ML19289D173
| ML19289D173 | |
| 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 | |
| 024B, 24B, NUDOCS 7902230159 | |
| Download: ML19289D173 (1) | |
Text
vaa u u::= : as em c:vuw February 16, 1979 Mr. James P. O' Reil ey, Director Serial No. 0243 Office of Inspection & Enforcement PSELC/LCK,Jr.:mac:C0913 U. S..Lclear Regulatary Cocmssion Region II Occxet No. 50-339 101 Marietta Street Suite 3100 Atlanta, Gecrgia 30303
Dear Mr. O'Reilly:
In accordance with 10CFR50.55(e), the NRC, Region II, was notified on January 8,1979 that tne Nortn Anna Unit 2 Axial Po er Distribution Monitcring System ( APGaS) providec by Westinghouse Elect-ic Corporation does not account for the in-ccre coveaole cet=cto-Backgroand signal nhei determining tSe axial flux snape, Fj(z).
If a significant sackgrounc ere present during surveillance, tr.e calculation of Fj{:) erouic be ncn-conservative for values greater than 1.0.
Tnis ceficiency will ce corrected by implementing an acministrative procecure requiring the reacter operator en North Anna Unit 2 to review th*
flux traces used by the APOMS in ceder to characterize cetector bact:-our.c levels and flux amolitude. Also the APDMS input values will de acjusted in ordar to conservatively account fer the effects of cetector backgroun3. _This accinistrative procecure is presently seing use: on North Anna Unit 1.
It should also te rientioned that safa Oparatien of the unit could centinae without APGMS since full oackup capability is providea on tne unit's P250 plant computer system wnien now taxes into consiceration tne cetector's tackground signal in the calculatiens, er ty canual calculations. Tnis backup capanility is provided in accordance with the proposed Nortn Anna Unit 2 Tecnnical Specifications Section 4.2.5.
Since tais ceficiency has now caen conservatively ta<en into acccunt, an:
since alternate acceptable means of performing axial power distribution surveillance ara availaola, it is considered that this itec is resolve 3.
ne consider tnis to be the final report under the pravisicns cf 10CFR50.55(c).
If ycu re:;uire any furtaer informaticn at this tir.e, please contact us.
Very,truly jours,
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3elior Vice Presidant - Power Station Engineering anc Ccnstructica N
cc: Mr. Jenn G. Davis, Acting Director D
Office of Inspection f. Enforcesent 9 0
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Mr. Harold R. Denton, Director Office of Nuclear Reactcr Regulaticn 7902230159