ML19290E804
| ML19290E804 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 01/31/1980 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Stampley N MISSISSIPPI POWER & LIGHT CO. |
| References | |
| NUDOCS 8003170044 | |
| Download: ML19290E804 (2) | |
Text
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,(ja jo, UNITED STATES y yv.,. j NUCLEAR REGULATORY COMMISSION 3 4 h_., f e
REGION 11 9, Q4,,
101 MARIETT A ST, N.W., SUITE 3100
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ATLANTA, GEORCI A 30303
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m;31 w In Reply Refer To:
RII:JPO 416, 50-41L-Mississippi Powe.r and Light Company Attn:
N. L. Stampley Vice President of Production P. O. Box 1640 Jackson, Mississippi 39205 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 vill 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.
Sincerely, v-
~1 James P.
eilly Director
Enclosures:
1.
IE Information Notice No. 80-03 2.
List of IE Information Notices Recently Issued 4
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I $E2 Mississippi Power and Light Company cc w/ encl:
C. K. McCoy Plant Manager Post Office Box 756 Port Gibson, Mississippi 39150 9
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UNITED STATES SSINS No.
6870 NUCLEAR REGULATORY COMMISSION Accession No.
OFFICE OF INSPECTION AND ENFORCEMENT 7912190666 WASHINGTON, D.C.
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January 31, 1980
_J e, 23_ ad IE Information Notice No. 80-03 MAIN TURBINE ELECTR0 HYDRAULIC CONTROL SYSTEM Description of Circumstances:
On September 6,1979, while performing a routine startup of the Trojan Nuclear Plant, a speed control problem war. 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 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 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 troublesnooting the speed control unit in accordance with existing instructions.
- GEK Instruction Book ll381-D, " Speed Control Unit", Maintenance Section, Page 4.
IE Information Notice No. 80-03 January 31, 1980 Page 2 of 2 This infocmation is nrovided 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.
IE Information Notice No. 80-03 Enclosure January 31, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Info rma tion Subject Date Issued To Notice No.
Issued 80-03 Main Turbine Electrobydraulic 1/31/80 All holders of power Control System reactor Operating Licenses and Construction Permits 80-02 8X8R Water Rod Lower 1/25/S0 All BWR Facilities End Plug Wear 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
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Computer Code Defect in 12/31/79 All power reactor OLs Stress Analysis of Piping and cps Elbow 79-35 Control of Maintenance 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 Impzoper Closure of 12/21/79 All power reactor facilities Primary Containment holding OLs and cps Access Hatches 79-32 Separation of Electrical 12/21/79 All power reactor facilities Cables for EPCI and ADS holding OLs and cps 79-31 Use of Incorrect Amplified 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 CP.s and vendors inspected by LCVIP 79-29 Loss of NonSafety-Related 11/16/79 All power reactor facilities Reactor Coolant System holding OLs or cps Instrumentation During Operation
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