[3J11-15] 核種移行・収着

[3J13] Gamma-irradiation-induced molecular-weight-dependent distribution of humic acid complexed with metal ions

*Qi Zhao¹, Taishi Kobayashi¹, Takayuki Sasaki¹, Takeshi Saito² (1. Kyoto Univ., 2. KURNS)

キーワード：Gamma irradiation, Molecular weight, Humic acid, Metal complexation, Ultrafiltration

After long-term corrosion of high-level waste in the deep geological repository, the radionuclides would be leached out and released to the biosphere through underground water media. Naturally occurring humic acid (HA) in natural water systems can react with radionuclides to form metal-HA colloids, which may significantly contribute to the apparent mobility of radionuclides, depending on the molecular weight of metal-HA colloids. Since the HA in the near-field of repository is exposed to gamma ray from the high-level waste, this study aims to assess the effect of gamma irradiation (0–100 kGy) on the molecular weight and complexing ability of metal-HA complexes by ultrafiltration technology (<10, 10–50, 50–100, >100 kDa).