ML20072P394
| ML20072P394 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 03/28/1983 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, 6276N, 83-02, 83-2, NUDOCS 8304040239 | |
| Download: ML20072P394 (2) | |
Text
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Commonwealth Edison i
/ One Firo N;tional Plat Chic]O. Illmois i
7 Addr:ss R; ply to: Post Ot.ics Box 767
/ Chicago. Illinois 60690
-s March 28, 1983 Mr. James G. Keppler, Regional AcministratGr
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Directorate of Inspecticn and
- x U.S. Nuclear Regulatory Commission 21-
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Enforcement - Region.Ill
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799 Roosevelt Road Glen Ellyn, IL 60137
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Subject:
Byron Generating Station-Units 1 and 2 Braidwood: Generating Station Units 1 gridz2 Westinghouse Gata Valve Mater 0perators. 7
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z NRC Occket Nos. 50-454, 50-435, SG.-45f, and 50--457
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Dear Mr. KeppInt:
On February 22, 1903, Commonwealth;Edisati notified Mr.
J.'M.
Hinds of your of fice of a cotential significant deficiency'perated gute
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reportable pursuant to lj_CFR 50.5jiled regarding Westinghouse moto_r c valves at Byron and Braidwood su tions.
This is the-30-day ~ report:On that deficiency.
For your tracking purposes it has_bben' numbered 63-02 for Byron and 83-02 for Braidwood.
Our delay in submittal of, this 30-day report. until March 28, o
1983, was discussed with'Pr. R.,C. knop on' Parch 2 5.- 1l963.
Description of the Deficiency Westingnouse has inf ormed us o'f the( pdtentie,1;f6r,'certain' Westinghouse manuf actured gate valves to indicate they are " Closed'.' prior to the valva disc fully isolating floi..
Should tiie valve' stall or bind t
following the premature indication, the' operator'would have an inac@ rd a indication of true valve position.
l A geared limit switch rotor as pet _to provide an electrical bypass of the OPEN torque switch at the beginniog of the 6pening stroke.
On a closing stroke, this switch changes st. ate befor'e, the. flow path ;is completely blocked.
As a result, it is likely-that monitor and/or.
indicator lights also operated by that rotor will in'dicMe val've closure'
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slightly before the flow path is completely shut off.
If the valve were to stop between this setpoint and the full shut of f position, a flow path. -
through the valve could exist even though a CLOSE indication had been achieved.
m 8304040239 830320 PDR ADOCK 05000454 S
PDR ft
J. G. Keppler March 28, 1983 The following valves are affected by this deficiency and must be modified to provide positive indication of full closure:
6 SI8802A,B SI8807A,8 SI8835 SI8923A,B e
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/,.i N SI8809A,8 SI8924 SI8840 CV112D,E
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CV8105 SI8806 CV8106 RH8716A,8 RY8000A,B SI8808A,B,C,0 4
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SI8821A,B RH8701A,8
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SI8801A,B RH8702A,B
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SI8803A,B
" Analysis Of Safety Implications
'Il-N> Incorrect valve indication by itself or in combination with f
V [",I' 9nother single failure could cause unacceptable operation of a safety
'related system.
For example, an undetected failure of a SI valve to i
fully close could allow a flow distribution in the ECCS that has not been s,
analyzed in the FSAR.
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~ Corrective Action _
,r For'411 the affected valves, wiring will be added to an alternate rotor t f the geared limit switch within the valve operator so that! the close s'..gnal can be obtained independent of the OPEN torque s
switgh bypepp setpoint.
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These' changes will be completed prior to fuel load on each unit.
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,Please' direct any questions you may have regarding this matter to thi.s, office.
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2 Very truly yours
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T. R. Tramm f
uclear Licensing Administrator 1m 6276N
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