IR 05000269/1986014
| ML16161A742 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/24/1986 |
| From: | Brownlee V, Bryant J, Sasser M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16161A740 | List: |
| References | |
| 50-269-86-14, 50-270-86-14, 50-287-86-14, NUDOCS 8607100418 | |
| Download: ML16161A742 (8) | |
Text
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UNITED STATES o
NUCLEAR REGULATORY COMMISSION
5REGION II
<101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report Nos:
50-269/86-14, 50-270/86-14, and 50-287/86-14 Licensee: Duke Power Company 422 South Church Street Charlotte, N.C. 28242 Facility Name:
Oconee Nuclear Station Docket Nos.:
50-269, 50-270, and License Nos.:
DPR-38, DPR-47, and 50-287 DPR-55 Inspection Conducted: A 11 15 - May 19, 1986 Inspectors:
r 1, 11,2 J. C. Bryant Vate S ne M. K. Sas'ser eSg e'
Approved by: _er_
__ _eSn V. L. Bownlee, Chief Date Signed Reactor Projects Branch 3 Division of Reactor Projects SUMMARY Scope: This routine, announced inspection was conducted on site in the areas of operations, surveillance, maintenance, verification of engineered safety features lineups, refueling activities, startup from refueling and plant trip Results: Of the seven areas inspected, no items of noncompliance or deviations were identifie REPORT DETAILS 1. Licensee Employees
- M. S. Tuckman, Station Manager
- D. S. Compton, Technical Specialist Other licensee employees contacted included technicians, operators, mechanics, security force members, and staff engineer Resident Inspectors J. C. Bryant
- M. K. Sasser
- Attended exit intervie.
Exit Interview The inspection scope and findings were summarized on May 19, 1986, with those persons indicated in paragraph 1 above. The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspectors during this inspectio.
Licensee Action on Previous Enforcement Matters Not inspecte.
Unresolved Items Unresolved items are matters about which more information is required to determine whether they are acceptable or may involve violations or deviations. One unresolved item was identified during this inspection and is discussed in paragraph 1.
Plant Operations The inspectors reviewed plant operations throughout the reporting period to verify conformance with regulatory requirements, technical specifications (TS),
and administrative control Control room logs, shift turnover records, and equipment removal and restoration records were reviewed routinely. Interviews were conducted with plant operations, maintenance, chemistry, health physics and performance personne Activities within the control rooms were monitored on an almost daily basi Inspections were conducted on day and on night shifts, during week days and on weekend Some inspections were made during shift change in order to evaluate shift turnover performance. Actions observed were conducted as required by Operations Management Procedure 2-1. The complement of licensed personnel on each shift inspected met or exceeded the requirements of T Operators were responsive to plant annunciator alarms and were cognizant of plant condition Plant tours were taken throughout the reporting period on a routine basi The areas toured included the following:
Turbine Building Auxiliary Building Unit 1 Reactor Building Units 1 and 3 Penetration Rooms Units 1, 2, and 3 Electrical Equipment Rooms Units 1, 2, and 3 Cable Spreading Rooms Station Yard Zone within the Protected Area Standby Shutdown Facility During the plant tours, ongoing activities, housekeeping, security, equipment status, and radiation control practices were observe Unit 1 began the report period in cold shutdown for the cycle 9 refueling and maintenance outage. The outage ended at 5:40 a.m. on May 2 when the reactor was taken critical for cycle 10 zero power physics testing (ZPPT).
On May 3, the reactor power was increased to 15%.
At this time, it became necessary to take the reactor to hot shutdown for balancing of a reactor coolant pump. The reactor was again taken critical on May 4 at 3:50 and power escalated for additional required physics testing. On May 9, the reactor was shutdown for repair of a reactor coolant system leak (see paragraph 9).
The unit was returned critical at 4:30 on May On May 10, the reactor tripped from 48% power on a loss of feedwater anticipatory reactor trip (see paragraph 9).
The reactor was returned critical the same day and power was increased to 100%.
On May 15, while conducting power escalation tests on Unit 1, the air ejector radiation monitor counting rate increased to approximately 1900 cpm, indicating a possible steam generator tube lea The count rate increased to about 10,000 cpm following which the tube leak was calculated to be approximately 0.1 gallons per minute (gpm).
The technical specification limit for Unit 1 is 0.3 gpm. The leak was determined to be in the "B" steam generator. On May 16, the unit was taken off-line for an expected outage of about ten days to locate and repair the leaking tube(s).
