The final calibration of the nuclear power channels of the IPEN/MB-01 reactor by the use of the activation fiels and the Monte Carlo method

Abstract

This work aims the final calibration of the nuclear power channels of the IPEN/MB-01 reactor using infinitely dilute gold foils (1% Au - 99% Al), this is, metallic alloy in the concentration levels such that the phenomena of flux disturbance, as the self-shielding factors become worthless. During the irradiations were monitored the nuclear power channels of the reactor used to obtain the neutron flux and consequently the power operation of the reactor. The current values were digitally acquired during each second of operation. Once the foils were irradiated for the analysis of its induced activity it was used a detection system of hyper-pure germanium. Ally to this experimental procedure it was used the computational code MCNP-4C as a tool for theoretical modeling of the core of the IPEN/MB-01 reactor. Thus it was possible to determine the parameters necessary to obtain the power operation of the reactor, such as the inverse of the thermal disadvantage factor and fast fission factor. Thus, using the correlation between average thermal neutron flux, proportional to a power operation and the average of the digital values of current of the nuclear channels, during the irradiations of the foils, it was obtained the calibration of the nuclear power channels, the ionization chambers number 5 and 6 of the IPEN/MB-01 reactor.