The IBR-2M high-flux pulsed reactor, operating at the Frank Laboratory of Neutron Physics (JINR) with a neutron flux density of ~5⋅10¹² n/(cm² s) will reach the end of its service life by the end of the 2030s and will be shut down. The main disadvantage of the neutron sources proposed instead of the IBR-2M is the need for significant development work. The essence of the proposal for the new source, provisionally called IBR-4, is as follows: in its development and construction, to a large extent use technical solutions that are already ready and tested at other nuclear facilities. Particular attention is paid to the problem of reactor operation stability. The results of preliminary calculations for IBR-4 with plutonium dioxide fuel are presented. In this case, the source is feasible, reliable and safe. At a frequency of 10 1/s and a power of 5 MW, the maximum density of the thermal neutron flux on the surface of the IBR-4 water moderators is about 1.5 10¹³ cm^-2∙s^-1, which is three times higher than that of IBR-2M.