ML20151C160
| ML20151C160 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 12/14/1973 |
| From: | Maloney J JERSEY CENTRAL POWER & LIGHT CO. |
| To: | |
| References | |
| AO-73-31, NUDOCS 8103040836 | |
| Download: ML20151C160 (4) | |
Text
--
~
x
....n ::.w._ m.A.a. a.
...:.. 2.s
_...c N
li ary "
i,
-Abnorcel occurrence.
~
jg
', s. a Rep' ort No.u73.-3h..
,4...
o 1
. '. m..,
4
..t.. '. --.
i ~
. ;. a,
- , i.
suaJECrf Homentary'..interuption of"125V :DC; power. supplying'instrimentation associated with various :safegu'ard system;o
'.i.*
1: ss v
.e r...
,., F. < 5;m
+-
' This event 1s considered.to'beinn abnornal'. occurrence as : defined.
i 4
in : the :Te chnical" Spe cifications y :pa ragraphp 1.,,15ffland fi' :.'. Notii fia.
.,- p
[
cation of.this oventrces aquirciby thei echnicil Specifichtions;i T
paragra#0.6,6;2.a;.was$made ato the AEC.Megion tIi JDirectorate -of -
f Regulatoryr Operations y-by :telephons. on. Friday ( -Dsc:csber *14y ID75,'!.
" ' c.
at".1610 pand bP.telecopicri cat 17.00.::.
.3, s
.?
SITUATIONC.. ~ An.cIcctrica152ro.und had.developedson <125V".DC: distribution bus. t
~
"A""re.sulting 1.n" electricians beingcc.alled '.in -at'.sppmximately -
t
,f-e 3.
2300, Decerber413,"'1973.to troubleshoot and trepatrc.thi's, problem'<.
~
Electrical grounds of thi.natumIh ye theen.anoinfrequent problem.:.
4
~
. in.tho :past :and' A$ cof thi$.. tid no.:apppved procedures have.been y developod.. It is' couron;knmriedge,that anyzintentption of ' power. '
t to powerganela"B".results ].fn sdverse cffects TcgArding service to s afeguard linstrumentiation r ':.Cmis equent1Mi:.thh. clectri ci a6 who :
a.
had performed this sarns maintenance activity. of troubicshooting i.
-ad"repaiwon-occasion'.in..tho pastqqproceeded focp1' ce -a jumper..
a s.
in.a position :that vould parallel.the""A""and. "B" ~ distribution.
t busose. Taisi"then; provided:non interuptible niternato feed to O pwct.panet.N" and by actunting the Afbrook before r.ake" throwover; suitch, :it could$be determinud.-if the ground lwas. in,the "E"'
I.
.~ $S DOCUMENT CONTA c
/
O M. d '
.?
Poor.al.JAh. T.1.1A. cts.
.._.u...,~...-_....-..
y._
. u..
...'~. 2. a 2..:.
L
- +-
'. ::(
- e:-.-.:.
Abnoms1 Uccurtsnce...
q
' ';. ; P scerbor ~13i' 1973.' ;
l
- h2; //-
u
- P.eportKo;.73y31Cl.
N a
v
.r-h....
o 1
a...
p u
power panci by. observing'.the indicatingPlights. con.the J'B"'bu.9 t
IIwever, the> electrician".placed the".iumper in the wrong. position v.
and.' effectively"did not havc4hc bbsei para 11elid -as:ilesired;-
Upon pushing ths/ local'.b'utton for'.trinsferring.thos"E" power.
panel..from the "h to'.the5B" bbs,o.th'ere was_a.notentary inter,,
a 7
uptien :of power on <thei.ordara of:millisecondsy.icapsed? by Ithe w.-
e 9
9 nomal. action of.tlio."'oroak hefore Me". switchj withDthe 'fol:-.
v.
.* P j..;.;
.t lowin2 results:e
~
L;..
3 ' :e 1.
