructions for operation of the system.
The OP and PAID were consistent with their valve positions for a standby lineup.
The inspector identified one minor inconsistency between the P&IDand the OP. Specifically, the P&IDvalve identification numbers for the bypass valves on the make up line to the emergency condensers (valves 60-48, 60-49, 60-50, and 60-51) did not match the OP valve identification numbers.
Positive configuration control over the EC system was found during the review ofvalve lineups, breakers, annunciators, and indicators. Allaccessible valves were verified to be lined up (i.e.,
open or closed) in accordance with the OP or properly controlled in accordance with NMPC procedures.
One minor observation was that the local leak rate test connections and drain valves from the EC steam line (valves 39-34, 39-48, 39-49, 39-50, 39-51, and 39-85) were found locked closed, while indicated as only closed in the OP and the PEcID. The cross connect valve between the two emergency makeup tanks was found closed vice open as required by the OP, with a yellow holdout tag hung on the control switch in the control room (to maintain proper configuration control). The SSS knew that this valve had been closed to allow evaluation of the leak rate from each EC makeup tank.
The inspector found this condition acceptable.
During the review of the EC system annunciators, one was in the alarmed condition. The SSS indicated that it was not a valid alarm and that a work request had been initiated. The inspector reviewed the work request and determined the deficiency was in the process of being resolved.
With minor exceptions, the EC supply and return isolation valve rooms and the areas around the emergency condensers and makeup tanks were clean, with the equipment in good condition. The handwheel on valve 60-49 was missing.
Four valves in the supply isolation valve room had steam packing leaks.
A deficiency tag was present which identified only one of the packing leaks; however, the remaining three had not been previously identified in the work request system.
The SSS initiated work requests and explained that operators did not enter these rooms" routinely on their daily tours, The SSS stated that operators were required to enter these rooms only once a week to minimize their radiation exposure; however, operators listened daily at the locked radiation protection gate and entered ifsomething unusual was heard.
The packing leaks were not visible or audible from the gate.
Based on these discussions, the operations manager was reviewing the adequacy of the operator rounds in the EC isolation valve rooms.
While performing the walkdown in the area of the emergency condensers, the inspector identified several unsecured items such as ladders, a large box, and an equipment cart.
The inspector was concerned that these unsecured items could damage system components if a seismic event occurred.
The reactor analyst in charge of the refuel floor stated that NMPC had previously identified this situation and was taking corrective actions.
Overall, the EC system was properly lined up and would have performed its safety function had it been called upon.
The above minor inconsistencies identified between the OP, P&ID and actual configuration were turned over to operations support for resolution. NMPC initiated work requests to repair the three valves with steam packing leak.1.2 Automa ic Reactor Scram An automatic high neutron flux reactor scram, from 98% power, occurred on April 18 due to reactor pressure fluctuations.
The pressure fluctuations resulted from a failure of the turbine control system.
Specifically, the backup mechanical pressure regulator (MPR) malfunctioned and took control of the turbine causing reactor pressure to oscillate.
When the chief shift operator (CSO) attempted to adjust the pressure setpoint downward (with the MPR) to gain positive control of reactor pressure, the control valves did not respond and a scram occurred.
All other systems performed as designed and no safety or electromatic relief valves lifted.
Reactor water level decreased to a minimum of 27 inches and the feed system started in its high pressure coolant injection (HPCI) mode, restoring level to the normal operating band.
NMPC made the appropriate four-hour non-emergency 10 CFR 50.72(b)(2)(ii) notification to the NRC and brought the unit to cold shutdown.
Inspector review determined that the CSO took appropriate actions in responding to the turbine control system failure.
When troubleshooting the turbine control system, NMPC identified improper adjustment of components in the MPR. As corrective actions, linkages and mechanical stops on the MPR were adjusted.
This troubleshooting also identified that the servo relay position indicator of servo stroke had failed and provided erroneous position indication for the MPR stroke.
