ML19207C433

LER 79-023/01T-1:on 790622,Westinghouse Notified Util That Addl Insulation to Steam Generator Level Instrumentation Impulse Lines Is Necessary to Avoid Heatup in Event of High Energy Line Break Occurring Inside Containment

ML19207C433
Person / Time
Site:	Farley
Issue date:	09/05/1979
From:	Hairston W ALABAMA POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19207C427	List: ML19207C426 ML19207C433
References
LER-79-023-01T, LER-79-23-1T, NUDOCS 7909110619
Download: ML19207C433 (3)

Text

NGC FORM LG U. ; NUCLt. AH HLGut AluH V COMM6553oN U.11l r.

LICENSEE EVENT REPORT coNTnot eLcCx- l l

l l l l l 6

l@ (PLC ASE PRINT OR TYPE ALL REcutRED INFORMATION)

[O i l A l L l J l M i F l 114 l@l35 0 l 0 l - l 0 0 l 0 l 0 l 0 l- l 0 l 0D l@l LICL Po is f*VT *uEil M 4 l1 l1 l1 l1 l@lSi CAI C8CLhal IYPC J'J l l@

Si J J L6C E *. 'dC wSE LON* T 7

O I 8

3 lL 60 l01510lOl0l3ll 08 DOCK E T *.U'.13 E i4 4

18 hJ0 l /i l ' ! ? !7 14 h!nlolnlr;l7l9l@

t,4 4 EVENT DAIE 34 7,4 HEPCHTDATE b0 Ever.T oESCRtPTicN AND PacaAaLE CCNSECUENCES h

[ o l 2 l [ Westinghouse notified Alabama Power Company that a high energy line brealC inside I Contairn ent could result in heatup of the steam generator level transmitter reference [

oraiI o 4 ggs. A resulting level bias Caused by reference leg density decrease could delay or i ogs l prevent automatic generar.icn of reactor trip and aux. feedwater initiation signals by l o ,; low-low steam generatar water level bistables. Review of this notification resulted l 0l7 lin a determination on 6/22/79 that this condition is potentially reportable under Tech.l, o g l Spec. 6.9.1.8(h). The health and safety of the public were not aff ected.

EU

[

7 8 9 SYSTEM CAust CAu;E COMP. VALVE CODE CC:;E SUdCODE COvPONE NT CODE SUBCOCE SUSCODE 7

O o 8

I zl zi@ lxl@ Iz l@ l zl zl zl z zi z l@ l z l@ I z l @

9 10 11 12 , 13 la 13 N

,, SE QUEN TI AL OCCURRENCE REFCRT R E VISio'd g EVENTYEAR

• REPOa T NO. CODE TYPE No.

@ ,g=a pg 17 19 I l-1 10 12 13 I le 101 i I Lr_J I-I Ltj

_ 21 22 23 24 24 27 2a 23 3J 31 32 ACitON F U Tus'E

• EFFECT SWJCC?;N A TT ACW E N T N PR O-4 PRIME COMP. CoVPCNENT Forut >US.

-[' T A N E 'd AC TI C P. ON PLANT A iTo.G;G HOURS e su a?.t. T T E D $UPPLIE A L'AN U F ACTUR E R LxJ@l 33 ,J4 x i@ Izi@

Jh IzlO 4

_l o l o l o l o43l 4/

IVl@

41 l N lh 42 l z lh [z I 9 l 9 l 9 [(

43 44 47 CAUSE DESCRIPTION AND CCRRECTIVE ACTIONS h -

i o l Increased reference le2 water colu n temp. will result in a decrease of the water I i i l column density with a cOnsecuent apparent increase in the indicated S.G. water level I i  ; l (i.e. apparent level exceeding actual level) . This in turn could delay or prevent  !

,,3 l generation of the signals described in item 10. A design change, Technical Specification i 4 l change and procedure chanzes have' been initiated to alleviate this notential nroblem. I 7 J 9 63 FACid?v , METHOO OF STATy; %PChER CTNER STA TUS

• DISCOV E R Y DISCOVERY DESCRIPTTON 3.

