用~(131)I模拟研究了在核动力堆UO_2燃料元件溶解过程中碘的走向。实验研究表明:UO_2溶解过程中产生的和HNO_3中存在的HNO_2能把元件中可能存在的I~-氧化、把IO_3~-还原成元素碘,在95℃和沸腾条件下溶解并保持5小时左右,可以挥发除去87～99.4%的放射性碘。以放射性碘同一化学形式加入稳定碘可以提高放射性硫的去除率;当溶解液中碘浓度低到10~(-6)mol/L数量级时碘很难从溶解液中挥发出来;加大气提量有利于碘的去除;90%以上的放射性碘随鼓泡气体进入尾气系统。 The (111) I simulation was used to study the iodine evolution during the dissolution of UO_2 fuel cell in nuclear power reactor. The experimental results show that HNO_2, which is produced in the process of UO_2 dissolution and exists in HNO_3, can oxidize the possible I ~ - in the component and reduce IO_3 ~ to elemental iodine, dissolve and retain at 95 ℃ and boiling for about 5 hours , Can be volatile to remove 87 ~ 99.4% of radioactive iodine. The addition of stable iodine in the same chemical form of radioactive iodine can increase the removal rate of radioactive sulfur. When the concentration of iodine in the solution is as low as 10 -6 mol / L, iodine is hardly volatilized from the solution; Is conducive to iodine removal; more than 90% of radioactive iodine with the bubbling gas into the exhaust system.