Computing neutron detector response to power reactor mechanical structure vibrations

Neutron detector response to power reactor mechanical structure vibrations is computed in order to obtain a quantitative reference for noise analysis. For a space-dependent approach in large cores, Cohnʹs method of reducing time-dependent neutron balance equations to statics equations was considered. In order to produce detector response matrices, depending on many vibrating sources1 and frequencies, a dedicated 3-D code was developed. Simulations indicated that response matrices could be used to locate vibrating sources for low local to global noise ratios and to obtain their vibration amplitudes.