ML19350A460
| ML19350A460 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 02/27/1981 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Counsil W CONNECTICUT YANKEE ATOMIC POWER CO. |
| References | |
| LSO5-81-02-067, LSO5-81-2-67, NUDOCS 8103160229 | |
| Download: ML19350A460 (3) | |
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E Mr. W.G. Counsil, Senior Vice President
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Nuclear Engineering and Operations Connecticut Yankee Atomic Power Company
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Post Office Box 270 Hartford, Connecticut 06101 96
Dear Mr. Counsil:
MN This is in response to your letter dated February 4,1981, concerning containment pressure during a loss-of-coolant accident (LOCA) at the Haddam Neck Plant.
In that letter you informed us that errors had been discovered in the pressure and temperature transient analyses for the containment building. The errors were related to the flow coefficients and Reynolds numbers used in the Babcock and Wilcox REFLOOD computer code. This code calculates the mass and energy release during a blowdown. The result of these errors is that under worst case conditions, the containment design pressure of 40 psig is exceeded by 0.6 psi.
The calculation which predicted that the containment pressure would exceed the design value assumed that the initial containment pressure was at the Technical Specification limit of 3.0 psig. We understand that you have evaluated the consequences of lowering the maximum containment operating pressure to 2.5 psig, and have determined that this change will prevent the conteinment design pressure from being exceeded.
Based on an audit calculation using the ideal gas law, we have deter-mined that reducing the initial pressure from 3.0 to 2.5 psig results in a reduction of the peak calculated pressure, during a LOCA, by approximately 0.7 psig. This reduction in peak pressure is sufficient to prevent the containment design pressure from being exceeded.
We have concluded trat your commitment to administratively reduce the maximum allowable containment pressure during normal operation from 3.0 psig to 2.5 psig is acceptable as an interim measure. However, you should submit, by April 1,1981, either (a) a reanalysis that confirms that the existing Technical Specification value will not result in exceeding the design pressure, or (b) a proposed change to the Technical Specifications which would reduce the maximum allowable containment pressure.
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2-February 27, 1981 Mr. Counsil i
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Please contact us if you have any questions.
Sincerely, k.......DiilfLiI Dennis M. Crutchff eld, Chief Operating Reactors Branch #5 Division of Licensing cc: See next page s
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Mr. W. G. Counsil February 27, 1981 cc:
Day, Berry & Howard U. S. Environmental Protection Counselors at Law Agency One Constitution Plaza Region I Office Hartford, Connecticut 06103 ATTN: EIS COORDINATOR JFX Federal Building Superintendent Boston, Massachusetts 02203 Haddam Neck Plant RFD #1 Resident Inspector Post Office Box 127E Haddam Neck Nuclear Power Station East Hampton, Connecticut 06424 c/o U. S. NRC East Haddam Post Office Mr. James R. Himmelwright East Haddam, Connecticut 06423 Northeast Utilities Service Cocpany P. O. Box 270 Hartford, Connecticut 06101 Russell Library 119 Broad Street Middletown, Connecticut 06457 Board of Selectmen Town Hall Haddam, Connecticut 06103 Connecticut Energy Agency ATTN: Assistant Director Research and Policy Development Department of Planning and Energy Policy 20 Grand Street Hartford, Connecticut 06106 Director, Criteria and Standards Division Office of Radiation Prograss (ANR-460)
U. S. Environmental Protection Agency Washington,' O. C.
20460
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