ML19329B914

LER 78-033/03L-0:on 780325,steam Generator L-2 Level Found Increasing After Closing Startup Feedwater Valve,Exceeding Max Limit.Main Feedwater Block Valve FW 0779 Closed Manually,Controling SG L-2 Level

ML19329B914
Person / Time
Site:	Davis Besse
Issue date:	04/20/1978
From:	Marley J TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19329B906	List: ML19329B905 ML19329B914
References
LER-78-033-03L, LER-78-33-3L, NUDOCS 8002060903
Download: ML19329B914 (3)

Text

,o _

67 7Ff

' 9'! %  :-- Ll0ENSEE EVENT REPORT . . . .

8 ALL REQU:nZO IN. 0MATloN)

CcNTROL BLOCK: l l l l l h (PLEASE PRINT OR Ti l1 JOj@l 57 i;AT 68l@

l o 0 l H l D l B l S l1 l@Q l0 l- l 0 l0 l3 lP lF l-l0l3l@l4 26 26 l1 LICE.s5E l1 11TYPE 9 14 :S LaCENSE NU'. sta 7 LICENSEE CODE CovT 10111 7 8

[n"et lL @l01510 l- 10131416 l@l0 l312 l5 17 18 'l@l01412 60 61 CoCKET NUYSER 68 69 EVENT QATE 74 it REPORT QATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h Io62l l After shutting down the unit to Mode 3 and raising Steam Generator (SG) 1-2 level, J

l SG 1-2 level continued to increase even after closing the Startup Feedwater Valve.

.I o i a l l This placed the unitj g o ,.i ; j At 0455 hours0.00527 days <br />0.126 hours <br />7.523148e-4 weeks <br />1.731275e-4 months <br /> on 3/25/78, the level exceeded the maximum li=it.

There was no danger to the health and safety of the publiq lo Is1 l in Action 3 of T.S. 3.4.5.

lo is l l or unit personnel. No steam line break occurred during the short period of time the 1 C;P-33-78-36) ( ,

[ g } - l l' Steam Generator level slightly exceeded 86%.

I l o I8 I l 7 8 9 COV P. VALv E SYSTEM CAUSE CAUSE SUSGooE SUSGooE CooE Suscoot COMPONENT CooE Coof joisl 7 8 lC lH l@ l Xl@ l Zl@ lV l A l L l V l 0 l P ]@ l A l@ lZREVIStoN 9 10 11 12 13 18 li REPORT 20 l@

SEoVENTIAL OCCURRENCE Coof TYPE No.

REPORT No.

@aEponT LEn no EVENT YE AR l7l8l ll l0[3l31 lfl l0 l3 l l Ll l_) l0 l 32 29 3,J 31 24 26 27 23 22 23

[

) ACTION . FUTURE 21 EFFECT ONPLANT SMUTooWN METwoo HoVR$

ATTACMMENT SUBulTT ED NPAC-4 FORMbuS.

PRIME COMP.

SUPPLIER COMPONENT MANUFACTURER TAKEN ACTION

\'

l36Z l@ lZl@ l0l0l0l l lYl@ l42Y l@ lAl@ l 112 l 0 l 0 l( 47 l E l@l34Z l@

44 36 37 40 44 43 44 CAUSE DESCRi? TION AND CORRECTIVE ACTIONS @ This caused the l l 7 l o 1 l An operator entered contain=ent and opened one SG drain on SG l-2.

l level in SG l-2 to decrease very slot.-14. Control of SG 1-2 level was obtained at J l3 ; 3j

[

,,,,, j 0517 hours0.00598 days <br />0.144 hours <br />8.54828e-4 weeks <br />1.967185e-4 months <br /> on 3/25/78 by =anually closing the =otor operated Main Feedwater Block Adjustments [

gi,3j l Valve W 779 which had not been cot:pletel,y closed by its =otor operator.

[

g , ,4 ; } Vere then made to the cotor operator of the valve .

7 8 9 o RY oIScoVERY oESCRIPTfoN ETHER STATUS

'sT$  % POWER l

l l A l@l Operator Observation of SG 1evel l1 } 5 ] dh l 0 ! O 10 lhlNA A Ti%ITY Co TENT location OF RELEASE mELEasto oF RELEASE AMoUNTof ACTIVITY l l1 l6 l l Zl @ Wgl NA l' l NA 60 44 45 7 8 9 10 11 PEnsoNNEL ExPosUnts Nuve E e Tv*E CE10 AIPTION l

i , 7 # 1 G i O i O !@l Z )@i A

' PEasoNNEL m u'dits NU =E n CEsCRiPTioN@ l l0lcl0f@l= ^ ,

s:

6 n..c. ,.=,w n g .