This inaccurate indication contributed to the MPR providing a larger signal than the normally controlling electrical pressure regulator (EPR), thus taking control of the turbine just prior to the scram.
The MPR servo motor was replaced.
The EPR was tested and found to be satisfactory.
The inspector found these actions acceptable.
The final corrective actions and analysis will be reviewed following NMPC issuance of the associated licensee event report (LER).
2.2 R utine ervation f Plan in -
nit2 During the period, the inspector observed that control room operators generally reflected a safety conscious approach to operations.
The SSSs conducted shift turnovers and briefings of the operator shifts in a professional atmosphere, with good exchanges of information.
Operations management showed very good involvement during turnovers and shift briefings.
I The plant, including the drywell, was toured to assess personnel safety, equipment conditions, radiological controls, fire protection, security, and general housekeeping practices.
The inspector observed generally good conditions, and plant management took adequate corrective actions on the minor deficiencies identifie m W lk wn f he nt Fuel P l
lin em A safety system operability verification of the spent fuel pool cooling (SFC) portion of the spent fuel pool cooling and cleanup system was performed.
The inspector reviewed the SFC system OP (N2-OP-38) and P&ID (12177-PID-38), and applicable sections of technical specifications, the updated safety analysis report (USAR), and 10 CFR 50, Appendix A. The inspector then conducted a detailed walkdown of the accessible portions of the system.
The OP startup valve lineup corresponded with the P&ID and the in-plant configuration, with several exceptions.
Ball valve 2SFC*V127B (instrument root isolation valve for the Division IIspent fuel surge tank 1B level hi-hi alarm) was throttled (20 degrees out ofposition) vice fully open.
The effect of this throttled valve was not significant, due to the characteristics of a ball valve and its purpose in the system.
However, this was an instance of a loss of configuration control.
The inspector'lso observed that the positions of the supply and overflow header isolation valves for the reactor refuel cavity and internals storage pit, the filter isolation valves, and both heat exchanger bypass valves were not in accordance with the valve lineup and the P&ID. The SSS knew that this lineup was in accordance with the OP and the normal valve positions for the given plant conditions. The inspector agreed with the information provided and concluded that the SSS was very knowledgeable of the current system conditions and that good configuration control was maintained, except for the throttled ball valve.
The SFC system instrumentation was properly installed and functioning, with the process parameters in the normally expected ranges.
The accessible portions of the SFC system, including the heat exchanger and pump rooms, were inspected for overall equipment condition and housekeeping/cleanliness.
A representative sample of snubbers, hangers, system supports, and breaker cabinets were also inspected.
The overall condition of the areas and components was satisfactory.
However, the housekeeping in the SFC pump P1A room was weak where the inspector observed excessive dirt and debris.
Some minor deficiencies were noted and brought to the attention of the system engineer.
These included:
valve operating air pressure regulator gauges with missing needles, minor leakage past a capped drain connection, and a loose manual valve handwheel.
In summary, the SFC system was properly lined up in accordance with the OP.
One valve was identified to be in a throttled position, this was an example of poor configuration control.
The inspector identified examples of poor housekeeping and minor equipment deficiencies.
In all cases, NMPC took adequate actions to correct the identified deficiencie p"p
2.2.2 Tw Inadve en Reac r Buildin Ven il i n mI lin Over the period two inadvertent reactor building ventilation (HVR) system isolations occurred.
On A'pril 16, the isolation followed a spurious high radiation signal on the above refuel floor radiation monitor 2HVR-RE14B.
On April 23, the isolation occurred following a sensed low flow condition in the reactor building exhaust plenum.
These isolation signals resulted in the automatic start of the standby HVR unit cooler and the closure of the six HVR system isolation dampers.
Normally both standby gas treatment system fans would automatically start on these isolation signals; however, both fans were out of service due to maintenance.
NMPC made the appropriate four-hour non-emergency 10 CFR 50.72(b)(2) iiNRC notifications.
