ML17326A580
| ML17326A580 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/31/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dolan J INDIANA MICHIGAN POWER CO. |
| References | |
| NUDOCS 8003140467 | |
| Download: ML17326A580 (7) | |
Text
JAN 31 1980 Docket Ho 90-315 Doc3cat IIo. 50~
ecezfccc Elecccrc pocaz Service Corporation Indiana and Michigan Power Coupany kTTH:
Mr. John E. Dolan Vice Chairm:5n Engineering and Construction 2 Broadway New York, NT 10004 Centlcnen:
This Infonaation Hotice is provided as an early notification of a possibly signif1cant aatter. It is expected that recipients will review the inforaation for possible app1icability to their facilities Ho specific action or response is requested at this ti9ae If further HBC evaluations so indicate,.an IE Circular or BulIetin vtll be issued to reco1amend or request specific licensee actions. If you have questions regarding this
- aatter, please contact the Director of the appropriate HBC Beg1onal Office.
Sincerely, James G. Xeppler Director
Enclosure:
IE Inforaation Hotice Hoi 8&43 cc w/encl2 Hr De V Sheller' Plant Manager Central Pi~
- Director, HBB/DPM Director, NBB/DOR PDR Local PDR HSIC TIC Ronald C2QIen, Stchigan Publ1c Service Comartssion OFFICE 5URNAME eishman/bl 1/31/80 K per NRC Fnrrn 316A (R IK) (5 76} NRCM 02040 U. 5. GOVERNMENT PRINTING OFFICEI 1979-269 125 8OOa I,4O/S7
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 January 31, 1980 SSINS No.:
6870 Accession No.:
7912190666 IE Information Notice No. 80-03 MAIN TURBINE ELECTROHYDRAULIC CONTROL SYSTEM Description of Circumstances:
On September 6, 1979, while performing a routine startup of the Trojan Nuclear
- Plant, a speed control problem was encountered during warmup 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 manual was commenced to resolve the apparent oscillation between the primary and backup speed control circuits which was hindering normal turbine startup operations.
The technical manual indicates that it is permissible to remove either the primary or backup low value gate circuits which contain speed and acceleration error amplifiers.
Upon removal of the primary low value gate 4
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 tur bine control valves.
Under existing plant conditions this appeared to the safety injection system 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 much more significant and tests conducted by "GEK Instruction Book 11381-0, "Speed Control Unit", Maintenance
- Section, Page 4.
I
IE Information Notice No. 80-03 January 31, 1980 Page 2 of 2 Trojan personnel 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 phe'nomenon observed and, if applicable, alert other facilities which operate a turbine with a l1K 1 EHC System regarding the potential oper ation 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 possible applicability to their facilities.
No specific action or response is requested at this time. If further NRC 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 NRC Regional Office.
Enclosure:
List of Recently Issued IE Information Notices
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IE Information Notice No. 80-03 January 31, 1980 Enclosure Information Subject Notice No.
RECENTLY ISSUED IE INFORMATION NOTICES Date Issued Issued To 80-02 80-01 79-37
.79-36 79-35 79-34 8XBR Water Rod Lower End Plug Wear Fuel Handling Events Cracking in Low Pressure Turbine Discs Computer Code Defect in Stress Analysis of Piping Elbow Control of Maintenance and Essential Equipment Inadequate Design of Safety-Related Heat Exchangers 1/25/80 1/4/80 12/28/79 12/31/79 12/31/79 12/27/79 All BWR Facilities holder power reactor OLs or CPs All holders of power reactor OLs and CPs All power reactor OLs and CPs'll power reactor OLs and CPs All power reactor facilities with an OL or CP All holders of power reactor OLs and CPs 79"33 Improper Closure of Primary Containment Access Hatches 12/21/79 All power reactor faci 1ities holding OLs and CPs 79"32 79"31 Separation of Electrical Cables for HPCI and'ADS Use of Incorrect Amplified
Response
Spectra (ARS) 12/21/79 12/13/79 All power reactor facilities holding OLs and CPs All holders of power reactor OLs and CPs 79-30 Reporting of Defects and 12/6/79 Noncompliance, 10 CFR Part 21.
All'ower,reactor facilities holding OLs and CPs and vendors inspected by LCVIP 79"29 Loss of NonSafety-Related Reactor Coolant System Instrumentation During,.
Operation 11/16/79 All power reactor facilities holding OLs or CPs