The Reactivity Effect of Void and Hole

抄録

The reactivity loss caused by a hole introduced in a reactor is calculated by using the two group perturbation theory based on neutron balance. In this paper it is shown that better agreement with experimental results is obtained by the use of a more reasonable probability function than those of Marti and Schneeberger.
The reactivity loss by the presence of a void is calculated by the same method, and results are obtained for several cases : When void volume is below a certain limit, Δk(z) is independent of and proportional to the void volume; in the limit of small void, Δk(z) is proportional to the square of flux. From these results the mechanism of reactivity loss is discussed. In order to justify the discussion, we have made a comparison of the theoretical results with experiments on JRR-2.