IR 05000269/1986021
| ML20203M423 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/15/1986 |
| From: | Bryant J, Peebles T, Sasser M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20203M419 | List: |
| References | |
| 50-269-86-21, 50-270-86-21, 50-287-86-21, NUDOCS 8609030417 | |
| Download: ML20203M423 (9) | |
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[A2 Ettg'o UNITED STATES NUCLEAR REGULATORY COMMISSION
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REGION il n
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,j 101 MARIETTA STREET.N.W.
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ATLANTA, GEORGI A 30323
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WG 151986
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Report Nos.: 50-269/86-21, 50-270/86-21, and 50-287/86-21 Licensee:
Duke Power Company 422 South Church Street Charlotte, NC 28242 Docket Nos.: 50-269, 50-270, and 50-287 License Nos.:
l Facility Name: Oconee Nuclear Station l
Inspection Conducted: July 8 - August 11, 1986
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7 -/ f 8 Inspectors:
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J. C. Bryant i
Date Signed
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Date Signed M. K. Sasser i
Approved by:
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F-/f 4 T. A. Peebles, Section Chief Date Signed Division of Reactor Projects SUMMARY
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Scope: This routine, announced inspection involved resident inspector inspection
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on-site in the areas of operations, surveillance, maintenance, verification of engineered safety features lineups, followup of events,- followup items of j
non-ccinpliance, and performance indicators. This report includes an information meeting held with Duke Power Company personnel and Reginnal management in the Region II office in Atlanta on August 1,1986 (Para.10).
Results: Of the seven areas inspected, no items of non-compliance or deviations were identified.
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8609030417 86001S PDR ADOCK 05000269 o
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REPORT DETAILS 1.
Persons Contacted Licensee Employces
- M. S. Tuckman, Station Manager
- T. 3. Owen, Maintenance Superintendent
- R. L. Sweigart, Operations Superintendent
- T. S. Barr, Technical Services Superintendent
- C. L. Harlin, Compliance Engineer
- D. S. Compton, Assistant Engineer, Compliance
- R. T. Entrekin, Assistant Engineer
- N. E. Estep, Assistant Engineer
- N. A. Rutherford, System Engineer, Licensing J.T. McIntosh, Station Services Superintendent T.K. McQuarrie, Contract Services Coordinator B. McAllister, Support Engineer B. Thompson, Assistant Engineer Other licensee employees contacted included technicians, operators, mechanics, security force members, and staff engineers.
Resident Inspectors:
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- J. C. Bryant
- M. K. Sasser
- Attended exit interview.
- Attended Information Meeting in Region II, Atlanta, August 1, 1986.
2.
Exit Interview The inspection scope and findings were summarized on August 11, 1986 with those persons indicated in paragraph I above.
The licensee did not identify as-proprietary any of the materials provided to or reviewed by the inspectors during this inspection.
3.
Licensee Action on Previous Enforcement Matters
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85-20-01 - Violation (Closed) Failure to list inoperable monitors in semi annual report.
85-37-01 - Violation (Closed) Failure to document malfunction of valve 3LP2 in RO or SRO log.
The inspectors reviewed the licensee corrective actions concerning these two i
violations and have no further questions.
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4.
Unresolved Items Unresolved items were not identified during this inspection.
5.
Plant Operations The inspectors. reviewed plant operations throughout the reporting period to verify conformance with regulatory requirements, Technical Specifications (TS), and administrative controls.
Control room logs, shift turnover records, and equipment removal and restoration records were reviewed routinely.
Interviews were conducted with plant operations, mair.tenance, chemistry, health physics and performance personnel.
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Activities within the control rooms were monitored on an almost daily basis.
Inspections were conducted on day and on night shifts, during week days and i
on weekends.
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 TS.
Operators were responsive to plant annunciator alarms and were cognizant of plant conditions.
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Plant tours were taken throughout the reporting period on a routine basis.
The areas toured included the following:
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Turbine Building Auxiliary Building Units 1 and 2 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 i
Standby Shutdown Facility Keowee Hydro Station Battery Room
During the plant tours, ongoing activities, housekeeping, security, equipment status, and radiation control practices were observed.
Unit 1 began the report period at 100% power. At 8:15 a.m. on August 6, 1986, the unit began shutting down due to a steam generator.(SG) tube leak (s).
