ML18283B403

LER 1978-006-00 for Browns Ferry Nuclear Plant, Unit 3, Electrical Connector Carrying Thermocouple Circuits Monitoring Primary Containment Atmospheric Temperature Not Included as Part of Modification Which Qualified Connector Assemblies for

ML18283B403
Person / Time
Site:	Browns Ferry
Issue date:	04/24/1978
From:	Fox H Tennessee Valley Authority
To:	O'Reilly J NRC/RGN-II
References
LER 1978-006-00
Download: ML18283B403 (8)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM <RIDS)

DISTRIBUTION FOR INCOMING MATERIAL 50-296 ORG: FOX H S DOCDATE: 04/24/78 TN VALLEY AUTH DATE RCVD: 04/28/78 DOCTYPE: LETTER NOTARIZED: NO COPIES RECEIVED

SUBJECT:

LTR 1 ENCL 1 FORWARDING LICENSEE EVENT REPT <RO 50-296/78-006) ON 04l10/78 CONCERNING ELECT CONNECTOR CARRYING THERMOCOUPLE CIRCUITS MONITORING PRIMARY CONTAINMENT ATMOSPHERIC TEMP. WAS NOT INCLUDED AS PART OF THE MODIFICATION WHICH QUALIFIED THE CONNECTOR ASSEMBLIES PLANT NAME:BROWNS FERRY UNIT 3 REVIEWER INITIAL: X JM DISTRIBUTOR INITIAL:QLr DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS INCIDENT REPORTS

<DISTRIBUTION CODE A002)

FOR ACTION: BR CHIEF LEAR4+W/4 ENCL INTERNAL: REG FILE+4W/ENCL NRC PDR<+W/ENCL NC MIPC4+W/3 ENCL SCHROEDER/I PPOL IT044 W/ENCL HOUSTON++W/ENCL NOVAK/CHECK+~W/ENCL EEB+~W/ENCL KNIGHT4H~W/ENCL BUTLER~~W/ENCL HANAUER++W/ENCL TEDESCO~~W/ENCL E I SENHUT+4 W/ENCL BAER44W/ENCL SHAO>>W/ENCL VOLLMER/BUNCH+>W/ENCL KREGER/ J. COLLINS++@/ENCL ROSA+4W/ENCL K SEYFRIT/IE++W/ENCL EXTERNAL: LPDR S ATHENS'L<<W/ENCL T I C+wW/ENCL NS I C++W/ENCL ACRS CAT B++W/16 ENCL COPIES NOT SUgxjiTTP)) PER REGULATORY GUIDE <10 1 DISTRIBUTION: LTR 45 ENCL 45 CONTROL NBR: 781180131 SIZE: 1P+1 P+1P THE END %4%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Nj",

'> ' )"lh ih '"

h

'I ~

i ) li N I h N hh l h h I

'I V

h I h I<

~ .I@<A I <I A .N Nih h

i h N N

N Nh "

I N

I'l II N ~ III

+E~gEssrE VALLEY AUTHORITY OH@ fTANOOGA. TENNESSEE 3740t r~

Mr. James P. O'Reill, Director ~T U.S, Nuclear Regul ory Cozxnission Off'ice of Xnspect n and Enforcement Region II A1 C

230 Peachtxee S eat, Sf., Suite 1217 Atlanta, Georg 30303 CA ca Dear Mr. O'Re lly!

TENNESSEE VAL -

AUTHORITY BROUNS PERRY NUCLEAR PLANT UNIT 3-DOCKET NO. 50-296 FACILITY OPERATXNG LICENSE DPR-68 REPORTABLE OCCURMKCE REPORT BFRO-90-296/786 The enclosed report provides details concerning an electrical Connector carrying thereocouple circuits monitoring printery containment atmospheric temperature vhich +as not included as part of the modification which qualified the connector assemblies for an accident envfgonment. This report is subtaitted in accordance with Brans Ferry unit 3 Technical Specification 6.7.2.a.(9) .

Very truly yours, TENNESSEE VALLEY AUTHORXTY H. S. Pox Director of Power Pxoduction

'll Enclosure (3) cc (Enclosure):

Director (3)

Office of Management Information and Prog xt Control.

U.S. Nuclear Regulatory Commission Ifashington~ DC 20555 Director (40)

Office of Inspection and Enforcement,'.S.

