Construction of analytical beta ray monitor for liquid waste

A radioactivity monitor for waste solution has been constructed using a liquid scintillation technique, which enables beta-emitter mixture to be analytically radioassayed. The method of least squares has been applied to the radioassay for relatively low-level beta-emitter mixture in radioactive waste solution. This system can get rid of the difficulty of analysis for beta-emitter mixture in a monitoring sample, and provides fundamental information for subsequent waste-treatment. Detection limit of five nuclides was estimated to be about 0.02 Bq/cm3, which is sufficiently low compared with the values of authorized safety guideline. (author)