ML20128D843

Advises of Recent Insps Have Determined That APRMs Found to Indicate as Much as 8% Less than Calculated Thermal Power. Guidance Requested for Amount of Deviation Between APRM Indicated Power & Calculated Power Permissible by TS

ML20128D843
Person / Time
Site:	Monticello
Issue date:	12/05/1973
From:	Fiorelli G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	Grier B US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9212070401
Download: ML20128D843 (2)

Text

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ATOMIC ENERGY COMMISSION y

T DIRECTOR ATE OF REGULATORY OPERATIONS

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REGION lli

,#%s 08" 799 ROOSEVELT ROAD wm GLEN ELLYN. ILLINOIS Sol 37 (Sit) 066-3600 December 5, 1973 B. H. Grier Assistant Director for Construction and Operation, Directorate of Regulatory Operations, Headquarters APRM CALIBRATIONS Recent inspections 1/ have determined that APRMs have been found to' indicate

.j as much as 8% less than the calculated thermal power. These non-conservative variances affect the trip settings of the rod block rt.aitor and over power protection system settings. Consequently, such conditions do not meet the intent of the limiting safety system setting provided in the Technical.

Specifications. We consider this matter to be generic and deserving of your review. We feel that some acceptable tolerance for the APRM-calculated power variance should be factored into the Technical Specifications for BWRs. For facilities currently in operation, guidance is requested for the amount of deviation between APRM indicated power and calculated power permissible by Technical Specifications.- We request this latter consider-l ation be given priority attention.

l 4l0% S lllS Gaston Fiore111, Chief Reactor Operations Branch l

Attachment:

List of References I

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H. C. Dance, RO:III J. G. Keppler, RO:III e

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1/ See references 5, 6, and 7.

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9212070401 731205 PDR. ADOCK 05000263 G

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References:

1. ' NSP letter to A. Liambuss'o dated 5/25/72.

2.

J. J. Shea Memo to Files (Docket No. 50-263) dated 5/14/72.

3. -NSP letter to A..Cumbusson dated 8/4/72..-

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RO. Inspection Report No. 050-263/73-01 Paragraph 7.

-5.

RO Inspection Report No.1050-254/73-04.

6. -RO Inspection Report _No.- 050-254/73-05.

7.- RO Inspection Report No. 050-237/73-05.

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