[en] For many years there has been a sustained international interest in partitioning and transmutation of the Actinides, and particularly americium, neptunium and curium, mainly because of the major contribution to the decay heat and radiotoxicity of spent nuclear fuel. Therefore in the current report are examined the possibilities for high level waste reduction through transmutation of these three minor Actinides. The main objectives of minor actinide partitioning and transmutation processes are described and the technological options of such process are revealed. A software experiment showing the possibilities of Actinides transmutation of the most utilized thermal reactors is conducted. The experimental results and comparison of the transmutation possibilities of thermal reactors is also shown. Keywords: minor Actinides, spent nuclear fuel, thermal reactors, transmutation

[en] Weapons-grade substance is a material with level of enrichment or with characteristic suitable for nuclear bombs production. The most commonly used weapon-grade isotopes in different experiments are uranium-235 and plutonium- 239. It is known that isotopes like uranium-233, neptunium-237 and some isotopes of americium have also been used for the purposes of experimental researches, but by now there is no information they have been used for a real nuclear weapons production. The goal of the present analysis is to be examined if the spent nuclear fuel of the most common nuclear reactors for electricity production, viz. pressurized water reactors, can be classified as practically unusable or not for nuclear explosive made-up. The possibilities for nuclear materials procurement are analyzed and the concentration levels of the main isotopes (plutonium-239, neptunium-237, americium-241, americium-242m and americium-243) are examined and estimated. The significant quantities necessary for nuclear bombs production according to International Atomic Energy Agency are also estimated by comparing them with the obtained results. The results of this analysis may be useful in specifying the technical and organization actions which can increase the proliferation resistance of the fissile materials. Keywords: explosive device, nuclear bomb, significant quantity, weapons-grade material

[en] Weapons-grade substance is a material with level of enrichment or with characteristic suitable for nuclear bombs production. The most commonly used weapon-grade isotopes in different experiments are uranium-235 and plutonium- 239. It is known that isotopes like uranium-233, neptunium-237 and some isotopes of americium have also been used for the purposes of experimental researches, but by now there is no information they have been used for a real nuclear weàpons production. The goal of the present analysis is to be examined if the spent nuclear fuel of the most common nuclear reactors for electricity production, viz. pressurized water reactors, can be classified as practically unusable or not for nuclear explosive made-up. The possibilities for nuclear materials production are analyzed and the concentration levels of the main isotopes (plutonium-239, neptunium-237, americium-241, americium-242m and americium-243) are examined and estimated. The significant quantities necessary for nuclear bombs production according to International Atomic Energy Agency are also estimated by comparing them with the obtained results. The results of this analysis may be useful in specifying the technical and organization actions which can increase the proliferation resistance of the fissile materials. Keywords: explosive device, nuclear bomb, significant quantity, weapons-grade material

[en] In the article are discussed the radiation effects on humans, which can be obtained during the process of commissioning and decommissioning of nuclear facilities. The effects of small and large dose rates and examined the relationship between radiation influence and the probability of stochastic and deterministic effects are presented. (authors)