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Q: What is a nuclear fuel? What does it consist of?
A: Nuclear fuel means fuel assemblies (FAs). FA is a complex construction, the main element of which being a bundle of fuel rods made from stainless steel or zirconium. A bundle of fuel rods is filled with uranium dioxide pellets, enriched to 5 % U235. Rods, sealed tightly and loaded with fuel pellets, are called "fuel rods". In order to reduce the gaps between fuel rods and to acquire the necessary structural rigidity, fuel assembly has a number of structural elements: tailpiece, cap and a set of spacing grids. In some cases, they are equipped with a shroud tube. Depending on the reactor types FAs have different number of rods.
Q: What companies in the world are manufacturing fuels for NPPs?
A: Presently, there are several major nuclear fuel producers in the world. Among them are: TVEL Corporation, AREVA - the Franco-German Group, BNFL - the U.S.-British Group, GNF - the Japanese-U.S. Corporation and others. TVEL Corporation holds a 17 % share in the world market. According to this indicator it is ranked the forth worldwide.
Q: Is there any difference between Russian and foreign-made fuel for power reactors?
A: The difference is in the FA design itself, as well as in applied structural materials - Zr-based alloys. Historically, FAs in Russian reactors have a hexagonal cross section. FAs for foreign PWR and BWR reactors have a square cross section. The dimensions of foreign and Russian-made FAs are practically the same.
Q: Where in Russia is uranium mined?
A: Uranium ore is mined in Chita and Kurgan regions, in Buryatia. Rich deposits have been also explored in Yakutia. JSC "Priargunsky Industrial Mining & Chemical Union" is the main uranium mining enterprise in Russia. It is situated in Krasnokamensk, Chita region. The mining is conducted by traditional (open pit) or underground in situ leach techniques.
Q: To what extent is natural uranium radioactive?
A: Natural uranium - is a slightly radioactive material, equal to 25 Bg per 1 mg U. The U235 content in natural uranium is only 0.7 %. Special techniques are applied to bring the U235 content to the level of 5 %.
Q: What are the processing stages of uranium?
A: To convert uranium ore to nuclear fuel it passes through several transformations. First uranium ore is crushed at milling facilities and then it undergoes a chemical treatment with acids. The separated uranium salts are concentrated from the solution, and uranium itself is extracted by the processes, called ion exchange. And consequently, U3O8 is obtained. Then it undergoes several chemical transformations, resulting in uranium hexafluoride (UF6), which passes treatment in special centrifuges with the aim of increasing the fissionable isotope (235U) content. After enrichment of uranium hexafluoride (UF6) it is transformed into uranium dioxide powder (UO2), serving as a material for pellets' manufacturing.
Q: Where is uranium enriched?
A: In Russia there are four processing works, which operate applying gaseous diffusion. These are: the Urals Electrochemical Combine, Siberian Chemical Enterprise, Angarsk Electrolysis Chemical Combine and Electrochemical Plant.
Q: What is a nuclear fuel with recycled uranium?
A: The original uranium has been used in spent fuel only to 3 % from its initial weight. Radiochemical techniques enable to separate it (recycle) for reutilization. More than 95 % of uranium after reprocessing can be returned to nuclear fuel cycle.
Q: How is nuclear fuel transported from the plant to NPP? To what extent this transportation is safe?
A: Nuclear fuel is delivered by air, sea, railway and motor special transport. Previously, it is placed in high-strength metallic containers, specially certified for transportation of nuclear materials. A special route and transportation schedule are worked out; an additional control of safe transportation on the way is provided.
Fuel transportation has never experienced a single accident resulted in enhancement of radiation background.  Printable version
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