Criticality Tester - An Application of the Rossendorf Mini Multi-Channel Analyzer

The Criticality Tester (CT) became an IAEA routine inspection device in 1997. It consists of a neutron detector with preamplifier, a multi-channel analyzer (MCA) operating in multiscaling mode and a computer with the software TREND95 for instrument control, data evaluation, automatic decision making and reporting of results. The device can be used to prove the presence of a critical mass in a research reactor by measuring the neutron flux in the supercritical state as a function of time. The CT was developed especially for verification of zero power reactors and critical assemblies. The main hardware component of the CT is a multi-channel analyzer. Here the Rossendorf MiniMCA is used preferentially. The MiniMCA includes a special software for the CT application, the MCS code. This code was tested at the Training Reactor AKR of the Dresden University of Technology. The tests have shown that the MiniMCA can be used successfully as CT hardware component. Furthermore, other safeguards applications of the Rossendorf MiniMCA were tested. The tests resulted in an improved MiniMCA software. The MiniMCA and the Criticality Tester were developed under the German Support Programme for the IAEA and the EURATOM Inspectorates.