05000338/LER-1979-107-03, /03L-0:on 790831,slug of Water Entered Process Vent Blower & Filter B Causing Vent Flow to Decrease to Zero & Blower to Stop.Caused by Water Entering from Spent Resin Dewatering Tank Vent.Water Drained & Filters Replaced

/03L-0:on 790831,slug of Water Entered Process Vent Blower & Filter B Causing Vent Flow to Decrease to Zero & Blower to Stop.Caused by Water Entering from Spent Resin Dewatering Tank Vent.Water Drained & Filters Replaced

ML19275A284
Person / Time
Site:	North Anna
Issue date:	09/28/1979
From:	Cartwright W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19275A281	List: 05000338/LER-1979-107, Forwards LER 79-107/03L-0 05000338/LER-1979-107-03, /03L-0:on 790831,slug of Water Entered Process Vent Blower & Filter B Causing Vent Flow to Decrease to Zero & Blower to Stop.Caused by Water Entering from Spent Resin Dewatering Tank Vent.Water Drained & Filters Replaced
References
LER-79-107-03L, LER-79-107-3L, NUDOCS 7910030459
Download: ML19275A284 (2)

LER-1979-107, /03L-0:on 790831,slug of Water Entered Process Vent Blower & Filter B Causing Vent Flow to Decrease to Zero & Blower to Stop.Caused by Water Entering from Spent Resin Dewatering Tank Vent.Water Drained & Filters Replaced

Event date:
Report date:
3381979107R03 - NRC Website

text

..

NRC F0RM 364 U. S. NUCLEAR REGULATORY N w.m LICENSEE EVENT REPORT CONTROL BLOCK: [l l

l l

ljh (PLEASE PRINT OR TY*f alt. REQUIRED INFORMATION) 1 6

l Vl Aj Nl Al Sl 1l@l 0l 0l -l 0l 0l 0l 0l 0l -l 0l 0lg 4l 1l 1l 1l 1l@l l

lg o

i 7

8 9 LICENSEE CODE 14 15 uCENSE NUM84R 25 26 UCENSE TYPE JO

$7 C.AT 58 CON'T lLg 0l5l0 0l 0l 3l 3l 8Ql 0l 8l 3l 1l 7l 9)@l 0l 9l 2l 8l 7l 9l@

0 1

3euRCE 7

8 60 61 DOCKET NuMG E R ed 63 EVE NT DATE 74 75 REPORT DATE 60 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h Log l On August 31, 1979, during Mode 1 operation, a slug of water entered the process vent l aj l blower and "B" f11ter causing vent flow to decrease to zero and the blower to be l

o l -topoed.

Because 1-GW-F1-1 A was not available for backup, the waste pas charcoal l

o 4

o s I f11ter system was declared inoperable.

The system was returned to operable status I

o 6

Iwithin the time limit allowed by the ACTIrW Stato-ent. therefore the health nna saferf 017 l of the ~ ~ ral nub 1ic wave rnt affected.

Penortable nursuant tn T.S.

6.4.1.9.b.

I o

e i

I 7

8 9 N

$OSE OE SL CODE COMPONENT CODE SuBCOOE SUB o

9 i el nl@ LsJ@ Lv.J@ 1 v 1717 I r i r i a l@ L2J@ Lz.J @

7 8

9 to

' 11 12 13 18 19 20 SEOuENTIAL OCrURRENCE REPORT REvtSaON L

EVENTvfAR REPORT NO.

CODE TYPE NO.

O a=ER/RO 1 Tl of I _j liini7l M

Ini,1 W

H W

s 21 22 23 24 26 27 28 23 30 35 32 T

N A ON ON, NT METH HOURS 8 TT D M

S.

MAN RER LcJ@LzJ@

l7I@

Lz.J@

lnInInIoI LxJ@

bl.J@

Ld@

l cl 71 al ol@

33 34 35 36 37 40 43 42 43 44 47 CAusE cESCRIPT10N AND CORRECTIVE ACTIONS h l A slug of water entered the process vent blower and filter from the Spent Resin l

i O

g l Dewatering Tsak Vent while transferring resin and dewatering the Spent Resin Dewaterlig l Tank.

Af ter the water was drained from the system, the hepa filters were replaced I

7 g l and the charcoal filters were repacked and reinstalled.

1-GW-F-1B was then satisfac-l g ltorily tested and returned to service.

l 7

a 9 Bo SA

%,0wER OTHER STATUS 08 R

DISCOVEftv OESCRtPT1oM l d@ l C{ 91 5l@l NA l ] @l Operator Observation l

i 5

• AETiviTv COSTENT AMOUNT O, Acuviry @ I i.OCAno,.O uEASE @

REu ASEO e,REtEASE LLis.1 LrJ @ lz l@SES l

NA I nA of DESCRi.nON@

lr- ) TH

,ERsON~EL Ex,OS

~uu.ER rv,E I n i n l ol@l zl@l NA I

i 7

,E.SO=El'imuLS DEstRi.no~@

- S g

l g,c NuoEER al I o oIol@l i

m LOSS O, OR DAM AGE YO FACIL*T" ga rg 91 0 y e) U 7

8 3 11 12 i

80 TY8E

DESCRIPTION

%./

i i lel@l n

I 7

d 9 10 60 ISSu DE CRtPTION u.LoJL.0E81 I

IIilIIIIII1III 7

8 9 10 68 69 S03 NAME OF P9EPARER PHON E:

a Virginia Electric and Power Company North Anna Power Station, Unit #1

Attachment:

Page 1 of 1 Docket No. 50-338 Report No. LER-79-107/03L-0

Description of Event

On August 31, 1979, during normal operation at 95% power, a slug of water entered the process vent blower and "B" filter rendering the waste gas charcoal filter system inoperable for 4 days due to the "A" filter being unavailable for backup operation.

This event is contrary to T.S. 3.6.4.3 and reportable pursuant to T.S. 6.9.1.9.b.

Probable Consequences of Occurrence The consequen.ces of this event were minimal because the waste gas charcoal filter system was returned to operable status within the time limit allowed by the ACTION statement.

As a result, the public health and safety were not affected by this event.

There are no generic implications associated with this occurrence.

Cause of Occurrence A slug of water entered the process vent blower and filter from the Spent Resin Dewatering Tank Vent while transferring resin and dewatering the Spent Pesin Dewatering Tank.

Immediate Corrective Action

The water was drained from the system and the process vent blower was restarted utilizing the filters in a degraded mode temporarily.

The redundant filters were not declared operable at t'.at time since ef ficiency testing had not yet been completed.

The hepa filters in 1-GW-F-1B were replaced and the charcoal filters were repacked with new charcoal and reinstalled. A penetration test was then performed on the hepa and charcoal filters with satisf actory results.

The "B" filter was returned to service restoring the waste gas charcoal filter system to operable status.

Scheduled Corrective Action A study is being performed to determine the actions necessary to prevent recurrence of this problem.

Actions Taken to Prevent Recurrence To be determined by the study.

\\ D' )

\\