ML18283B400

LER 1978-010-00 for Browns Ferry Nuclear Plant, Unit 3, Both RBM Channels Which Became Continuously Bypassed During Power Ascension

ML18283B400
Person / Time
Site:	Browns Ferry
Issue date:	05/01/1978
From:	Fox H Tennessee Valley Authority
To:	O'Reilly J NRC/IE, NRC/RGN-II
References
LER 1978-010-00
Download: ML18283B400 (8)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM<RIDS)DISTRIBUTION FOR INCOMING MATERIAL 50-296 REC: OREILLY J P NRC ORG: FOX H S TN VALLEY AUTH DOCDATE: 05/04/78 DATE RCVD: 05/ii/78 DOCTYPE: LETTER NOTARIZED:

NO COPIES RECEIVED

SUBJECT:

LTR i ENCL i FORWARDING LlCENSEE EVENT REPT (RO 50-296/78-0i0)

ON 04/09/78 CONCERNING RBM CHANNELS BECAME CONTINUOUSLY BYPASSED...

ALL ROD MOVEMENT WAS TERMINATED....

W/ATT.PLANT NAME:BROWNS FERRY-UNIT 3 REVIEWER INITIAL: X JM DlSTRIBUTOR INITIAL:Q~

DISTRIBUTION OF THIS MATERIAL IS AS FOLLOWS INCIDENT REPORTS (DISTRIBUTION CODE A002>FOR ACTION: INTERNAL: BR CHIEF LEA.0/4 ENCL REG FILE++W/ENCL E~4W/2 ENCL S ITO>+W/ENCL NOVAK/CHECK4~W/ENCL KNIGHTS+W/ENCL HANAUER~~~W/ENCL EISENHUT++W/ENCL SHAO<+W/ENCL KREGER/J.COLLINS>~W/ENCL K SEYFRIT/IE+~~W/ENCL NRC PDR++W/ENCL MIPC<4W/3 ENCL HOUSTON++W/ENCL EEB~+W/ENCL BUTLER~~~W/ENCL TEDESCO+4W/ENCL BAER~~W/ENCL VOLLMER/BUNCHw+W/ENCL ROSA~~W/ENCL EXTERNAL: LPDR S ATHENS'L++W/ENCL TIC4+W/ENCL NSIC++W/ENCL ACRS CAT B++W/16 ENCL COPIES NOT SUBNITTED PEP.,'EGULATORY GUIDE 10'DISTRIBUTION:

LTR 45 ENCL 45 8 I ZE: iP+iP+iP CONTROL NBR: 78i320020%%4M%%%4%%4M%%%%%%%%%0$

%44%%%03%%%4%%

THE END 4%%%%%%%4%%4%%%%%%%%%%%%%%%%%%%%%%%

4~, J Wa TENNESSEE VALLEY AUTHORITY CHATTANOOGA, TENNESSEE 37401 MN c'197S Itll,II@II(Ogrffl g~[tropIr" Mr.James P.O'Reilly, Dirac r U.S.Nuclear Regulato Comnission Office of Inspection and Enforcement Region II 230 Peach ree Street, m., Suite 1217 Atlanta, Georgia 30303

Dear Mr.O'Reilly:

" TENNESSEE VALLEY AUTHORITY-BROGANS PERRY NUCLEAR~DOCKET NO.50-,296-FACILITY OPERATING LXCENSE MR-68-OCCURRENCE REPORT BPRO-50-296/7810 Cp C~r roc,>-c~~~Cn~Po fV UNQ3-REPORTABLC r CT.,~C7>~Crs fC B The enclosed report provides details concerning both RBM channels which became continttously bypassed during power ascension.

This report is submitted in accordance with Browns Perry unit 3 Technical Specification 6.7.2.a.(2).

Very truly yours, TENNESSEE VALLEY AUTHORXTY H.S.Pox Director of.Power Production Enclosure (3)cc{Enclosure):

Director (3)Office of Management Information and Program Control U.S.Nuclear Regulatory Co ssion Washington, DC ,20555 Director (40)Office of Xnspection and Enforcement U.S.Nuclear Regulatory Commission Hashington, DC 20555 gng An Equal Opportunity Employer A' d ,d V I meg F-C vd E n v I 1 v<Lf fll"CC" 4 v Jf I f'J.I pd (.K'.IL~I f"'A il I II I II d Cg~df ('f j 1 I" v v td C C~d,'

