ML19256E493

LER 79-032/03L-0:on 791002,during Repairs to Metrascope, Control Element Assemblies 6 & 7 in Shutdown Group B Indicated Low Readings.Caused by Faulty Input Amplifiers. Metrascope re-energized

ML19256E493
Person / Time
Site:	Millstone
Issue date:	11/01/1979
From:	Foster E NORTHEAST UTILITIES
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256E488	List: ML19256E487 ML19256E493
References
LER-79-032-03L, LER-79-32-3L, NUDOCS 7911070518
Download: ML19256E493 (1)

Text

(7 77)

LICENSEE EVENT REPORT Con,TnOL BLOCK: { l l l l l l :PLEASE P'llNT 00 TYPE ALL HEQUIRED INFOilMAllON;

- i e lo l t 8l 9l Cl T LICENSEE l 11 l !!CODE l S l 214l@llb0 0 l- l0 l0 l0 [0j0 l- l0 l0 l@l4l1l1l1l1l@l 25 2G LICLNJE TYFE JJ

[_j @

bl CAi b8 7 LICENSE FvU.s10LH CON'T O i [j'y [Lj@l0l9l0 0 l0 l 3 l 3 l6 l@l l l 0l 0 l 2 l 7 l 9 l@[ l l 1 l 0 l 1 l 7 l 980l@

7 8 60 68 DOCKET NU'.?3ER ES G3 EVEN T DATE 74 75 REPORT DATE EVENT DESCalPTION AND PROBABLE CONSEQUENCES h FO l2 l lDuring repairs to the lietrascope, CEA's 6 and 7 in shutdown group B indicated low I O 3 l readings on the Backup Scanner Digital Readout. In accordance with Technical l l 014 l l Specifications, Section 3.0.3, the plant commenced a shutdown until the problem was l l 0 l s l l investigated and repaired. Total time of this event was one (1) hour and 10 minutes l l O ls l lwhen the plant resumed full power operations. I O 7 l l 0 8 l 1 7 8 9 .

. 60 C DE CODE SUBCO E COf.tPONENT CODE SUDC d5 SU OCE l0l91 l I l F l@ [E_j@ lG l@ I l f' l S l T l R l U l@ W@ [Zj @

7 8 9 10 11 12 13 18 19 20

_ SEQUENTI AL OCCURRENCE REFORT REVISIOfJ LE R E VENT YE AR REPORT NO: CODE TYPE N O.

O ajg/RO RT g 17 19 l l--J l 0 l 3l'2 l l/ l013 l lLl [-] l 01

_ 21 22 23 24 2G 27 20 23 30 31 32 T Kf A Ef O PL fT 1E HOURS S Bf a r i D. S PPLIE MAf FA TUTEH lAl@l7l@

3J 34 I B l@

35 L1.J@ 3/

01010111 L1JJ@ vl@ INI@ IF l0 l1 l3 l@

3G 40 43 42 43 44 47 CAUSE DESCnlPTION AND CORRECTIVE ACTIONS h li lO l l lietrascope de-energization resulted in incorrect Backno Scanner position readout due tol li li i faulty input operational amplifiers for CEA 6 and 7 (Fairchild No. UA 747). This re- I li 1211 duced sional voltage to the Backoo Scanner resultino in low readinos. Tho Metrascoe 1 i 3 l was re-energized resulting in normal readings for CEA's 6 and 7 until the op-amps were i 4 l replaced, restoring normal Backup Scanner indication with lietrascone de-eneroized. I 7 8 9 80 ST  % POWE R OTHER STATUS IC fY DISCOVE RY DESCRIPTION 1 5 [_Fj@ ll l 0 0 l@l NA l lBl@l Surveillance Testina l A TIVITY CO TENT nrtEASED Or PELE ASE AP.iOUNT OF ACTIVITY LOCATION OF RELEASE c NA l  !!A 7

i 8 9

[Z_] @ tolZl@ 11 44 l

45 CO l

PERSONNEL EXPOSURES NUM8E R j qD ')Q

(/

M TYPE DESCillPTION

[' t [ 7 l l 0l 0 l 0 l@l Z l@l NA a l PCHSOnNe't m;uEtS HUYDER DESCRIPTION c0 D h@ "

li la 8l l9 0l 0 l 0 l@l12 7

NA N(\ \\\\ '

l 11 \j W 60

'^

'TSSE "o E^Cl, ,%', '^ "" @ 7 9110 70 v{I t M [_Zj@]

7 8 9

[1A l to 83 I

• 3 8[SSt0

@DE l 10 CRIPilCN NA l t,8 l l l l l i l l ! I I i 15 09 E3*J m i.c nr nor n . ,a n Edwin R. Foster , , _ , , , (207) 4 - o  ?