RADIATION INDUCED FORMATION OF LIGHT WATER FROM ION EXCHANGE RESINS IMMERSED IN HEAVY WATER

In an operating heavy water reactor, the ion exchange resins used in the purification system are subjected to long term irradiation. Under these conditions some of the C- H-- linkages in the resin structure are destroyed, a process which finally leads to the formation of H/sub 2/O and to a corresponding dilution of the D/sub 2/O-moderator. This radiation-induced formation of H/sub 2/ O was measured by gamma irradiation of ion exchange resins immersed in D/sub 2/O. From these experiments, the production of H/sub 2/O per gram of dry resin e.g. at a dose of 10/sup 8/ r was found to be 0.3 g for Duolite A-102D, 0.008 g for Duolite C-20, and 0.03 g for the 1:1 mixed bed. The dilution rate of the D/sub 2/ O in the DIORIT research reactor due to this effect was calculated to be about 0.003% per year, thus being small compared to the observed overall dilution rate of 0.02% per year. (auth)