Calculation of the kinetic parameters for homogeneous fuel systems (MOX powder with zinc stearate and plutonium nitrate solution)

Sato, Shohei; Okuno, Hiroshi  

This report represents the kinetic parameters for homogeneous fuel systems obtained in the cooperative study with the Institut de Radioprotection et de Surete Nucleaire (IRSN) in France. The subject fuels for calculation are MOX powder mixed with zinc stearate and plutonium nitrate solution. The TWODANT code is utilized with 17 energy groups JENDL3.3 cross section collapsed by SRAC. As a result of the calculations, it was found that (1) The kinetic parameters of MOX powder is dependent on plutonium enrichment and the fraction of hydrogen, and is not dependent on the density of MOX powder and the fuel height except for the neutron lifetime, despite the kind of fuel system, (2) The kinetic parameters of plutonium nitrate solution depend on the concentration of plutonium; the temperature coefficient of which plutonium concentration is below 19g/l is positive.