Digital instrumentation for reactor control

The paper describes neutron flux surveillance and monitoring instrumentation based on four M 6800 microprocessors. The structure comprises three channels, which correspond to the three power levels: source, intermediate and high level. Each of these calculates the flux rate and can give power alarm signals. A common subsystem controls the channels, i.e. it determines the validated channel and calculates the reactor period and reactivity from the signals issued by it. This instrumentation has been designed for experimental reactors, fast breeders and low power reactors. An industrial prototype has been manufactured and tested on a reactor, and is to go into continuous service on a reactor at the end of 1982. (author)