ML19248D028

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Forwards NRC to Licensees of Westinghouse two-loop Plants Re Rod Bank Exchange Method for Verifying Shutdown Margin of two-loop NSSS
ML19248D028
Person / Time
Site: Yankee Rowe
Issue date: 05/15/1979
From: Ziemann D
Office of Nuclear Reactor Regulation
To: Groce R
YANKEE ATOMIC ELECTRIC CO.
References
NUDOCS 7907310560
Download: ML19248D028 (2)


Text

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,1 NUCLEAR REGULATORY CO*.;foitsSION WASHINGTON, D. C. 20555 g tu.~..g May 15,1979 Docke t No. S'-29 Mr. Robert H. Groce Licensing Engineer Yankee Atomic Electric Company 20 Turnpike Road

estboro, Massachusetts 01581

Dear Mr. Groce:

Enclosed for your infomation is a copy of a letter sent to one of the licensees of a Westinghouse two loop plant.

A similar letter has been sent to the licensees of the othar Westinghouse two loop plants.

Note that the use of the rod bank exchange program has not yet been approved for other than these two loop plants.

Sincerely, J 'lLlvn., +

J ja Dennis L. Zienann, hief Operating Reactors Branch =2 Division of Operating Reactors

Enclosure:

As Stated cc:

See r. ext page 559354 q @ M o g te 19073tg

". Ecber: H. Grcce May 15, 1979 cc

  • '. Laurence E. !'innick, President Yankee Atomic Electric Company 2C iu npike Road Westbcrc, Massacnusetts 01581 Greenfield Cccounity College 1 Col',ece Drive Green #ield, Massachusetts 01301 e

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May 15,1979 Docket No. 50-305 Mr. Eugene R. Mathews, Vice President Power Supply and Engineering Wisconsin Public Service Corporation P. O. Box 1200 Green Bay, Wisconsin 5"305

Dear ilr. i'athews:

The !!uclear Regulatory Commission staff has revietec infornation submitted by the Westinghouse Corporation and two licensees of

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two loop plants regarding the use of the rod bank exchange (rod swap) method to verify shutdown margin for two locp Westinghouse nuclear steam supply systems.

Based on our review, we approve the use of this method as an alternative to the boron exchange method of verifying shutdown margin for these two loop NSS$s providing the following conditions are met:

1.

The analysis for predicting rod worths and shutdown margin is performed by Westinghouse using the technique proposed to the NRC at the September 1978 meeting.

2.

All rod banks are raeasured.

3.

Written approval is obtained from the NRC prior to use of the rod exchange method. Approval will be t.ased on NRC review of your review and acceptance criteria for these rod exchange tests. Once we approve your review and acceptance criteria, they need not be resubmitted unless changed.

4.

The test procedure for this method is that icentified in a Westinghouse letter to NRC dated April 24, 1979.

To0 60801 91 5595E6

Bir. Eugene R. fiathews May 15,1979 5.

Within 45 days after the first verification of shutdown margin using the rod bank exchange method, the test data is formally submitted to the fiRC.

This approval is only for plants with a two loop fiSSS.

Acditional information and further review will be required before we can reach a conclusion on the use of this method for three and four 1 cop plants.

Sincerely,,

//

m 4 ~. ~, -

A. Schwencer, Chief Operating Reactors Branch 71 Division of Operating Reactors cc:

See next page 55 % 57

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