ML19317F362

RO 287/76-01:on 760113,charcoal Absorber Filters in B Penetration Room Ventilation Train Found Inoperable During Leakage Test.Caused by Excessive Moisture Collected During Quarterly Sys Test.Filter Replaced.Test Procedure Revised

ML19317F362
Person / Time
Site:	Oconee
Issue date:	02/12/1976
From:	DUKE POWER CO.
To:
Shared Package
ML19317F355	List: ML19317F354 ML19317F362
References
RO-287-76-01, RO-287-76-1, NUDOCS 8001140616
Download: ML19317F362 (2)

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o Rehort No. :' }RO-287/76-I .

~ Report Date:- February 312, 1976

-Occurrence-Date:fJanuary13,I1976' .

'l Facility: ~ ~ Oconee' Unit 3, Seneca, South. Carolina

' Identification of Occurrence: Charcoal absorb'er filters-in B Penetration

> ~ Room ventilation train found inoperable during test.:

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Conditions Prior to Occurrence: Unit at 100. percent' full power. l

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Description of^ Occurrence:- ,

Un: January 13,';1976, annual "in place" leakage testing was performed on

the Penetration. Room'Ve'ntillation System. The "A" train of the Penetration

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L Room Ventilation Sy' stem (PRVS) met the acceptance _ ctiteria of Technical f ' Specification!4.5.3.2; however,.tne "B" train ~ charcoal filter unit did not-

-meet the' acceptance criteria.~ Maintenance. action was immediately initiated,

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andinew charcoal filters were installed and tested within eight hours.  :

i iDesignation of Apparent Cause of Occurrence:

The apparent-!cause~of the/ failure of the "B" train PRVS charcoal filter

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j- unitivasidue to excessive moisture which:had collected on the unit. This

!' ;probably/ occurred during a quarterly system test which was conducted when  ;

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Lsteam leakslexistedgin'the penetration room.-

Analysis of Occurrence:

.In-the eventLof.al postulated loss _of. coolant: accident, it was assumed.

in- thf Safety: Evaluation Report that 50 percent of Reactor Building leakage L would' occur in the Penetration Room. Two; redundant trains of Penetration

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JRoomlventilationLare provided:to filter this leakage to reduce the amount Jof'. radioactive materialJwhich would. reach the atmosphere. The charcoal filters were assumedito be 90% efficient in the removal of iodine. In this

a.  : incident, Lone. train of the PRVS charcoal . filters did not meet ' the -

. requirements"of Technical Specification 4.5.3.2'in that it'did not remove.

-99% of thel Freon-112fwhich was used in'the. test. The redundant train of'

~ Jthe.PRVS was7 tested, and its operability was demonstrated. The affceted trainfwould also hav'e been partially ~effectivejin'the unlikely event of-a

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?lossio'f coolant-accident. EIt'is, therefore,' concluded ~that the health

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- and safety 'of :the' public was not affected by this sincident. q l

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. February 12, 1976

Page 2 Corrective Action:-

The'"B" train PRVS charcoal filter.was. replaced and satisfactorily tested.

In addition, the procedure for the quarterly system. test will be changed to require that.the' filter housing' drain valves are opened for ten minutes ,

prior.to the performance of the test. This will prevent any excess-moisture _from passing through the filters.

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