Text

Forwards Draft IE Info Notice, Potential Failure of BWR Backup Manual Scram Capability, Per 801208 Meeting Agreement
	ML20027C007
Person / Time
Site:	Pilgrim
Issue date:	12/15/1980
From:	Lainas G; Office of Nuclear Reactor Regulation
To:	Jordan E; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
Shared Package
ML20027C005	List: ML20027C004; ML20027C007;
References
	AEOD-E018, AEOD-E18, NUDOCS 8210120164
	Download: ML20027C007 (4)
	v • d • e

.

DISTRIBUTION:

Central Files DEC 15 iB80 ORAB Reading MCiORANDUM FOR: Edward L. Jordan, Deputy Director Division of Resident and itegional Reactor Inspection 9 IE FROM:

G.C. Lainas, Assistant Director for Safety Assessment Division of Licensing MRR

SUBJECT:

DRAFT INFORMATION NOTICE NO. 80-

POTENTIAL FAILURE OF BWR BACKUP MANUAL SCRAM CAPABILITY As agreed during a meeting of DL. IE, and AEOD staffs' on December 8,1980, our draft of the proposed OIE Infonnation Notice on this subject is enclosed, for your dispatch.

Ox!sdnal W W G.C. Lainas, Assistant Director for Safety Assessment Division of Licensing

Contact:

c d.T. Beard, X28352

Enclosure:

As stated y

cc w/ enclosure:

bec w/ enclosure:

G. Lainas JMauch C. Michelson JTBeard D. Ross NVillava i

P. Check CDeBevec mSE R. Satterfield DThatcher s

g mn J. Olshinski KWichman

,0 GHolahan er JDonohew 88 TNovak NQ RTedesco MSrinivasan g

no M.waun.r co a.co e

.DLIORAB DL:

D A3/.SA orrice)

Ishinski G i'h s

-suaume). 4TEAcrA t ah...KR.[hman......./.2/IO -

'5MU8d'."..', ",\\,,,/ ' '/8E ",, ",", ",, ",, ", ", ", ", ", ',

i, oy,)...../.t //o. /.80

/

D U *.. G.*.

1973 289 349 hier* FORM 11 A f47M NRPM af an

_ ________________'r

" N?

P!:? r.ft 1NTING OF Fic E s

e--

.~,

DRAFT IE Inforrt.ation Notice No. 80-

POTENTIAL FAILURE OF BNR BACKUP MANUAL SCRAM CAPABILITY The primary purpose of this Notice is to advise other BWR licensees that a mechanism exists which could defeat or.e of the backup manual scram (reactor trip) features normally available to the reactor operator.

In the GE-designed BWR Reactor Protection System (RPS) l when the reactor Mode Selector Switch is placed in the Shutdown position, a scram should occur. This feature is used at some facilities as part of a nomal reactor shutdown. Also, for certain plant situations, the facility Technical Specifications require placing the mode switch in the Shutdown position, as a means of immediate shutdown. As described below, this scram may not function.

The Pilgrim Nuclear Power Station has reported that, following the loss of power from a vital M-G set and manual transfer to the alternate power source, the annunciator " shutdown scram reset permissive" was actuated.

We understand that such an annunciator may not be provided for all BWRs.

Subsequent investigation revealed that the restoration of power in the Run mode initiated a " relay race" in the RPS, between relays K-16 and K-17.

Since the wrong relay " won the race," the scram contacts from the mode switch were bypassed after a 2-second time delay.

In the Run mode, normally the K-16 relay is de-energized and K-17 energized. However, due to the power interruption and consequential relay race, K-16 became energized and K-17 was prevented from energizing.

. u

. At Pilgrim, the immediate corrective action was to manually energize K-17, which in turn de-energized K-16.

We understand also that a very slow, deliberate changing of modes (i.e., hesitating in Refuel) will pemit the relays to reset and thereby cause scram when Shutdown is reached.

