ML19317D734
| ML19317D734 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/06/1977 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML19317D731 | List: |
| References | |
| RO-269-77-15, NUDOCS 7912100502 | |
| Download: ML19317D734 (2) | |
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DUKE POWER COMPAhT OCONEE UNIT 1 Report No.:
R0-269/77-15 Report Date:
June 6, 1977 gd)
Occurrence Date: May 6, 1977 Facility:
Oconee Unit 1, Seneca, South Carolina Identification of Occurrwnce:
One channel of borated water storage tank level instrumentation inoperable Conditions Prior to Occurrence: Unit at 100 percent full power Description of Occurrence:
On May 6, 1977, it was determined that Channel 1 of the Oconee Unit 1 borated water storage tank (BWST) level instrumentation was indicating a lower level than Channel 2 of the instrumentation.
Channel 2 indicated that the level of borated water required by technical specifications was being maintained.
A work request was promptly issued, the line was cleared, and in less than one hour the Channel 1 level indicator was declared operable.
Apparent Cause of Occurrence:
The cause of this occurrence has not been determined.
It is postulated, however, that the Dekoron trace heating controller was failing intermittently resulting in boiling of the borated water in the process line and bubbles of steam.
Analysis of Occurrence:
This condition is considered to be reportable since it constituted operation in a degraded mode permitted by a Limiting Condition for Operation.
Technical l
Specification 3.3.5 makes provision for the removal from service for test l
or monitoring of any component of the high pressure injection, low pressure l
injection or Reactor Building spray for a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided not more I
than one train of each system is affected. This occurrence resulted in the loss of one of two redundant channels of BWST level indication for less than one hour. During this period, the redundant level transmitter properly indicated the true level of the BWST. The conditions of the BWST required by Technical Specification 3.2 were maintained and the emergency core cooling i
systems would have performed as required in the unlikely event they were needed.
It is concluded that the health and safety of the public were not affected by this incident.
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Corrective Action:
The BWST level transmitter process line was bled and returned to service within one hour of the incident. The Dekoron heat tracing controller was turned off pending installation of a modification which will replace the j
present Dekoron heat tracing system, which surrounds the process line, with a Nelson heat tracing system as committed in our letter of January 31, 1977, 791g199 $Op
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which transmitted Reportable Occurrence Report R0-270/77-1. This modifica-tion will be implemented-by October.), 1977. The modification should i
eliminate problems experienced with the Dekoron heat tracing system.
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DUKE Powsa COMPANY Powrn Buzz.orno U* S* M. E. (
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Og pg June 5, 1972 Mr. John G. Davis U. S. Atomic Energy Commission Directorate of Regulatory Operations Region II, Suite 818 230 Peachtree Street, Northwest Itlanta, Georgia 30303 Re: CO:II:CDI 50-269/71-9 50-269/71-10 50-269/71-11 50-270/71-5 50-287/71-5
Dear Mr. Davis:
In reply to your letter of Marcit 8, 1972 and as per our discussion at Oconee Nuclear Station on May 19, 1972, please find attached a progress report pertinent to Items 4, 5, and 8(b) of the March 8 letter.
Please note that the attachment states that approximately six weeks will be l
required to upgrade the quality assurance records; then a re-audit will be performed and a report written documenting improvements in the welding program and acceptability of welding completed. This report should be l
available for your review by August 31, 1972.
1 Please be advised as pe-our May 19, 1972 meeting at Oconee Nuclear Station that we are de eloping supplementary information to my May 3, 1972 letter and will forwr.d that information to you in approximately two weeks.
Very truly yours, l
l em
&c.ec T r Attachment ec:
Mr. W. S. Lee Mr. W. H. Owen Mr. R. L. Dick np Mr. s. D. ro.e11
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~-~~~~' Attachment to'A. C. Thias' letter of Juna 5, 1972 to J. G. Davis s
Dmsa POWER COMPANY \\
- e. o. cox rire GENEllAL OFFICES Ttternenti anta ro4 422 SOUTH CHURCH STREET 374 4011 CIIAltLOTTE 1C. 28201 June 2,1972 Progress Report Responding to John G Davis' letter of March 8,1972 Re:
Oconee 1-3 4.5,8b To evaluate and resolve apparent deficiencies, Southwest Research Institute was employed to conduct an audit of the welding program at Oconee.
Southwest Research Institute found that documentation was incorrect or inadequate in certain areas.
They indicated that the welding procedures were technically correct and met code requirements but did suggest that the procedure format be standardized.
All procedures have now been standardized, revised, reviewed, approved, implemented and meet all code requirements.
After. evaluation of Southwest Research institute's findings, we employed Helmut Thielsch, an independent specialist in the field of welding and metallurgy, to review the total welding program at Oconee.
Mr Thielsch has undertaken a
. major review of welding procedures and qualifications, welder qualifications, NDE records, filler me~tal chemistry and completed welding in various systems. This review covers nuclear safeguard systems plus main steam and feed water.
For these systems we are upgrading weld joint identification records, radiographic film, Identification of flim to weld Joints, welder qualification and records of magnetic particle
,and IIquid penetrant examinations where applicable.
I The review we are now making is very comprehensive and requires a considerable amount of work. Work performed to date does not Indicate any serious deficiencies; however, we are carefully reviewing each element. When this review is complete, we are confident that there will be adequate documentation to give assurance that safety systems meet all requirements and that welding already completed is acceptable.
It is expected that an adbitional six weeks will be required'to complete the upgrading of quality assurance records.
When this is completed, Mr Thielsch will perform another audit and prepare a written report.
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I Please consider..is as a progress report. As soon as our consultant's report has been completed, we will submit a detailed written report stating the steps that have been taken, improvements in the program to prevent recurrence, and documentation of acceptability of welding already completed.
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