Operating.CRD~ pump ;"A""trippodJdueHto ;1ossaof power to low u, pump.isuction trip icircuitg Operator irmediatelycrestarted, b-n g..
g pu=p.:
2;'.."B" isointion teondenser isolated due.to :1oss, of power to -
pipc-break. monitoring systemp '. Operator i =nediately renet.
isolation condenker isolation button and valving:Tc-aligned -
~
c proporly for nor..stestandbyeservice.g...
~
~
Clean-up.syst'em. isolated due to z. loss of power. to relaying -
3.
s I
associatodi.with.this. function. : Operator returned systen :to :'
l l
y service as por nbmali iroccddre,:.'
~
I
- 4..."pc power.was lost to llogic:channSI C (Core ^ Spray Systcc :I) l and': logic chonnel :D _(Core Spray System.II)1for'.the brief.
intervali. Meseechannois imediately reset automatically-rr.guiring no. operalf or. action.. Logic.. channels ?!A""ar.d "B" warc i
t not effe'cted and.the redundant equipment in each system was available."..
u.
3
.t t
~
s e
i f
e a
e
l s
v
......_,,.,.e.._._......
cember.13,1973 l
R'oport No. 73.31 '
(
-3 ;..
t
. - u. %.,..s:
,i :.
.r.
- e.,,
- y r
S' a.DC owcr.was, laat.to :the logic...c anne s of Containment h
l Spray System.I. ~ Again, with.the rapid.: restoration of power, 1
.the logic was autostically. restored.. The.Todundant system -
11.was not offected'and would have operated if necessary. -
4 No operator action regidredt t;.
6 A tro1610 'ninrm was received on"both diesel '.gencraton, but was.iccediately 'rcsot from tfic 'controliroon and was strictly'
.s; dua :to, loss.of DC pow'er to the alarm relay.and.had no effect l
on..suton.stic operation of tho' diesel gien. rators.
e
~
7, Lost.'DC pWer.to main steam lsola' tion valvesy but had no e effect on valve. operation since MC yiower.wss stl11'available and.pormitted vaIves to > stay' open...
- 8.. DC power was lost. to niseclloneous<. annunciators a'nd panels,
~
" tut did not have any addit'ional' effactdin the 'safc.bperar. ion i
of..the plant.
+
c,.'.
a r,
PREDI AL ACTIOlh.
r g
g*
Restoration.of the equipment.to norbal status was accomplished -
through.the' automatic reset" fun'etion of effetted instrumentation.
As noted above; the isolation condonscri CRD pump,~.clesn-up systen and miscollancout. glare functions were manually ' reset and restored to normal sorvice iscdiately.'..'
?.
.1 1 -
o
- .s t
l s
i a
e
...a, s.
i c'h,.','
's
+
/*#
e g
ge
.-4
...- nnutun uwn s ww.
..i I
1 metber:13,' 1973..
1
..-p.c.
Report No 75.
~
.i.-. r n. q. -.
.y,
}.
, sdTrry simIFiscE! '
i r
Athe interval:of.tice; involved in this.incidintcis.on the :i-
' order' of millisocands and al). cffceted syster.s. reset '.imediately or within severaliecomis,where. operator : action' mas Tequired,-
t.he-safety:/signi.ficmco sf'this..cVent is minimal'.:. In 'the case-of.tho : isolation.condenserj.: design <redtmdancy ws;. lost. for' the.-
interval prior.t.o the operator.resettingitheisystem.?.lkwever,".
i.
- the: redimdant: isolation (condensermas :available :and:would have i
y.
s.
-i.
performed..if rcquiredi.
P
,:,. t
.'a i.
7.
--/,
Acrb.,,.--
.Dato :.. -
12/14 /73 ^-
Prepared by:: _
.3.,g.x i
N.
[!
d.M... -.- -
, t,.
- -~~ 7-
- r. ' '
..F :.
w r -
,