The main task of the Salaspils Research Nuclear Reactor IRT was to develop the classical science research branches associated with the use of nuclear energy (1961−1998). At the same time, nuclear technology problems were investigated at the reactor. IRT was modernized and its capacity increased to 5 MW, and possibilities of its application were expanded. A new source of gamma rays was created – a radiation circuit with the activity of 1.1×1015 Bq (1963−1998). The original non-power nuclear reactor RKS was built (1966–1990). The works related to power reactors were carried out, and the project of the Radiation department at the III block of Ignalina NPP was developed. Electrical insulation for nuclear fusion reactors was developed and used in the Tokamak device. Cylindrical and liquid metal regulators were designed for space nuclear reactors. Research on radiation resistance was carried out for electronic elements, and properties of semiconductors were improved. It should be noted that publication of the results in the open Soviet press area was very limited.