Preliminarily, NMPC believed that the spurious high radiation signal was related to preventive maintenance on the radiation monitor power supply, 2VBS*UPS2B. For the second isolation, NMPC believed that an isolation damper momentarily cycled open on the restoration of power to a power panel during the Division IIelectrical bus restoration causing the low flowcondition.
The inspector assessed that NMPC properly responded to these inadvertent HVR actuations.
2.2.3 m r en Die I
enerator eration a P-M in n nce Te Operators adequately performed a post-maintenance operability test on the Division I EDG, per operations surveillance procedure N2-OSP-EGS-M001.
The inspector reviewed and discussed the procedure with the control room and local operators, and observed the machine start at the local control panel
~ Operations personnel, the system engineer, and the inspector independently walked down the EDG and its support systems.
Operations personnel identified a minor leak on the jacket water pump.
NMPC took appropriate actions to determine and correct the cause of the leak, which was due to minor corrosion on the pump shaft.
The inspector noted a
disparity between the engine jacket water pressure indication at the control panel and locally on the machine.
The system engineer stated that these indications were normal and that they would converge as the jacket water heated up. The inspector verified that the pressure indications did converge.
In summary, operators performed the post maintenance test in accordance with the procedure, All personnel involved in the evolution were knowledgeable of the procedure and system operation.
The inspector observed active participation in the test by the system engineer.
2.2.4 b erva ion f en F el Pool Clean i Fil r D min liz r Prec a
The inspector observed precoating of spent fuel pool cleanup filter/demineralizer 2SFC-FLT1A according to OP N2-OP-38.
Good procedural compliance and proper resin handling safety precautions were observed.
The systems engineer, present at the time, provided valuable guidance and insight to the operators.
The inspector identified no deficiencie.0 RADIOLOGICALAND CHEMISTRY CONTROLS (71707)
3.1 Ruine erv i n
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ni land ni 2 The inspectors made en'tries into several locked high radiation and/or contaminated rooms including: the emergency cooling isolation valve rooms and refuel floor area at Unit 1, and the drywell, SFC rooms and refuel floor areas at Unit 2.
In general, the radiation protection controls and requirements over these areas were thorough and effective in minimizing personnel radiation exposure and the spread of contamination.
Positive controls were observed while touring the Unit 2 drywell.
3.2 ntamination Event -
ni 2 When an operator was venting an emergency core cooling system injection line, on the reactor building elevation 289, airborne particulate contamination vented resulting in contamination of the operators a'nd other personnel walking in the vicinity. Radiation protection (RP) performed extensive surveys, temporarily secured personnel egress from the reactor building, and performed decontamination of the affected areas.
As corrective action, RP initiated a
deviation/event report (DER) and required the installation of a high-efficiency particulate filter on the end of the tygon vent hose.
This response was prompt and effective.
4.0 MAINTENANCE(62703)
4.1 Routine 0 servation of Maintenance Activi ie -
nit 1 The inspector observed and reviewed selected portions ofpreventive and corrective maintenance to verify: adherence to regulations, use of administrative and maintenance procedures, conformance with codes and standards, proper QA/QC involvement, and proper equipment alignment and retest.
4.1.1 Electrical Maintenance Troubleshootin On April 10, 1992, the inspector observed electrical maintenance personnel performing troubleshooting on the No. 11 drywell equipment drain tank pump, at,the pump breaker cubicle, without the required work request.
Operators had observed that this pump, located in the drywell, was not pumping down the drain tank.
The SSS.directed that electrical maintenance perform the troubleshooting to determine ifthe pump was operating properly.
The inspector observed two electricians and an operator at the breaker cubicle taking voltage and amperage measurements.
The pump breaker was cycled on and off several times, and the inrush and steady state currents were measured using a clip-on ammeter.
The workers concluded that the motor was running, but drawing less current than normal; indicating a mechanical problem restricting pump flow (such as clogged piping or a broken pump shaft).
