| Abstract: | Equations describing the kinetics of the swelling of fissionable materials are derived for a model presupposing the existence of pores in the fissionable material. The operating conditions preceding the beginning of swelling are considered in greater detail. The concept of the time when swelling begins is introduced. Expressions which relate the time of initial swelling to the diffusion coefficient of gaseous fragments, the material's strength characteristics, the temperature, the size and concentration of pores, and the rate at which gaseous fragments are generated are derived for a number of cases.In conclusion, he authors extend their thanks to L. P. Semenov for the valuable discussion concerning a number of problems. The authors are also grateful to O. D. Kazachkovskii, S. T. Konobeevskii, and A, I. Leipunskii for the discussion of the results and many valuable remarks. |
