Maximum neutron flux in thermal research reactors

This paper deals with the determination of the space distribution of fuel concentration in thermal reactors for the purpose of obtaining maximum neutron flux. With some approximations, this problem is reduced to a nonclassical variational problem, which is solved by using Pontryagin's maximum principle. It is shown that the optimal fuel configuration of the reactor core consists of a reflector in its center, a zone of constant (permissible) power density, a zone of constant (maximum) fuel concentration, and a peripheral reflector of infinite thickness.