ML13308B470
| ML13308B470 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 03/02/1977 |
| From: | Ottoson H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| RO-77-04, RO-77-4, NUDOCS 8103060050 | |
| Download: ML13308B470 (3) | |
Text
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LICENSEE EVENT REPORT LER 77-04 CONTROL BLOCK: L[LL (PLEASE PRINT ALL REQUIRED INFORMATION]
6 LICENSEE LICENSE EVENT NAME LICENSE NUMBER TYPE TYPE l
ASos 1 00 1010 1010l1-10 01 i4 11 11111111011 7
89 14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE
.DOCKET NUMBER EVENT DATE REPORT DATE CON'T [
IT_]
[L..
l0150l-l020l6l 1012115l7171 1013 0121717 7
8 57 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION E2 I During a hydrostatic test of the containment.spray system, two leaks in 7 8 9 80 the heat affected zone of welded joints in Line 734 were discovered. Line 734 7 89 80 is fabricated from SA 312, TV 304, Schedule 10S stainless steel.
Line 734 will be 7 B 9 replaced during the present outage. The schedule 10S pipe will be upgraded to 80 7 8 9
[iD6 I schedule 40.LER 77-02 describes a related incident (77-04) 8o 7PRIME 80 SYSTEM CAUSE COMPONENT COMPONENT CODE CODE COMPONENT CODE SUPPLIER MANUFACTURER VIOLATION 07 ISIFj I
I P I I IpI X.1 X
[ 1B 1113101 L NJ 7
8 9 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION 0 The mechanism of failure is presently under study. An updated report will be 7
8 9 09 Isubmitted when this study has been completed.
7 89 10 I8 7 89I FACILITY METHOD OF.
80 STATUS
% POWER OTHER STATUS DISCOVERY, DISCOVERY DESCRIPTION Gj 01 0 01 1 NA I
NA 7
8 9
10 12 13 44 45 46 80 FORM OF ACTIVITY COI TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 12 I V I NA NA 7
8 9
10 11 44
-45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION
[I101010 1 lZ I NA 7
8 9 11 12 13 PERSONNEL INJURIES NUMBER DESCRIPTION 4 10 lo lo I NA 7
8 9 11 12 80 OFFSITE CONSEQUENCES Is NA 7
89 LOSS OR DAMAGE TO FACILITY TYPE DESCRIPTION 16 106 1 I NA 7
8 9 10 80 PUBLICITY 1
NA 7
8 9 80 ADDITIONAL FACTORS 18I NA 7
8980 80 19 7
8 9 7 8 9 NAM:
80 NAM.E:
H. L. Ottoson PHONE:
492-7700 8
PHONE:
~/6 o(~o~oGPO 881.667
Southern California Edison Company
=
E P. 0. BOX 800 2244 WALNUT GROVE AVENUE J. T. HEAD, JR.
ROSEMEAD, CALIFORNIA 91770 TELEPHONE VICE PRESIDENT March 2, 1977 2135721472 U. S. Nuclear Regulatory Commission Region V Office of Inspection and Enforcement Suite 202, Walnut Creek Plaza 1990 North California Boulevard Walnut Creek, California 94596 Attention Mr. R. H. Engelken, Director Docket No. 50-206
Dear Sir:
Reference:
(1) Letter from SCE (H. L. Ottoson) to USNRC, Region V dated February 16, 1977 (2) Letter from SCE (J. T. Head) to USNRC, Region V dated February 7, 1977 Reference (1) presented prompt notification to the Regional Office of two leaks discovered at welded joints in the containment spray system at San Onofre Unit 1. This letter is a follow-up report to the notification made in the referenced letter and is submitted in accordance with provisions of Section 6.9.2.a of Appendix A to the Provisional Operating License No. DPR-13.
On February 15, 1977, a hydrostatic test of the safety injection recir culation system was conducted following the installation of piping modifications described in Amendment 52 to the Final Safety Analysis and in preparation for the containment sphere integrated leakage test outlined in Section 4.3.III.A of San Onofre, Unit 1 Technical Specifications.
The hydrostatic test revealed leakage of less than one drop per minute in the heat affected zone of two welds:
- 1. The welded union of lines 734 and 6016 where flow from the refueling water pump discharge would divide between the spray header and reactor coolant loops under accident conditions.
- 2. At the downstream mating flange of the discharge control valve for the south refueling water pump.
MP 1977 owE1O
-2 Deficiencies in this line had been encountered previously during the current refueling outage. Reference (2) discussed a through wall flaw found in Line 734 discovered during examinations incidental to issuance of IE Circular 76-06..Metallurgical examination of samples from Line 734 indicated that one 40-foot section of pipe had been improperly annealed during initial fabrication. Based on the metallurgical examination, that section of pipe was replaced.
A detailed examination of the recent failure in Line 734 is in progress.
The results of this examination will be included in our report of the results of inspections performed in response to IE Circular 76-06.
Line 734 is constructed of six inch diameter, Schedule 10S, ASTM 312, TP 304 stainless steel pipe. Based on the previously discussed pipe degrada tion together with the results of the recent hydrostatic test, Line 734 will be replaced in its entirety during the current outage. In addition, the schedule 10S pipe will be upgraded to schedule 40 pipe. Following pipe replacement, a hydrostatic test of the safety injection recirculation system will be conducted in accordance with San Onofre Unit 1 Technical Specifica tions. Commitments previously made to the Commission concerning IE Circular 76-06 will be met during this outage and a complete report forwarded to the Regional Office within sixty days.
Sincerely, cc: Director, Office of Management Information& Program Control Director, Office of Inspection & Enforcement