ML20084E637

Ro:On 710422,during Diesel Generator Load & Safeguard Sequence Test,Valves 826 A,B,C & D Failed to Open.Caused by Momentary Loss of Voltage on 480-volt Safeguard Busses.Power Supply Transfer Recommended

ML20084E637
Person / Time
Site:	Ginna
Issue date:	04/29/1971
From:	Amish K ROCHESTER GAS & ELECTRIC CORP.
To:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084E628	List: ML20084E637 ML20084E666
References
NUDOCS 8304150184
Download: ML20084E637 (2)

Text

F. 1- ,

m u , n. . . . .

.r , f"" n 'WT ** '%

{ ,, h-1. - * . L~m e - #

. J/

57 ,

YY ,

ik . - .

ROCIIESTER CAS NID ELECTRIC CORPORATION e W Ei ',7 AVEllIJE. RoalES TER, II.Y.140-t

, , n n w m ,, m W I s

• I' A i e 6 ;Ia ,/('

, April 20,1071 w/h .. ?>' .

C ; < , 'O . i

,/v / .t ij - 1 L ,,..

is. -

J C. ' 4:s

^'-

Dr. Futer A. Morris, Director "

, Division of Ihactor Licensing 1a , 1 U. 3. Atomic Energy Commission ' i

Washington, D. C. 20545 i

3

Subject:

Failure of Valves 826 A, 826 B,826 C, and 820 D to open

! Ginna Station Unit #1 Docket #50-244 I

Dear Dr. Morris:

i j Thurcday evening, April 22, 1971, Hochester Gas and Electric men were doing the Diesel Generator Load and Safeguard Eaquence Tect.

The acom of the test was to prove that the Emergency Dienel Generators will automatically start, automatically tie into the safeguard buc ces, and j nulomatically accume their required load upcn the cimulnilon of station blackout and concurrent cafety injection signal. The unit was in a cold chutdtwn condition, as it had been out cince 7ebruary 20, 1971 for its

! annual refueling, i <

l When the cimulated station blackout and cafety injection algual was mitiated, it was found that the valvec 820 A, B, C, and D between the Concentrated Boric Acid Tanka and the Safety Injection 1Nmpa failed to onen

'/3 @ A w p. Invectigation chowed that when the station blackout condition gg ' cecurn, the voltage 10 momentarily loat.cn all 480 volt nafeguard I

bucnes (!!c 14,10,17, and 18). . The loss of bus 14 also recults in the .

loas of Instrument Bus 1 B. Instrument Buc 1 B, in turn, feeds the "A" l Concentrated Boric Acill Tank level channetc LC 102 and LU l'/2. There-  !

fore, when thq 1 B Bus voltage was lost a downceale indication was shown ,

en LC 102 and LC 172. Law level Indication from these two channeln actuaten an interlock which prevents the Co.ncentrated Boric Acid Tank ,

outlet valvec 826 A, B, C, and D from opening.

[

05M4 COPY S N RE ON l

Pn -- . _ . . . - _ - - . - - .. - -- . --

w

• • l' I L L C l H:( L l'l:P.

s LioCE T 140 7 ' i.

RGCHL$1Ltlt.A\a

-ont' April $, IV

• o g g Dr. Peter A. ?. rin Y Durino. h: t functional tectina. pricr to initial criticalitu, s the

' fact that the mt:mentar.v. loco of bua 14 would enu:f thin n.rchlem wa: not discovered due to the fact that two different tectc were involved. The two tents were RGE Sn - 4.30 Diesel Generatar Test and RGE 4.5.1 "afety Injecticn Pre-operational Test. Each test thoroughly co'/ered the prerer equipment, but due to the fact tbat the tests were not run concurrently, the above problem was not discovered.

T:le Plant Crerating Re'/iew Ccnunittee met cn April 93, 1971 l i

and reviewed the problen'. It wa: rec mmended that the Pcwer supply O'r the "A" t'cncentra%i Horic 'scid Tant level channels lee transferred I to the 1 A Inrtri:mcnt ' ". Thir Bur is fed A om the "? " battery bank t

through an in;erter; therefore, it will alwwcs be active even if <;tation I'lackout ecnditicn:: cccur. We will still be maintaining ceparativeness for the Concentrated 12 3ric acid Tank level inctruments because the "B" Cencantrate ' R:ric Acid Tank level channele are being fed from Instru-ment Bua ' ' which is being fed ' rom the "B" battery rank througb another Inverte r.

The " 7;er ~;rry. 'ca: cinnged few the ! P Inotr'anent 1;uc to the 1 . Instruimnt Euc an > n rete:: tina < hav a that the valves P'?u A, B, C, and D did opan nremely.

tr'dy your:,,

/}

[' ,!

h

/ , ' i, ,' /

'~e itI! W. AlniCh

'!ic e Preuident Electric and Steam

/

l l

- .