ML19340C795
| ML19340C795 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/10/1980 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8012170457 | |
| Download: ML19340C795 (2) | |
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December 10, 1980 3
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[j Ab Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555
Subject:
Virgil C. Summer Nuclear Station Docket No. 50/395 FSAR Open Item - Diesel Generator
Dear Mr. Denton:
In the Staff's review of the FSAR South Carolina Electric and Gas Company (SCE&G) was requested to provide additional information regarding vibrational loads developed during operation of the diesel generators.
Specifically, the Staff required that test results and results of analyses which validate that the skid-mounted control panels and mounted equipment have been developed, tested and qualified for operation under severe vibra-tional stresses encountered during diesel engine operation be provided or floor mount the control panels presently furnished with the diesel generator separate from the skid on a vibration-free floor area.
In response to this request, a related discussion and a sit > verification program is presented to address the staff's concerns.
Colt Pielstich model PC-2 units are installed at the Virgil C. Summer Nuclear Station. These units have undergone extensive shop and on site testing and will continue to be tested in the startup program. Colt l
and SCE6G have both observed that these diesel engines run quite smoothly with littic vibration. Th e ends of the skid, where the subject relay box and gage panel are mounted, are away from the excitation source and are well anchored. Measurements at there two locations have confirmed the low vibration 1cvels.
Colt's experience has shown instrument failure due to vibration for similarly mounted components is not a problem. They have successful com-mercial applications which accumulate more running hours in a year than most nuclear plants will see in a lifetime.
Colt has accumulated a large number of hours of operation of the model PC-2 unit with similar instrument mountings in commercial and nuclear appli-cations.
The only problem related to mounting of which Colt is aware is that many years ago the bourdon tube pressure gages suffered from vibration. At that time, the isolator system for the gage board was developed and the difficulty was eliminated.
8012170437
4 Mr. liarold R. Denton December 10, 1980 Page Two In summary, Colt's experience and our own' observations indicated there is no problem. However, to provide additional assurance, during the next testing phase of the diesel engines during t'ne startup program, SCE&D will take confirmatory vibrational measurments on mounted equipment.
This data will be analyzed by Colt engineers and our een engineering de-partment to assure design and operational limits have not been executed.
The results of this program will be sent to the NRC.
Also, plant maintenance procedures are being revised to require that connections and terminations in the panels be checked for tightness on an annual basis. This will provide an additional check of vibrational loading.
In summary, the discussion and verification programs described above should provide the Staff with adequate assurance that vibrational loading is not a problem.
If you require additional information, p3 case let us know.
Very truly yours, f)
T. C. Nichols, Jr.
RBC:TCN:rh cc:
V. C. Summer G. H. Fischer T. C. :Lehels, Jr.
E. H. Crews, Jr.
O. W. Dixon, Jr.
D. A. Naum.tn O. S. Bradham W. A. Williams, Jr.
R. B. Clar:
A. R. Koon A. A. Smith J. B. Knotts J. L. Skolds B. A. Bursey H. E. Yocom D. K. Kelly S. J. Smith l
J. G. Connelly M. Moriarty NPCF/Rhitaker File I
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