ML19261C738

LER 79-012/03L-0 on 790214:air Found Blowing Through Weld on 3/4 Inch Vent Line.Caused by Component Failure.Vent Line Inserted Into Sockolet & re-welded

ML19261C738
Person / Time
Site:	Quad Cities
Issue date:	03/12/1979
From:	Tietz G COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19261C735	List: ML19261C734 ML19261C738
References
LER-79-012-03L, LER-79-12-3L, NUDOCS 7903280327
Download: ML19261C738 (2)

Text

U. S. NUCLEAR HEGULAToRY CoMMISSloN

.4kC FonM 366 (7 77) **

, LICENSEE EVENT REPORT l l l l l l (PLEASE PRINT OR TYPE ALL REoVIRED INFoRMATION) dONTHOL BLOCK: [ 6 1

f0 1 1 I l- OlAlDl1 hl 0 l0 0 l In ln ln l- ln ln ln j h ! 4l UCENSE 1! 1l TYPE 1l 1JJ h{57 LA T $8l@

LICtiNS: fvu.YBEH 26 26 E 9 LICENSEE CODE 14 15 COTT ie i M",n"C; I Ll@ 01 Sl 0l ol 01 21 5l 4l@ fil (/>

l oi 21 1 14l 7I 9 l@ l0REPORT EVE *.T D ATE 14 75 l3 l1 l7 l7 80l 9h DATE B ti0 61 COMET NUM6ER EVENi DESCRIPTION AND PROS ABLE CONSEQUENCES h I

o 2 l While pressurizing the volume between MO 1-1001-50 and 47 for leak rate testing, o a ir was found blowing through a weld on a 3/4 inch vent line, line number 1-10102-3/4"1A.

l o a [ A visual inspection revealed two linear surface indications on the socko!et-to-vent line weld, each one was approximately one i nch in length and 1800 apart. The conse- l g 3  ;

g g g quences of this occurrence are minimal due to the fact that the vent line is isolated l lgg7j l when reactor pressure is greater than 100 psig.

OIS l 80 CAUSE C O'.' P. VALV E SYSTEM CAUSE SU8 CODE SUBCODE CODE CODE SU8 CODE COMPONENT CODE o 9 C lF l@ lE l@ l Cl @ l Pl ll Pl El Xl X l@ [_A.Lj @20 d @ 18 19 9 10 18 12 13

, G OCCURRENCE REFORT REVlSION SEQUENTI AL CODE TYPE NO.

EVENT YE AR REPORT NO.

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@ sg.g'RO a 17191 l- 1 01 11 21 [gj 10 l3 l lL1 L-j 31 lol 32 24 26 27 28 23 30

_ 23 27 23 HOURS 22 SB I D FO 1 UB. S P LI E MAN FA TUREH TAKE J A ON O J PLANT E LA j @ l z l g l35 z g l36 zig l o l o l o Yl l 3/ 40

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43 lZ 44 9]9[9_J@47 33 34 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o l The cause of this occurrence is component failure. The root cause of the weld [

3 3 indication is unknown. The defective fillet weld was ground out and the 3/4" vent I

, , j line was removed from the sockolet. The bottom few inches of the vent line were l

, g then cut-off. The vent line was then inserted in to the sockolet and re-welded. The l 3

, ,, g new weld was dye penetrant tested and determined acceptable. l 3 a o OTHER STATUS ISCO HY DISCOVERY DESCRIPTION STA S  % POWER NA l lB l@l46 Test and insoection  !

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a d 9 l H l@ l100 l 0 l 012l@l13 44 43 80 ACTivl TY CONTENT J LOCATION OF RELEASE RELEASED OF nELE ASE AMOUNT OF ACTIVITY l NA l e NA l

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8 I z_l @ l10z l@l 11 44 45 80 PEHSONNEL E xPO5URES NU*/ tlE n TYPE DE SCHIP TION -

l t 7 l o l o lo l@lz l@l13 11 NA 80 8 9 12 PEHSONNE t IN JURIES NOVBEn DESCHIPTID s NA i

d 9 l o l o lo l@l 11 12 80 t O'.S OF On D A',1 Au6 TO FACILITY fvPE D E SC C< t P TION NA l ji

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[. .llNlhl NA l C3 t?) EJ.3 G. Tietz ggang 309-654-2241, ext. 247 (

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d I. LER NUMBER: LER/R0 79-12/03L-0

11. LICENSEE NAME: Commonwealth Edison Company Quad-Cities Nuclear Power Station 111. FACILITY NAME: Unit One IV. DOCKET NUMBER: 050-254 V. EVENT DESCRIPTION:

On February 14, 1979 while performing a local leak rate test on the MO 1-1001-50 and 47 Shutdown Cooling isolation valves, i t was noticed that the air pressure was decreasing rapidly.

An investigation of the pressurized volume revealed that air was blowing through a weld on a 3/4" vent line, line number 1-10102-3/4"-A. The vent line is a stainless steel pipe, class 900 lb., ASTM specification A312 Grade TP304. A visual inspec-tion of the 3/4" pipe revealed two linear surface indications on the sockolet-to-vent line weld, each one was approximately one Inch in length and 180 apart.

VI. PROBABLE CONSEQUENCES OF THE OCCURRENCE:

The consequences of this occurrence are minimal due to the fact that the vent line is located downstream of valve MO 1-1001-50, and by closure of valves MO 1-1001-47 and MO 1-1001-50 when reactor pressure is greater than 100 psig. The refo re ,

any leakage from this line would be at a minimum. Had a continuous leak occurred, the drywell floor drain sump level sould have detected the condition.

Vll. CAUSE:

The cause of this occurrence is component failure. The root cause of the weld indication is unknown.

Vill. CORRECTIVE ACTION:

The corrective action performed was to grind out the defective fillet weld and remove the 3/4" vent ilne from the sockolet.

The bottom few inches of the vent line were then cut-off. The vent line was then inserted into the sockolet and re-welded.

The new weld was dye penetrant tested and determined to be acceptable. No further action was deemed necessary. The re has been no previous occurrences of this nature on the RHRS piping.