ICP-MS/MSによるアクチノイド核種分析に向けた気相反応挙動の予測

Prediction of gas-phase reactivity of actinide ions using triple quadrupole ICP-MS for fuel debris analysis

風間 裕行  ; 関尾 佳弘  ; 前田 宏治  ; 小山 真一  ; 鈴木 達也*; 小無 健司*; 阿部 千景*; 永井 康介*

Kazama, Hiroyuki; Sekio, Yoshihiro; Maeda, Koji; Koyama, Shinichi; Suzuki, Tatsuya*; Konashi, Kenji*; Abe, Chikage*; Nagai, Yasuyoshi*

燃料デブリ中のアクチノイドを高精度かつ迅速に分析するために、ICP-MS/MSの利用を検討している。本研究では、アクチノイド同重体の干渉除去に向けた基礎的知見を得るために、セル内で生じる反応ガスとの気相反応に着目し、Th, U, Np, Pu, Am, Cmを使用したICP-MS/MS測定を実施した。各生成イオンの検出傾向から、アクチノイド系列のセル内での気相反応挙動を予測可能とする相関関係を見出した。

Triple-quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) is an attractive technique to perform rapid and highly sensitive analysis. The collision/reaction cell (CRC) technology incorporated in ICP-MS/MS is an available option to eliminate isobaric interference, being expected to discriminate actinide nuclides involved in fuel debris. Meanwhile, in order to discriminate against these isobaric interferences using ICP-MS/MS, it is necessary to understand actinide gas-phase reaction behavior associated with the injection of reaction gases into the CRC. In the present work, the actinide molecular ion formations correlating with the excitation energy from the ground state of actinide monoatomic cation to their reactive state (5f6d) were investigated by injection of reaction gases into CRC. The obtained correlations allow us to predict the reaction behaviors towards mutual discrimination of actinide series using ICP-MS/MS.