Preparation And Evaluation Of New Reference Materials For Naturally Occurring Radioactive Materials (Norm): Zirconium Silicate, Bauxite, And Phosphogypsum

New reference materials (RMs), zirconium silicate, bauxite and phosphogypsum, were produced and characterized according to an ISO guide. The homogeneity of the three RMs was evaluated using X-ray fluorescence (XRF), and characterizations of the three candidate materials were performed through a collaborative study with nine expert radioanalytical laboratories. The assigned radionuclides are Th-230, Th-232, U-234, U-235, and U-238 for zirconium silicate; Th-230, Th-232, U-234, and U-238 for bauxite; and Ra-226, Th-230, U-234, and U-238 for phosphogypsum.