Proliferation resistance problem is one of the central in developing nuclear power reactors and its fuel cycle for future nuclear power system. In particular, the Initiative of the President of the Russian Federation (announced at the UN Millennium Summit on September 6, 2000) and International Project INPRO are drawing much attention to solving of non-proliferation problem. Analogous goals in non-proliferation area are under consideration in Nuclear Energy Research Initiative (NERI) and in Generation IV International Project started to support International Program on development of nuclear power systems on new generation.

In order to chose the most effective strategy among alternatives available it is necessary to have a tool for detailed comparative analysis of various technologies using number of criteria including safety, economics, environment protection, proliferation resistance.

Proliferation resistance is a criterion among listed criteria that the most difficult to be quantitative assessed. Many papers have been published on this issue recently, though. Development of such kind of tools started comparatively not long ago and therefore there doesn't exist at the moment in the world universal and internationally agreed approach that can do objective analysis of different nuclear technologies towards their proliferation resistance.

One of the practical approaches towards quantitative assessment of attractiveness of nuclear materials of nuclear power fuel cycle for its use in creating nuclear weapons is discussed in this paper.

Attractiveness of nuclear materials in the first place depends on their inherent nuclear properties due to which sustainable chain reaction can be carried out. Besides, some additional factors have an influence upon the attractiveness of nuclear materials are available in nuclear fuel cycle of peaceful nuclear power. These factors take into account the necessity to apply additional technologies to convert nuclear fuel cycle materials - source materials to weapons-usable materials. These factors call technological factors.

Doing analysis of nuclear data for enriched uranium and civil plutonium accumulated in spent fuel of nuclear reactors of different types it is possible to assess attractiveness and hence the possibility to use these materials for nuclear weapons production. Taking into account critical mass, spontaneous neutron source, heat generation, and radioactivity it is possible to make classification of enriched uranium of different enrichment and civil plutonium of different sources by their suitableness to be used in nuclear weapons or nuclear explosive devices. In this paper the authors proposed to use the following four classes: “Very attractive”, “Attractive”, “Low attractive”, Non-attractive”.