ML19260D227
| ML19260D227 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 01/31/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Papay L SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| NUDOCS 8002080143 | |
| Download: ML19260D227 (1) | |
Text
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o UNITED STATES l ' ".,,
',j NUCLEAR REGULATORY COMMISSION e
REGION V
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1990 N. CALIFORNI A BOULEVARD
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SUITE 202, WALNUT CREEK PLAZA WALNUT CREEK, CALIFORNIA 94596 January 31, 1980 Docket flos. 50-206, 50-331, 50-362 Southern California Edison Comoany P. O. Box 800 2244 Walnut Grove Avenue Roseme sd, California 91770 Attention: Dr. L. T. Papay, Vice President Advanced Engineering Gentlemen:
This Information flotice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities.
flo specific action or response is requested at this time.
If further flRC evaluations so indicate, an IE Circular or Bulletin will be issued to reconnend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate flRC Regional Office.
Sincerely, mdb R. H. Engelken Director
Enclosures:
1.
IE Information flotice flo. 80-03 2.
List of IE Information flotices Recently Issued cc w/ enclosures:
J. M. Curran, SCE R. Dietch, SCE 1943 147 8002 80 / b 0
UtlIT2D STATES SSINS No.: 6870 NUCLEAR REGULATORY C0ffilSSION Accession No.:
OFFICE OF INSPEC TION AND ENFORCEMENT 7912190666 WASHINGTCN, D.C.
20555 January 31, 1980 IE Information Notice No. 80-0'i
'tAIN TURBINE ELECTR0 HYDRAULIC CONTROL SYSTEf1 Description of Circunstances:
On September 6,1979, while cerforming a routine startup of the Trojan Nuclear Plant, a speed control problem was encountered during warnup of the General Electric turbine and increase of turbine speed to normal operating speed (1800 RPM). Technicians were notified and trouble shooting in accordance with the technical nanual was comenced to resolve the apparent oscillation between the primary and backup speed control circuits which was hindering non al turbine startup operations. The technical nanual indicates that it is permissible to renove either th' primary or backup low value gate circuits which contain speed and acceleration error amplifiers.
Upon removal of the prinary low value gate circuit card, the backup card amplifiers, coming from a saturated condition, became the controlling circuit.
During the shift in control circuits (primary to backup), the speed / acceleration error signal went to maximum which resulted in a full open' signal to the turbine control valves.
Under existing plant conditions this appeared to the safety injection systen as a major steam break downstream of the main steam isolation valves which resulted in a safety injection system actuation and reactor trip.
The Electrohydraulic Control System (EHC) technical manual indicated that slight load changes are likely when a low value gate card is removed. The effect on an unloaded turbine appears to be nuch nore significant and tests conducted by
- GEK Instruction Book 11381-D, " Speed Control Unit", Maintenance Section, Page 4.
1943 148
IE Information flotice flo. 80-03 January 31, 1980 Page 2 of 2 Trojan cersonnel indicate that the transient is initiated whether the turbine is at a set speed or in an acceleration mode to a set speed. Discussions with General Electric personnel by the licensee have been initiated in an attempt to verify the phenomenon observed and, if applicable, alert other facilities which operate a turbine with a MK 1 EHC Systen regarding the potential operation of the control valves when trouble shooting the speed control unit in accordance with existing instructions.
This information is provided as an early notification of a possible significant matter.
It is expected that recipients will review the information for oossible applicability to their facilities. fio specific action or response is requested at this time.
If further flRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate flRC Regional Office.
Enclosure:
List of Recently Issued IE Information flotices 1943 149
IE Inforration flotice No. 80-03 Enclosure January 31, 1980 RECEllTLY ISSUED IE IflF0P1tATION fl0TICES Informa tion Subject Date Issued To flotice t'o.
Issued 80-02 8X8R Water Rod Lower 1/25/80 All BWR racilities End Plug Hear holder power reactor OLs or cps 80-01 Fuel Handling Events 1/4/80 All holders of power reactor OLs and cps 79-37 Cracking in Low Pressure 12/28/79 All power reactor OLs Turbine Discs and cps 79-36 Computer Code Defect in 12/31/79 All power reactor OLs Stress Analysis of Piping and cps Elbow 79-35 Control of !?aintenance 12/31/79 All power reactor facilities and Essential Equipment with an OL or CP 79-34 Inadequate Design of 12/27/79 All holders of power reactor Safety-Related Heat OLs and cps Exchangers 79-33 Ir.oroper Closure of 12/21/79 All power reactor facilities Prinary Containnent holding OLs and cps Access Hatches 79-32 Separation of Electrical 12/21/79 All power reactor facilities Cables for HPCI and ADS holding OLs and cps 79-31 Use of Incorrect Anolified 12/13/79 All holders of power reactor Response Spectra (ARS)
OLs and cps 79-30 Reporting of Defects and 12/6/79 All power reactor facilities Noncompliance,10 CFR Part 21.
holding OLs and cps and vendors inspected by LCVIP 79-29 Loss of flonSafety-Related 11/16/79 All power reactor facilities Reactor Coolant System holding OLs or cps Instrumentation Curing Operation
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