ML18138A075
| ML18138A075 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 01/31/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Proffitt W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8003170066 | |
| Download: ML18138A075 (5) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION REGION II 101 MARIETTA ST., N.W., SUITE 3100 ATLANTA, GEORGIA 30303 JAN 3 1 1980.
In Reply Refer To:
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0 Virginia Ele<:tric and Power Company Attn:
W. L. Proffitt Senior Vice President, Power P. 0. Box 26666 Richmond, Virginia 23261 Gentlemen:
This Information Notice 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.
Enclosures:
- 1.
IE Information Notice No. 80-03
- 2. List of IE Information Notices Recently Issued Sincer:y
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Director
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e Virginia Electric and Power Company cc w/encl:
W.R. Cartwright, Station Manager Post Office Box 402 Mineral, Virginia 23117 P. G. Perry Senior Resident Engineer Post Office Box 38 Mineral, Virginia 23117 W. L. Stewart, Manager Post Office Box 315 Surry, Virginia 23883 JAN 31 1980
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e UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.*
20555 January 31, 1980 e
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 troubleshooting 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 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 appear~d 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 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 phenomenon observed and, if applicable, alert other facilities which operate a turbine with a MK 1 EHC System regarding the potential operation of the control valves when troubleshooting the speed control unit in accordance with existing instructions.
- GEK Instruction Book 11381-D, "Speed Control Unit", Maintenance Section, Page 4.
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IE Information Notice No. 80-03 January 31, 1980 Page 2 of 2 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.
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e IE Information Notice_No. 80-03 January 31, 1980 Information Notice No. 80-03 80-02 80-01 79-37 79-36 79-35 79-34 79-33 79-32 79-31 79-30 79-29 RECENTLY ISSUED IE INFORMATION NOTICES Subject Date Issued Main Turbine Electrohydraulic 1/31/80 Control System 8X8R Water Rod Lower 1/25/80 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 Improper Closure of Primary Containment Access Hatches 1/4/80 12/28/79 12/31/79 12/31/79 12/27/79 12/21/79 Separation of Electrical 12/21/79 Cables for HPCI and ADS Use of Incorrect Amplified 12/13/79 Response Spectra (ARS)
Reporting of Defects and 12/6/79 Noncompliance, 10 CFR Part 21.
Loss of NonSafety-Related 11/16/79 Reactor Coolant System Instrumentation During Operation e
Enclosure.
Issued To All holders of power reactor Operating Licenses and Construction Permits All BWR Facilities holder power reactor OLs or CPs All holders of power reactor OLs and CPs All power reactor OLs and CPs All power reactor OLs and CPs All power reactor facilities with an OL or CP All holders of power reactor OLs and CPs
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All power reactor facilities holding OLs and CPs All power reactor facilities holding OLs and CPs All holders of power reactor OLs and CPs All ~ower reactor facilities holding OLs and CPs and
. vendors inspected by LCVIP All power reactor facilities holding OLs or CPs