Maximum calculated leakage was 0.26 gallons per minute (gpm)
during a transient condition. Reactor power had been reduced from 100% to 55% during the night. Maximum leakage calculated at 100% power was 0.08 gpm and steady state leakage at 55% power was 0.12.
The first indication of a possible tube leak was on July 24; however, the calculated leak rate was so small that the leaking tube (s) probably could a
not have been detected had the unit been shut down at that time. The technical specification limit for a steam generator tube leak on Unit 1 is
0.3 gpm.
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At the close of the report period a leaking tube.had been found in each of the two steam generators. Eddy current testing had found additional tubes with wall thickness less than the minimum required. The exact number had not been determined. Further details will be provided in the next monthly report. The unit is expected to be back on line by August 15.
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Unit 2 began the report period at 100% power. On July 8 the unit tripped on an anticipatory turbine trip following the failure of a feedwater flow transmitter which provides input to the integrated control system (ICS).
The unit was returned to power operations later that same day, operating at 100% until July 23 at which time a reactor coolant flow transmitter failed.
The failure of this transmitter's input to the ICS resulted in a transient similar to the July 8 trip with the reactor tripping on an anticipatory turbine trip. The reactor returned to power operations later the same day and operated at 100% power throughout the remainder of the report period.
Both reactor trips are discussed in greater detail in paragraph 9.
On August 9 at 5:45 p.m.,
Unit 2 experienced a runback when the 2A main feedwater pump (MFWP) tripped. The unit was stabilized at approximately 600 power. Extensive troubleshooting on the MFWP found no problems.
The 2A MFWP was placed back into service at 2:20 a.m. on August 10.
Reactor power was being increased and was at 90% wnen the 2A MFWP again tripped off at 4:56 a.m.
The integrated control system again initiated a unit runback; the reactor being stabilized at 70% power.
Subsequent investigation of the MFWP this time revealed problems in the thrust bearing wear circuit.
The problem was resolved and the 2A MFWP was in service at 1:35 p.m. on August 10. The reactor was then returned to 100% power.
Unit 3 operated at 100% power until July 16 at which time the 3D2 heater drain pump (HDP) experienced a mecnanical seal failure. Power was reduced to 85% power during the time the pump was taken out of service for replacement.
A new pump was installed on July 17; however, alignment problems prevented placing the HDP in service until July 25. Following the HDP return to service, the unit returned to 100% power. The unit remained at essentially 100% power for the remainder of the report period.
No violations or deviations were identified.
6.
Surveillance Testing The surveillance tests listed below were reviewed and/or witnessed by the inspectors to verify procedural and performance adequacy.
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 acted, and review of completed wor ___
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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 completed.
Surveillances reviewed:
PT/2/A/1103/15 Reactivity Balance, Estimated Critical Rod Position PT/2/A/1103/15 Reactivity Balance, Shutdown Boron Concentration PT/2/A/305/1 Reactor Manual Trip Test PT/2/A/600/10 Reactor Coolant Leakage PT/2/A/610/18 Emergency Power Switching Logic Operability Test
PT/2/A/230/15 High Pressure Injection Cooler Flow Test WR 5'5128A Control Battery ICA, ICB Daily Test WR 55968A SSF 125VDC Daily Battery Test WR 55129A 230KV Switchyard Battery Daily Test Surveillances witnessed in whole or part:
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PT/1/A/251/1 Low Pressure Service Water Pump Performance Test IP/0/0/3000/21 Inspection of FNA Fuses IP/0/A/3000/1 Daily Battery Check, Unit 3 PT/0/A/290/4 Turbine Stop Valve Movement PT/0/A/290/3 Turbine Control Valve Movement 7.
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 trade. Activities, procedures and work requests were examined to veri fy 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 met.
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Maintenance witnessed in whole or in part:
WR 01162C Repair 1010 Static Inverter i
WR 51946 Change or Jumper Cell 2 of 2CA, Cell has Low Voltage WR 51980E Upgrade Cell 2 of 2CA
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WR 52714E Inspect Internal Wiring on Limitorque, IPR-9
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WR 52713E Inspect Internal Wiring on Limitorque, IPR-7
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l WR 52701E Inspect Internal Wiring on Limitorque, ICC-7 Maintenance work requests reviewed in detail:
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WR 50640 Obtain Design Information Data for Unit 1 Bulletin 85-03 Valves and Operators.
