ML19340C108

Forwards Corrections to XN-NF-77-57,Suppl 1,Exxon Nuclear Power Distribution Control for Pwrs:Phase 2, June 1979. Revisions Do Not Change Intent of Related PDC-2 Procedure But Clarify Requirements

ML19340C108
Person / Time
Site:	Cook
Issue date:	11/04/1980
From:	Owsley G SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER
To:	John Miller Office of Nuclear Reactor Regulation
References
GFO:150:80, NUDOCS 8011140002
Download: ML19340C108 (3)

Text

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E@ NUCLEAR COMPANY,lnc.

2101 Horn Rapids Road P. O. Box 130. Richland. Washington 99352 Phone- (509) 375 8100 Telex: 15 2878 November 4, 1980 GF0:150:30 str. James R. Stiller, Chief Standardization 5 Special Projects Branch Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Reference:

XN-NF-77-57, Supplement 1, '?xxon Nuclear Power Distribution Control for Pressurized Water Reactors: Phase 2," June 1979

Dear Str. Stiller:

During the recent implementation of the PDC-2 procedure in D. C. Cook Unit 1, it was determined that two equations in the referenced report required corrections. The corrections do not charge the intent of the procedure as approved by the NRC, but rather clarify the cequirements.

The corrections and a discussion of the corrections are attached.

Sincerely, i'

, ,L t.. Cupc~ m-G. F. Owsley, 3 tanager Reload Fuel Licensing GFO :Stf .(: g f Attachment As noted CC: Str. St. S. Dunenfeld (USNRC) 0

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AN AFFILIATE OF EXXON CORPORATION 801114000 1 C_

Exxon fluclear Power Distribution Control For Pressurized Water Reactor, Phase II -

Corrections to Xfi-t1F-77-57, Supplement 1 Corrections are required for two equations shown in Xft-tiF-77-57, Supplement 1. The corrections are as follows:

Section 4.2.2.2.f.2 (Page 32)

The equation I

F (Z) x V(Z) max. over Z of 2.20 x 100 P>.5 p x K(Z) should be corrected to F' (Z) x V(Z)-

max. over Z of 2.20 -1 x 100 P z .5

.- p x K(Z) ~ .)

Section 3.2.6, APPLICABILITY (Page 36)

The equation 2.20 P K(Z)

, APL = crn over Z of P>.5 FgZ)xV(Z)x100%

should be corrected to APL = min over Z of 2 0 P>.5 Z) x 100~

t i

l l

Both of these equations are related to the power level at which the power peaking limits can be protected with the PDC II operating procedures.

The equations are of significance only if there is insufficient margin for continued operation at the power level for which the target flux has been determined. In the event sufficient margin does not exist, appropriate action must be taken to insure that the core power distribution remains within the specified limits Either the core power must be reducec, or an alternate measurement system, such as APDMS, must be utilized. The maximum allowable power in the absence of alternate measurement systems is propor-tional to the power level at which the target flux is measured. These equations have been corrected to accurately reflect the required propor-tionality.

The corrected equations are consistent with current implementa-tion of the PDC II operating requirements.

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