Modal analysis of spatial effects on transients in nuclear power reactor

The solution of the linearized space dependant reactor kinetics equations with fuel and moderator temperature coefficient feed backs are obtained by modal analysis. The heat transfer from fuel to moderator is explicitly considered through the heat balance equations. The delayed neutrons are lumped into one group. The space dependant transients due to localized perturbation such as insertion of fuel rod or withdrawal of control rod and uniform perturbation such as fractional loss of the coolant flow in a PWR are determined and compared with the solutions of space independent solutions. Transients resulting from a simultaneous introduction of localized and uniform perturbation are also examined. (author)