Calculation of the neutron noise induced by shell-mode core-barrel vibrations in a 1-D 2-group 2-region slab reactor
The subject of this work is the calculation of the in-core neutron noise, induced by the shell-mode vibration of the core-barrel. The original motivation was to investigate whether an out-of-phase behaviour can exist between the in-core and ex-core detectors lying on the same azimuthal position. To this order a two-region two-group diffusion model was used in one dimension. The noise was calculated in the adiabatic approximation. It was found that an out-of-phase behaviour can exist between in-core detectors, close to the core boundary, and the ex-vessel detectors, for large systems. In addition, due to the use of two-group theory, the strong local noise component at the boundary of the vibrating core was also found. The paper gives details of the calculations and the results.