Unit 2 operated at 100% power throughout the report perio Unit 3 began the report period at 100% powe On May 2 power reduction began in order to repair a steam leak on the 3C2 heater steam supply for the 3B moisture separator reheater. Power was reduced to 21%,
the leak was repaired and the unit was returned to full power on May The unit remained at 100% power through the remainder of the report perio No violations or deviations were identifie.
Surveillance Testing The surveillance tests listed below were reviewed and/or witnessed by the inspectors to verify procedural and performance adequac The completed tests reviewed were examined for necessary test prerequisites, instructions, acceptance criteria, technical content, authorization to begin work, data collection, independent verification where required, handling of deficiencies noted, and review of completed wor The tests witnessed, in whole or in part, were inspected to determine that approved procedures were available, test equipment was calibrated, prerequisites were met, tests were conducted according to procedure, test results were acceptable and systems restoration was complete Surveillances witnessed in whole or in part are as follows:
PT/O/A/150/22/D Valve Stroke Test, 1FDW-31 PT/O/A/600/12 Turbine Driven Emergency Feedwater Pump Performance Test, Unit 1 Completed survei.1lances reviewed are as follows:
PT/3/A/600/10 Reactor Coolant Leakage WR 55175A Unit 2, RPS Channel 'A' On-line Test IP/O/A/300/11 125 VDC Battery Monthly Surveillance No violations or deviations were identifie.
Maintenance Activities Maintenance activities were observed and/or reviewed during the reporting period to verify that work was performed by qualified personnel and that approved procedures in use adequately described work that was not within the skill of the trad Activities, procedures and work requests were examined to verify proper authorization to begin work, provisions for fire, cleanliness, and exposure control, proper return of equipment to service, and that limiting conditions for operation were me Maintenance witnessed in whole or in part:
WR 30396B Adjust relief setting on #1 TDEFWP steam relief valve, 1MS-92 WR 30387B Investigate and repair 1MS-87
Maintenance work requests reviewed in detail:
WR 25949B Repair Leaking Casing on 3C Spent Fuel Pump WR 27071B Calibration of Unit 3 Power Range Instruments WR 55887A Unit 2, Calibration of Reactor Building Hydrogen Sampling System, Train A WR 90859C Repair of Reactor Building Personnel Hatch Inner Door Equalizing Valve Seal, Unit 3 No violations or deviations were identifie.
Resident Inspector Safeguards Inspection (IP71707)
In the course of the monthly activities, the Resident Inspector(s) included a review of the licensee's physical security progra The performance of various shifts of the security force was observed in the conduct of daily activities which included; protected and vital areas access controls, searching of personnel, packages and vehicles, badge issuance and retrieval, escorting of visitors, patrols and compensatory post In addition, the Resident Inspector(s) observed protected area lighting, protected and vital areas barrier integrity and verified an interface between the security organization and operations or maintenanc The Resident Inspectors also visited the central alarm statio No violations or deviations were identifie.
Unit 1 Startup After Refueling The Unit 1 turbine generator was placed on line at 2:16 p.m. on May 5 after a total elapsed time of 81 days for the cycle 9 refueling outag The inspectors witnessed the initial rod withdrawal and rod worth determination, the rod drop test, and portions of the temperature coefficient determina tio The inspectors began a detailed review of the startup physics tests completed for Unit 1, including the zero power physics test and power escalation tes This review will be completed during the next report perio Unit 1 was shut down from 70% power at 9:00 on May 9 due to leakage from a reactor coolant system instrumentation root valve into a collection funnel and thence to the containment sum Leakage varied from 0.8 to gpm in six samples over a 27 hour3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br /> perio The leakage sources, as one of several root valves feeding the collection funnel, was identified on May 8, but the shutdown was delayed while preparations were made for the repai Technical Specifications permit operation with up to 10 gpm of identified leakage from the primary syste The root valve was furmanited and the reactor returned to operation at 5:00 p.m. on May Unit 1 tripped from 48% power at 6:16 on May 10 due to loss of main feedwater and the resulting reactor anticipartory trip. Only one feedwater pump was in operation at the time due to the low power leve Emergency feedwater and all other reactor protection systems responded normall There was no engineered safety features actuatio The main feedwater pump.trip was due to the trip of a condensate booster pump because of low suction pressure. Low pressure to the booster pump was the result of the discharge check valve from the D1 heater drain pump sticking open after the drain pump trippe This permitted the condensate booster pump discharge flow to back flow through the D1 pump to the condenser. The booster pump increased its speed in an attempt to supply additional flow to the feedwater pump and in doing so developed low suction pressure and subsequently trippe The check valve was repaired and Unit 1 returned to criticality at 11:53 a.m. on May 1.
