The trial apparatus manufactured for the decontamination of urine of patients treated with131Iconsists of two types of vessels, A and B. In the type of A, the urine is poured from the upper portion of the vessel and flows from the upper portion of the outer pipe of the vessel through a siphon. In the type of B, the urine is forced from the lower portion of the vessel and flows out from the upper portion. Type B vessel can be connected to B type vessel as well as to type A vessel. Seven litters of charcoal mixed with resin was put into the A type vessel and the absorption rate of131Iin water was almost 100 percent after treatment by this type A vessel. The 5.5 litters of ion exchange resin was put into the B type vessel with an absorption rate was 99.9 percent after treatment by the B type. These results show that this trial apparatus connecting vessels of type A and B can be practically used for the decontamination of urine of a large number of patients treated with131I.
We applied a new fingerprint checker for complete access control to the radiation controlled area and to the radioisotope storage room, and prepared softwares for the best use of this checker. This system consists of a personal computer, access controllers, a fingerprint register, fingerprint checkers, a tenkey and mat sensors, permits ten thousand users to register their fingerprints and its hard disk to keep more than a million records of user's access. Only 1 % of users could not register their fingerprints worn-out, registered four numbers for a fingerprint. The softwares automatically provide varieties of reports, caused a large reduction in manual works.