WR 54024D Inspect and Refurbish Limitorque Operator for 1-MS-79 j
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WR 54023D Inspect and Refurbish Lim ;orque Operator 1-MS-76 WR 50105E MOVATS Testing of 1-MS-84 WR 52436 Perform Equalizing Charge on 2CA Batteries No violations or deviations were identified.
.8.
Resident Iuspector Safeguards Inspection (IP 71707)
In the course of the monthly activities, the Resident Inspectors included a review of the licensee's physical security program.
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 posts.
In addition, the Resident Inspectors observed protected area lighting, protected and vital areas' barrier integrity and verified an interface between the security organization and operations or maintenance.
One violation was identified and is discussed in Report No. 50-269/86-22.
i 9.
Unit 2 Trips Due to Failed Transmitters i
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July 8,1986, Failed Feedwater (FDW) Flow Transmitter
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a On July 8, with the reactor at 100% power, the 2A FDW flow transmitter i
failed low. There was no actual loss of feedwater flow. This caused a reactor cross limits (mismatched power generation and heat removal)
i signal to the Integrated Control System (ICS), resulting in increased FDW flow and a reactor power runback.
At the time of the flow transmitter failure, 2A steam generator was operating at about 85% and
2B at 90% of the operating range level. The operating limit is set at
92% and the trip set at 96%.
By the time reactor power had been reduced to 92%, the 2B steam generator level had increased to 96%, causing a FDW and turbine i
generator trip.
The reactor then tripped on an anticipatory trip due to turbine failure. All systems responded normally.
All three emergency feedwater pumps started and there was no ESF actuation.
When the transmitter failed, reactor control operators took manual control of feedwater flow but were unable to reduce it sufficiently in the short time interval prior tu the SG high level trip.
Following corrective action and the post trip review, the reactor was returned to l
critical at 3:55 a.m. on August 9, and the turbine was placed on line
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at 9:10 a.m.
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July 23, Failed Reactor Coolant (RC) Flow Transmitter i
l At 9:44 a.m. on July 23, with the reactor at 100% power, the A loop RC flow transmitter, which provides input to the Integrated Control System
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(ICS), failed low.
The ICS response was to immediately re-ratio i
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feedwater flow, decreasing flow to the A steam generator and increasing flow to the B steam generator.
Re-ratio of feedwater caused the
'B' steam generator level, which was already high (90%) due to crud buildup, to increase very quickly past its operating limit (92%) and trip setpoint (96%). At 96% steam generator level, both main feedwater pumps and the turbir.e generator automatically tripped.
The reactor subsequently tripped on an anticipatory turbine trip.
Only 7 seconds elapsed from the time of transmitter failure until the reactor tripped.
The ICS initiated an RC flow runback when the steam generator reached the 92% operating limit; however, no appreciable effect was seen prior to the trip due to the short time from transmitter failure to reactor trip.
All systems responded as designed following the trip. The emergency
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feedwater system actuated, maintaining the steam generators at their post trip levels. There was no Engineered Safety Features actuation.
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Following the post trip review and corrective actions, the reactor was
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returned to critical at 1:06 p.m. on July 23. The generator was placed l
on-liae at 6:16 p.m. the same day.
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10.
Information Meeting Concerning IE Bulletin 85-03 and Enhanced Motor Operated Valve Refurbishment
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On August 1,1986, Duke Power Company representatives from the Oconee site and Duke corporate offices met with NRC management in the Region II offices to describe the Oconee motor operated valve (MOV) rework program.
The licensee made an excellet.t presentation describing the immediate and long range programs which will refurbish, test and, in some cases, modify approximately 100 MOV's during each refueling outage until the 900 onsite M0V's have been completed in about five years.
i The presentation described refurbishment (disassembly, cleaning and replace-ment of any worn or damaged parts) and MOVAT's testing of all Limitorque gate and globe valve operators, and refurbishment of butterfly /diaphram valves. Also, Rotork operators for gate valves will be refurbished.
Teams for the valve refurbishment and testing are being trained extensively for the program.
Teams will include Babcox and Wilcox support personnel and, initially, will include vendor specialists.
