For study of distribution of several elements (mainly boron) in the brazed joints of Ni-base alloys and for optimization of post-bond heat treatment of the joints the neutron induced autoradiography (NIAR) using solid state nuclear track detectors (SSNTD) has been applied. For a big isotopic neutron source252Cf a special hexagonal tank was constructed, which is filled with water and in which walls the irradiation channels are placed. The comparative autoradiographs of the same samples have been performed both on the isotopic neutron source252Cf and the reactor ŠR-0.