Reactor Protection System (RPS)
Instrumentation Less Than Minimum Requirements On May 2 with unit 1 reactor critical following completion of zero power physics testing (ZPPT),
the technical specifications requirement of three operable RPS reactor coolant temperature instrument channels was not me This occurred when channel 'B' was taken to manual bypass with the channel
'A' T-hot instrumentation failed lo The minimum number of operable channels as specified by TS 3.5.1.1 was not me The incident occurred following completion of ZPPT when I&E was requested to increase the RPS high flux trip setpoints to 70% per the startup procedur At the time, channel 'A' was in manual bypass due to the failure of RC hot leg temperature instrumentation. The I&E technician adjusted the channel
'A' high flux tri He then took channel 'A' out of manual bypass and placed channel 'B' in manual bypass. While channel 'B' was bypassed the control room operations personnel realized that the same components in channels 'A' & 'B' were inoperable, reducing the RPS protective trips to less than the minimum required. This situation existed for approximately 7 minutes. Channel 'B' was immediately taken out of manual bypass and I&E was instructed to place channel
'A' in the tripped state before proceeding to the remaining channel TS 3.5.1.1, table 3.5.1-1 requires that at least three channels be operable for the RPS reactor coolant temperature instrument channels and RPS pressure-instrument channels. During the 7 minute period when Channel 'B'
was in trip bypass, with failed instrumentation in channel 'A', there were only two channels operabl The residents have not completed their inspection of the circumstances existing at the time of the incident, the procedures in use, and the corrective action taken by the licensee. Until further review is completed this will be identified as unresolved item, UNR 269/86-14-01, Operable RPS Channels Less Than Minimum Require.
Procedural Limit for LPI Pressure Exceeded, Unit 1 On April 24 the procedural limit for the Unit 1 LPI system pressure in the decay heat cooling switchover mode was exceede The unit was in cold shutdown, preparing to go to hot shutdown following the cycle 9 refueling outage. The switchover mode is an intermediate lineup of the LPI system used during heatup of the reactor coolant system prior to placing the reactor coolant pumps in servic Procedural requirements specify that the LPI pumps should not be operated with the reactor coolant (RC)
pressure above 314 psi During the beginning of this event the unit 1 nuclear control operator (NCO)
had adjusted the setpoint on the RC volume control valve, 1HP-120, when he subsequently noticed that RC makeup flow had increased to maximum, the letdown storage tank (LOST) level was decreasing, and the pressurizer level was increasing. There was no response when the NCO attempted to isolate 1HP-120 by taking its controller to manual. The control room senior reactor operator (SRO)
then instructed the NCO to close a block valve upstream of 1HP-120, isolating makeup flow, and to open a suction valve from the borated water storage tank to provide additional makeup to the LDS Following these actions the operators noted that the pressurizer level was decreasing at a faster than normal rate, leading to the belief that the LPI suction relief valve (1LP-25)
may have lifted during the transient. This was confirmed by a nuclear equipment operator (NEO)
in the reactor buildin The RC pressure was reduced to approximately 150 psig in order to reseat 1LP-2 During the incident the highest RC pressure observed was approximately 345 psig while the LPI decay heat line pressure was indicated to be approxi mately 400 psig. The relief setpoint of 1LP-25 is approximately 360 psi An evaluation and review of system design data by the station mechanical engineer in conjunction with licensee design engineering staff concluded that system pressure remained within the design hydro pressure of the system. While the LPI pump discharge design pressure is 370 psig, the system was originally hydro tested to 550 psig. In addition the system is hydro tested to 407 psig when required by the inservice inspection progra Later on the same day the LPI relief valve was found to be relieving at pressure much lower than its setpoint. The valve began relieving at about 195 psig, remained open during attempts to reseat it while decreasing RC pressure, and finally was gagged to prevent additional loss of wate RCS makeup during this event was approximately 3000 gallon Investigation into the failure of the RC makeup control valve found a failure of a set screw internal to the valve's positioner. The failed parts were replaced and makeup flow control returned to norma After the LPI decay heat cooling system was taken out of service the relief valve, 1LP-25, was replaced with a new relief valve. The plant Onsite Review Group (OSRG)
is investigating the above described transients for additional lessons learned and recommendations.