Safe Handling and Reduction of Low-Level Radioactive Waste from Radioisotope-Handling Facilities of Universities.

在大学的许多高级科学研究中，放射性同位素经常被用作不可避免的工具。大多数同位素在使用后被回收，必须移交给日本放射性同位素协会进行处置，并支付高昂的费用，或者必须根据《关于防止放射性同位素等造成的辐射危害的法律》在大学的废物处理设施中储存，即使放射性水平很低。本研究与国立大学放射性同位素中心的研究人员合作，研究了如何提高对处置在大学设施中的此类低放射性废物的安全处理水平，并采取多种符合规律的方法减少废物的体积。对纸、布和塑料等极低放射性水平的可燃废物进行了燃烧、低温灰化和干馏等方法的减容试验，并在Vaiou…下进行了处理过程中放射性同位素的行为对S条件进行了较多的研究。初步实现了提高效率、防止弥散和安全回收同位素的目的。在科技厅的许可下，对5种放射性核素(H-3、C-14、P-32、S-35、Ca-45)的液体闪烁体鸡尾酒溶液进行了燃烧研究。在不同的燃烧条件下，研究了它们在燃烧过程中和燃烧后的行为，以及它们在废气和处理水中的分布和化学形态，以及它们在炉膛中的残留率。研究了通过沉淀、吸附、离子交换、蒸馏等方法从液体有机和/或无机废液中去除放射性同位素，以及通过几种洗涤方法重复使用放射性同位素仪器来降低废液中放射性或减小体积的其他可能性。较少

Radioisotopes are often used as inevitable tools in many advanced scientific researches at universities. Most of the isotope is recovered after the use and must be transferred to Japan Radioisotope Association for disposal with paying the high cost or must be stored in the waste disposal facilities in the universities by the Law Concerning Prevention from Radiation Hazards due to Radioisotopes, etc. even at very low level radioactivity. In this research, were studied the improvement of safe handling of such low level radioactive waste disposed at university facilities and the reduction of the waste volume by several methods following the Law by cooperation of the researchers belonging to the Radioisotope Centers of the National Universities.Combustible waste such as paper, cloth and plastics with extremely low level activities were tested to reduce the volume by combustion, low temperature ashing, or dry distilllation, and the behaviors of radioisotopes during the treatment under vaiou … More s conditions were studied. The improvement of efficiency and the prevention of dispersion and the safe recovering of isotopes were preliminarily achieved.Combustion of the liquid scintillator cocktail solution after the measurement of 5 kind betaray emitting nuclides (H-3, C-14, P-32, S-35, Ca-45) were investigated under the permission of Science and Technology Agency. The behaviors of these unclides during and after the combustion, their distribution and chemical forms in the exhausted gas and treated water, their remaining fraction in the furnace were investigated under the various combusting conditions. The obtained results gave the guideline for the safe combustion of higher concentration liquid scintillation cocktail.Other possibilities of the reduction of the radioactivity in the waste solution or reduction of the volume were studied by the removal of radioisotopes from liquid organic and/or inorganic waste solutions by precipitation, absorption, ion-exchange, and distilllation, etc. and by the re-use of the radioisotope-used apparatus by several kind washing methods. Less