ML20235H424
| ML20235H424 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 09/18/1987 |
| From: | Hunsader S COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| 3593K, NUDOCS 8710010048 | |
| Download: ML20235H424 (3) | |
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. Commonwealth Edison-l / One Fir.:t National Plaza, Chicago, Illinois J Address Reply to: Post Offica Box 767 v
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Chicago, Illinois 60690 0767.
September 18, 1987 Mr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 Attn: Document Control Desk
Subject:
Byron Station Unit.2 Braidwood Station Units 1 and 2 Initial Test Program-Startup Test - Power Reactivity Coefficient Measurement NRC Docket Nos. 50-455, 456 and 457 Reference (a): December 1, 1986 S.C. Hunsader letter to H.R. Denton
Dear Mr. Murley:
Reference (a) provided a response to a request for additional information based upon changes that had been made in Amendment #47 to the Byron /Braidwood FSAR.
In subsequent conference telephone calls, questions were asked by the NRC Staff with respect to Commonwealth Edison's response j
to Item #1 included in reference (a). The purpose of this letter is to" I
answer those questions to provide a satisfactory resolution.
The NRC Staff questioned why the new criteria in Table 14.2-82 in Amendment #47 disregarded the sign of the measured power coefficient-verification factor by taking its absolute value. This would appear to allow the measured power coefficient to be either positive or negative, as long as its magnitude is within 1 0.5'F per percent power of the predicted power coefficient verification factor.
i The answer to this matter is provided in Attachment A.
To determine the power coefficient, an equation is used which is the absolute value of the difference in absolute values of a measu' red (C ) and a M
predicted (CP) power coefficient. verification factor. This relationship is taken from the Westinghouse guideline procedure on power coefficient measurement and the result is expected to be less than or equal to 0.5"F per-percent power.
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T.E. Murley September 18, 1987 To ensure that any unexpected result is not overlooked, (such as, CM being a positive number) a " note" is included in the applicable startup test procedure at the Byron and Braidwood Stations before acceptance criteria 4.1, stating that CM is expected to be negative and CP is expected to be positive. Any deviation from this or any unusual results are required to be reported to the " Station" Nuclear Engineer for evaluation and action. Therefore the measured power coefficient is maintained "less than" rather than "within plus or minus" 0.5'F per percent power.
)
.please address any questions concerning this matter to this office.
Very truly yours, l
J(.
_mA S.C. Hunsader-Nuclear Licensing Administrator cc:
L. Olshan S. Sands Byron Resident Inspector Braidwood Resident Inspector Region III i
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., 4. 0 '- ACCEPTANCE CRITERIA c
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NOTE i
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The value of C" is expected to be a, negative-number and the value of C is expected to be a 3
positive number. Any deviation from the above j
should be~ reported to the Station' Nucle'ar Engineer ' *'
.s
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- for evaluation.
..i 4.1 The absolute value of the difference between the absolute value of the measured doppler only power coefficient verification factor (Cb and the absolute value of the predicted doppler only power coefficient verification factor (C ) is less than or equal to P
0.5 'F/%.
In equation form:
[
CP f,0.5 'F/% Power.
1 I
4a
.A3PROVEJ
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.(007EU/0029U) a
.