[en] A neutron feasibility study for HEU (90%)-MEU (36%) conversion of the reactor PIK was performed. The weak absorbing aluminum matrix was proposed in meat of the new PIK-2 FE instead of copper in reference case of standard PIK. The stainless steel cladding was left the same. For the additional gain in reactivity the stainless steel vessel and housing were changed for aluminum ones. The neutronics of the full scale computer model of PIK reactor core was computed with Russian Monte Carlo code MCU PR. Calculations show that a uranium density of 3.64 gU/cm³ of MEU (36%) fuel leads to better core parameters. Compared to reference case, the PIK-2 FE with MEU fuel and 1/3 lower loading by ²³⁵U have a longer equilibrium fuel cycle (27 fpd instead of 24 fpd) and higher burnup (37.3% instead of 23.7%). Due to lower neutron absorption in aluminum vessel and housing, all thermal neutron fluxes in D₂O-reflector increased about 1.4 times. The worth of control regulators increased several times. This neutronic feasibility study of fuel enrichment reduction of PIK reactor is sufficient to start the fabrication feasibility study and subsequent in-pile irradiation tests of PIK-2 FE with MEU (36%) fuel. (author)