Fuel light-water reactor

Eig. 8. Cost of electricity (COE) comparison where represents capital charges, Hoperation and maintenance charges, and D fuel charges for the reference cycles. A, steam, light water reactor (LWR), uranium B, steam, conventional furnace, scmbber coal C, gas turbine combined cycle, semiclean hquid D, gas turbine, semiclean Hquid, and advanced cycles E, steam atmospheric fluidized bed, coal E, gas turbine (water-cooled) combined low heating value (LHV) gas G, open cycle MHD coal H, steam, pressurized fluidized bed, coal I, closed cycle helium gas turbine, atmospheric fluidized bed (AEB), coal J, metal vapor topping cycle, pressurized fluidized bed (PEB), coal K, gas turbine (water-cooled) combined, semiclean Hquid L, gas turbine... 

Mixed oxide fuel is not appropriate for all nuclear reactors. Plutonium requires faster neutrons in order to operate in a sustained chain reaction. Light-water reactors operate in a highly moderated environment. 

In the light water reactor, the circulating water serves another purpose in addition to heat transfer. It acts to slow down, or moderate, the neutrons given off by fission. This is necessary if the chain reaction is to continue fast neutrons are not readily absorbed by U-235. Reactors in Canada use heavy water, D20, which has an important advantage over H20. Its moderating properties are such that naturally occurring uranium can be used as a fuel enrichment in U-235 is not necessary. 

The phrase "nuclear power" covers a number of technologies for producing electric power other than by burning a fossil fuel. Nuclear fission in pressurized water-moderated reactors—light water reactors— represents the enrrent teehnology for nuclear power. Down the line are fast breeder reactors. On the distant horizon is nnclear fusion. 

France has the largest implementation of breeder reactors with its 250-MW Phenix reactor and 1200-MW Super-Phenix. The Phenix went into operation in 1973 and the Super-Phenix in 1984. Japan has its 300-MW Monju reactor which was put into service in 1994. While India has the 500-MW PFBR and 13.2-MW FBTR. These reactors produce about 20% more fuel than they consume. Optimum breeding allows about 75% of the energy in natural uranium to be used compared to 1% in a conventional light water reactor. 

The concentration of fission and neutron capture products in a light water reactor (LWR) fuel (30 MWd/kg U) are listed in Table 1 and presented in graphical form in Figure 2 (adapted from Oversby 1994). 

Hanson, B. D. 1998. The Burnup Dependence of Light Water Reactor Spent Fuel Oxidation. Pacific Northwest National Laboratory Report, PNNL-11929. 

The baseline process, including the pressure sintering step, was demonstrated with both simulated high level waste and under hot cell conditions using a waste solution prepared from typical spent light water reactor fuel. A batch contacting method using sodium titanate was also evaluated, but the overall decontamination factor was much lower than obtained in the column process. 

As discussed earlier, natural uranium is 0.72 atom % 235U, and the fuel used in light-water reactors is typically 3% 235U. This means the refined uranium must be enriched in the lighter 235 isotope prior to fuel fabrication. This can be done by a... 

Wymer R. G. and B. L. Vondra. Light Water Reactor Nuclear Fuel Cycle, CRC, Boca Raton, FL, 1981. 

After a peak at 2010, the amount of Pu stored is supposed to start decreasing due to the expected increase in MOX fuel fabrication and its usage in Light Water Reactors (LWRs). Obviously, the utilization of MOX fuel by LWRs would gradually reach a balance in which the fissile Pu in the LWR fuel is ca. 5% of the total fuels. Consequently, the utilization of U resources would not be drastically improved. The ultimate utilization will be attained in the Fast Breeder Reactor (FBR) fuel cycle, in which a conversion of fertile 238U to 239Pu overwhelms the consumption of the 239Pu. 

Kang, J., von Hippel, F. 2005. Limited proliferation-resistance benefits from recycling unseparated transuranics and lanthanides from light-water reactor spent fuel. Science and Global Security 13 169-181. 

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