The process used to determine whether the motor was running was effective.
However, there was no work request (WR) used to perform the troubleshooting activities.
The maintenance technicians stated that a WR and associated troubleshooting log were not needed because the work was performed under the direction of the SSS and was within the skills of the trade.
The inspector reviewed Administrative Procedure (AP) 5.5.1 and AP 5.4.2, and determined that a WR and troubleshooting plan were necessary.
AP 5.5.1 stated that only in an emergency situation can the SSS initiate troubleshooting without using a WR. The failure ofNo. 11 drywell equipment drain tank pump was not an emergency.
The Unit 1 maintenance manager stated that a WR should have been used.
As corrective action, the maintenance manager and operations manager reminded maintenance workers and operators of the requirements for conducting emergency work without a WR.
The troubleshooting performed without the use of a work request was a violation of AP 5,5.1.
The violation was not cited because the criteria specified in Section V.A of the Enforcement Policy were satisfied (50-220/92-11-01).
The inspector assessed that the troubleshooting was effective in determining that a mechanical problem existed with the pump; however, operations and maintenance personnel did not follow the proper process.
The inspector was concerned that this was the same root cause of the loss of ultimate heat sink where'improper work control practices resulted in placing the plant outside of its design basis.
4.1.2 Mechanical rrectiv M intenance During rounds an operator identified that the No. 102 EDG lube oil circulating pump was making excessive noise. The operations department declared the pump and the EDG inoperable.
Examination of the pump coupling revealed a broken plastic insert, A work request was generated and the coupling replaced.
The inspector reviewed the work package and found it to be properly utilized, including procurement of the new coupling as a safety-related component.
The inspector assessed that the operator on rounds properly identified the deficiency.
Further, the mechanical maintenance personnel promptly replaced the coupling.
These actions resulted in increased availability of the EDG.
4.1.3 tion Worker Fell Int Water in the Screenh u e B ildin -
nit 1 On March 22, a quality control (QC) technician, inspecting welds for a temporary modification on the "D" gate in the screenhouse, slipped and fell into the water in the fore bay.
The technician fell as he got down from a work platform and held onto a liftingchain until he could be pulled out of the water, without injury.
This ASME code visual weld examination was classified as a safety-related activity.
The inspector reviewed the technician's use of overtime prior to the event and found it within the requirements ofTS 6.2.2., which stated that an individual should not work more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> in any seven-day perio NMPC safety department performed an investigation of the circumstances of this event and issued a near miss fatality report.
NMPC identified several contributing factors to the event including: poor work practices, failure to secure floor openings, and an inadequate work platform.
NMPC took appropriate corrective actions.
The inspector assessed that a prompt response by station personnel prevented injury of the fallen QC inspector and that excessive overtime did not appear to be a contributor to the event.
4.2 in rv ion fMin n n A ivii
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ni 2 The inspector observed and reviewed selected portions ofpreventive and corrective maintenance to verify:
adherence to regulations, use of administrative and maintenance procedures, conformance with codes and standards, proper QA/QC involvement, and proper equipment alignment and retest.
No safety concerns were identified during the maintenance observations.
4.2.1 Elec rical Correc ive M in enance n Hi h Pr re r
Limi r e V lve The inspector observed corrective maintenance on the HPCS test valve to the suppression pool, (CSH*MOV111) to correct hardened grease in the valve operator.
A preventive maintenance item performed during the operating cycle had identified the hardened grease.
The corrective maintenance was performed in accordance with electrical maintenance procedure N2-EMP-GEN-510, which addressed the disassembly, cleaning, greasing, and reassembly of the actuator. The inspector reviewed and observed portions of:
the procedure, the cleaning and greasing of the valve actuator and gear assembly, and the installation of the worm/torque spring and declutch lever.
The maintenance personnel performed properly, according to the procedure, using good radiological work practices, and proper cleanliness controls.
