ML17339A725

Safety Evaluation Supporting Amend to App a of Licenses DPR-31 & 41

ML17339A725
Person / Time
Site:	Turkey Point
Issue date:	01/25/1977
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17339A722	List: ML17339A721 ML17339A723 ML17339A724 ML17339A725
References
NUDOCS 8003240545
Download: ML17339A725 (4)

Text

SAFETY EVALUATION

==

Introduction:==

This safety evalua ion supports a proposed change to Table 4.1-1 o the Turkey Point,.Technical Specifications.

Item 1, Remark 1 is revised to, add the option of using the "'hT vs. reactor power curve" during shift checks of the Nuclear Power Range instrument channels.

Discussion:

The present Technical Specification requires use of the "load vs. flux curve" during shift checks of the. Power Range instrumentation. The proposed change adds the option of using the "bT vs,. reactor power curve".

The Power Range nuclear -instrumentation is presently checked at'east once per shift by comparing level with the power level derived from the "load indicated'ower vs. flux curve". .By knowing the generator load and back pressure, the "load vs.. flux curve"can be used to determine reactor power. However,, because -of secondary inefficiency caused by such things as opening heater bypasses, changes in intake cooling water temperature, or changes in back pressure, large corrections may be needed in order'o derive the correct power level .from the "load vs. flux curve".

Therefore, it is proposed that the Technical be amended to permit the use of the "dT vs.

Specifications reactor power curve" when checking the accuracy of'he Poorer 'Range instrumentation..

Secondary inefficiency will not affect the power level derived from this curve, and the curve will be easy to use because the relationship between hT and reactor power is linear.

The purpose of the channel check is to detect gross failures such as blown fuses, defective indicators, or faulted amplifiers which result in "upscale" or "downscale" indica-tion. The capability of detecting such failures will not be reduced by, use of the "bT vs. reactor power curve". In addition, tne Power Range shift checks are backed-up by a daily calibration which provides a more accurate determination of instrument operability.

80082406 P

igi 0

==

Conclusions:==

~

Based on these considerations, (l) the proposed change does not increase the probability or cons'equences of accidents or malfunctions of equipment important to safety and does not reduce the margin of safety as. de-fined in the basis for any technical specification, therefore, the change does not involve a significant hazards. consideration, (2) there is reasonable assur-ance that the health and safety of the public will not be endangered by operation, in.,the proposed manner, and (3) such activities will be, conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common de-,

fense and security or to the .health and safety of the public.

i5 0