ML20113D141
| ML20113D141 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 04/09/1985 |
| From: | Dixon O SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20113D144 | List: |
| References | |
| NUDOCS 8504150017 | |
| Download: ML20113D141 (3) | |
Text
_ _ _.
SOUTH CAROLINA ELECTRIC & GAS COMPANY POST OFFICE 764 COLUMBIA. south CARouNA 2921E o.w.omON.3 April 9, 1985 VICE PRESIDENT NUCLF Am OPERATIONS Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission (NRC)
Washington, D.C.
20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Diesel Generator Testing
Dear Mr. Denton:
South Carolina Electric & Gas Company (SCE&G) hereby requests an exigent Technical Specification change in accordance with Title 10 of the Code of Federal Regulations, Part 50.91.a.6 for the Virgil C. Summer Nuclear. Station Technical Specifications. This proposed change to specification 3/4.8.1, "A.C. Sources," as shown on Attachment A modifies the testing schedule for the diesel generators by determining the last 100 valid tests on a per diesel generator basis as opposed to a per nuclear unit basis, a~nd by providing a temporary alternate testing frequency for the "A" diesel generator. These proposed Technical Specification changes offer an interim solution to prevent excessive testing of the "A" and "B" diesel generators which could potentially i
lead to the degradation of these components. SCE&G's position is that this potential degradation, as noted by the NRC Staf f in Generic Letter 84-15, " Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability," could lead to decreased reliability of the diesel generators located at the Virgil C. Summer Nuclear Station. SCE&G is investigating proposing a future revision to Technical Specification 3/4.8.1 to provide for a reliability program for the diesel generators.
/
On March 28, 1985 SCE&G determined from a review of the diesel generator testing logs that three failures which occurred in June / July 1984 for the "A" diesel generator were previously determined to be invalid failures, but were actually valid failures per the guidelines found in Regulatory Guide 1.108.
These failures were all common and determined to be a result of a sticking jacket water cooling system thermostatic control valve that became dirty from a fuel oil injector leak into the jacket water cooling system. After the first failure the injector leak was repaired and the valve was cleaned and flushed.
Corrective actions after the second failure were also the cleaning and flushing of the valve. However, after the third failure the valve internals.were replaced. No further valid failures of the "A" diesel generator have occurred since this time. The only other valid failure of the A" diesel generator was in September 1983, and corrective actions at the time of that failure eliminated the possibility of a similar event. Therefore, on March 28, 1985, SCE&G was required by Technical Specifications to begin testing the diesel generators at a staggered test frequency of at least once every three days.
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Mr. Harold R.s Denton LPage Two.
April 9,.1985
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As shown on Attachment A, the proposed amendment would allow for each -
of the two diesel generators at the Virgil C.
Summer Nuclear Station to be tested at a' frequency dependent only on its particular failure rate. 'The change would prevent excessive testing of a diesel generator which' demonstrates satisfactory performance, and would -only require ^ increased testing of the one which did have increased failures.-
Also as shown on the note on Attachment A, because of the three common ifailures associated with diesel generator "A" as discussed previously.
in the text of this letter, SCE&G is requesting that this diesel
- generator be ~ considered to only have two valid failures as of March 28, 1985. This change would allow the "A" diesel generator to enter into'the 14; day testing, frequency, and any subsequent failures in the last 100 demands would increase the testing frequency of the diesel generator as:shown in Table 4.8-1.
As discu'ssed in the proposed "No Significant Hazards Consideration" provided in Attachment B, this amendment does 'not pose.a hazard to the
- general public. Thisfamendment is being requested to further protect the public by attempting to decrease any excessive wear or degradation of the onsite emergency A.C. power supply. Attachment C reflects SCE&G's basis ~ for requesting this. exigent review.
This change has been reviewed and approved by both the Plant Safety Review Committee and the Nuclear Safety Review Committee.
Please find enclosed the application fee of one hundred fifty dollars ($150.00) required by Title - 10 of the Code of Federal Regulations, Part 170.-
If you ~ have any questions, please advise. Your cooperation in this matter is greatly appreciated.
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- 0. W..]ixoh, Jr.
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Mr.. Harold R. Denton Page.Three April 9, 1985 AMM:OWD/tdh Attachment cc:
V. C. Summer T. C. Nichols, Jr./O. W. Dixon, Jr.
E. H. Crews, Jr.
E. C. Roberts W. A. Williams, Jr.
D. A. Nauman J. N. Grace Group Managers O. S. Bradham
.C. A. Price C. L. Ligon (NSRC)
K. E. Nodland R.:A. Stough' G. Percival C. W. Hehl J. B. Knotts, Jr.
H. G. Shealy NPCF File t
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