For the estimation of the leachability of several important radionuclides from the solidified wastes with cement, some adsorptive behaviours of them in cement milk were studied experimentally. Main results obtained are as follows. Cesium could not be adsorbed at all on any crystalline cement-hydrates in the cement milk. Then high leachability from the solidified can be deduced. A some amount of strontium was incorporated into the cement-hydrates by mixing crystallization in the cement milk. In the solidified, therefore, a larger amount of it is assumed to be distributed in the stable crystal of cement-hydrates. The greater parts of zirconium, cobalt, zinc, and cerium were adsorbed firmly in this order on the cement-hydrates, ruthenium and its nitro complex were less adsorbed, showing no significant difference in their behaviour. These adsorptive characteristics were little changed by the presence of carriers and other salts.
The gamma-ray spectroscopy method was used to determine the natural activity of soil samples taken from twenty-six locations including three nuclear reactor sites in order to obtain the average background activity of Taiwan. Direct measurement of natural activity was also carried out by means of ionization chambers coupled with a vibrating reed electrometer. Fallout activity was detected during this investigation by spectroscopy method, and chemical method was used to analyze its main components 90Sr and 137Cs nuclides. The background radiation thus measured varied from 5.2μR/h to 15.2μR/h with an average value of 11.8μR/h while the gross activity concentration in air varied from 1.94×10-13μCi/cm3 to 4.95×10-13μCi/cm3 with an average value of 3.58×10-13μCi/cm3.
The Fuel Reprocessing Test Plant at JAERI was operated during the period of 1968-1969 to gain experiences of the fuel reprocessing. Fuel elements reprocessed were irradiated in the JRR-3 reactor up to about 700MWD/ton and cooled for 87-300 days. The purpose of this paper is to describe the experiences of radiation monitoring including contaminations and radiation levels encountered during the fuel reprocessing, and the results of inplace test of air cleaning filters installed in the plant.
The Fuel Reprocessing Test Plant at JAERI was operated during the period of 1968-1969 to gain experiences of the fuel reprocessing. Fuel elements reprocessed were irradiated in the JRR-3 reactor up to about 700MWD/ton and cooled for 87-300 days. The purpose of this paper is to discribe the measured results of airborne radioiodine released in each stage of chemical processing and discuss collection efficiency of the charcoal impregnated filter paper for radioiodine in the presence of process off gas such as NO, NO2, NH3, HNO3 and solvent encountered during the fuel reprocessing.