On-line monitoring of the reactivity and control rods worth at the IPR-R1 TRIGA reactor

Abstract

On-line monitoring of several new process variables of the IPR-R1 TRIGA reactor of the Nuclear Technology Development Center - CDTN became possible after the data acquisiton and processing system implementation and the installation of one instrumented fuel rod in the reactor core. Several neutronics and thermo-hydrailics parameters are now registered, such as the opeation power, the reactivity insertion in the core, the control rod position, the fuel and the water temperature, and so on. Since the inherently safe operation of a reactor is dependent on the reactivity control, it is essential to have information on this parameter over many different temperature ranges. The fuel elements have been designed to provide a significant prompt negative temperature coefficient that allow safe reactor operation. This paper describes the methodology and the results found with in the on-line monitoring of the reactivity behavior of the IPR-R1 TRIGA reactor.