I8 158 l9 l C l@ l0 l 0 l 012l@l11NA 44 l M 45 hl Notificarion 46 from NSSS vendor. 30 I

7 to A C T1VI T Y C O*4 T E N T HELEA40 OF AELE ASE A?'CwNT CF ACTIVITY LOCATION OF RELCASC p i

c> i LzJ O IJI z l@l:s n I i u i ,

7 4 3 44 45 6J PERSCNNEL EXPOSVaES s If a TY PE CGC83:PTICN s i i l Ol 0 Ojhl zl@l NA l

' ' "o n - s . N a',,o,Ro

'2 Ne tu D ncm p r e li l ll0 l 0IOl@l i a 9 is i2 NA m

I

u. . t " 2m'." "" @ 7909ijo6l9~

f E l 7 @lm 4 3 NA

.J l

Pu l t l '"I T V nec on oy, y

o. 7m '

'l"I M. ,m:uanU,v v l y Ju l y , , , ,

i a 9 w u a ~

. . .. W. G. Hairston, III  :. . - . . . . ( 2 0 5 ) #99_5156 _

ALABAMA POWER COMPANY JOSEPH M. FARLEY NUCLEAR PLANT DOCKET No. 50-348 ATTACICfENT TO LER 79-023/01T-1 Facility: Joseph M. Farley Unit 1 Report-Este: 9/5/79 Event Date: 6/22/79 Identification of Event:

-- On 6/22/79 it was determined that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs, which in turn could initiate a sequence of events resulting in delay or prevention of the automatic generation of reactor trip and auxiliary feedwater initiation signals.

Conditions Prior to Event:

Plant was in Mode 5.

Description of Event:

Westinghouse notified Alabama Power Company that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs. A resulting level bias caused by reference leg density decrease could delay or prevent automatic generation of reactor trip and aux. feedwater initiation signals by low-low steam generator water level bistables. Review of this notificatica resulted in a determination on 6/22/79 that the condition was potentially reportable under Tech. Spec. 6.9.1.8(h). The health and safety of the public were not affected.

Designation of Apparent Cause:

Increased reference leg water column temperature will result in a decrease of the water column density with a consequent apparent increasa in the indicated S.G. water level (i.e. apparent level exceeding actual level).

This in turn could delay or prevent generation of the signals listed in the " Description of Event".

Analysis of Event:

(

An analysis of this potential occurrence has resulted in the identification of three areas requiring corrective action.

Corrective Action:

1. A design change (addition of insulation to the steam generator level instrumentation impulse lines) will minimize the magnitude of th steam generator level measurement error during the first fewjMJ$e1tes of a postulated high energy line break.

r .' q

d:' }

NO

______...._ _ ~. .

LER 79-023/01T-1

2. The low-low steam generator level setpoints will be changed from the present 115% to 217% and a Technical Specification change will be submitted for NRC approval. This 2% change accommodates the shift associated with the temperature change.

3. Plant emergency operating procedures FNP-1-EOP-1 (Loss of Reactor Coolant) and FNP-1-EOP-2 (Loss of Secondary Coolant) will be revised.

The revisions will caution the operator as to the possibility of erroneous steam generator water level indications. The operator will be directed to use several plant indications to verify the existence of steam generator water level.

Failure Data:

~~

None 1

ALABAMA POWER COMPANY JOSEPH M. FARLEY NUCLEAR PLAhr DOCKET NO. 50-348 ATTACHMENT TO LER 79-023/01T-1 Facility: Joseph M. Farley Unit 1 Repor: Date: 9/5/79 Event Date: 6/22/79 Ideatification of Event:

-- On 6/22/79 it was determined that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs, which in turn could initiate a sequence of events resulting in delay or prevention of the automatic generation of reactor trip and auxiliary feedwater initiation signals.

