帯水層における放射性核種の移動, (II)

⁹⁰Srの予測濃度分布と実測分布との比較

抄録

In the previous paper, transportation of ⁹⁰Sr which leached out from cemented solid into a model saturated stratum was experimentally discussed. In this paper, two kinds of techniques were examined for predicting the ⁹⁰Sr distribution in a model stratum. The first technique consists of numerical solution of a transportation-diffusion equation, which describes the transportation phenomena of ⁹⁰Sr in the stratum. The second one consists of time-transformation technique which predicts a ⁹⁰Sr distribution in the stratum based on the distribution of a tracer of water such as tritiated water (HTO).
Some significant results have been obtained, such as that: (1) The first technique has, at present, some difficulties in predicting a ⁹⁰Sr distribution. The difference between a predicted and an observed ⁹⁰Sr distribution should be minimized through taking into consideration local disturbance of stratum characteristics. The mathematical model should also be cheacked on the usefulness for predicting the ⁹⁰Sr distribution. (2) The ⁹⁰Sr distribution predicted by using a HTO tracer test agree well with an observed distribution. It takes only about 1/50 of time which would be required for actual distribution of ⁹⁰Sr in the stratum.