| 摘要 |
<p>PURPOSE: To remove iodine in a fuel element by continuously dissolving the fuel element in a nitric acid soln. at predetermined temp. and desorbing iodine in the soln. in a first desorbing device at separate temp. and again desorbing the obtained soln. in the presence of nitrous acid vapor in a second desorbing device at different temp. CONSTITUTION: A fuel element is continuously introduced into a dissolving container 2 from a supply part 24, and nitric acid is introduced thereinto from a supply part 7. The dissolving container 2 is heated to about 95 deg.C by a device 5. The soln. issued from the dissolving container 2 by piping 8 is heated to about 105 deg.C by a heater 13 to enter a first desorbing device 10. The soln. at a time of the issue from the desorbing device 10 contains iodic acid ions, a very small amt. of an organoiodine substance and a very small amt. of metal iodide. The soln. issued from the desorbing device 10 enters second desorbing device 16 heated to about 100 deg.C by a heater 15 to receive second desorption in the presence of nitrous acid vapor from supply piping 17. Iodine formed by desorption is discharged from the top parts of the desorbing devices 10, 16. The soln. issued from the desorbing device 12 contains no iodine any more and is supplied to an apparatus for purifying and extracting uranium and plutonium.</p> |
