L. J Csider, A. J. Hornfeck, D. Wurster, and R. W. Check

4- 1 INTRODUCTION

The term “process instrumentation” in nuclear power plants refers to all the out-of-core (exposed to <10’ 1 fast neutrons cm 2 sec 1) instrumentation except nuclear- radiation instrumentation.

Emphasis in this chapter is on the techniques used to measure the most important plant operating parameters— temperatures, pressures, flow rates, and coolant properties Many other process instruments are involved in nuclear power plant operation, ranging from those associated with auxiliary chemical processes (waste treatment, coolant purification, etc ) to those involved in maintaining the plant atmosphere (air filtration and conditioning, ventilation, etc )

Certain process instrumentation is so closely associated with specific plant components (e. g, control-rod position sensing) or with a particular reactor type (e. g, moisture detection in gas-cooled reactors) that it is more properly discussed in other chapters Cross references are provided in these cases

No single book (and certainly no single chapter in a book) can cover all significant aspects of even one category of process instrumentation m nuclear power plants