Carbon - 14 removal from spent ion exchange resin wastes

In heavy water CANDU reactors the C-14 activities can be as high as 6 Cilm' for the spent ion exchange from Primary Heat Transport purification system and 210 Ci/m 3 spent resins from Moderator purification system. This study is focused on the method of acid stripping by reacting the resin with HCI in an agitated batch reactor. Simulated spent resins were then prepared by equilibrating a known amount of fresh resin with a known amount of CO 3 -2 from the stock solution. The C loaded resin is mixed with a stripping solution in a glass flask and the slurry is agitated by a magnetic stirrer CO 2 generated to carry through three absorber traps containing sodium hydroxide solutions. The experiments of acid-stripping the simulated spent resins with HCI in a agitated batch reactor indicate that 98.5% of the C can be removed (acid concentration HCl=2-6N; acid waste production about 300-400ml/100ml resins; reaction time 45-60 min; agitation speed = 60 rpm). These experiments were repeated sufficiently to verify statistically the consistency of the performance. There are significant advantages removing C-14 from the spent resins and immobilizing it for separate storage Acid stripping was found to be very efficient for C-14 removal.