APPARATUS FOR MEASURING RADIOACTIVITY

PURPOSE:To prevent mutual contamination accompanied by the variation in the concn. of radioactivity during measurements and to remove the effect of the accumulation of a radioactive substance over a long period of time, by preventing the direct contact of the wall surface of a specimen container and a measured waste liquid by using a membrane. CONSTITUTION:When a radioactive waste liquid is supplied from a water supply pipe 16, tensile force acts on a membrane 18 under the own wt. of said waste liquid and, at the same time, the membrane 18 is sent out from a supply roll 19 to be pressed along the inner wall of a specimen container 14 to isolate the waste liquid and said inner wall. Measurement is performed in this state by a detector 15 but said measurement is performed by a batchwise or continuous system. In continuous measurement, the supply of the waste liquid is performed continuously and the flooded waste water is drained to a drain trough 14c along the inclination of a slide plate 14b. After the completion of measurement, a drain pipe 17 is fallen and the greater part of the waste liquid in the specimen container 14 is drained.