I EP fl 1 P~l;,~"AOOfj%I<<I EL N.SEUCLEAR REGULATORY COMMISSION

,.LICENSEE EVENT REPORT EXHIBIT A BFA85~'."..~-~.-."..':.'l0/5/77 kAC SOAM SSE~,~IP'TTI I CONTROL SLOCKI 0 (PLEASE PRINT OR TYtd ALL AEOUIREO INFORh'IATIONI

'I~.4$~$~~0 0 LICKNZKE CODE 14 1$LICENSE NUMSKR LICENSE TYPE JO'I UAF$11 CAPT$$"'.".:I LJS'~$DOCKET IEVMSER IES 4&KYKNT OA'IS 14)S RCPORT DATE SP EVENT OESCAIPTION ANO PROBABLE CONSEQUENCES QIO~o 1 Durin ower ascension both RBM channels became'continuously bypassed.~o The RBM was not, o erable as s e'cified in technical d ecification 3.2.C.1~~~o'I I~E~o 4 U n discover all rod movement was terminated.

There have been no revious~OS~OG~o r to the discover of the malfunction all rod rescribed b nuclear en ineers core thermal f c t mar in to all thermal lim ts wer'e'I~t" i I.~E I~I~Oe 4 9 1 r haz rd to ublic safet~09 o SYSTEM CAVSE CAUSE COMP VALVE CODE CODE SVSCODE COMPONENT CODE sUecood sUscoDE uLJS LOS L<<S~i'S LOS ILIS 0 10 II ll IS IS I 0 10 SEOVEri TIAL OCCURRENCE FIEPOAT REVISION EVENT YEAR R EPOAT NO.CODE TYPE No Qli Ellioii~rl 0~~O1 0~~QJ~1~$~~0 I 11 11 11 14 EF 14 19 SI 41 ACFION FUTURE EFFECT sHUTD prrN ATTACHh'TNT IESRO4 PAIMECOMP.

COMPOh EN T TAKEN ACT ICrl O'I PLANT hlKTHOO HOURS QT2 SUSMITIK9 FOESM$VS.SUPPLIER 4ANVSAC'TVRKR ILISLLIS'LJS O-IS I'-L<<-'E-'I IPIS LEIS I IS I~S CAUSE OESCAIPTION AND COAREC'FIVE ACTIONS QST C-03~C P.Clare MR4MC-1023 d28 on the ed e rod bus This condition e defective rela ,,~func ional hlETHOD OF OTHER STATUS~DISCOVERY N/A kAME OF PAEPAREA h~4 T 4 9 FACILITY STATUS'4 POAEA."00$LOS~S~I 9 4 9 10 11 44 AC'IIVITY CONTENT RELEASED OF RELEASE AMoUNTos ACTIVITY QSs Lgl Qss~zQ>4 N A T 4 0 HI 44~EASDNNKL EXPOSURES NVMSER TYPE DESCRIPTION QP LL9JO~zS.N A 9 4 9 11 11 IS PERSONNEL ItIJURIKS fiij 0 0 Qio N/A 9 4 0 11 11 L<<EO OO O*LE EO EEOILEEEQEE TYPE OKSCRIPTIOEI

~TO~ZQ49 9 4 9 IP~USLICITY ISSUED DKSCAIPTION Qds O~(~4I N/A 4 0 IP~'ll" SO I NRC USE ONLY'HONE:

44 49 DISCOVERY<<oESCAIPTICN QS2 or bservation.

LOCATION OS AEL'EASE Q N A*Revision.

Oi E I WE.

REPORTABLE OCCURRENCE REPORT Report Number: BFRO<<'50-296/7810 Report Date: May 2, 1978 Occurrence Date: April 9, 1978 Facility Browns Ferry Nuclear Plant Unit 3 Identification of Occurrence Operator observation of RBM recorders downscale and RBM bypass lights on.Conditions Prior to Occurrence Normal operation at 77-percent power, during ascension to full load.Descri tion of Occurrence Both RBM channels became continuously bypassed.Review of potential reportable occurrence report revealed report should have been a prompt report as required by Technical Specification 6.7.2.a.(2).

, Desi nation of A arent Cause of Occurrence Maintained voltage on edge rod selected bus.Misinterpretation of the technical specifications.

Anal sis of Occurrence Contact 5-6 of rod select relay KXB for CRD 38-03 stuck closed.Corrective Action Replacement of defective relay.Discussed meaning of technical specification with plant staff.Failure Data No previous failures.JGD: SGS 5/A/78 4'e"<s U 3 f