Conditions Prior to Event:

Plant was in Mode 5.

Descriotion of Event:

Westinghouse notified Alabama Power Company that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs. A resulting level bias caused by reference leg density decrease could delay or prevent automatic generation of reactor trip and aux. feedwater initiation signals by low-low steam generator water level bistables. Review of this notification resulted in a deteraination on 6/22/79 that the condition was potentially reportable under Tech. Spec. 6.9.1.8(h). The health and safety of the public were not affected.

Designation "of Apparent Cause:

Increased reference leg water column temperature will result in a decrease of the water column density with a consequent apparent increase in the indicated S.G. water level (i.e. apparent level exceeding actual level).

This in turn could delay or prevent generation of the signals listed in the " Description of Event".

4 Analysis of Event:

An analysis of this potential occurrence has resulted in the identification of three areas requiring corrective action.

Corrective Action:

1. A design change (addition of insulation to the steam generator level instrumentation impulse lines) will minimize the magnitude of the steam generator level measurement error during the first few minutes of a postulated high energy line break. ,-

OJ

}hb

LER 79-023/01T-1

2. The low-low steam generator level setpoints will be changed from the present > 15% to > 17% and a Technical Specification change will be submitted for NRC approval. This 2% change accommodates the shift associated with the temperature change.

3. Plant emergency operating procedures FNP-1-EOP-1 (Loss of Reactor Coolant) and FNP-1-EOP-2 (Loss of Secondary Coolant) will be revised.

The revisions will caution the operator as to the possibility of erroneous steam generator water level indications. The operator will be directed to use several plant indications to verify the existence of steam generator water level.

Failure Data:

3 At One m

e 1

ALABAMA POWER COMPANY JOSEPH M. FARLEY NUCLEAR PLAhT DOCKET NO. 50-348 ATTACHMENT T9 LER 79-023/01T-1 Facility: Joseph M. Farley Unit 1 Report Date: 9/5/79 Event Date: 6/22/79 Identification of Event:

-- Cn 6/22/79 it was determined that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs, which in turn could initiate a sequence of events resulting in delay or prevention of the automatic generation of reactor trip and auxiliary feedwater initiation signals.

Conditions Prior to Event:

Plant was in Mode 5.

Description of Event:

Westinghouse notified Alabama Power Company that a high energy line break inside containment could result in heatup of the steam generator level transmitter reference legs. A resulting level bias caused by reference leg density decrease could delay or prevent automatic generation of reactor trip and aux. feedwater initiation signals by low-low steam generator water level bistablec. Review of this notification resulted in a determination on 6/22/79 that. the condition was potentially reportable under Tech. Spec. 6.9.1.8(h). The health and safety of the public were not affected.

Designation of Apparent Cause:

Increased reference leg water column temperature will result in a decrease of the water column density with a consequent apparent increase in the indicated S.G. water level (i.e. apparent level exceeding actual level).

This in turn could delay or prevent generation of the signals listed in the " Description of Event".

4 Analysis of Event: ,

An analysis of this potential occurrence has resulted in the identification of three areas requiring corrective action.

Corrective Action:

1. A design change (addition of insulation to the steam generator level instrumentation impulse lines) will minimize the magnitude of the steam generator level measurement error during the first few minutes of a postulated high energy line break.

,"]

Sv

. . . . . . -. - ~ - - - -

LER 79-023/01T-1

2. The low-low steam generator level setpoints will be changed from the present > 15% to > 17% and a Technical Specification change will be submitted for NRC approval. This 2% change accommodates the shift associated with the temperature change.

3. Plant emergency operating procedures FNP-1-EOP-1 (Loss of Reactor Coolant) and FNP-1-EnP-2 (Loss of Secondary Coolant) will be revised.

The revisions will caution the operator as to the possibility of erroneous steam generator water level indications. The operator will be directed to use several plant indications to verify the existence of steam generator water level.

Failure Data:

~~

None I

940 3:6