ML19263C325
| ML19263C325 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/16/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 7902210249 | |
| Download: ML19263C325 (1) | |
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VIRGINIA ELECTRIC AND PCMER COMPANY February 16, 1979 Mr. ' James P.~.0'Refily, Director Serial No~. 575B Office Inspection & Enforcement PSELC/LCK:LO914
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U. S. ' Nuclear Regulatory Commission Region 11 Docket Ho. 50-339
-101 Marietta Street,- Suite 3100.
-Atlanti, Caorgia' 30303
Dearfrk.O'Reilly:
In accordance with'10CFR50.55(e), the NRC, Region II, was_ notified on October 6,1974 that-the North Anna Unit.2 Axial' Power Distribution Honitoring System (APDb15) provided by Westinghouse Electric Corporation contsined 'a non-conservatism
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capable. of causing in error in the calculation of LOCA peaking factor shape limitsc This error was caused by a: calculational round off which increased the set point above the. desired value by as much as 1.1%.
This deficiency will be correctea by implementing an administrative procedure 3
wMch lowers the inputEvalues used by the APDNS 1.5% in order to accunodate the no_n-conservatism in the limit setpoint, values calculated by the APDMS.
This administrative procedure,is presently being used on North Anna Unit 1.
(It.should also$ba mentioned that-safe. operation of -the' unit could continue without AP0 tis since full backup capability is provided on the unit's P250 plant computer 1 system or by manual calculations.s -This backup capability is provided in accordance with the proposed horth Anna Unit 2 Technical Specifications Section
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Sir.ce this deficiency has now been conservatively taken into account, and since alternate acceptable means~ of performing axial power distribution surveillance are available, It ~is considered that this item is. resolved.
We consider this to be the final report under the;provisiens of 10CFRS50.55(e).
If you require any further information at this time, please contact us.
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Senior Vic/ President - Potyar/ Station s
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[Mr. John G.l Davis, Acting Director cc:
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.k.r. Harold R. Denton, Director.
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Office of' Nuclear ~ Reactor Regulation 9
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