05000237/LER-1950-237, Updated LER 50-237/75-048:on 751007,through-wall Crack Found in Drywell/Torus Nitrogen Purge Line 1604-18.Addl Mods, Including Temp Controlled Isolation Valve Installation, Delayed Until Proposal Review

Updated LER 50-237/75-048:on 751007,through-wall Crack Found in Drywell/Torus Nitrogen Purge Line 1604-18.Addl Mods, Including Temp Controlled Isolation Valve Installation, Delayed Until Proposal Review

ML20090E440
Person / Time
Site:	Dresden
Issue date:	06/10/1977
From:	Stephenson B, Weidner R COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20090E444	List: 05000237/LER-1950-237, Updated LER 50-237/75-048:on 751007,through-wall Crack Found in Drywell/Torus Nitrogen Purge Line 1604-18.Addl Mods, Including Temp Controlled Isolation Valve Installation, Delayed Until Proposal Review ML20090E447
References
77-476, LER-50-237-75-048, LER-50-237-75-48, NUDOCS 8303310617
Download: ML20090E440 (3)

LER-2050-237, Updated LER 50-237/75-048:on 751007,through-wall Crack Found in Drywell/Torus Nitrogen Purge Line 1604-18.Addl Mods, Including Temp Controlled Isolation Valve Installation, Delayed Until Proposal Review

Event date:
Report date:
2372050237R00 - NRC Website

text

m---- -

^ ~ Update Report CONTR0'. ELCW l l l l l l p " Mbnigort R Date: 10/17/75 ALL REQUIRED INFORM ATIO

• m 6 ME UCdNSE NUMBER T TYPE O1 ll lLlDlRl5l2l l 0l 0l-l 0l 0l 0l 0l 0l-l0 l 0l [ 4l 1l 1l 1l 1l l0l1l 7 89 14 15 25 26 30 31 32 CATECCRY TYP s DOCKET NUMBER EVmf DATE REPORT DATE QCONT l l l lT l bj l 0l 5 l 0 l-l 0 l 2 l 3 l 7 [ l 1l 0l 0l 7l 7l 5l l0l6l1l0l7l7 7 8 57 58 59 60 61 68 69 74 75 6 EVENT DESCR:PTION ,

Q l in October 1975. a through-wall crack was discovered durir.g normal operation in the >

7 89 E

@ l Dresden Unit-2 drywell-torus nitrogen purge line 1604-18". Nitrogen leakage was minimal.;

7 89 E; Q l Secondary containment integrity was not affected, and the pressure suppression system ggfandallemergencycorecoolingsystemsremainedoperable. In September 1974, a crack o 7 89 6' Q l had been found in the similar nitrogen purge line for Dresden Uni t-3. (50-237/1975-48) D 7 89 , pnug '

EQ C CCE COMACNENT C30F MAN ACTUMI VOLATVN sg I Si el Lej lP ll lP l El Xl Xl W lz l 9 l 9 l 9 l W 7 89 10 11 12 17 43 44 47 48 CAUSE DESCRPTION 3G 4 This supplemental report documents the current status of lonq-term corrective action to  !

7 89 gg l prevent reoccurrence of the event. BGl The stapected cause and immediate corrective action i 7 89 EG Qg [were described in the original LER. That report also described an interim solution I 7 89 E'

1. ACuTv STATUS 4 POWER OTHER STATUS utTweO C, DISCOVERY

.(continued)

Dec0VERY DESCR:7TCN 1

7 8 9 y l 0 l8 l 4 ] l NA l d45 l NA l 10 12 13 44 46 SGl 7CETTY CCATENT , ,

RELEASED AMOUNT OF AcTMTY LOCATION OF RELEASE 35 tzj OF [zj 9ELEASENAl l l NA I 7 8 9 10 11 44 45 6J PERSONNEL EXPOSURES NUtASER TYPE CEsCRPTON 810101 ol

~

LzJ l NA I 7 89 11 ,12 13 ,

60' PERSONNEL INJURIES NUMBER CESCR:PTON

• b l Ol 0l 0l 7 89 l NA l 11 12 t; OFFSITE CONSEQUENCES -

,QE l j' NA

• 7 89 -

E's LOSS OR DAMACE TO FACIUTY ,

TvPE DESCapf+N hhl P 89 10 NA 3

i i PusuCtry 8303310617 770610

, QG l 3 DR ADOCK 0500 NA 7 89 . bv

• ~

ADDITIONAL FACTORS .

Q[ l NA- '

l 7 89 W' D8 l .' I 7 89 W L y f%y.WLFbMhrm  % N

O O CAUSE DESCRIPTION'(continued) which ' included posting operators to monitor pipe temperature during Inerting, procedures to ensure the nitrogen is vaporized, and requirements that the pipe 5

temperature be maintained above 800F. The interim program has proven to be effective in preventing a reoccurrence of the pipe failures. Since the NRC is currently reviewing proposals which would eliminate inerting requirements upon Installation of the ACAD/ CAM system, additional modifications, including the -

l. Installation of a temperature controlled Isolation valve in the vaporizer discharge line, are being delayed. If the deinertion pronosal is accepted, the modifications will be cancelled.

4 4

e s

i k

9 i

d w

OT k

,- , ,, r

y q

o Commonwg'i Dresden Nucle Edison wer Stti;n

@ Telephone 815/942-2920 R.R. #1 Morris. Illinois 60450 '

'h

" gqg, BBS Ltr. # 77-476 May 31, 1977 fp j  %

Mfaf{f 4

Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations - Region lli

$>l4Vf'Sg}A p{

\'

/ e U. S. Nuclear Regulatory Commission '% fr-799 Roosevelt Road +

g, (kbg(

Glen Ellyn, Illinois 60137 . F' Enclosed please find an update report to Reportable Occurence report number 50-237/1975-48. This report is being submitted to your office in accordance with the Dresden Nuclear Power Station Technical Specifications, Section 6.6.B.

w '

G'

.<' f p.y

~

't . Ste henson

_ Station Superintendent Dresden Nuclear Power Station BBS:skm ,

Enclosure cc: Director of Inspection & Enforcement Director of Management information & Program Control File /NRC 1

E i

4 *

~