We understand that General Electric is aware of this potential condition and is preparing a Service Infomation Letter (SIL).

s

~

t.s r. b W 8&

1

.p g t,q a,n w.

a.. m.

l--

g 7 'g g

g- (atAC, gore MA.

J, 4:*&,__.________-.,[J suunn fs SM*p l'$ N'#)

bees d (***2 848) 1M Wmat sene sua quessann anvehammasur)

,{ so enl s

=

I..skeaM r L; A'..I.

[

s,

'h.

, kan>=h g

=='='

(inssasws.m m-I manen s

haas n

c.r m.

v.-r

,1e.us s,> l *.a o s y

.se p,,,

am ss

?

sos ci.e.es l 5

p p.sapegg '

s

- - - - _j s sa **.

.,::3,=

orp.ne d (vane igg.,e TDc

e. eat 1p.mac g*w *.*

.s.ng ses rue a m

i,

~

ay,

s

. en,,u.a,g g,,gg s

g

.aii

,gs o---

+

s fi.,.,,,_

1 pp.

IA,a f j wou x.as ='tamia.s.sa TJo _7 s _ _:, s>ts g

M'..'----

-- 8 gsawese sep "

lisesusa.; : sa. art.

e=.

(E- 'lTs"'sD l

sss6vos mas g,,,,g 6'."T.' a TE.'**'** "')

8 e

, w;,

(n.n * *l ' Nas

E.**a*s!W l

8**"

o**

e" 6-v - a,~,---- a e,,. sa ***

8 8

a g -~a.

(

-w 5

d s

,, [

so s.a t s.u.,u.

b m.

s w s.

sa.se s.a 3.,

i

'p},u is x s,

p g

-an._ve. -

es m

i 8

sn o-'**

o fp.,

l on,_

>a a

.g.

p

~

o g, p*

s.1 ****

7=_==__ _ _ ~1

.. g t so= nomaa.a 3

.]

s)

. s*ura u sew ss Jan es l

a.inieenI

./

e, com.o e

u re g1s ss c. sa.anc g wawes._=e_s=mman 1

q = k"-",f-** g, ='

d asmi.

_=

is.mx q

s,,a q

y '- "

~

_w a

_ m _ _ _ _ _ _._ _ _ _ _ _ _._ _,_ _

I weno,- sca naar essurs

..5s I_

es.cesa %*=ua6, sco.

j vai me ar emie ianc as

[

[sn..as (t ap

~'

Pa.

O so ass I

' b6k CM y

i p,.gge a

t.cPru eh 4 b. 0

&8

.(. n c

m

'S L

s* sc

-n L.f: cW o,._ese e esa es.s.sames rs saa ss.*

r r

,.s ac

/4 -(7 -88 1I5**a ;isa eas ;lna. ness r - - -,c

/(,, m A-

<a a

e a

a n s.-te.a.n.se.. t s6 e

3 as-s sa. vc s

tsme_.3 fu.s

_ _ _s..w s'...

,oM.,,

8 k f '. - c F/'

, cP - TD Osmae.y.,a.sse ne f..

,, sa..,c

s...e e

ie.aese mas s ro

. h,. -

7

-C4.

-f a'#Fr-as ap ai. I.

e

_ _s_

e e

a a

as

[

sa e,.sc see me a I

C>M y

a 3..

C,

,4 W

o on 8

. c.

g sa ust

.)

,w, f F70 r" r ".

CE

88

o. 3

&d.

- vr j Y *=en

$-!(

?d s

v,,,

...a..; em s,..My.

ea

hog

h

hoe

, sa 41 3

r4 < g7 3

{, i g

aso E

f Y

0 SkJ6

[

6-4 cd 8

U A-M

(.,, 5 I @C.4 s.

