Gallium in MOX Fuel
Studies of the Influence of Ga Available in Weapons Grade Plutonium on the Quality of Produced Fuel and Serviceability of Fuel Rods
Tech Area / Field
- FIR-FUE/Reactor Fuels and Fuel Engineering/Fission Reactors
8 Project completed
Senior Project Manager
Genisaretskaya S V
All-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- Oak Ridge National Laboratory, USA, TN, Oak Ridge
Project summaryFrom the time of nuclear power utilization Russia is known to adhere to the concept of the closed nuclear fuel cycle. To realize this concept the Ministry for Atomic energy created the entire needed infrastructure which made it possible to close U fuel cycle 15 years ago. However, Pu has not yet essentially been used. Currently more than 30 t civil Pu have been accumulated in Russia; it has been recovered from spent fuel rods. The forthcoming reduction of nuclear weapons will increase much more excess Pu thus, making the problem of disposition, storage and utilization of Pu and primarily weapon's grade one, still more urgent. Different countries may use various approaches to the solution of the problem relevant to Pu utilization. Russia proceeds from the fact that Pu is good nuclear fuel that may support NPP now in operation and under construction for many decades to come. However, Russia is not prepared to immediately start using weapon's Pu as nuclear fuel. This is due not only to the fact that there are presently insufficient reactors that may operate with MOX fuel and there is no production utilities that could produce this type of fuel in large amounts, but also due to the fact that a large scope of research is to be accomplished the final result of which is the well studied and improved technology that would guarantee the production of nuclear fuel, namely powder oxides, pellets, fuel rods, that would comply with all the specifications.
Weapon's Pu is known to contain appreciable amounts of Ga and a relatively low quantity of Am. The experience gained in using MOX fuel indicates that this low content of Am that may be available in weapon's Pu does not have an appreciable influence on the fuel quality and fuel rod serviceability. The issues related to the Ga influence on the fuel production process, on the compatibility with a fuel cladding material during operation have not been studied since there was no problem of this kind.
In the framework of suggested project the following issues are anticipated to be studied, namely, the influence of Ga on:
- processes of oxide powder preparation and on physico-chemical characteristics of those powders; comprehensive studies and improvement of the process conditions of preparation of powder meeting the specifications;
- behavior of Ga at different process stages and primarily upon pellet sintering at 1750°C in hydrogen;
- mode and extent of interaction between Ga containing fuel and claddings in thermal and fast reactors (with steels and Zr-alloys).
The final goal of the suggested project is to issue recommendation on the tolerable Ga content of the initial powders of MOX-fuel and sintered fuel pellets; validation of suggestions relevant to fabrication of this type of fuel to be in-pile and post-irradiation tested; with this aim in view in the framework of the project pilot fuel rods of ampoule type will be fabricated (in-pile and post-irradiation tests are expected in the framework of a next project).
The suggested work is an inherent evolution of investigations that are supported and funded by the world scientific community in the framework of ISTC Project # 290-96.