The licensee also described the controls being established to verify correct lubrication of all valves.
f 11.
Licensee Event Reports LER 50-269/85-14, (Closed) Reactor Building Spray Valve Operability. This Licensee Event Report concerned a design review which determined that under a degraded voltage condition, there could possibly be insufficient voltage r
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to operate six building spray valves due to long conductor runs from the motor control center to the valve operator.
Corrective action was to replace the deficient conductors with a larger size.
12. Unusual Events Due to Slight Earth Tremors At 6:30 p.m. on July 14, 1986, a slight earthquake was felt at Oconee by a few persons. An Unusual Event was declared at 6:50 p.m. after verifying with the Jocassee plant that the event had occurred. Jocassee recorded a disturbance of 2.2-on the Richter scale with a duration of 97 seconds.
Notifications were made and a plant inspection was performed. The Unusual
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Event was terminated at 8:15 p.m.
At 1:45 p.m. on July 15, 1986, another Unusual Event was declared for a slight tremor.
This event measured 2.6 on the Richter scale. One of the resident inspectors was in or near the control room at the time and did not feel or hear anything unusual. Notifications and an inspection were made.
The Unusual Event was terminated at 2:55 p.m.
The epicenter for the two events was about ten miles northwest of Oconee.
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13.
Inspection of Bussman Type FNA Fuses The licensee continues to perform weekly inspections of Bussman type FNA fuses installed at the station.
The weekly inspections were initiated following licensee discussions with Region II and documented in a July 2 letter from the licensee. Mechanical failure of this type fuse has been identified as a problem at other nuclear plants. Mechanical failure of the fuses could result in undetected component inoperability such that the component's safety related function would not be performed.
The licensee has identified 211 Bussman FNA fuses installed at the Oconee Station; about 200 of which are associated with the Standby Shutdown Facility.
Through the end of the report period, only one failed fuse has been found.
The fuse in question was located in a non-safety related circuit in a security system for which the installation was not complete at the time.
It is believed that the tuse failure was electrical and not mechanical in nature.
The weekly surveillance will continue until resolution of the deficiency currently associated with Bussman FNA fuses either through modification or replacement with an alternate type fuse.
14.
Inspection of Wiring on Enviromentally Qualified (EQ) Limitorque Valves As a result of deficiencies found at other Duke stations in the wiring of EQ Limitorque operators, the Oconee maintenance department initiated a program to inspect wiring on all EQ Limitorque operators. The deficiencies involve the use of ncn-environment' ally qualified wires for internal jumpers in the operators.
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During the Unit 1 maintenance / steam generator tube repair outage all EQ Limitorques are being inspected and non-EQ wires replaced.
Initial inspections found many operators with limit switch jumpers using Hypalon wire which is not qualified.
All EQ operators will be inspected and -
upgraded, as necessary, prior to restart of Unit 1.
Because of problems found during inspection of Unit 1, the licensee began a limited inspection of Unit 3 Limitorques and initiated discussions with Region II management to justify continued operation (JCO) of Units 2 and 3.
Limited inspection of Unit 3 inside containment valves revealed the same Hypalon wire and, in one case, a white jumper wire.
The licensee's JC0 states that Hypalon wire, though not qualified, could withstand the postulated Oconee post accident environment for up to 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.
The licensee feels the white jumper wire is acceptable based on its similarity to wire which has been qualified.
All EQ valves in Unit 3 containment which are accessible have been inspected and upgraded as necessary. Other inside containment valves, where possible, are deenergized in their safe, post engineered safety feature actuation
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position.
Several valves which could not be deene.rgized or upgraded with the unit at power were added to a procedure change requiring the nuclear control operators to deenergize the valves in their safe position within 30 minutes following a containment isolation signal generated during an accident. Outside containment Limitorques are to be inspected and upgraded within the next six weeks.
Unit 2 is scheduled to begin a refueling outage on August 16. The licensee plans to inspect and upgrade all EQ valves on the unit during the outage.
The resident inspectors will fallow the licensee's activities in this area until all EQ Limitorque operators have been inspected and upgraded as necessary. This will be tracked as inspector followup item; IFI 269, 270, 287/86-21-01, Inspection of Internal Wiring on EQ Limitorq'ue Operators.
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