ML19246A543

Forwards Environ Monitoring & Ecological Studies Program 1978 Annual Rept, Vols 1 & 2

ML19246A543
Person / Time
Site:	Prairie Island
Issue date:	06/29/1979
From:	Ward E NORTHERN STATES POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19246A544	List: ML19246A543 ML19246A546
References
NUDOCS 7907030272
Download: ML19246A543 (1)

Text

Qv Wisconsin Electnc ecw cc.m 231 W Y!CHIGAN. P,0 BCV ::45 v!LA AUMEE Al 53:^1 June 20,1979 Mr. Harold R. Denton, Director Office of "uclear Reactor Regulation U. S. NUCLEAR REGULATORY CO?f1ISSION Washington, D. C. 20555 Attention: Mr. A. Schwencer, Chief Operating Reactors Branch #1 Gentlemen:

POINT BEACH UNIT 2 CYCLE 6 STARTUP PHYSICS TESTING - ROD WORTH MEASUREME"TS REPORT Attachment A to our letter of May 24, 1979, reported the results of the Unit 2 beginning-of-Cycle 6 rod worth measurements which employed the

" rod swap" methodology. As a result of discussions with a member of your staff it was discovered that the formulation of Section 3.2 of the Rod Worth Measurements Report was not consistent with the equations submitted to the NRC by Westinghouse in November 1978. The results presented in Table 2 of the report should accordingly be changed to reflect the -1978 fomulation.

Specifically, the equation and definitions presented in Section 3.2 should read as follows:

Wf = 1/ -ai-(2x)(ap2)+Wfwhere:

p Wf = The inferred war .h of Bank X, pcm W = The measured worth of the reference bank, Control A, from fully withdrawn to fully inserted with no other bank in the core.

3x = A design correction factor taking into account the fact that the presence of another control rod bank is affecting the worth of the partially inserted reference bank, a;2 = The measured worth of the reference bank from its elevation, at which the reactor is just critical with Bank X in the core, to the eference bank fully withdrawn condition.

This ucrth cf the reference bank is measured with no other bank in the core. Therefore, the ax correction factor is . ; J, r [

used.

7907030372_ D h j

R Mr. Harold R. Denton - Page Two June 20,1979 api = The measured worth of the reference bank from the fully inserted condition to ti.a elevation at which the reactar was just criticai prior to the worth measurement of Bank X. In the test api is zero.

e W{ = The worth of Bank X from the iriitial position (before the start of the exchange) to 228 steps. This worth is raeasured by the normal endpoint worth method.

Using this formulation, Table 2 should read as follows:

TABLE 2 COMPARISON OF INFERRED / MEASURED BANK WORTHS WITH OESIGN PREDICTIO;.S UNIT 2 CYCLE 6 "X(pcm) W (pcm) W (pcm)

Bank X (ck) g , g, CC 658 0.977 40 966 1005 -3.9 SB 815 0.997 20 776 807 -3.3 SA 459 1.026 23 1121 1125 -0.4 CD 902 0.994 34 706 742 -4.3 CB 959 1.041 39 610 606 +0.7 CA -

1569* +0.6 1560 TOTAL 5748 5845 -1.7 I

• 'f

.'R = 1569 P

• • (WI - W ) 100 W

X As you will note, the conclusions of the May 24, 1979 letter are unchanged. The review and acceptance criteria for the measurements were met and the adequacy of the nuclear design rod worth predictions was demon-s tra ted.

Very truly yours,

(' . W. Fay, Director huclear Power Department

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