ML20002E404
| ML20002E404 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 01/21/1981 |
| From: | Mcgaughy J MISSISSIPPI POWER & LIGHT CO. |
| To: | Tedesco R Office of Nuclear Reactor Regulation |
| References | |
| AECM-81-38, NUDOCS 8101270843 | |
| Download: ML20002E404 (2) | |
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MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. O. B O X 1640, J AC K S O N, MIS SIS SIP PI 3 9 2 05 January 21, 1981 JAMES P. McGAUGHY, JR.
Assistant vics paEsaNT Mr. Robert L. Tedesco Assistant Director of Licensing Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Tedesco:
SUBJECT:
Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416 and 50-417 File 0262/0755/L-860.0 Ultimate Capacity Analysis of Grand Gulf Mark III
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Containments AECM-81/38 Your letter of December 19, 1980 requested that an analysis of the Grand Gulf Mark III Containment be performed in accordance with certain enclosed guidance. You further asked that we identify a schedule for submitting the results of this analysis.
In our letter to you dated December 9,1980 (AECM-80/300), we described to you our plans to improve hydrogen control capability at Grand Gulf.
In that letter, we committed to perform a containment analysis comparable to that which you have requested. We further committed that the results of the analysis would be available June, 1981.
The methods of analysis and resultant information will conform to your request with one exception. The Grand Gulf containment analysis does not consider dynamic pressure effects.
In selecting a hydrogen control system, design criteria prohibit conditions leading to a hydrogen explosion. This eliminates the narrow pressure spike which results from hydrogen detonation. Having eliminated hydrogen detonation, hydrogen combustion remains to be considered.
Our investigations indicate that approximately 20-30 seconds are required for a flame front to propagate through the containment. The pressure increases associated with hydrogen combustion take place too slowly for dynamic effects to be of concern. Pressure decreases due to the effects of such things as heat sinks are even slower, on the order of several minutes. Thus we feel a dynamic pressure analysis provides little additional information and is not likely to affect the conclusions of the analysir.
Yours truly,
\\
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JPM:lm cc:
(See Next Page)
Member Middle South Utilities System
MISSISSIPPI POWER O LIGHT COMPANY Mr. Robert L. Tedesco AECM-81/38 Assistant Director of Licensing Page 2 cc:
Mr. N. L. Stampley Mr. G. B. Taylor Mr. R. B. McGehee Mr. T. B. Conner Mr. Victor Stello, Jr., Director Division of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 a
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