ML20128D871

Provides Info Re First Reload of Monticello Core as Adjusted During Apr 1973 Following Reactor Shutdown & Fuel Insp. Reduced Value Is Above 0.01 Delta K Minimum Required by TS & Acceptable

ML20128D871
Person / Time
Site:	Monticello
Issue date:	05/08/1973
From:	James Shea US ATOMIC ENERGY COMMISSION (AEC)
To:	US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9212070408
Download: ML20128D871 (2)

Text

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UNITED STATES f0S i ATOMIC ENERGY COMMISSION ,

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WASHINGTON, D.C. 30549 {

I lV} G MAY 8 W3 Files -(Docket No. 50-263) "

TIUtU },7 emann, Chief, ORB #2, L

.Ti FIRST RELOAD OF NTICELLO CORE AS ADJUSTED DURING APRIL 1973 FOLLOWING 1 REACTOR SHUTDOWN AND FUEL INSPECTION (NORTHERN STATFS POWER COMPANY)

By letter dated February 20, 1973, Northern States hver Company (NSP) requested authorization to use up to 28 Reload 1 fuel bundles to replace fuel bundles revealed to be leaking fission product gases excessively.

The first partial refueling during March-April 1973 was, _according to NSP, to assure the availability of the plant at high power for approxi-mately an annual cycle while reducing the core off-gas to the lowest practical value. On the basis of our review of the information pro-vided by the licensee, we authorized, by a letter dated March 5,1973, the use of 28 Reload 1 fuel bundles as- replacements for leaking fuel bundles and retention of 64 of the original 216 temporary fixed poison curtains.

By letter dated April 13, 1973, NSP informed the AEC that the average core exposure at the time of reactor shutdown in March was 7100 MWD /STU, slightly greater than the predicted value of 6800 MWD /STU originally stated as the exposure for which the referenced reload core conditions were based. Therefore, revised core loading plaa was selected for cycle 2 consisting of 20 Reload 1 fuel assemblies with 464 initial core assemblies and 44 temporary control curtains instead of 64 as planned prior to shutdown.

We note that the shutdown margin with the most reactive rod fully with-drawn at the time when the original core was most reactive was 0.02 delta k/k as reported in the FSAR and that the initially planned reload core for cycle 2 would retain - this shutdown margin. According ta calculated results presented in the most recent letter dated April- 13,1973, the shutdown margin under similar circumstances for the revised cycle 2 core-vill be reduced to 0.015 delta k/k.The reduced value is above the 0.01 delta k minimum required by the Technical Specifications and therefore is acceptable.

o nuo 9212070408 730508 PDR ADOCK 05000263 p PDR

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'.. 6 Files g g3 Our conclusions, as stated in our authorization dated March 5,1973, remain unchanged and no further evaluation or action with regard to the as-loaded core configuration for cycle 2 is warranted or planned.

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/OperatingReactorsBranch#2 Directorate of Licensing cci AEC PDR local PDR DJSkovholt, L:0R TJCarter, L:0R R0 (3)

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