Total Reflection X-ray Fluorescence Analysis for Uranium Determination on the Surface of Simulated Uranium-Contaminated Demolition Debris

Abstract

The decommissioning of TEPCO's Fukushima Daiichi Nuclear Power Plant is expected to result in demolition debris, which has the potential to be contaminated with uranium, in the near future. Consequently, rapid analysis of the uranium surface contamination density will be required. Since uranium has a long half-life, it is difficult to be quantified by radiation measurements. Hence, inductively coupled plasma-mass spectrometry (ICP-MS) is generally used for analysis. However, in this method, it is necessary to perform an ashing treatment to remove organic substances, and the analysis is time-consuming. In this study, a method for quantifying the uranium surface contamination of demolition debris is developed, which includes the following sequence of steps: preparation of a sample simulating the surface of rubble contaminated with uranium; acid elution of the components from the sample, extraction of uranium by solid-phase extraction, and total reflection X-ray fluorescence (TXRF) analysis. Furthermore, the improvement of the detection limit by physically concentrating the uranium extract was investigated.