ML20151C148
| ML20151C148 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/16/1974 |
| From: | Rone A JERSEY CENTRAL POWER & LIGHT CO. |
| To: | |
| References | |
| AO-50-219-74-4, NUDOCS 8103040625 | |
| Download: ML20151C148 (3) | |
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7 OYSTIR CilEEK NIELEtJ1 GENERATING STATION-FOPSID Rivrk, En! JE,nSEY 0d* 731 Abnormal Occurrence Repo t Ho, 10.219/74/ 4 r
IDD;TIFICATION Violation of the Techni cal Speci fications, paragraph _N/ A _,
OF OCCJRENCE:
1%ilure of 14ain Steam Isolation Valve NSOM to close upon receiving a manual signal to close.
i.
This event is considered to be on obnormal occurrence as de-fined in the Technien1 Specifications, paragraph 1,1573 C 'DlT!ONS PRIOR iO OCCURhBNCE:
Stendy 5tute Power Routine Shutdown Hot Standby r., Operation
] Cold Shutdown Load Changes During Refueling Shutdown Routine Powcr Operation Routine Startup' Other (Specify)
'Cperation The reactor was in the shutdown conditis.n with'the mode switch in refuel.
kesctor coolant temperst.ure was less than 212 F with the reactor head vented.
THIS DOCUMENT CONTAINS l
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POOR QUAUTY PAGES i
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DESCRIPTION in order to minihi;c airborne radioactivity in the drywcII, OF CCCurs:E:
a tregative pressure wu impressed on the reactor vessel vis i
the mochanical vacuun pump through Hain Steam Isolation Valves NS03B and NShan, At this time, o ce;Lplete inspection and i
cleaning of the " spool" valves used in the control scher.+ for Hnin Stena isolation Valves N503A and N504A was in progress which necessitaLed theSe Valves being ' closed. After the in-I gspection/c)cening Wim completed,.iteps were taken to open
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these valycs end' close valves usnW and usata so :that the s.ene j
preventive ordntenenec steps could be performed on their assoc-H hhen'llie close signal was itpressed on
- isted spool-valves.
)tSOMi,. the valve' did not respond.- Subsequent'sttempts wete sde to close the vnive and on the third try the valve closed.
An operstor loented in' the davail noted -that the solenold ~
- I valve khich operates the power valve was fcnctioning pr6perly,
it. should' bs noted that this valve had preyhavsly been'alven s closure ;ignal on.lamssry 11,. 297d during the pinnt shutdwn at approy.inotc3y.2701&c and a' gain on January 13, 1974 in pre-
-r puration for a t.tW1 leid: rate test.
In both of these cases.
valvo operation was satisfactor/.
Procedure APPAEliT Cid1SP.
,,, Design linusual Service Condition Nanufacture
~ ~ Insta11stion/
Inc, rmvirontental l
OF OCCUlu2NCE; Cons t ruction Corponent Failurc Operstor
'Other (Specify)
The cause of this event is under investigation at this ' tine, It should be noted that. this valve (NS03D) operator is con-nected to the nitrogen system during power operation. 'hhile-x
.sh tdown,-the valve operators of the two 1GIV's innido the drfwell are switched over to the station air system when the drywell is purged and open for access, Jt.is possible that dust in the air. line (dead-ended during power operstion) had become lodi!cd in the air' ports of the Valve 6perator durink the switchover from nitrogen to air.
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binvisd; vusm nonu
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keport No,' 50-2,19/74/4 V
e 3-Jam 2 pry 16,1974 -
'the linin Stcom isolation Ya ves are ' intended to provids a l
NU,1.ySTS OF
- 00CUlWeERCE:
means of,nininizing fission product. relehre. under design.beses condif.14n t since the redundant valve HSO4B elued In'the s
Thir.
proper nanner, thi.s 6metion would-have been perforred.
consideration is only inportant had the' valve failed to close-while at po er operation, -Since the plant v:as in'. cold. hut-s w
down, the safety signifiennce of this particular event ircon--
81dered minimal, C$nnEchv5 The spool'velve was disasserhind, inspected and cleaned.. The ACTION:
valve spool assembly was ~ observed to operate freely after"re--
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- esscnbly, FAILUri DATA:
Hanufact urcr; $1:u:; tics Inc.
Vsive Division Type:
Pilot Operated Power Valve Model'. l'rint !!eference No. 01746tl-and modified by Genera 1{ Electric Company TDI t.U2[91700 r
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