[en] The activity sources of the primary circuit of a sodium cooled fast reactor are considered. The circuit activity caused by solid and gaseous fission products is shown to be coamparble with the activity of corrosion products and sodium in the case of failure of approximately 1% of total number of fuel elements. The activity of the reactor gas system at a specific activity of ⁴¹Ar 2x10^-4 Ci/l is determined by fission products already at 10^-4-10^-3% fuel element failure. The dependence is shown of the shielding thickness around the column with protection and control system o(PCS) mechanisms n radiation of radioactive inert gases at different share of fuel elements with failed cans. Exposure doses to population outside the sanitary-protection zone would not exceed the rated value (0.17 rem per year) provided not more than 1-2% of total number of fuel elements fail

[en] Possibility of GT-MHR spent fuel storage during long time without additional processing is discussed in this paper. Spent fuel elements discharged from this reactor type are ideal waste forms for permanent disposal in a geologic repository. The graphite fuel elements and the ceramic coatings on the fuel particles are as-manufactured engineered barriers that provide excellent near field containment of radionuclides and minimize reliance on the waste package and surrounding geologic media for long-term containment. Because of the high level of plutonium destruction and degradation achieved by GT-MHR, the isotopic composition of residual plutonium in spent fuel elements would not be practical for use in nuclear weapons and for energy production. Dilution of plutonium within the relatively large volume of GT-MHR fuel elements provides excellent resistance to diversion throughout the fuel cycle. This is accomplished without adversely impacting repository land requirements, since repository loading is determined by decay heat load and not by physical volume. These conditions of safe fuel storage: criticality conditions, conditions of decay heat removing and radiation doses are discussed as well. (author)