ML20052E980
| ML20052E980 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 04/27/1982 |
| From: | Root R WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Faulkenberry R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, G1-82-162, GO1-82-0162, GO1-82-162, NUDOCS 8205110588 | |
| Download: ML20052E980 (2) | |
Text
Docket Nos. 50-460/513
,4 50.55(e) Report gyggjvE0 JWn in Washington Public Power Supply System P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 99352,, J509) 372-5000 a f a f}! l: gt m
April 27, 1982 G01 0162 g,.s.- !.
Mr. R. H. Faulkenberry Nuclear Regulatory Commission 9
e Region V 1450 Maria Lane, Suite 210 C.
Walnut Creek, California 94596
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RECEIVED S um. 01992> \\
Subject:
SUPPLY SYSTEM NUCLEAR PROJECTS NOS 1 AND 4 MAY 1 DOCKET NOS. 50-460 AND 50-513
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REPORTABLE CONDITION 10CFR50.55(e)
EMyf INDUCED NEUTRON FLUX ERROR - STATUS REPORT g
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Reference:
1)
Telecon, TJ Houchins, Supply System 4
N to DF Kirsch, Region V, NRC dated November 13, 1980 2)
Letter, DW Mazur, Supply System to RH Engelken, NRC same subject, dated December 12, 1980 3)
Letter, DW Mazur, Supply System to RH Faulkenberry, NRC, same subject, dated July 28, 1981 4)
Letter DW Mazur, Supply System to RH Faulkenberry, NRC, same subject dated December 28, 1982 In reference 1) the Supply System reported the existence of a reportable condition to your office under the provisions of 10CFR50.55(e). References 2), 3) and 4) were interim status reports on the subject condition.
The concern is related to errors in the measurement of core neutron flux during certain postulated accidents. The status of the resolution of this concern to date is a follows.
STATUS The Project has decided following indepth reviews and correspondence with Babcock and Wilcox (B&W) to implement a hardware change to provide an alternate measurement of core power.
The hardware change provides for increased conservatism in measuring core power.
The change would be to measure the temperature differential ( AT) across the core via cold and hot leg temperatures. Core power would be computed from the AT and pump status then auctioneered with the neutron detector output.
In the case of an overcooling event the 6T would be conservative by overestimating power. Conversely, in the case of an overheating event, the neutron detectors would be conservative by overestimating power.
Thus, for either event, the maximum output would be provided to the reactor trip bistables.
8205110588 820427 3
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R. H. Faulkenberry April 27, 1982 Status Report G01-82-0162 Page 2 B&W has been directed by the Project to proceed with the implementation of the alternate power measurement system design, analysis, and installa-tion. The implementation schedules ha w not been developed as of the time of this letter. Therefore, we will continue to provide your office with semi-annual status reports on our progress.
If you have any questions or desire further information, please advise.
R. W. Root Acting Program Director RWR:MER:Im cc: CR Bryant, BPA/399 EW Edwards, Bechtel/860 V. Mani, UE&C/896 V. Stello, Director of Inspection, NRC A. Toth, NRC FDCC/899 l
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