Physical startup of the IVV-2 nuclear research reactor at nominal power 5 MW was conducted 50 years ago. Designers, builders, and personnel at the Institute of Reactor Materials needed about 10 years to develop a new reactor – IVV-2M – on the basis of the IVV-2 design. The redesign, which was accomplished in 1974–1982, made it possible not only to increase the neutron-physical parameters of the reactor but also the nuclear and radiation safety. The structural features of the IVV-2M reactor and the basic problems now being solved as well as the prospects for new advancement are shown in the present article.