An advanced model for grain face diffusion transport in irradiated UO2 fuel. Part 1: Model formulation

Abstract An advanced model for the grain face transport of gas atoms, self-consistently taking into consideration the effects of atom diffusion over the grain surface, their trapping by and irradiation induced resolution from intergranular bubbles is presented. The model allows prediction of a noticeable gas release from UO 2 fuel without visible interlinkage of grain face bubbles, i.e. at very low grain face coverage, below the critical value manifested by formation of bubble channels on grain faces interconnected with open porosity, in accordance with experimental observations of UO 2 and MOX fuel behaviour under various irradiation conditions.

[1]  J. Turnbull,et al.  Swelling in UO2 under conditions of gas release , 1974 .

[2]  Shinji Kashibe,et al.  Fission Gas Release during Post Irradiation Annealing of BWR Fuels , 1990 .

[3]  J. C. Fisher,et al.  The influence of grain boundaries on the nucleation of secondary phases , 1955 .

[4]  S. Lansiart,et al.  Thermal treatment of uranium oxide irradiated in pressurized water reactor: Swelling and release of fission gases , 1998 .

[5]  J. A. Turnbull,et al.  The effect of grain size on the swelling and gas release properties of uo2 during irradiation , 1974 .

[6]  Shigeharu Ukai,et al.  Evaluation of the fission gas release behavior from fast reactor mixed oxide fuel based on local concentration measurement of retained xenon , 1988 .

[7]  R. Dubourg,et al.  Mechanistic modelling of urania fuel evolution and fission product migration during irradiation and heating , 2007 .

[8]  F. Nichols.  A simplified model for stable open porosity , 1987 .

[9]  R. J. White,et al.  A new fission-gas release model , 1983 .

[10]  A. R. Massih,et al.  Diffusion theory of fission gas migration in irradiated nuclear fuel UO2 , 1985 .

[11]  K. Une,et al.  Effects of Temperature Cycling and Heating Rate on Fission Gas Release of BWR Fuels , 1991 .

[12]  C. A. Alexander,et al.  VICTORIA: A mechanistic model of radionuclide behavior in the reactor coolant system under severe accident conditions , 1990 .

[13]  R. Dubourg,et al.  Development of the mechanistic code MFPR for modelling fission-product release from irradiated UO2 fuel , 2006 .

[14]  M. Mogensen,et al.  Concerning the development of grain face bubbles and fission gas release in UO2 fuel , 1988 .

[15]  M. V. Speight,et al.  A Calculation on the Migration of Fission Gas in Material Exhibiting Precipitation and Re-solution of Gas Atoms Under Irradiation , 1969 .

[16]  Toshiaki Kogai,et al.  Modelling of fission gas release and gaseous swelling of light water reactor fuels , 1997 .

[17]  J. R. Matthews,et al.  A simple operational gas release and swelling model: II. Grain boundary gas , 1980 .

[18]  M. S. Veshchunov,et al.  Modelling of grain face bubbles coalescence in irradiated UO2 fuel , 2008 .