4.2.2 Mechanical Preventive Maintenance n Air erat V lv Ac a
r Maintenance was observed on the air operated valve actuator for containment purge system valve 2CPS*AOV106, per mechanical preventive maintenance procedure N2-MPM-GEN-5Y301. This included a five year rebuild and replacement of environmentally qualified parts on the actuator.
The inspector reviewed portions of the procedure and technical manual, observed torquing of the torque piston, and the cleaning and reassembly of the valve actuator.
The maintenance personnel performed the activities well, following the procedure and technical manual.
Maintenance supervisory involvement was good.
The mechanics performing the maintenance were experienced with the procedure and were knowledgeable of the actuator operation.
4.2.3 T
in andIn ll i n f n
r Observations of snubber installation and testing indicated good adherence to procedures.
The inspector observed that mechanics properly installed a residual heat removal (RHR) system mechanical snubber, in accordance with mechanical maintenance procedure N2-MSP-GEN-V351 for snubber functional testing. The inspector observed a subsequent visual inspection performed
per N2-MSP-GEN-V350, then independently verified the results, and noted no discrepancies.
The inspector also observed shop testing of a removed reactor water cleanup system snubber, per N2-MSP-GEN-V351.
The test measured the acceleration characteristics of the snubber under tensile and compressive loads.
The inspector noted no discrepancies upon an independent verification of the test data and calculations.
NMPC contractors performed the snubber functional test and snubber installation
. NMPC mechanical maintenance personnel performed the snubber post-installation visual inspection.
Contractor maintenance supervisory involvement and NMPC oversight were satisfactory.
4.2.4 nr Iv I m-41 1-17-1'uhri Rmvl f R
Mr This issue was left unresolved pending inspector review ofNMPC root cause determination and corrective actions taken for the unauthorized removal of a red markup tag.
Two electrical maintenance technicians (one senior and one junior) removed a red tag and subsequently operated a switch yard operating linkage in the generator output 345 KV line.
An electrical maintenance supervisor noticed this condition while walking by.
The independent safety and engineering group gSEG) root cause investigation determined that the primary cause was poor work practices.
The red markup violation resulted from the junior electrician focusing 'on the senior electrician's experience'nd both individuals not paying attention to detail.
The technicians did not knowingly violate the red markup, but erroneously treated it as a blue markup, which allowed repositioning of components.
The senior technician had been performing maintenance on another job under a blue markup and didn't realize the current job was under the control of a red markup.
The junior electrician didn't raise the concern of operating the disconnect linkage under the control of a red markup. Both technicians exhibited poor self-checking techniques.
The inspector agreed with NMPC's root cause analysis.
NMPC took numerous short term and long term corrective actions in response to this event, including an accountability meeting with the individuals involved.
Markup training was enhanced to stress the potential consequences of markup violations and to further heighten awareness of the importance of following markup restrictions.
Plant management grouped this event with several others and took a broad approach to address the problems with work practices at Unit 2.
In July 1991, the plant manager issued a stop work order to communicate iiynagement's expectations on proper work practices.
The inspector reviewed the corrective actions and found them comprehensive.
This item is close.0 SURVEILLANCE(61726)
R in rv i n f urv illance Acivi i
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i 2 The inspector reviewed selected surveillance tests to verify: the use and adequacy of approved procedures, the use ofproperly calibrated test instrumentation, the qualification of personnel to perform the tests, and that test results satisfied technical specifications requirements or were properly dispositioned.
5.1.1 n
inmen I I
i n Valve Leak Rate Tes The inspector reviewed and witnessed portions of instrument surveillance procedure N2-ISP-LRT-Rlm089, for local leak rate testing (LLRT) of several RHR system isolation valves.
The instrumentation and controls g&C) maintenance crew properly performed the surveillance using an approved procedure, appropriately calibrated equipment and proper radiological controls; however, during the re-performance of a test, data was not recorded on a procedure data sheet.
