Effect of Fe2O3 on the structure and properties of Mo‐containing borosilicate glasses for nuclear waste immobilization

Abstract As a fission product in high‐level radioactive nuclear waste, Mo has low solubility in borosilicate glass. Fe 2 O 3 is not only a prevalent transition metal element but also a major corrosion product in high‐level radioactive nuclear waste. Against this backdrop, the effect of Fe 2 O 3 content on the structure and chemical durability of typical molybdenum‐containing sodium borosilicate glasses for nuclear waste immobilization are studied. The results show that the samples containing more than 3.85 mol% Fe 2 O 3 , a completely homogenous amorphous glass sample is obtained. Moreover, the mechanism of the effect of Fe 2 O 3 on the solubility of Mo is discussed in detail. In this work, a portion of Fe 3+ is reduced to Fe 2+ and enters into the glasses as a charge compensation ion as Fe 2+ O 6 . Concurrently, Fe 3+ ions contribute to the formation of the glass networks as Fe 3+ O 4 . Iron incorporation can improve the chemical durability of the sample.