ML19329B097

Final Deficiency Rept Re Broken Valve Actuator Yoke on Isolation Valve MU-HV66B.Cast Iron Yokes Replaced W/Steel

ML19329B097
Person / Time
Site:	Davis Besse
Issue date:	10/27/1976
From:	Roe L TOLEDO EDISON CO.
To:
Shared Package
ML19329B081	List: ML19329B083 ML19329B089 ML19329B094 ML19329B095 ML19329B096 ML19329B097
References
137, NUDOCS 8001300683
Download: ML19329B097 (2)

Text

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TOLfiDO 1

EUEE3ON Serial No. 137 -

LOWELL E. ROE Vies fveneeat Fw..= oe. easement l

,0ctober 27, 1976 ,

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Docketi No. S0-346 -

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t Mr. James G. Keppler i

,. Regional Director, Region III Directorate of Regulatory Operations '

, U.S. Nuclear Regulatory Commission - ,

799 Roosevelt Road

. Glen Ellyn, Illinois 60137 -

Dear Mr. Keppler:

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l This le.tter is submitted in accordance with 10CFR 50.55(e) as a final report regarding the Davis-Besse Nuclear Power Station-Unit I reactor c coolant. pump seal injection isolation valve yoke material deficiency, s

which was reported by telephone conversation between our Mr. C. Domeck and your Mr. F. Jablonski on October 1, 1976.

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Previously reported by phone on 9/20/76 and by interim report dated 10/25/76 was a significant deficiency of a broken valve actudt'or yoke on

. isolation valve Tag No. MU-HV66B. This valve ;.'as supplied to Toledo

, ,. Edison Company by Babcock and Wilcox Company as part of.the NSSS and is

a Velan valve with a Kieley & Mueller Incorporated valve actuator j ~ assembly. . .

Description of the Deficiency

• During Toledo Edison Company investigation of possible reasons for the above yoke failure, we were informed by Kieley & Mueller that on this l , order Velan had requested a standard actuator assembly,.which has a cast iron yoke, for seven (7) valves to be used on the Davis-Besse Station Unit 1. These seven valves are shown on Figure 9-21, Revision 14 of the j FSAR and are Tag Numbers:

HU-HV3, which is a 2b" gate valve l MU-HV33, which is a 2h" gate valve HU-HV38, which is a 1" globe valve MU-HV66A, which is a 1 " globe valve HU-HV66B*, which is a lb" globe valve k

• HU-HV66C, which is a lh" globe valve MU-HV66D, which is a ly" globe valv 001300

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• = Kieley 5 Mueller also stated that the cast iron yoke is satisfactory for valve closure forces involved and the y'oke material supplied is not directly related to the breakage of the cast iron yoke.

$twasalsolearnedthatKieley&Muellerisnormallyrequestedto s'u pply actuator assemblies with steel yokes, instead of their standard cast iron yokes, when the application has seismic requirements.

The possible deficiency of cast iron versus steel yokes was brought to .

the attention of Babcock and Wilcox who confirmed the deficiency on 10/1/76 that the yokes should be steel since th.ey are for seismically qualified valves. . .

Corrective Action Taken -

7 The seven valves in question are the only valves at the Davis-Besse

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facility with Kieley & Mueller actuators; B&W has arranged with Velan to

, replace the present seven cast iron yokes with seccl yokes. The replace-ment yches are on site and are expected to be completely installed by

.the end of October.

Safety implications p ~

The seven actuators are installed in nucicar safety related applications as containment vessel isolation valves. The corrections of the defi-ciencies as described above prior to the operation of the facility assures that the health and safety of the public are not jeopardized. ,

,Yours very truly, -

AW ~ W l bj pc 29/25-26 .

cc:

Dr. Ernst Volgenau, Director Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission ,

Washington, D.C. 20555 .

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