The shutdown cooling inboard suction valve, 2RHS~MOV112, initiallyfailed its leak rate test.
The technicians appr'opriately stopped the procedure and made the proper notification to their supervision.
The crew foreman initiated a procedure change to evaluate both the failed valve and the test lineup.
Subsequently, it was determined that the LLRT drain valves had partially checked closed, as designed, while pressurizing the test volume.
Technicians mechanically agitated these valves, the conditions for a retest were established, and the system responded properly.
The inspector reviewed the appropriate documentation and considered the problem solving methodology and procedure change to be satisfactory.
During reperformance of the leak rate test, the technicians recorded the test data on a blank piece of paper instead of the approved test data sheet.
The procedure change to allow retest had not included a new data sheet. The inspector discussed this with the technician, who temporarily stopped the test, obtained another data sheet, and satisfactorily completed the test. The inspector discussed this minor problem with the crew foreman and supervisor.
In summary, the. inspector concluded that the I&C technicians performed the leak rate testing properly, using good problem solving methodology and a procedure change as appropriate.
The inspector independently reviewed the test data for the three valves and found it acceptable.
The surveillance procedure met the requirements of the technical specifications.
The failure to use an approved test data sheet during the surveillance was a minor weaknes h
5.1.2 w Pre ure ore S ra Low Pressure oolan In'
n harm l F nc ional Tes The inspector reviewed and witnessed the performance of portions of electrical maintenance surveillance procedure N2-ESP-ENS-M731 for testing of time delay relays for the low pressure core spray and low pressure coolant injection pumps.
The electrical maintenance crew properly performed the surveillance using an approved procedure, appropriately calibrated equipment, proper electrical safety precautions, and good communication techniques.
The inspector noted, on several occasions, that when the maintenance crew did not fully understand the procedure, they consulted their supervisor.
The supervisor, who was present throughout the surveillance, was very knowledgeable on the details and impact of the procedure.
Coordination with outage planning management was necessary because one half of the reactor building lights were deenergized as part of the surveillance.
The "as found" conditions of the time delay relays and the surveillance procedure met the requirements of the technical specifications.
In summary, the inspector concluded that the surveillance was performed properly with good communication and coordination between electrical maintenance, operations and outage planning personnel.
6.0 ENGINEERING AND TECHNICALSUPPORT (92701,92702)
6.1 en Unresolved I em 22 2-7- 2 econda n
inmen Leak Testin
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As discussed in Inspection Report 220/92-07, the inspector identified an inadequate methodology used to test the secondary containment integrity and the ability of the reactor building emergency ventilation (RBEV) to maintain a differential pressure of -0.25 inches ofwater. NMPC had been performing the test using a secondary containment in-leakage acceptance criteria of less than or equal to 2000 cfm, with both RBEV trains operating.
The inspector determined that using both trains and the 2000 cfm value was non-conservative since, based on a single failure, only one RBEV train, with a design flow rate of 1600 cfm (with a +4 10
% error for instrument uncertainties), was postulated in the USAR. NMPC changed surveillance test N1-ST-C5 to run a single train with an acceptance criteria of 1760 cfm (1600 +10%).
NMPC needed to take corrective actions to lower the in-leakage to allow the test to be completed satisfactorily.
During this report period, NMPC engineering determined that the proper reactor building in-leakage rate was 1600 cfm, which would ensure one reactor building volume change per day through the RBEV. The initial ac,.eptable criteria of 2000 cfm had been based on preliminary assumptions for the secondary containment.
Subsequently, NMPC changed Nl-ST-C5 to incorporate an acceptance criteria of 1600+0/-160 cfm since the 10% band was for instrument uncertainties and not intended to be applied to the high end of the band (1760 cfm).
The inspector reviewed these actions and found them acceptabl ~ f
Prior to the reactor startup, commenced on April28, NMPC performed the testing with the new acceptance criteria, and after taking corrective actions, completed it satisfactorily. NMPC was preparing an LER discussing this secondary containment issue.
