Comparison of different methods to determine the retardation factor of 137Cs transport through granite in column experiments

Abstract

Retardation factor (Rf) is the most frequently used indicator to describe the transport of radionuclides through geological substances. In this work, we compare the Rf values determined by four methods including direct experimental data, model fitting curve, integration technique and modeling at two relative concentration (C/C0) 0.5 and 1.0 in a case study of Cs transport through crushed granite. A simple Q-test indicated all Rf values are valid at 96% confidence level. Meanwhile, the T-test demonstrated that the precision of Rf value is 4.21±0.39 at 90% and ±0.45 at 95% confidence level, which is about 9.3% and 10.7% of the average value of the Rf value. An uncertainty window of 10% is recommended in Rf value determination.