Experimental Mixed-Oxide Fuel
Fabrication of Experimental CANDU MOX Fuel Pins for Irradiation Testing in the MIR Reactor
Tech Area / Field
- FIR-FUE/Reactor Fuels and Fuel Engineering/Fission Reactors
3 Approved without Funding
All-Russian Scientific Research Institute of Non-Organic Materials named after A. Bochvar, Russia, Moscow
- NIIAR (Atomic Reactors), Russia, Ulianovsk reg., Dimitrovgrad
- Atomic Energy Canada Limited, Canada, ON, Chalk River
Project summaryIn the 1990s, as part of major arms control initiatives in the aftermath of the Cold War, the U.S. and Russia have each declared several tons of weapons plutonium (WPu) to be surplus to their defence needs. Thus, a challenge appeared as to how to dispose of surplus WPu to ensure that it is permanently removed from defence inventories and safeguarded from proliferation. As well, the amounts of uranium and plutonium recovered from the spent nuclear fuel (SNF) of power reactors are increasing. After numerous feasibility studies, the international experts have chosen the use of MOX fuel in commercial nuclear reactors to be the basic way to reduce plutonium inventories. One of the options identified in several studies is the concept of using CANDU reactors to generate electricity from MOX fuel that is derived from U.S. and Russian surplus WPu.
The Project is aimed at the fabrication and examination of experimental CANDU MOX fuel pins, in preparation for their subsequent irradiation testing. It is planned to fabricate experimental MOX fuel pellets using the Russian vortex milling technology (VR-process) that was previously used for fabrication of similar fuel within the framework of the international Russian-Canadian-U.S. Parallex Project. The standard zircaloy parts applied for the CANDU fuel will be used in the course of assembling the fuel pins. The fuel will be fabricated at the VNIINM for future irradiation in the MIR Reactor and examination in the RIAR hot cells.
The laboratory, which is intended to do the work, has successfully executed the contract on fabrication of similar fuel under the Parallex Project. The project activities will be carried out by the experts with extensive experience in the area of MOX fuel. The laboratory is comprised of candidates of science, the experts involved in weapons issues, designers and highly skilled specialists in various kinds of fuel assay and characterization.
Implementation of the work will result in fabrication of 30 to 40 MOX fuel pins, and determination of the main characteristics of the fuel and fuel pins that are required for placement of these fuel pins in the MIR research reactor (RIAR). The future irradiation of the fuel pins will provide valuable scientific data on behavior of homogeneous CANDU MOX fuel under various conditions of irradiation in a reactor. The experimental data will also contribute to qualification of the MOX fuel for use in commercial CANDU reactors.
The project will allow the scientists of the Russian institutes to take part in the international research activities conducted currently in the area of MOX fuel fabrication. In addition, the activities associated with MOX fuel fabrication technology are within the framework of the search for solutions of topical problems related to use of reprocessed fissile materials. Use of MOX fuel is one way of recycling such materials. This project will direct this experience towards development of civil technologies as the MOX fuel is widely used for commercial electric power generation.
The major tasks on the path to this Project implementation are:
- Develop the detailed design and the design documentation for an experimental CANDU MOX fuel pin. Develop a quality assurance program. Prepare the equipment and materials.
- Fabricate, inspect and characterize the fuel pellets as well as weld and inspect the fuel pins. Acceptance testing of the finished fuel pins for their subsequent irradiation in the research reactor.
- Develop a conceptual program for the fuel pin irradiation.
The role of the collaborator, the Canadian company AECL, is to ensure applicability of the fuel design and testing conditions to the CANDU MOX fuel qualification program.
The project will be based on effective Russian-Canadian-U.S. cooperation, which has been achieved within the framework of the Parallex Project. The MOX fuel fabricated in Russia and in the U.S. (i.e. at the VNIINM and LANL respectively) has been delivered to Canada where it is now being tested. The technical confidence between the participating parties has been established, and the close cooperation between experts of different levels has been formed in the course of the project implementation. The Parallex Project activities made possible the creation inside the VNIINM’s MOX fuel laboratory of a quality assurance program that meets Canadian standards. Positive results from the irradiation testing of the first Parallex fuel bundle point to the benefits of continuing the work aimed to qualify MOX fuel use in CANDU reactors. Thus, the proposed new project will be built upon a solid foundation laid earlier.
To carry out the work, the VNIINM will utilize an existing set of process equipment, which was installed and used within the framework of the Parallex Project as well. However, some additional equipment are needed for part of the process and some analytical methods.