8002060 % 3 i.,.. (Tg[H"'"

"' C 'C CN '

' ' h,. ' ..n .,, : @

!l!!IIlIII II ;

l

[.i j b[.h ,NA .;a c s

,,,,-.q -ic-23 R C00.

ht . 2 7 t, Jenos M:rley

. . . ?~ , +  :

' 'r. .

i-

<- s , -

/

TOLEDO EDISO3 COMPANY

\

DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION i-

- SUPPLEMENTAL INFOPJiATION FOR LER NP-33-78,36 i:

f

DATE OF EVENT

March 25,1978 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Steam Generator 1-2 level exceeded 86% .

j.

Conditions Prior to Occurrence: The unit was in Mode 2, with Power (MWT) = 0, and Load (MWE) = 0. [

Descrintion of Occurrence: While performing a reactor shutdown to Mode 3 for main-tenance work, Steam Generator 1-2 (SG l-2) level was raised to between 35% and 70%

on the operating range per SP 1102.10, " Station Cooldown and Shutdown Procedure".

- Re'act'or power was reduced to 0%. SG 1-2 level continued to increase even though the Startup Feedeater Valve SP7A was closed. An operator then closed the Startup Feedwater Isolation Valve'FJ 162. The level in SG l-2 continued to increase. At 0455 hours0.00527 days <br />0.126 hours <br />7.523148e-4 weeks <br />1.731275e-4 months <br /> on March 25,1978, SG 1-2 level exceeded the 86% naximum limit and in- .

4 ,

creased to a level of 88%, which placed the unit in Action Statement B of Techni-cal Specification 3.4.5. ,

At 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, an operator entered containment and opened 'one drain on each Steam [

GeneYator. The level in SG 1-2 decreased very slowly until the operator manually l closed the Main Feedwater Block Valve FW 779, which had not closed tightly even though Control Room indication showed a green light indicating FW 779 was closed.

After manually fully closing FW 779, SG 1-2 level decreased rapidly. At 0517 hours0.00598 days <br />0.144 hours <br />8.54828e-4 weeks <br />1.967185e-4 months <br /> on March 25,1978, SG 1-2 level was less than the 86% limit on Steam Genera-tor Feedwater Level. On the operating range instrumentation, 86% corresponds to 348 inches.

Designation of Apoarent Cause of Occurrence: The cause for the SG 1-2 level to exceed 86% was the failure of FW 779's motor operator to completely close the valve causing the overfilling of SG l-2.

Analysis of Occurrence: There was no danger to the health and safety of the public or unit personnel. No steam line break occurred during the short period of time the Steam Generator level slightly exceeded 86%.

LER 178-033

'\

. .".~. ,

. *,, . ==.. .:-

p;\

t TOLEDO EDISON COMPANY DAVIS-BESSE-UNIT ONE NUCLEAR POWER STATION PAGE 2 SUPPLE} ENTAL INFORMATION FOR LER NP-33-78-36 Corrective Action: The operator closed the Startup Feedvater Isolation Valve; he entered containment and opened a drain on SG l-2. Both actions had relatively little effect on SG l-2's l'evel. The operator manually closed FW 779 tightly causing the_ level to drop quickly. At 0517 hours0.00598 days <br />0.144 hours <br />8.54828e-4 weeks <br />1.967185e-4 months <br /> on :: arch 25, 1978, SG 1-2 level was less than 86% which removed the unit from Action State =ent B of Technic,al Specification 3.4.5. A Work Request, MWO 78-740, was written and under Mainten-ance Work Order 78-191, Maintenance investigated the problem with FW 779. Adj ust-ments were made to the number two rotor contact in the valves motor operator.

- Failure Data: This is not a repetitive occurrence. One prior occurrence of Steam Generator level exceeding 348 inches was due to personnel error while pre-paring for a turbine roll (see Licensee Event Report NP-33-77-30).

LER #78-033 8

. e e

e

,- w ,- - - , , -

, . , , , - - , - - - - , - ,