ML19259D215

Interim Deficiency Rept 79-14 Re Asco Solenoid Valves Becoming Inoperable When Exposed to Radiation Doses & Temps Specified in Purchase Requirements.All Corrective Actions Taken & Final Interim Rept Will Be Submitted by 791221

ML19259D215
Person / Time
Site:	Grand Gulf
Issue date:	10/10/1979
From:	MISSISSIPPI POWER & LIGHT CO.
To:
Shared Package
ML19259D213	List: ML19259D212 ML19259D215
References
NUDOCS 7910170382
Download: ML19259D215 (2)

Text

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I';TERIM RINRT FOR REPCRTA312 OZyICIINCY SC. 79/14 AS DEFINID IN 10 CFR 30.33(e)

P00R ORGINAL I. Cescriotion of Deficiencv As par: of :he evaluacion of II Sulletin 79-01A, i: was necessary to concac: our suppliers of air ac:ua:ed valves :o see if :he solenoid valves in question were used en Our valves. In response :o cur in-quiry, the Henry ?ra:: Cc=pany sen; a letter sta:ing : hey had repor:ed a potential defec: vi:h :he solencids under 10 CTR, par: 21, sec:1:n

. n. o .

The problen vi:h the solenoids is :ha: : hey have a naxinun ra:ing of AX10 3 rad in:egrated dosacs and 200 F te=perature. Our specifica:icns 0

require a rating of 1.6X1CI rads in:egrated desage and 330 ? tenper-a:ure.

These solenoid valves or che actuators are a critical par: of the systen as the pneu=acic ac:ua:or syste= is designed to open the valve and hold it open when the ASCO solenoid valve is energized. When deenergized, i:

is designed to vent air frem the cylinder :o allow a heavy coil spring to close the valve and hold it closed. For exa=ple, if :he ASCO solenoid valve is energi:ed bu: is incperable, with the valve in :he open position, deenergizing :he ASCO solencid valve vill not cause :he valve to close.

Conversely, if :he ASCO solenoid valve is deenergized but is inoperable in :he closed positica, energi:ing 1: vill not cause che valve to open.

Af ter reviewing :he functica of valves using the ASCO solenoid valves in ques:ica, 1: has been decernined that sone valves are loca:ed in safety-related systens and : heir operation during an accident is required.

7910170 lb351-

Of fica of Inspec:1:n and Infor:enen: Ocecher 'O, 1979 U. S. ::u:laar .ca gula:::y CO :nissi:n AIC4-79 /113 II. Safe:y In:lications

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he safety opera:1:ns of the plan:. in addi:ica, i: cens:1:u:ed a significan: deficiancy in :he design of :he valve in ::at :he design did no: : nfor= :o :he dasign ::iteria included in the purchase spect-fica:1 n.

III. C7: e::1re A::1:n Takan All cc rective ac:1ca, including ac:1:n :aken : preven: recurrence vill be subni::ad :: /cu in a final rep :: by Ceca =ber 21, 1979.

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