ML20210T740

Proposed Tech Specs,Revising TS to Allow Use of Elbow Tap Differential Pressure Measurements Instead of Precision Heat Balance Measurements to Determine RCS Total Flow Rate

ML20210T740
Person / Time
Site:	South Texas
Issue date:	09/04/1997
From:	HOUSTON LIGHTING & POWER CO.
To:
Shared Package
ML20210T738	List: ML20210T740 ST-HL-AE-5743, Application for Amends to Licenses NPF-76 & NPF-80,revising TS to Allow Elbow Tap Differential Pressure Measurements to Be Used Instead of Precision Heat Balance Measurements to Determine RCS Total Flow Rate
References
NUDOCS 9709160054
Download: ML20210T740 (3)

Text

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I ATTACIIMENT 2 ANNOTATED TECIINICAL SPECIFICATION AND IIASES PAGES 4-9709160054 970904 8 ADOCK 0500

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POWER DISTRIBUTION LIMITS 4

i '3/4.2.5 - DNB PARAMETERS LIMITING CONDITION FOR OPER ATION 3.2.5 The following DNB-related parameters shall be maintained within the limits following:

a. Reactor Coolant System Tavg, <_598'F

b. Pressurizer Pressure, > 2189 psig*

c. Reactor Coolant System Flow.2 392,300 gpm**

APPLICABILITY: MODE 1.

ACTION:

With ar.y of the above parameters exceeding its limit, restore the parameter to within its limit withm 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or reduce THERMAL POWER to less than 5% of RATED THERMAL POWER within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

SURVFII1 ANCE REOUIREMENTS 4.2.5.1 Each of the parameters shown above shall be verified to be within its limits at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The provisions of Specification 4.0.4 are not applicable for ve.ification that RCS flow is within its limit.

4.2.5.2 The RCS How rate indicators shall be subjected to a channel calibration at least once per 18 months.

4 NOTE SRL4.2.5.3 is required at beginning4f-cycle With it.actof pswer 2 90% RTPi 4.2.5.3 The RCS total llow rate shall be determined by precisian heat balance EciSwt$dM)) measurements at least once per 18 months. The provisions of Specification 4.0.4 are not applicable.

• Limit not applicable during either a Thermal Power ramp in excess of 5% of RTP per minute or a Thermal Power step in excess of 10% RTP.

• • Includes a 2.8% Oow measurement uncertainty.

SOUTH TEXAS - UNITS 1 & 2 3/4 2-11 Unit 1 - Amendment No. (4 Unit 2 - Amendment No. 50

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_ -o POWER DISTRIBUTION LIMITS 4 BAS $S -

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3/4.2.5 DNB PARAMETERS (Continued) initial FSAR assumptions and have been analytically demonstrated adequate to maintain a minimum DNBR of greater than or equal to the design limit throughout each analyzed transient. The Tavg value of 598 F and the pressurizer pressure value of 2189 psig are analytical values. The readings from four channels will be averaged and then adjusted to account for measurement uncertainties before comparing with the required limit. The flow requirement (392,300 gpm) includes a ineasurement uncertalaty of 2.8%.

The RCS flow measurement uncenainty of 2.8% bounds the precision heat balance and the elbow tap Ap measurement methods; The elbow' tap Ap measurement uncertainty presumes _that elbow tap Apl measurements are obtained from either QDPS or the plant process computer. Based on instrument uncertainty assumptions, RCS flow measurements using either the precision heat balance or the elbow tap Ap measurement methods are to be performed at greater than or equal to 90% RTP at t_he beginning of a new fuel cycle.' _.The elbo_w tap Ap measurement methodology is described in Westinghouse report SAE/FSE-

- TGX/fHX-0152.

The 12-hour periodic surveillance of these parameters through instrument readout is sufficient to ensure that the parameters are restored within their limits following load changes and other expected transient operation.

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- SOUTH TEXAS - UNITS 1 & 2 B 3/4 2-6 Unit 1 - Amendment No. 61 !108 95 Unit 2 - Amendment No. 60