/ sapoeng */ses.ac '8/sassunn */ sa.e,,gt,

8SeF sr a

E'8r g,

mag

.:;magne g gee,ng j4,u*-

==

a is e

A aJ F04 3

. commcm.

y a gi,,,,

ef4 e e>

u s,s. _., _ _ _ _,, _ _. _ _ g_ _ _y,_

g,,,,a,,,,,,,s,=,,

1 s

cae ssame s.sc aans ieu,.a g,=,,=,,=,,=,,=,*,,,,

g.. _

~ ?g.*****

g g,a

,a paa sa

- fate sys* tan *mt -

nev. eses wy La u.m.agr.a.pw nea ik, 7

-'*,-YA

.",,ev sp #,,.e

+

~.

,,, _,, %,h L

,p.

~<. m. ~ ui se e it*1**.I.

4

-4

+ i 4 88.

t sa w., 6 es,

e 4

4 I

6 7

igi 1

.,,. n a m.., '

-]

~ ' " --

gg.g.gg,d1 son cotsm E

PIL3 RIM Nu=.rAR P=wtm ERAT! N R F"O *1 R c=xy %:. R =Ao

, NYWC:.?M.,Ma33AC,*usCT 3 322 6 0 August 29, 1980 BEco Ler. #80-205 Director, Region I Office of -Inspection sed Enforcement U. S. Nuclear Regulatory Connaission 631 Park Avenue King of Prussia, PA 19406 Licensee Event Report 80-038/01T-0 Docket Number 50-293 License DPR-35 Gentlemen:

The attached Licensee Event Report 80-038/01T-0, " Mode Switch in shutdown", is hereby submitted in accordance with the requirements of Pilgrim Nuclear Pcwer Station Technical Specification 6.9.B.1.1.

If there are any questions on this subject, please contact us.

Respectfully submitted, Y

.7 P. J. McJuire Station Manager Nuclear Operations C.2:ep

Enclosures:

(3 copies)

LER.80-038/01T-0 cc: Director (40 copies)

Office of Management Information and Program Control U. S. Nuclear Regulatory Commission Washington, D.C.

20555 48 se,

" c e^ &G+[F a

/

i

' ONTRa.sL6Cm l 1

l l

l@

tei. East eRiNT cR Tves Au. RE:UIRE3 INFORMATt!NI C

i

. TG l M I A l P l P l S l 1 l@l 0 l 5 l 0 l - l 0 l 0 l 0 l 0 l-l0 l 0 @284 l1 l 1 l1 l 1 lgl57 CAT 54lg l

i 8 9 UCENsEE CooE 14 il WCENSE NUMSEA di uCENst TYPE 40 CON'T Eu% l L @l015 l0 l-l012 l 9 l 3 @l018 l1 l818 l0 @l018 l2191810 l@

10111

't a

60 si coexET NupeER e4 69 EVENT D ATE 74 75 REPoAT DATE 80

]

EVENT DESCRIPTION ANO #908ABLE CONSEQUENCES iContrary to Technical Specification, able 3.1.1, the," Mode Switch in Shutdown" trip lo i2i Public health and safety if g ; function of the RPS failed when "B" vital NG set tripped.

i o i,i j wers not affected since =ovement of the mode switch through startup to shutdo1.n would l have scrammed the reactor on 15" APR11 trip had a scram been necessary.

1o isl I l

lo is i l I

10171 I I

C6 Tin I-a a9

'c'E Ea" Tois su$ciEs ccMPoNENT Coot sus s

og l I] Al@ W@ l A l@ l Il Nl Sl Tl Rl Ul@ l S l@ l Zl@

lo691 7

8 9

10 11 12 13 18 19 20 sE QutNTI A.,

CCCuRRENCE REPORT mgVisioN EVENT YEAR REPoRTht.

CooE Tvet No.