Nucleax'egulatory Commission washington DC 20 781180131 An Equal Opportunity Ernpioyer

fI )E R

'<<E P

' l 1 I

$ I P

<< ll Il EECE E I It P ~

P ' ~

P EI A

BFA85 r

~

10/5/77

~0 1IRC FORM 868 V S NUCLEAR RECULATORY ET 77I COMMISSION'XHIBIT UCENSEE EVENT REPORT A CON'T 8 9 CONTROL BLOCK:

LICENSE e CODE 14 l5 Qi 4

LICENSE NUMBER IPLEAsE PRINT oR TYPE ALLREQUIRED INFDRMATIONI

' ' 24 LICENSE TYPE

'~$

JO OI CAT SB DOCKET hUMB EA 64 69 EVENT DATE I4 IS REPOA'T DATE BO 0

EVENT DESCRIPTION AND PROGAGI.E COIISEOUENCES Qlo

[oO~J An electrical connector carr in thermocou le circuits monitorin rimar

~OS

~o4 fication which uglified the connecto a m i o

~o s ment. There was no effect on the ublic health or safet . A revious report concernin connectors on unit 3 was re orted in BFRO-50<<296/784.

7

~OG 7

joo~)

8 9 LERIRO iiiiiiiii 9

SYSTEM Q(MU CODE EVENT YEAA

~lo 10 QII CAUSE CODE

~B 11

~

QI2 CAUSE

~

SUBCODE 12

~0 QIS SEOUENTIAL RftORTNO.

~0 12 COMtONENT CODE 16 OCCURRENCE CODE COMP SUBCOOE LJQ 19 AEPCAT Tytf VALVE 0io SUBCODE 20 REVISION ~

NO.

~lo Qii 0 '7 21 22 26 2$ 29 20 Sl 22 ACTION FUTURE EFFECT SNUTOOWN A'TTACNiATNT htROR PAIMfCOMP, COMPONENT TAKEN ACTION ON PLANT METHOD NOURS +22 sUBMITTED FDRAI oUB. SUPPLIER MANUFACTUAER 8 QIg ~FQIg ~BQ2D 26

~BQ?I 26 Sl 0 0 0 LJ0 Leo LJo 41 42 44 41 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q>7 o The cause was a desi n deficienc The conn cto i an e i onm t resistant Am henol t e 69R series and contains onl the thermoco Io cable. Due to the ver .low volta e and current s. o electrical failure of l

~0~

couples, the connector assembl is unlik The n e qualified RDlice durin a unit outa e which 7 8 9 began on April 15; 1978.

FACILITY STATUS Y POWER OTAEASTAruS Q DISCOVER V MISCOVERY Of SCRIPTION ~44

'iOO8 LJQ 9 lo 12 44

~D'>> Notification b desi n ersonnel 46 LT ACTIVITY CONTENT RELEASEO OF RELEASE 7 ~BQ84 AMOUNTOF ACTIVITY N/A Q LOCATION OF RELEASE N/A Q

8 9 IO 44 PERSONNEL EXPOSURES NUMBER TYtf DESCRIPTION Q29

~>>

7 8

~00 9

o II QFi ~sQTi 12 12 N/A Pf RSONNE L INIUR ITS

~is 00 0 Q4n N A 7 8 9 11 12 LOSS OF OA DAMAGE TO FACILITY TYtf Of SCRIPTION Q42

~TG ~iQ47 N/A 7 8 9 Io Sa PUBLICITY NRC USE ONLY ISSUf 0 Of SCRIPTION Q4S

~70 ~NQ44 N A

~ 9 IO 6$ 69 IIAME OF PREPARER PHONE:

• Revision f

t.

h

Report Number  : BFRO-50-296/786 Report Date: April 19, 1978 Occurrence Date: April 10, 1978 Facility Browns Ferry Nuclear Plant - Unit 3 Identification of Occurrence During verification of the temperature versus time profile used in the post-accident environmental qualification testing for electrical connector assemblies on unit 3, Division of Engineering Design employees noted that the TVA response to AEC question 12.2.16 dated March 25, 1971, committed TVA to monitoring primary containment atmospheric temperature. It has been determined that the circuits for these temperature sensors on unit 3 contain an electrical connector assembly within primary containment that was not included as part of the modification which qualified the connector assemblies for an accident environment. (Refer to LER BFRO-50-296/784.)

The circuit is used to annunciate when a drywell atmospheric temperature of 281 F or higher still exists 30 minutes after an incident begins (drywell pressure exceeds 2 psig).

Conditions Prior to Occurrence Unit at approximately 95-percent power.

Descri tion of Occurrence An electrical connector carrying thermocouple circuits monitoring primary containment atmospheric temperature was not included as part of the modifi-cation which qualified the connector assemblies for an accident environment.

Desi nation of A arent Cause of Occurrence Design deficiency.

Anal sis of Occurrence The connector assembly is an environmental-resistant Amphenol 69R series and contains only thermocouple cable. Due to the very low voltage and current associated with thermocouples, electrical failure of the connector assembly is very unlikely. There was no effect on the public health or safety.

Corrective Action The connector was replaced with a qualified splice during a unit outage which began on April 15, 1978.

JGD:SGS 4/20/78

r I