First, search of uranium ore deposits and assessment of found rock shelves is carried out, during which the uranium concentration in the ore is determined and, upon calculation of its extraction costs, a decision regarding further development of a deposit is made.

Brief presentation of uranium resources in the world: uranium is a widespread element on the Earth. Uranium in nature exists in a form of two natural isotopes: U-238 (99.3 %) and U-235 (0.7 %), including numerous fission products. Uranium is more abundant than gold or silver, but is less common than lead or copper. The average uranium concentration:

• In the upper soil layer – 2-3 g/t
• In granites – 4-5 g/t
• (to compare: gold – 0.004 g/t, iron – 50,000 g/t)

Uranium is found in many kinds of rocks as well as in sea water. The total assessed amount of uranium ore U3O8 in the world is about 4,000,000t.

After a decision to start development of a deposit is made, extraction of uranium ore starts. Depending on the depth of a deposit, mining can be carried out on the surface of the ground or deeper in dug pits. After that, uranium ore (containing up to 1% of uranium oxide (U3O8)) is transported to a reprocessing plant, in which it is milled. There, alkali reactions yield the so called yellowcake,which contains about 80 percent uranium oxide. Milled uranium oxide must be converted to uranium hexafluoride (UF6). Sometimes U3O8 is converted to uranium dioxide UO2 of ceramic form, which can immediately be used as fuel in nuclear reactors not requiring enriched fuel, such as CANDU.

Since only 0.71 percent of uranium U-235, that is found in nature, is available to sustain a chain reaction (the rest 99.3 percent is made by U-238), uranium needs to be enriched. Enrichment is accomplished using the methods of isotope separation, gaseous diffusion or gas centrifuge. The concentration of U-235 in UF6 produced after enrichment, which is needed to sustain a chain reaction, is increased to 3.5 percent (depending on the type of the reactor, in which fuel will be used).

Finally, enriched uranium hexafluoride at a nuclear fuel plant is converted into uranium dioxide (UO2) powder that is then pressed into a pellet-shaped form. After thermal treatment, uranium pellets become very hard and are inserted into metal (most often, zirconium) rods, which, when assembled in a certain form (depending on the reactor, for which fuel is produced), make up a final product of the first nuclear fuel cycle stage.

At a nuclear power plant, nuclear fuel is stacked into the reactor core. To ensure normal operation of a 1,000 MW reactor, 75 tons of enriched uranium should be stacked into the reactor core. When spent nuclear fuel is replaced by a new one, a reactor is usually shut down. At some nuclear reactors, fuel can be replaced without shutting down the reactor (for example, at RBMK or CANDU reactors).

Spent nuclear fuel is firstly stored in the water pools constructed in the reactor building or in the area close to the reactor. If the area of the pools is sufficient, when removed from the pools, spent nuclear fuel can be stored in special spent nuclear fuel storage facilities. Spent fuel rods are stored in the pools for several years. If the nuclear fuel cycle has a reprocessing phase, spent fuel, which contains many parts of uranium U-235 and plutonium Pu-239, non-fissionable uranium U-238, and other radioactive elements, is transported to a reprocessing plant, in which chemical elements suitable for a chain reaction are separated from spent nuclear fuel during chemical reactions. Fuel reprocessing is carried out in those countries, economic possibilities of which allow supporting this costly procedure and thus reducing environmental radionuclide pollution. Sometimes, advanced reprocessing is performed, during which the flow of photons or neutrons is directed to spent nuclear fuel. So, the most hazardous long-lived radionuclides can be converted to short-lived radionuclides. This method is called radionuclide transmutation.

The last and the most controversial stage of the nuclear fuel cycle – storage and disposal of spent nuclear fuel and radioactive waste. There are three possible methods of nuclear reactor fuel management:

• Spent nuclear fuel is stored (together with fission products, unspent uranium, and plutonium) and provided that it is to be further disposed of as completely unprocessed;
• Spent nuclear fuel is reprocessed by separating uranium, while waste containing plutonium and fission products is stored and disposed of;

The largest part of funds is allocated to isolation of high-level waste from the environment. In order to accomplish this, near surface disposal facilities and deep geological repositories can be used, in which waste is disposed in accordance with the main internationally recognized radioactive waste management principles and the most progressive disposal methods.