@ a* fR'Rol21 8l 0l l-l 1013l8J l/l l0 l 1 l lTl b

l 0l eg 22 23 24 26 27 28 29 30 31 32 E N *Ac$cd eYp3T

- SE" wouns Ot2 ^E.T,"Tu' o'AT.it.:

'"s'u",'.u*t*-

AT?Nu"' a u

[X_,,jgl24? l g

[sZl@

l Z l@

l0 l 0l0 lU l lT lg l N[g

{g lG l0 l8 l0 l a

26 v

O

i 42 4a a

41 2s CAUSE DESCRIPTION AND CORRECTIVE ACT10NS @

l i i o i ] Investigation showed that relay SA-K163 was energized and relay SA-K173 was de-energize l The problen vas resolved by nanually picking up the SA-K173 which dropped out SA-K16B i iiiil g land reset the logic. A design change is being processed to provide pernanent correctig i,i3i l of the problen.

1 li t A t i eTwensTATus @"EovSN oiscoveny cascaimon @

' *lE s>owem N.A.

l l A lgl Operational Event l

l i 6 5 I [,,,EJ@ l 0 [ 9 l 8 l@l i

is n

u es-

=

so a,c.ny,,v ccg,,,,

7 AmounTon Activity @ l tocATiono,netAss@

metEAsto osRetsAsa N.A.

l N.A.

l l1 l6IIZl@lZI@l

,Ense==EL ExecsOes ossemierien@

suveen Tves N.A.

l, l i 17 ] l 0 l 0 l 0 l@J@[

so is

' stascame'L ouu'dits ossenirTio=@

suwsea N.A.

ll l1lall0l0l0l@l 7

8 9 11 12 goj toss oF em oAMAGE To 7ActuTY j

i TYPE oEscRipT1oM N.A.

l l 1 l 9 l l Z l@l l

g 7

4 3 to Eemimom @

~

- MUh NRC USE ONLY l 2 i o l l k@l iss N.A.

l lllllllllllil 68 69 8Q' 7

8 9 io Charles J. Mathis 617-746-7900 i

(

NAME CF PREPARER PHONE-e I

tdste 89.95wJ mu g;ff a.

PILGRD1 NUCLEAR p0WER STATION DOCKET NO. 50-293

/)

s/

Attachment to LER 80-038/01T-O gr,

9

(-.g

\\ f.' J} */

b Y

/

l-gn ~, ' - \\(//

q

\\r on 8/18/80 at 1100 hours0.0127 days 0.306 hours 0.00182 weeks 4.1855e-4 months the "B" vital MG set failed causing the associated '

When the -iteme*= p=ar===

reactor protection system bus to go dead.

' applied, operations noted that the annunciato(" shutdown scram reset came in and stayed in. A rsquest was made to im.. d sm6. sh. ywhles eth the alarm.

At 1530 hours0.0177 days 0.425 hours 0.00253 weeks 5.82165e-4 months , investigation showed that relay 5A-K16B was energized, and' rel 5A-K17B was de-energized.

. With this configuration, the mode switch channel "33" manual. scram by going to the shutdown position was bypassed.

~

I' The scenario of this event follows:

On loss of AC power SA-K17B timed out in 2 seconds and closed 1.

contacts 1-2 and 3-4.

When power was re-established to the "B" RPS bus, the 5A-K163 relay 2.

picked u[immediately]d opened contacts.1-2 preventing SA-K17B from resettin P x !>> uj Qg With SA-K17B contacts 3-4 closed and SA-K16B contacts 3-4 closed, 3.

the shutdown position mode switch scram.is precluded for channel "B3."

80-3138 being generated The immediate problem was resolved at 1730 hours0.02 days 0.481 hours 0.00286 weeks 6.58265e-4 months by MR to manually pick up 5A-K17B which dropped out 5A-K16B and reset the logic.

The final resolution, however, vill require a design change.

e 0

e 4

e d

4 i

l l-I e

e l

l-

ML20027C007

Contents

Text

SUBJECT:

Contact:

Enclosure:

Enclosures:

Navigation menu

ML20027C007

Text

SUBJECT:

Contact:

Enclosure:

Enclosures:

Navigation menu

Search