Radiation Damage of Fluorocarbon by Krypton-85 Beta-Rays, (II)Radiolysis of Some Fluorocarbons by Cobalt-60 Gamma-Rays

摘要

Ampoule irradiations using 60Co γ-rays were undertaken on CCl2F2, C2Cl4F2 and C2Cl3F3 to gain information concerning the radiation damage of fluorocarbon, used as solvent in the recovery of 85Kr from the off-gas of fuel reprocessing plants operating on the solvent absorpdon process. The dose rate was varied in the range of 2.6 x 1048.0 x 105 rad/h and the irradiation temperature in the range of -10070°C. Identified among the numerous degradation products were six compounds deriving from CCl2F2, eleven from C2Cl4F2, and eleven also from C2Cl3F3. The decomposition yield of each of these fluorocarbons increased with irradiation temperature, and decreased with dose rate. It rose roughly in proportion to the absorbed dose. Comparison of decomposition behavior between the four fluorocarbons (including CCl3F covered in the preceding report) was made in reference to the irradiation temperatures corresponding to those at which these fluorocarbons would respectively be applied in practice as solvent for 85Kr absorption. At these temperatures, the decomposition yields of the fluorocarbons decreased in the order C2Cl4F2>C2Cl3F3>CCl2F2>CCl3F. At these same temperatures, the yields of Cl- decreased in order CCI3F>CCl2F2>C2C14F2=C2Cl3F3, while conversely those of F- decreased in order C2Cl3E3>C2ClLF2>CCl2F2>CCl3F.