The article describes and proves the possibility of increasing the protection against neutron radiation for personnel by means of immersion liquid without major changes in the design of the equipment used and without reducing the safety of the radiation object. Studies of the components properties of the protection glass and the immersion liquid have shown that the properties of the immersion liquid reduce the dose rate of neutron radiation significantly compared to the protection glass, which is used for the main protection against ionizing radiation when working with uranium-plutonium fuels. The use of two-layer protection in viewing windows allows reducing the dose rate of mixed gamma-neutron radiation to values that do not exceed the safe radiation dose for personnel when working with an ionizing radiation source, which in this case is 50 kg of uranium-plutonium fuel