ML20063N676

Proposed Revision to Tech Spec Table 4.3-11 Re Steam & Feedwater Rupture Control Sys Instrumentation Surveillance Requirements.Safety Evaluation Encl

ML20063N676
Person / Time
Site:	Davis Besse
Issue date:	09/30/1982
From:	TOLEDO EDISON CO.
To:
Shared Package
ML20063N672	List: ML20063N671 ML20063N673 ML20063N676
References
TAC-48816, NUDOCS 8210050318
Download: ML20063N676 (3)

Text

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o Docket No. 50-346 License No. NPF Serial No. 864 September 30, 1982 i

i Attachment l I. . Changes to Davis-Besse Nuclear Power Station Unit 1,' Appendix A Technical Specifications Table 4.3-11.

A. Time required to Implement. This' change is to be effective upon NRC approval.

B. Reason for Change (Facility Change Request 82-149).

I C. Safety Evaluation

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8210050318 820930 i PDR ADOCK 05000346 P PDR

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SAFETY EVALUATION Davis-Besse has exceeded the Surveillance Test Period on the Steam and .

Feedwater Rupture Control System Main Steam Line Low Pressure Switches.

The Technical Specifications require that the switches be tested on a monthly basis with a 25% time allowance. The licensee has exceeded the Technical Specification Surveillance Interval since midnight of September 12, 1982.

Past' history of the switches has shown no tendency for instrument drift such that there is currently no technical reason to suspect that the switches are inoperable. The switches have been recently calibrated during the last refueling outage. A strict interpretation of the Technical Specifications currently requires rapid shutdown. navis-Besse is pre-sently at about 75% of rated power. To avoid an vs.necessary transient on the unit due to a shutdown, Toledo Edison wants to extend the surveillance period for 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> to extend the time limit to 2400 hours0.0278 days <br />0.667 hours <br />0.00397 weeks <br />9.132e-4 months <br /> on September 16, 1982.

The safety function of these pressure switches is to provide a steam pressure input to the SFRCS indicating a rupture in the main steam system.

The SFRCS is composed of two actuation channels, each of which will

-isolate both main steam lines and associated feedwater lines upon the detection of a rupture'in either main steam line.

Each SFRCS actuation channel will also initiate the train of auxiliary feedwater and isolate one steam generator. One of the two actuation trains has been completed and satisfactorily tested. Each train picks up pressure indications from both steam lines, therefore, the plant presently -

has the ability to sense loss of steam pressure and provide subsequent protective action as described above assuming no failures occur in the tested train prior to completing the required surveillance.

Toledo Edison, therefore,' feels that the granting of this emergency Technical Specification change is justified.

9/16/82 nif

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a . TABLE 4.3-11 .

a g STEAM AND FEE 0 HATER RUPflJRE CollTROL SYSTEH e, , INSTRUMENTATION SURVEILLANCE REQUIREMENTS' 9

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X; CHAHEEL E CFANNEL CHANNEL FUNCTIOK4L

$ FUNCTIONAL UNIT CHECK CALIBRATION TEST

1. Instrument Channel

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a. Steam Line Pressure - Low S R H

b. Steam Generator Level - Low S R* H )

c. Steam Generator - Feedwater S R  !! I Differential Pressure-High

d. Reactor Coolant Pumps-Loss of S R H u -

h 2. Manual Actuation NA NA R* il i

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• Eighteen-month surveillance test due in March 1982 delayed until EE" g 8 lT 8 g March 31,1982. 8"?

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+ The Surveillance Period for Steam Line Pressure - Lou Switches is extended by 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> to-end at 2400 hours0.0278 days <br />0.667 hours <br />0.00397 weeks <br />9.132e-4 months <br /> on 9/16/82.

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