This unresolved item will continue to remain open pending review of the safety significance and corrective actions taken by NMPC, as documented in the LER.
6.2 Hi hPr s r r
Nzzl In in-i 2 The inspector observed good pre-planning and execution of the automatic ultrasonic testing on a flaw in the HPCS nozzle safe end weld.
Inservice testing during the first refueling outage detected the flaw. Based on the results of the inspection, which indicated that the flaw had not propagated, NMPC was preparing to submit, to the NRC, a request allowing continued power operation without repair of the flaw. The inspector assessed that NMPC planned and performed the ultrasonic inspection in a controlled manner.
6.3 Hi h Pres ure re ra Emer en DI
neraor lin W er D si n
~Dficienc During the March 23 sequential loss of off-site power (LOOP) event (see Inspection Report 410/92-08), NMPC discovered a design deficiency in service water (SW) cooling supply to the Division III(HPCS) EDG. NMPC determined that ifthe Division IIIEDG was running at the time of a LOOP a loss of SW cooling would result.
The Division IIIEDG powers it own safety bus; however, it does not power its own SW pump.
It relies on cooling water flow from Division I and IISW through automatically controlled motor operated valves, A LOOP causes a temporary loss of SW until the SW pumps load onto their respective Division I and II safety buses.
However, before the SW pumps can be loaded onto their respective safety buses, a low pressure isolation signal from the SW header willisolate cooling water to the Division IIIEDG header.
Isolation ofSW to the running Division IIIEDG would result in a control room alarm. Without operator action to restore SW flow, the EDG would trip on high temperature in the cooling water system.
The time before the trip would occur would be dependent on the load that the machine was carrying (i.e., higher load shorter timt! to trip). Should a loss of coolant accident occur simultaneously with the LOOP, the HPCS EDG high temperature trip would be bypassed which could result in damage to the EDG without operator intervention. In either case, the EDG would not be available for accident mitigation purposes as. currently designed, NMPC made the appropriate four-hour non-emergency 10 CFR 50.72(b)(2) iiiNRC notification.
NMPC plans to conduct a modification to correct this condition, prior to unit restart from the current refueling outage.
The root cause of this event and the corrective actions taken willbe reviewed upon issuance of the LER. This item willremain unresolved (410/92-13-01) pending inspector review of the NMPC modification to be performed as corrective actio r
7.0 SECURITY AND SAFEGUARDS (71707)
in rv in The guard force exercised positive control over personnel and vehicles entering and exiting the protected area.
Proper precautions in transmitting safeguards information were evident on a change issued to the security plan. Security force personnel properly controlled normally closed and locked vital areas, opened to support Unit 2 refueling outage activities.
Guards were observed to be alert when stationed as a watch and during rounds.
8.0 SAFETY ASSESSMENT AND QUALITYVERIFICATION(71707)
8.1 Pro er Re ol ion f nfi urati n
n r l I
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nit 1 During a reactor building tour, the inspector noticed that the containment spray raw water heat exchanger vent valves on all four of the heat exchangers were open, with yellow holdout tags attached.
The Chief Shift Operator was aware of an open DER on this issue, because the OP and P&ID specified a different normal position for the vent valves.
DER 1-92-Q-1362 had been initiated to resolve the position discrepancy, which an operations support engineer identified during a procedure review.
The DER disposition stated that the original design of the heat exchangers called for these valves to be open and that keeping them open assured that the heat exchangers would perform adequately.
The vent lines were on the discharge end of the heat exchangers, so there was no concern about raw water being diverted.
The disposition required that the yellow holdout tags be attached to the vent valves until the issue was adequately resolved.
The inspector assessed this as a good example of problem identification and use of a DER, and had no further questions.
