IR 05000269/1978011
| ML19316A157 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/24/1978 |
| From: | Jape F, Jenkins G, Robert Lewis NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML19316A151 | List: |
| References | |
| 50-269-78-11, NUDOCS 7911280697 | |
| Download: ML19316A157 (4) | |
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O Kic UNITED STATES
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NUCLFAR REGULATORY COMMISSION
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Report No.: 50-269/78-11 Docket No.:
50-269 License No.: DPR-38 Licensee: Duke Power Company Box 2178 South Church Street Charlotte, North Carolina 28242 Facility Name:
Oconee Unit 1
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Inspection at:
Oconee Nuclear Station Inspection conducted: May 5 and 6, 1978 Inspectors:
F. Jape G. Jenkins Accompanying Personnel:
None Reviewed by: [. 6.
oM Y2//76 R. C. Levis, Chief Date Reactor Projects Section No. 2 Reactor Operations and Nuclear Support Branch Inspection Summary Inspection on May 5 and 6, 1978 (Report No. 50-269/78-11)
Areas Inspected:
Special, unanounced insp:ction of circumstances surrounding and the radiological aspects of the May 4 event which resulted in 50,000 gallons of reactor coolant overflowing onto the reactor building floor thru an open manway on the primary side of a steam generator.
The inspection involved 17 manhours onsite by two NRC inspectors.
Results:
No items of noncompliance or deviations were identified during the inspection.
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RII Rpt. No. 50-269/78-11 1-2
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3.
Unresolved Items No new unresolved items were identified during the inspection.
4.
Management Exit Meeting An exit meeting was conducted on May 5, with Mr. J. E. Smith, Station Manager. The circumstances, apparent cause, and corrective actions to restore decay heat removal were discussed.
Licensee management stated that their investigation was underway and a report of their findings would be submitted to the NRC in 14 days.
The inspector's findings were acknowledged by the licensee without significant comment. The inspectors indicated that additional review would be conducted following receipt af the licensee event report.
The inspectors informed licensee management that the review of the radiological aspects of the event would continue until May 6.
At the conclusion of that review, on May 6, the inspector discussed the results by telephone with the Health Physics Supervisor.
5.
Temporary Loss of Decay Heat Removal System On May 4 between 11:30 a.m. and'5:00 p.m., while the reactor coolant system (RCS) was open to the reactor building atmosphere, 50,000 gallons of reactor coolant overflowed onto the reactor building floor.
The reactor was shutdown April 21 to repair a steam generator tube leak. The RCS was drained to the center-line of the RCS cold leg piping to permit draining the steam generator.
The RCS temperature was being controlled at 70 degrees F by recirculating through the low pressure injection system, the normal path for decay heat removal.
The suction valve, LP-2, was closed to permit a surveillance test on LP-105, LOCA Boron Dilution Valve. The test on LP-105 required approximately 10 minutes and following completion of this test, LP-2 failed to open normally.
Maintenance personnel re-opened LP-2 within two hours after it failed.
During the two hour period RCS temperature increased to 215 degrees F.
Reestablishment of normal decay heat removal flow path was attempted using the borated water storage tank (BWST).
During this period, an estimated 50,000 gallons of reactor coolant flowed out of the open lower manway of the steam generator. The water was contained within the reactor building and all personnel had evacuated the building.
By 4:30 p.m. RCS temperature was reduced to 180 degrees F and normal
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decay heat removal flow was established.
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RII Rpt. No. 50-269/78-11 I-3 i
i A special unannounced inspection was conducted at the site on May 5 and 6 to examine circumstances related to the event and to review the licensees actions taken to restore normal decay heat removal flow. Discussions with plant personnel, and examination of related records, logs and recorder charts did not reveal any items of noncompliance.
Licensee management advised the inspectors that the event was being investigated and a report would be submitted to the NRC by May 18.
T5.e inspectors agreed with this schedule and indicated followup would be conducted upon receipt of the report.
6.
Radiological Aspects of Reactor Coolant Overflow of May 4, 1978 On May 5 and 6, 1978, an inspector reviewed health physics
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records and interviewed persennel to ascertain the extent of radiological problems associated with the overflow of reactor coolant through a steam generator to the reactor building basement.
Based on a review of air sample records, MPC-hour log, and whole body count results, the inspector determined that appropriate evaluations of airborne activity and internal exposure were made.
No significant external or internal personnel exposures to radioactivity resulted from the incident.
b.
A reactor building purge was in progress at the time of the overflow.
The purge was stopped at 5:04 p.m. on May 4.
An inspector reviewed records of gaseous effluents released from the Unit 1 vent on May 4, and verified that the radioactivity released that day was typical of that released on other days during the outage and was well within limits established by Technical Specifications.
All of the reactor coolant overflow was collected in the basement of the reactor building; none was released directly to the environment.
Licensee management stated that all of the liquid to be released would be processed through the radioactive liquid waste processing system prior to release in a controlled manner after sampling, analysis, and accountability.
c.
The inspector identified no noncompliance or unresolved items.
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RII Rpt. No. 50-269/78-11 I-1 DETAILS I Prepared by:
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F. Jape, Reactor Ipsp6cp6r '
/ Dat6 Reactor Projects Seftion No. 2 Reactor Operations and Nuclear Su o ranc b A3
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_G. R. J ins, Radiation Specialist Date Radia n Support Section Section Fuel Facility and Materials Safety Branch Date of Inspection: May 5 and 6, 1978 Reviewed by: [,C,
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R. C. Lewis', Chief Date Reactor Projects Section No. 2 Reactor Operations and Nuclear Suppo t ran
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A. F. Gibson, Chief Date Radiation Support Section Fuel Facility and Materials Safety Branch 1.
Persons Contacted J. E. Smith, Station Manager H. W. Morgan, Shift Supervisor R. T. Bond, Licensing and Projects Engineer W. M. Harris, Operating Engineer N. F. Edwards, Assistant Operating Engineer D. L. Davidson, Health Physics Supervisor G. F. Davis, Health Physics Supervisor M. D. Thorne, Health Physics Supervisor J. Stewart, HP Labman
- C. T. Yongue, Station Health Physicist
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- by telephone 2.
Licensee Action on Previous Inspection Findings Not inspected.
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