Monitoring around radioactive waste burial site, (2). Preliminary discussions on predictor materials and their use

Predictor materials which could be used in an environmental monitoring for depicting radionuclides migration around a radioactive waste ground disposal site were discussed from an engineering feasibility aspects. Predictor materials are defined as materials (1) which migrate faster than the critical radionuclides in the ground, and (2) which is less hazardous than critical radionuclides. The domain, where predictor materials (e.g. ⁹⁰Y and HTO) could be used effectively for depicting migration of a critical radionuclide (⁹⁰Sr), is analyzed. Some instructive results were obtained as follows: (1) Predictor materials could be used effectively for depicting critical radionuclide migration in the ground. (2) The domain, where predictor materials could be useful, become larger under the condition with larger distribution coefficient of a critical radionuclide, with smaller detectable limit concentration of a predictor material in ground water, with larger half-life of a predictor material and with larger diffusion coefficient of materials in the ground. (author)