ML13308B495
| ML13308B495 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 07/27/1976 |
| From: | Ottoson H SOUTHERN CALIFORNIA EDISON CO. |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| RO-76-14, NUDOCS 8103060558 | |
| Download: ML13308B495 (3) | |
Text
LICENSEE EVENT REPORj CONTROL BLOCK:
(PLEASE PRINT ALL REQUIRED INFORMATION]
1
'6 LICENSEE LICENSE EVENT NAME LICENSE NUMBER TYPE.
TYPE 01 IC IA 15 101 51 1 01 01-10 0 101 01 01-10 10 1 4 11 1 1 101 3 7
89 14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE DOCKET NUMBER EVENT DATE REPORT DATE oNCON'T[1 L]
0 1 51 01-10 1210161 016 l 218 17 16 1 01 710 12 17 161 7
8 57 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION 702 L On June 28, 1976 at 0416 hours0.00481 days <br />0.116 hours <br />6.878307e-4 weeks <br />1.58288e-4 months <br /> Unit #1 tripped off the line while carrying 330 MWe.
7 89 80 The reactor tripped from a spurious low Reactor coolant flow signal from Loop C s
7 8 9 8
IMII I R.C. Flow transmitter. Investigation of the transmitter revealed a failed feedbackso 7 8 9 80 05 I motor. The motor was replaced, the. transmitter was calibrated and returned to, s
7 89 06 I
service (76-14) 80 7
89 PRIME 80 SYSTEM CAUSE COMPONENT COMPONENT CODE CODE COMPONENT CODE SUPPLIER MANUFACTURER VIOLATION 7
11 Al IJ I IINISI TIRIUI
[Nj
[Fj118 101J 7
8 9 10 11 12 17 43 44 47 48 CAUSE DESCRIPTION I No apparent cause was found for the failure of the feedback motor.
7 8 9 80 7
89
[M 1 80 7
8 91 FACILITY METHOD OF 80 STATUS
% POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION E
10 117 10 1 N/A
[Z N/A 7
8 9
10 12 13 44 45 46 80 FORM OF 8
ACTIVITY COr TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 12 UZ I I
I N/A AMUN OF ACTVIT 7
8 9
10 11 44 45 PERSONNEL EXPOSURES 80 NUMBER TYPE DESCRIPTION 13 10 10 l I I N/A 7
8 9 11 12 13 PERSONNEL INJURIES NUMBER DESCRIPTION 1
10_1011 I N/A 7
8 9 11 12 OFFSITE CONSEQUENCES 15 I N/A 7
8 9 LOSS OR DAMAGE TO FACILITY0 TYPE DESCRIPTION 71 I
I N/A 7
8 9 10 PUBLICITY Event occurrence released to standard publicityvist.-
7 89 80 ADDITIONAL FACTORS 7
89 80 19 I N/A 7
89 NAME :
PHONE:_80 PH N:GPO 881.667
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE DAVID J. FOGARTY ROSEMEAD, CALIFORNIA 91770 TELEPHONE J u l y 1 4, 1 9 7 6 2 3 -
Z I!
U. S. Nuclear Regulatory Commission Region V o'
Suite 202, Walnut Creek Plaza v-;
1990 North California Boulevard Walnut Creek, California 94596 Attention: R. H. Engelken, Director C&'
Dear Sir:
Regulatory Docket Fild Docket No. 50-206 San Onofre Unit 1 This letter describes a reportable occurrence concerning the San Onofre Nuclear Generating Station Unit 1 Instrumentation and Control System.
Sub mittal is in accordance with the reporting requirement stipulated in section 6.9.2.b(2) of the Technical Specifications.
On June 28, 1976 at 4:16 a.m., Unit 1 tripped while carrying 330 MWe.
The reactor tripped from a spurious low reactor coolant flow signal from the loop C flow transmitter. All plant tripping schemes initiated by the spurious low flow signal functioned as designed.
Following removal of the transmitter from containment, limited operation was resumed while effecting repairs. Reactor thermal power was maintained below sixty percent in accordance with Technical Specification requirements.
The unit was subsequently removed from service to replace the repaired trans mitter. Unrestricted operation resumed June 28, 1976.
Generation of the spurious low flow signal was due to failure of the feedback motor in the flow transmitter. The feedback motor was replaced and the device successfully calibrated prior to replacement.
Sincerely, Attachment cc: Director, NRC Office of Inspection and Enforcement Director, NRC Office of Management Information and Program Control 7290
ICENSEE EVENT REPORT CONTROL BLOCK:
[PLEASE PRINT ALL REQUIRED INFORMATION]
LICENSEE LICENSE EVENT NAME LICENSE NUMBER TYPE TYPE
}Iicl A510151 0
141111 1111 1013 7
89 14 15 25 26 30 31 32 REPORT REPORT CATEGORY TYPE SOURCE DOCKET NUMBER EVENT DATE REPORT DATE 0CONT I1.J L i 10 I 51 01-0 t2 10 6 016 218 :17.16]
10l 7j0 12 17 161 7
8 57 58 59 60 61 68 69 74 75 80 EVENT DESCRIPTION L On June 28, 1976 at 0416 hours0.00481 days <br />0.116 hours <br />6.878307e-4 weeks <br />1.58288e-4 months <br /> Unit #l'tripped off the line while carrying 330 MWe.
7 89 03 I The reactor tripped from a spurious low Reactor coolant flow signal from Loop C 7
8 9 R.C. Flow transmitter. Investigation of the transmitter revealed a failed feedbackso 7
8 9 motor. The motor was replaced, the. transmitter was calibrated and returned to 7
89 06 [
service (76-14) 7 8 9 PRIME 80 SYSTEM CAUSE COMPONENT COMPONENT CODE CODE COMPONENT CODE SUPPLIER MANUFACTURER VIOLATION 17 IE1 A LU
[IINISTIR U 1 Lj I F1 18101 VIIO 78910 11 12 17 43 44 47 48 CAUSE DESCRIPTION 8 I No apparent cause was found for the failure of the feedback motor.
7 08 9 80 7
8 9 80 7
8 9 FACILITY METHOD OF 80 STATUS
% POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION EDi Li 1071 10 N/A I
i I N/A 7
8 9
10 12 13
.44 45 46 FORM OF 80 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF. ACTIVITY LOCATION OF RELEASE 1
Z I ZJ I N/A N/A 7
8 9
10 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION 1E0 10 101 I I N/A 7
8 9.
11 12 13 8
PERSONNEL INJURIES NUMBER DESCRIPTION
[10 10101
, N/A 78 9
11 12 80 OFFSITE CONSEQUENCES 15 N/A.
7 89 LOSS OR DAMAGE TO FACILITY TYPE DESCRIPTION 6 _I N/A*
I 7
8 9 10 80 PUBLICITY 7l 1 Event occurrence released to standard publicity list.
7 8 9 80 ADDITIONAL FACTORS 18 N/A 7
89 8
830 19 N/A 7
8 9 NAME:
PHONE:
80 GPO 881*667