Screening of uranium contamination on waste surfaces using X-ray fluorescence analysis

X-ray fluorescence (XRF) analysis is useful for detecting radionuclides with long half-lives, such as most isotopes of uranium (234U, 235U, and 238U), as the detection of uranium by radiation measurements can be difficult. Therefore, we propose energy dispersive X-ray fluorescence (EDXRF) analysis as a method for the rapid screening of pollution from substances that are contaminated with uranium-containing water droplets. Sealed uranium-containing filter paper, which was used as the contaminated area model, was layered on top of a rubber plate to simulate a rubber plate whose surface was contaminated with uranium. The measured EDXRF spectra revealed a U Lα peak at the tail of a strong Br Kβ peak, and the contribution of this U Lα peak was extracted by peak fitting. The obtained results suggested a linear relationship between the uranium concentration of the filter paper and the signal intensity of the U Lα peak. The proposed method is more sensitive than the α-particle counting method for long half-life radionuclides, and can be used at uranium handling facilities.