Identification of carbon in glassy cesium-bearing microparticles using electron microscopy and formation mechanisms of the microparticles

Hidaka, Akihide

Nuclear Technology, 208(2), p.318 - 334, 2022/02

https://doi.org/10.1080/00295450.2021.1929767

The author previously proposed that the Cs bearing microparticle (Type A) may have been formed by melting and atomization of glass fibers (GF) of the HEPA filter in the SGTS due to flame and blast during the hydrogen explosion in Unit 3. If this hypothesis is correct, the Type A could contain or accompany carbon (C), that ignites spontaneously above 623 K, because of the limited time to be heated up, inclusion of C in the binder applied on the GF surface and closely located charcoal filter. As the previous studies did not focus on C, the present analyses were performed with EPMA whether the Type A contains C. The results showed that the Type A contained C originating from the binder, and non-spherical particles accompanied by the Type A and the film surrounding the Type A contained more C, which is thought to originate from the charcoal filter. These results cannot be explained by the other mechanisms proposed so far, and can be explained consistently by the author proposed hypothesis.