ML19326C058

RO 50-313/76-07:on 760506,as Built Control Room Ventilation Sys Isolation Damper Does Not Meet Closure Time.Caused by Design Deficiency.Control Sys Mod Will Assure Isolation Damper Meets 3-s Closure Time Requirement

ML19326C058
Person / Time
Site:	Arkansas Nuclear
Issue date:	05/19/1976
From:	Cook R ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML19326C055	List: ML19326C058
References
NUDOCS 8004180733
Download: ML19326C058 (4)

Text

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LICENSEE EVENT REPORI s

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NAME LCENsE NUMDFD Y E T

IAIRIAIRIKlil l O101-10101010101-10101 l 41 1 l l l 111 1 10111 si 1

7 89 14 15 25 28 30 31 32 T7P CATEGORv 00CKET NUMBER EVENT DATE AEPORT DATE E CONI l I

I LTJ I LI 1015101-1o1311131 loisloisl7161 toisii 1917161 7 8 57 58 59 80 61 68 69 74 75 80 EVENT DESCRIPTION UE lDtAring Yokiine Pfevenkive MtnlenaN:e 'll w&S hund thal lhe &S-bu'Ik tonkrel Syskem [op.

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@ lContTot bm Vewkilation System did m.t. agree with desiq crawing. biew sLowe4 eve *if l 80 3

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@ l btAI!k per desiqw k,he sut.klen damper which closes on k'ok radiakion tigmal do e'sol&ke cankro!

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@ l room will no[ meel cloiure kime retu remenk of 3 Seconds &S Toet kd s w FIAR Volo..

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@9l o. *).84 9. Mod;ficati. ie syskew will be made le meet closure tin e. (50-313/76-7) l 80 7

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7 89 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION

@ lDesi.w and ove-ooerali.wal fedine. omaram did not nei. ire closure time festa, c,0 suctiew I 7 89 80 N Idampers which Wot4lj have idenkified desiqw de(icieHCv. Modification lo the control l

7 89 lsestem will be_ made to meet closure fime Yeouireavens.

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10 11 44 45 PERSONNEL EXPOSURES 80 NUMBE R TYPE DEsCAIPTON DE 1010101 LZJ l

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I 7 83 11 12 13 PERSONNEL INJURIES NUMBEA DESCRIPTON 8 1o1 0101 [_

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u 7 89 11 12 80 OFFSITE CONSEQUENCES EL NA 1

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"m I-Reportalilo Occurrence Report thi.

50-313/76-7 l

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Report Date: 5/19/76

.i. Occurrence I)aty;: 5/6/76 4

Facility:

Arkansas Nuclear One-Unit 1 Russc11ville, Arkansas 72801 s,

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Identification of Occurrenec:

Control Room Ventilation System isolation damper does not meet closure time.

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Conditions prior to Occurrence:

Steady-State Power _

Heactor Pow'er o

FlWt h llot Standby Nec Output.

O We Cold Shutdown Percent of Full Power o

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Refueling Shutdown X

Load Changes During Routine Power Operation Routine Startup t

i Operation Routine Shutdown l

Operation i

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Other (specify) i 7.

Description of Occurrenec:

1 During routine preventive maintenance it was discovered that the as-

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j built control system for the Control Room Ventilation. System did not i

agree with design drawing. A design review showed even if built per j

design drawing the suction damper which closes on high radiation to isolato the control room would not meet the closure timo requirement of l

3 seconds as' stated in the FSAR, Volume IV, page 9.49.

Attachuent "C" l'

.!! arch 23, 1976-NSP-10, Rev. 4 Page 2 of 4 I

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!!eportatile Occurrence I:cport No..50-313/76-7 o

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Desi;!nat ion of Appa rent Cause_ of,,0c,cu,rrenec:

j Design Procedure I

!!anufacture Unusual Service Condition including linvironmental Installation /

Construction Component Failure j

Operator f

Other (specify)

Design and pre-operational testing program failed to require closure time testing which would have identified the design deficiency.

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9.

Analysis of Occurrence:

These dampers close to isolate the control room in order that the dose to the operators will be minimized. No direct effect on the health or safety of the public can result due to this occurrence as only the operators may be affected.

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Pbrch 23, 1976 NSP-t o, Rev. 4 Page 3of4 g

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g licportable Occurrence !!cport ilo.

50-313/76-7

10.. Corrective Acth;r,:

A modification will be made to the control system to assure t!ie damper

' meets the closure time of 3 seconds.

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Failuro Data:

Control system manufacturer:

j Powers Regulator Company l

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At ta cInnent "C" Flarch. 23, 1976 NSP-10, Rev. 4 Page 4 of 4 4

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