ML19261A416
| ML19261A416 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 01/11/1979 |
| From: | Whitmer C GEORGIA POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7901180153 | |
| Download: ML19261A416 (5) | |
Text
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E ng meyring January 11, 1979 Director of Nuc1 car React 'r Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 TURBINE CONTROL VALVE FAST CLOSURE TRIP OIL PRESSURE Gentlemen:
Pursuant to 10 CFR 50.90, as required by 10 CFR 50.59(c)(1), Georgia Power Company hereby proposes an amendment to the Technical Specificaticas (Appendix A to the Operating License). This proposed change wil.1 minimize the inadvertent scramming of the reactor during turbine control valve (TCV) l maintenance testing by the lowering of the setpoint for the fast closure j
trip of the TCV.
Enclosed is supporting information for the proposed technical specification along with a copy of the proposed revision. Your attention given this matter is appreciated.
Yours very truly, 1
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-Chas. F. Whitmer WEB /mb Enclosuren Sworn to and subscrib_ed before me this lith day of January, 1979.
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George F. Trowbridge, Esquire 901180153
SUPPORTING INFORMATION FOR PROPOSED TECilNICAL SPECIFICATION TURBINE CONTROL VAINE FAST CLOSURE TRIP SETPOINT 1.
SCOPE:
The proposed change to the Technical Specification 2.2.1 Table 2.2.1-1 will reduce the trip setpoint and allowable values for the turbine control valve fast closure trip oil pressure from > 1100 psig to > 600 psig.
2.
PURPOSE The change is proposed to minimize unnecessary turbine control valve fast closure trip switch actuation and subsequcnt reactor scram uuring the expected electrohydraulic control (EHC) oil pressure transients experienced at the turbine control valves during testing.
3.
JUSTIFICATION The incorporation of this change into the Technical Specifications would greatly decrease the probability of an inadvertent reactor scram due to EHC oil pressure fluxuations by increasing the margin between normal operating EHC oil pressure and the trip setpoint.
The consequent decrease in unwarranted thermal cycles on the reactor vessel provides significant justification for the proposed change.
The margin of safety as defined in the Technical Specifications is not reduced by this change.
The Reactor Protection Systcm (RPS) initiates a scram when the turbine control valves start to close.
The control valves begin te fast close when the EHC pressure drops below that pr essure required to maintain the disk dump valve closed.
The RPS pressure switches monitor this EHC pressure and ihitiates a scram before the pressure decreases low enough to permit the disk dump valve opening and subsequent control valve fast closure.
The pressure setpoint propored has sufficient margin above the control valve trip setpoint to assure maintenance of the conservative mar-gins of the FSAR evaluation while improving reactor reliability through minimizing the scrams caused by EHC test condition fluctu-ation.
4.
Evaluation The Plant Review Board and Safety Review Board have reviewed and approved the proposed change _to the Technical Specification and have determined that they do not involve an unreviewed safety question since the safety margins of the FSAR Chapter 15 analysis are not reduced by the lowering of the RPS pressure switch setpoint to a polat which is still adequately above the pressure at which a fast closure of the control valve begins.
It can be conc 1'uded that the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety is not increased nor is the possibility of a new accident or malfunction of equipment important to safety created.
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ATTACllMENT 1 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. !!ATCil NUCLEAR PLANT UNIT 2 PROPOSED CilANGES TO TECllNICAL SPECIFICATIONS Pursuant to 10 CFR 170.12 (c), Georgia Power Company has evaluated the attached proposed amendment to Operating License NPF-5 and have determined that:
a)
The proposed amendment does not require the evaluation of a new Safety Analysis Report or rewrite of the facility license; b)
The proposed amendment does not contain several complex issues, does not involve ACRS review, or does not require an environmental impact statement; c)
The proposed amendment does not involve a complex issue, an environ-mental issue or more than one safety issue; d)
The proposed amendment does involve a single issue; namely the reducing of the trip setpoint for the turbine control valve fast closure trip oil pressure.
c)
The proposed amendment is therefore a Class III amendment.
ATTACllMENT 2 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I.11ATCll NUCLEAR PLANT UNIT 2 PROP 0st.D Ciiiea;ES TO TECllNICAL SPECIFICA CIONS The proposed changes to Technical Specifications (Appendix A to Operating License NPF-5 would be incorporated as follows:
Remove PaEc Insert Page 2-4 2-4 e
9
Ej TABLE 2.2.1-1 ej[
REACTOR PROTECTION SYSTEM INSTRUMENTATION'SETPOINTS E
-d ALLOWABLE
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FUNCTIONAL UNIT TRIP SETPOINT VALUES 1.
Intermediate Range Monitor, Neutron Flux-High
< 120/125 divisions of fusi scale < 120/125 divisions (2C51-K601 A,B,C,D,E,F,G,H) of full scale 2.
Average Power Range N'..itor:
(2C51-K605 A,B,C,D,E,F)
Neutron Flux-High, 15%(a)
< 15/125 divisions of full sca'_
< 15/125 divisions of a.
full scale b.
Flow Biased Neutron Flux-High(b)
- L(0.66 W + 54%)
y;(0.66 W + 54%)
3.
Reactor Vessel Steam Dome Pressure - High 5,1045 psig 5,1045 psig (2B21-N023 A,B,C,D) no 4.
Reactor Vessel Water Level - Low
-> 12.5 inches above instrument
> 12.5 inches above )
E (2B21-N017 A,B,C,D) zero(c) instrument zero(c 5.
Main Steam Line Isolation Valve - Closure
-< 10% closed
< 10% closed (NA)
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6.
Main Steam Line Radiation - High
-< 3 x full power background
-< 3 x full power (2Dll-K603A,B,C,D) background 7.
Drywell Pressure - High
- E 2 psig
- L 2 psig (2C71-N002A,B,C,D) 8.
Scram Discharge Volume Water Level - High
__ 57.15 gallons 5,57.15 gallons (2Cll-N013A,B,C,D) 9.
Turbine Stop Valve - Closure
< 10% closed
< 10% closed (NA)
- 10. Turbine Control Valve Fast Closure, Trip Oil Pressure-Low
> 600 osig
> 600 psig (2C71-N005A,B,C,D)
-