[1M14-19] Criticality Safety 2

[1M19] Development of the insoluble neutron absorbers using self-assembled surfactant aggregates(2)

*Noriaki Ushio¹, Kouji Koyanagi¹, Hiroyuki Terazaki¹ (1. Kao Corporation)

Keywords:Insoluble neutron absorbers, Surfactant, Viscotop, Worm-like micelle

For the purpose of removing fuel debris from the Fukushima-Daiichi Nuclear Power Plants safely and smoothly, we are developing a re-criticality prevention technology using insoluble neutron absorbers. We have found out that high viscosity fluid insoluble in the water which can hold B₄C particles stably by using the VISCOTOP (complex of alkyl aryl sulfonate and alkyl ammonium salt). VISCOTOP forms self-assembly surfactant aggregates known as a worm-like micelle. From the results of previous studies, we also studied improvement of radiation resistance and elution resistance in hot water using VISCOTOP as a key compound, then found a improved formulation. As a result of analysis, various degradation products generated by radiolysis of improved VISCOTOP were identified. The results of the analysis and the physical property change of underwater irradiation are reported.