ML20064D462
| ML20064D462 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/03/1978 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Parr O Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20064D468 | List: |
| References | |
| NUDOCS 7811070146 | |
| Download: ML20064D462 (1) | |
Text
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November 3,1978 Mr. Harold R. Denton, Director Serial No. 237C Office of Nuclear Reactor Regulation PSE&C/RLR:bep/mc
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Docket Nos. 50-338 ' /
Attention: Mr. O. D. Parr, Chief Light Water Reactors Branch No. 3 Division of Project Management 50-339 - O U. S. Nuclear Regulatory Comission License No. NPF-4 Washinton, D..C.
20555
Dear Mr. Denton:
The possibility of short-circuiting the North Anna Service Water Reser-
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voir.. Spray System has been under study for some time.
Our letter of June 2, 1978 (Serial No. 237A) transmitted the results of an analytical study of the effectivenessoftheServiceWaterReservoir(SWR)pumphouseintakestructure in resisting this type of condition. This study was performed by 'the Ralph M.
Parsons Laboratory at the Massachusetts Institute of Technol.ogy (MIT).
The MIT study indicated that at design conditions over four hours would be required for an appreciable change to' occur in t..e temperature of the water reachi.ng the pump intake. This would mean that over one third of the volume of the SWR would have to be circulated through the system before an appreciable increase in water temperature occurred at the intake.
A short-circuiting test was conducted on July 14 and 15 of this year prior to the main thermal performance test of the North Anna Service Water Reservoir spray system.. The report on this short-circuiti.ng test is sub-mitted with this letter for your information.
The results of this test are in agreement with the previous analyses of the system. The design of the SWR pumphouse is effective in resisting short-circuiting. The test results combined with the analytical studies of the SWR pumphouse provide a sufficient basis to conclude that short-cir-cuiting to the detriment of the plant will not occur.
Work is continuing on the data reduction and analysis of information ob-tained during the thermal performance testing of the SWR spray system. We will submit a thoro. ugh report on this test and the thermal performance capa-i bilities of the spray system at the completion of all data analysis work.
Please contact us if you should require additional information.
1 Very uly r/
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cePresident-Powergttion Enclosures (40) ngineering and Construc ion cc: Mr. James P. O'Reilly, Director Office of Inspection & Enforcement Region II
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