ML20214H317

Proposed Tech Spec 3/4.3.4, Turbine Overspeed Protection, Increasing Test Frequency to 120 Days

ML20214H317
Person / Time
Site:	Beaver Valley
Issue date:	05/15/1987
From:	DUQUESNE LIGHT CO.
To:
Shared Package
ML20214H277	List: ML20214H276 ML20214H317
References
NUDOCS 8705270346
Download: ML20214H317 (2)

Text

INSTRUMENTATION o

3/4.3.4 TURBINE OVERSPEED PROTECTION LIMITING CONDITION FOR OPERATION 3.3.4 At least one of the following Turbine Overspeed Protection Systems shall be OPERABLE:

a. Mechanical overspeed

b. Electrical overspeed channel #1, and Electrical overspeed channel #2 APPLICABILITY: MODE 1 for testing, Turbine Start-Up** for OPERABILITY ACTION:

a. With one throttle valve or one governor valve per high pressure turbine steam line inoperable and/or with one reheat stop valve or one reheat intercept valve per low pressure turbine steam line inoperable, restore the inoperable valve (s) to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or close at least one valve in the affected steam line(s) or isolate the turbine from the steam supply within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

b. With the above required Turbine Overspeed Protection Systems otherwise inoperable, within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> isolate the turbine from the steam supply.

SURVEILLANCE REQUIREMENTS 4.3.4.1 The provisions of Specification 4.0.4 are not applicable.

4.3.4.2 The above required Turbine Overspeed Protecticn System shall be demonstrated OPERABLE:

• This 120 day testing may be postponed by the Plant Manager if plant or equipment deficiencies exist which could be aggravated by the conduct of the test, e.g., high vibration, low grid reserve, etc. Credit may be taken for testing if the unit was shutdown, or a trip occurred providing that all valves closed properly. If 120 day testing is not completed within the surveillance interval plus 25%, a Special Report shall be filed to the NRC within 30 days, explaining the nature of the problem and the details and schedule for corrective actions.

• • Turbine Start-Up is defined as the period under which the turbine is taken off the turning gear and increased to synchronous speed for paralleling the main unit generator with the grid.

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e SURYEILLANCE REQUIREMENTS (Continu d)

a. At least once per 120 days *, and each Turbine Start-Up** and shutdown if not performed in the previous 7 days, by cycling each of the following valves through at least once complete cycle from the running position:

1. [Four] high pressure turbine throttle valves,

2. [Four] high pressure turbine governor valves,

3. [Four] low pressure turbine reheat stop valves, and

4. (Four] low pressure turbine intercept valves.

b. At least once per 120 days *, and each turbine startup** and shutdown if not performed in the previous 7 days, by direct observation of the movement of each of the above valves through one complete cycle from the running position,

c. At least once each Turbine Start-Up**, if not performed in the past 7 days, by testing the electrical and mechanical overspeed trip circuits during performance of the Turbine Pedestal Checks,

d. At least once per 18 months by performance of a CHANNEL CALIBRATION on the electrical Turbine Overspeed Protection Systems and trip testing of the mechanical overspeed device,

e. At least once per 40 operating months by disassembling at least one of each of the above valves and performing a visual and surface inspection of valve seats, disks, and stems and verifying no unacceptable flaws or excessive corrosion. If unacceptable flaws or excessive corrosion are found, all other valves of that type shall be inspected unless the nature of the problem can be directly attributed to a service condition specific to that valve,

f. Performance of a MANUAL TRIP TEST during each Turbine Start-Up** if not performed in the previous 7 days, and

g. Performance of a Overspeed Protection Control (OPC) Test during each Turbine Start-Up** if not performed in the previous 7 days.

• This 120 day testing may be postponed by the Plant Manager if plant or equipment deficiencies exist which could be aggravated by the conduct of the test, e.g., high vibration, low grid reserve, etc. Credit may be taken for testing if the unit was shutdown, or a trip occurred providing that all valves closed properly. If 120 day testing is not completed within the surveillance interval plus 25%, a Special Report shall be filed to the NRC within 30 days, explaining the nature of the problem and the details and schedule for corrective actions.

• • Turbine Start-Up is defined as the period under which the turbino is taken off the turning gear and increased to synchronous speed for paralleling the main unit generator with the grid.

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