Fast reactors and nuclear nonproliferation problem

The growing number of countries wishing to use nuclear energy, and the expansion in the geography of NPPs entails the risk of nuclear weapons proliferation, given that political leaders in some countries may want to purchase or develop sensitive nuclear technologies. A certain risk of proliferation through nuclear power technologies and materials cannot be excluded altogether. In the nuclear fuel cycle there are large inventories of nuclear materials, including fissile materials, (many hundreds and thousands of tons). The problem of spent nuclear fuel with plutonium in it, especially for novice countries and countries with small nuclear power program, also increases the risk of proliferation, including the growing risk of actions on the part of subnational or terrorist organizations because of the proliferation of nuclear technologies and materials as respective protection measures are insufficient in these countries.In the event of thermal reactors, uranium enrichment is indispensable to production of fuel. Long-term storage of SNF from thermal reactors in an open fuel cycle, which is a common practice nowadays, entails an increased risk of proliferation due to the weakening of the radiation barrier over time and the potentiality of unauthorized removal of fuel by the proliferator state and its theft by criminals and terrorists.Fast-neutron reactors started up and operating on plutonium fuel do not require uranium enrichment. There is no long-term storage of SNF in the closed fuel cycles of fast reactors. Gradual replacement of thermal reactors by fast reactors, due to natural uranium being in short supply, creates prerequisites for phasing out uranium enrichment. However, countries having small nuclear power programs and, therefore, a limited number of nuclear units will use thermal reactors still for a long time, which will require uranium enrichment.Creation of nuclear weapons based on energy-grade plutonium using a simpler “gun-type” design is practically impossible because of a high neutron background inherent in this kind of plutonium. However, this does not exclude the potentiality of terrorist attempts to fabricate a primitive nuclear explosive device.Both sensitive technologies (uranium enrichment and SNF processing with separation of plutonium) will be used to start up fast reactors on uranium fuel with the subsequent transition to plutonium fuel. In this case, plutonium with a small content of higher isotopes will be bred not only in the blanket, but also in the reactor core in much greater quantities.The paper considers various technological and institutional approaches to solving the problem of fast reactor blankets in terms of ensuring a strong proliferation resistance.