PISTIL, a reactivity modulation device to probe the transfer function of the nuclear reactor CROCUS

The present article summarizes the development and testing of a reactivity modulation device developed by French Atomic Alternative Energies Commission (CEA). It was installed in CROCUS reactor Swiss Federal Institute Technology Lausanne (EPFL). Experimental tests were performed framework collaboration between CEA EPFL. so-called PISTIL aims at measuring nuclear transfer function frequency range interest 1 mHz 200 Hz, order to probe in-core kinetic behavior prompt delayed neutrons. is obtained from rotation cadmium foils. design system driven with objective installing center reactor. Neutronic simulations TRIPOLI-4 Monte Carlo code select suitable parameters meet safety requirements operation. total worth device, as estimated calculation, approximately 0.16 $ maximum amplitude about 0.013 $. In-core calibration then consistent compared estimations.