ML19254F458
| ML19254F458 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 11/02/1979 |
| From: | Macdougall E BROOKHAVEN NATIONAL LABORATORY |
| To: | Sylvester E Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7911090469 | |
| Download: ML19254F458 (2) | |
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.JJ'j BROOKHAVEN NATIONAL LABORATORY
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ASSOCIATED UNIVERSITIES, INC.
Upton, New York 11973 Department of Nuclear Energy (516) 345-2362 November 2,1979 Mr. Ernest Sylvester Plant Systems Branch U.S. Nuclear Regulatory Commission Washington, D.C.
20555 REF: Maine Yankee, Supplement Item 3.2.4
Dear Etnie:
The Safety Evaluation Report (SER) dated April 24, 1978 states that the licensee will provide information relative to the failure of both fire mains simultaneously. The mains are 12' ductile cast iron with bell and spigot joints; they run approximately 400 feet in a common trench and are set about 3 feet apart.
The licensee responded to the SER provision on May 31, 1979 by stating that no modifications are required based on various installation features.
However, Mr. Ingemar Asp still contended in his letter to Brookhaven National Laboratory (BNL) of June 25, 1979 that the two mains could be lost at the same time thereby endangering all fire protection water supply.
The NRC is investigating the Beaver Valley fire main break of July 17, 1979. This information is not available to us at the time of this writing.
From the information on hand, we support Mr. Asp's position and recommend that a second fire water main be installed.
In order to arrive at our post-tio.n, we recently contacted the Suffolk County Water Authority. They stated that it was their policy to separate water mains by the width of the road involved; it was not their policy to run 2 mains in a common trench. They did not have available infomation of the size of washouts from pipe breaks. They did say the washout size was dependent on water main size and pressure and the time it took to find and isolate the break. A typical good time was 45 min-utes to one hour.
We also contacted the Americal Iron and Steel Institute. They did not have a;tual numbers to pin down the recommended spacing of water mains, but agreed that using a common trench was not a good idea. They suggested the the State of Maine might have code information that would give further information.
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E. Sylvester November 2,1979 The Cast Iron and Pipe Research Association (CIPRA) acknowledged that the fact that the pipes were ductile iron rather than grey iron was reason to con-clude that there was more strength in the pipes to withstand a.ashout. How-ever, they recommended placing the pipes "a good distance apart." They also pointed out that corrosion could play part in the strength of the pipe.
The final contact was the American Water Works Association (AWWA). They will fontard to BNL a committe report recommending that the horizontal dis-tance between water and sanitation pipes be a minimum of 10 feet. We will comment further to you on this when we've reviewed the report. The AWWA re-presentative also stated that there is no AWWA standard on water main spacing.
However, they do have a computer search program to bring forth previously published information on matters pertaining to water work problems. We will proceed to look for more infomation by way of this source.
Very truly yours, Edward A. MacDougall Reactor Engineering Analysis EAM:sd cc.:
R. Cerbone L. Dere r'an R. Ferguson R. Hall W. Kato V. Panciera
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