The Synthesis and Durability of Cs-Bearing Analogue Glasses Relevant to the Meltdown of the Fukushima Dai-ichi Nuclear Power Plant

In 2011, the Fukushima Dai-ichi nuclear power plant was hit by a 14 m high tsunami which resulted in one of the worst nuclear disasters in history. As a consequence of the meltdown of reactor units 1-3, radiation was spread widely across Japan (up ~280 km) with radioactivity entering the environment in a variety of forms. A key form of radioactivity was the Cs-bearing microparticle, or CsMP, which consists of glassy silica microparticles embedded with a variety of debris and radionuclides, most prominently ¹³⁷Cs. Due to the small size (~20 µm) of the particles and their distribution throughout the environment in Japan, studying the materials properties of CsMPs is challenging. To this end, analogue glasses have been synthesised with the aim of studying the durability and environmental behaviour of CsMPs, whilst determining the potential for ¹³⁷Cs leaching. Three analogue glasses have been produced based upon compositions of CsMPs scavenged from the environment, with one candidate glass chosen for dissolution testing by the ASTM PCT-B protocol. Over 112 days, the Cs-bearing analogue glass showed dissolution behaviour similar to that reported for soda lime silica glass and was comparable with the limited studies performed on environmentally-sourced single ¹³⁷CsMPs. The results of this study validate the use of analogue glasses in the study of the materials properties of Cs-bearing silica glasses, laying the foundation for further investigation into the durability of CsMPs and informing any environmental remediation or mitigation that may be required.