ML112900889

LER 79-015/03L-0 on 790712:discovered Steam Leak from Intermediate Pressure Feedwater Heater.Cause Undetermined. Temporary Patch Installed Pending Replacement of Heater Shell

ML112900889
Person / Time
Site:	Monticello
Issue date:	08/10/1979
From:	Hammer S Northern States Power Co
To:	NRC/OI/RGN-III/FO
Shared Package
ML112900890	List: ML112900889 ML19242D272
References
LER-79-015-03L-01, LER-79-15-3L-1, NUDOCS 7908140783
Download: ML112900889 (3)

Text

REGULATORY INFORMATION DISTRIBUTION SYOTEM (RIDS)

ACCESSION NBR:7908140783 DOC.DATE: 79/08/10 NOTARIZED: NO DOCKET #

FACIL:50-263 Monticello Nuclear Generating Plant, Northern States 05000263 AUTH,NAME AUTHUR AFFILIATION HAMMERS,J. Northern States Power Co, RECIPNAME RECIPIENT AFFILIATION Region 3, Chicago, Office of the Director

SUBJECT:

LER 79-015/03L00 on 790712:discovered steam leak from intermediate pressure feedwater heater,Cause undetermined.

Temporary patch installed pending replacement of heater shell.

DISTRIBUTION CODE: A0028 COPIES RECEIVED:LTR i ENCL SIZE:,

TITLE: INCIDENT REPORTS NOT ES :-----------------------------------

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL ACTION: 05 BC ORB'#3 4 4 INTERNAL: 0 EG F 1 1 02 NRC PDR 1 09 2 2 11 MPA 3 14 TA/EDO 1 1 15 NOVAK/KNIEL 1 16 EEB 1 1 17 AD FOR ENGR 1 18 PLANT SYS BR 1 1 19 I&C SYS BR 1 20 AD PLANT SYS 1 1 21 AD SYS/PROJ 1 22 REAC SAFT BR 1 1 23 ENGR BR 1 24 KREGER 1 1 25 PWR SYS BR 1 26 AD/SITE ANAL4 1 1 27 OPERA LIC SR 1 28 ACDENT ANLYS 1 1 29 AUX SYS BR 1 E JORDAN/IE 1 1 HANAUERPS, 1 I&C SYS BR 1 1 TMI-H STREET 1 EXTERNAL: 03 LPDR 1 1 04 NSIC 1 1 29 ACRS 16 16 aok UL-p TOTAL NUMBER OF COPIES REQUIRED: LTTR 49 ENCL 49

NORTHERN STATES POWER COMPANY MINNEAPOLIS, MINNESOTA 55401 August 10, 1979 Mr J G Keppler Office of Inspection & Enforcement U S Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Mr Keppler:

MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 13A Feedwater Heater Shell Leak The Licensee Event Report for this occurrence is reproduced on the back of this letter. Enclosed are three copies.

This event is reported in compliance with Technical Specification 6.7.B.2.d in that it represents degradation of piping designed to contain radioactive material resulting from the fission process.

Yours very truly, L O Mayer, PE Manager of Nuclear Support Services LOM/DMM/ak cc: Director, IE, USNRC (30) 4- rector, MIPC, USNRC (3)

MPCA Attn: J W Ferman

-over-7 908140~?

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IMINIMINIP 1 0101-101010 1010 1- 1010 1Q14 11 111 1 0)j KJJQ 7 8 9 LICENSEE CODE 14 lb LICENSE NUMIILII 7b 26 , LICENSE 1YPE JO 57 CAT bO CON'T R~o'e LIi SORELLJ@f~~l fn i10 10n19163 nI n s1 LO-M I11 1 I7I.7i 19810 i8 is 11 jO 10 17 19 10 7 8 60 61 DOCKET NUMBER 68 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES DURING NORMAL OPERATION ROUTINE OPERATOR INSPECTION DETECTED THE EXISTENCE OF A STEAM LEAK FROM THE E-13A INTERMEDIATE PRESSURE FEEDWATER HEATER. REMOVAL OF SHELL INSULATION REVEALED A THROUGH-WALL FLAW IN THE HEATER SHELL WHICH CONSTITUTES AN AB NORMAL DEGRADATION OF A SYSTEM DESIGNED TO CONTAIN RADIOACTIVE MATERIAL RESULTING FROMI THE FISSION PROCESS AS DEFINED BY T.S. 6.7.B.2.d. THIS EVENT HAD NO EFFECT ON SYSTEM OPERATION OR THE PUBLIC HEALTH OR SAFETY. THERE WERE NO PREVIOUS SIMILAR OCCURRENCES.;

7B E608 7 8 80 SYSTEM CAUSE CAUSE COMP VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE 7

I0I 8 9 l lG LEJ 0 10 11 LxJ G IH ITIEIx IC IH ISI1zIG 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION LET/RO EVENT YEAFR REPORT NO. CODE TYPE NO.

i(17 REcP"OT NUMBER LII 21 22 23 24 26 L0-L9 27 UOL-J 28 29 LsJ 30 31 10 32 ACTION FUTURE EFFECT SHIDOWN , ATTACHMENT NPRD-4 PRIME COMP. COMPONENT TAKEN ACTION ON PLANT METHOD HOURS 22 SUBMITTED FORM bUll. SUPPLIER MANUFACTURER L @LEJ_

33 34 LB@ LZiO 10 10 10 181 INJ@ LYJ LAJ ISI 21 9 01 35 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 36 37 D 40 41 42 43 44 , 47 W I NDE EXAMINATION OF THE FEEDWATER HEATER SHELL REVEALED AN AREA OF EROSION LOCALIZED

[ T IN THE VICINITY OF THE EXTRACTION STEAM INLET NOZZLE. CAUSE OF THE FLAW IS UNDETER 1MINED. THE FLAW IS 1"1 LONG AND IS CRACK-LIKE IN APPEARANCE. A TEMPORARY PATCH TO 1 3 STOP THE STEAM LEAK WAS INSTALLED PENDING REPLACEMENT OF PORTION OF HEATER SHELL 1r-4 SCHEDULED FOR NEXT APPROPRIATE OUTAGE.

7 8 9 so FACILITY METHOD OF STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION 1 LE 11 I 0 10 NA IlJI OPERATOR OBSERVATION 7 89 In 12 11 44 45 46 80 ACTIVITY CONTENT f.EASE ON I Of ACI VI 1 Y LOCA ION OF RELEASE 7

Ll 8 LzJ 0 9

1 zg 10 11 NA 44 1

45 1 NA 80 PEISONNEL FXPOSUIIES NIJMERFI TYPF )ESC1P1ION 8 L01 0i 11 Z IJSi13 NA 1 8 9 12 80 PERSONNEL INJUnIES NJMRER1 DESCIllPTION 8

[1 1 8 9 0 01 J 11 12 NA L o05nr OIl DAMAGE TO FACILITY TYPE DESCRIPTION

[II IZ18 NA 8 9 ID PrULICITY UF ESCRIPTIONSE ONLY

DISCOVERYEDESCRIPTION I N18)I NA_ __

OPRAO OBSERVATION9 o

NAME OF PREPARER -. HANWR J. PE: 612/295-5151 Y 290814 0U? '3