Part 2 of 2 Parts (Please read Part 1 first)
Vergazov was asked about whether vibropacked MOX is seen as the best way forward, or whether future production is likely to be conventional sintered MOX. Vergazov said: "We’re taking both approaches and are not limiting ourselves to just one." He added: "Although there are certain difficulties with vibropacked fuel, during fabrication, we still think this direction is a prominent one. This type of fabrication is technologically more complex than classical ceramic fuel pellets made from uranium dioxide. If we’re talking about the so called MNUP fuel - mixed nitride uranium-plutonium fuel - then this involves nitrate technology. We’ve fabricated a number of such fuel samples that are currently loaded in the BN-600 fast reactor, and we’ve also completed a feasibility study into the safety and reliability of the reactor core exploitation."
TVEL is working on four different options for ATF at the same time. The MIR reactor in Dimitrovgrad is being used to irradiate all four of the options. There are two different choices for cladding the fuel rods being explored. One applies a coating over the zirconium cladding and the other uses a non-zirconium cladding. There are two options for the fuel matrix. One of them utilizes the traditional uranium oxide matrix and the other employs a uranium and molybdenum alloy. A uranium and silicon alloy is also being considered. Each fuel assembly consists of twenty-four fuel rods, each of which contains a different combination of materials. The fuel assemblies are being tested in the MIR reactor under conditions as close to operational as possible.
Vergazov said, “In January, we loaded the first experimental fuel cycles into the reactor. One fuel assembly is for a classical VVER reactor, another is for a PWR reactor. Each fuel assembly has fuel rods with four different combinations of the cladding materials and fuel matrix materials and that’s why we say that all four options are being irradiated now. We’re testing them simultaneously using different water loops.”
TVEL has been working on a “fourth-generation” fuel line called TVS-4 for use in VVER-1000 reactors. These new fuel assemblies have increased capacity and more advanced design. TVEL says that they should improve economic performance of nuclear power plants while, at the same time, providing the same level of safety. They are hoping for a reduction of two to four percent for the cost of electricity.
These new fuel assemblies are being used to fuel existing VVER power reactors outside of Russia. TVEL is also getting ready to introduce fuel assemblies that have an enrichment level above five percent. (The current enrichment level of fuels for these reactors is four and eighty-five one hundredths percent.) Reactors utilizing these new fuel assemblies will only have to be shut down and refueled once every two years instead of eighteen months as is now the case.
Russia is hoping to create nuclear fuel from recycled spent nuclear fuel and also to breed fuel in their fast neutron reactors. Ultimately, they hope to close the fuel cycle by eliminating the need to mine uranium and eliminating the waste produced in conventional reactors. If other nations decide to rely heavily on nuclear power in the future, Russia will have a preeminent position in the global reactor and nuclear fuel market.