Modular Electronics for Reactor Control Instrumentation in France

The purpose of actual studies concerning reactor control instrumentation connected with neutron detectors are essentially 1. The possibility to put far away electronic devices from the neutrons detectors, eventually to cancel preamplifiers (so that the electronic devices will operate in normal conditions without damage due to radiations and temperature). 2. The increase of the scale and the discrimination ratio between neutrons and gamma measurements, chiefly for pulse amplifiers. 3. A better compromise between time constant and noise for all the levels of electric information given by the neutron detectors. The results of these studies are given and also the description of the different "modular blocs" is done; main characteristics are mentioned: scale, accuracy, time constant, etc... The various possibilities for connection between the different "blocs" show that modular electronics for reactor control instrumentation is well fitted with the increase of automatic devices and the concentration of measurements in reactor control. A great number of tests of this new instrumentation have been done on several experimental reactors and the results are given (including the rate of failures).