8.2 Eliminati n f Redundan afet em T in
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NMPC submitted a license amendment, dated March 10, 1992, to delete the TS requirements to demonstrate operability immediately and daily thereafter when a system/component becomes inoperable.
The operability verification would be changed to aii administrative check of surveillance tests and other appropriate records.
The affected systems include:
liquid poison, core spray, containment spray, control rod drive pump coolant injection, and high pressure coolant injection.
The amendment addressed NMPC's and the inspector's concerns that excessive testing can result in unnecessary wear on safety-related equipment and unnecessary challenges to the safety systems.
This amendment was an example of NMPC being proactive in improving TSs and plant safet.3 Assessment of Mee in
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nit 1 and ni 2 Throughout the period the inspectors attended site operations review committee (SORC), plant manager department and outage planning meetings to assess the safety perspective of site management.
The inspector attended the April 28 Unit 1 management meeting at which the secondary containment integrity issue, described in section 6.1 above, was discussed.
This meeting was well conducted with good safety perspective demonstrated.
The offgoing SSS and acting operations supervisor actively participated in this meeting.
Daily discussions held during the Unit 2 plant managers meeting were observed to be effective.
8.4 R
tine Review fLicen ee Event Re
'1R s
The inspector reviewed the following Unit 1 LER and found it to be satisfactory:
LER 92-04, Reactor scram and HPCI initiation caused by a sticking pivot and worn pin to lever connection on turbine stop valve.
9.0 MANAGEMENTMEETINGS At periodic intervals and at the conclusion of the inspection, meetings were held with senior station management to discuss the scope and findings of this inspection.
Based on the NRC Region I review ofthis report and discussions held with Niagara Mohawk representatives, it was determined that this report does not contain safeguards or proprietary informatio ATTACHMENT1 Attendees at A ril
2 Enforcement onference ia ara M hawk Power C ti n C. Beckham, Manager, QA Operations - Unit 2 A. Bianchetti, Nuclear Communication K, A. Dahlberg, Plant Manager - Unit 1 R. Draper, Attorney - Winston & Strawn D. Greene, Manager - Licensing M. Kenific, President IBEW Local 4008, I&CTechnician W. Mercier, Electrical Maintenance - Unit 1 L. Pisano, Outage Manager - Unit 1 G. Roarick, SSS - Unit 1 G. Shelling, SSS - Unit 1 J. Sherman, Electrical Maintenance - Unit 1 N. Spagnoletti, Licensing Program'Director B. Ralph Sylvia, Executive Vice President - Nuclear C. Terry, Vice President - Nuclear Engineering R. Tessier, Manager - Operations - Unit 1 M. Wetterhaan, Attorney - Winston & Strawn G. Wilson, Managing Attorney N clear Re lato ommis ion C. Anderson, Acting Chief, Engineering Branch, Division of Reactor Safety (DRS)
R. Bhatia, Reactor Engineer, DRS J. Beall, Team Leader, Systems Section, DRS D. Brinkman, Project Manager, Office of Nuclear Reactor Regulation (NRR)
R. Capra, Director, Project Directorate I-l, NRR C. Cowgill, Chief, Projects Branch No. 1, Division of Reactor Projects (DRP)
P. Eapen, Chief, Systems Section, DRS T. Easlick, Enforcement Specialist N. Greca, Senior Reactor Engineer, DRS C. W. Hehl, Director, DRP W. Hodges, Director, DRS W. Kane, Deputy Regional Administrator W. Lanning, Deputy Director, DRS t
R. Laura, Resident Inspector, Nine Mile Point J. Menning, Project Manager, NRR L. Nicholson, Chief, Reactor Projects Section No. 1B, DRP D; Roberts, Office of Enforcement W. Schmidt, Senior Resident Inspector, Nine Mile Point K. Smith, Regional Attorney W. Troskoski, Office of Enforcement T. Walker, Senior Operations Engineer, DRS J. Yerokun, Project Engineer, DRP chery P. Eddy, Power Division, NYS, PSC