Investigation of cesium chemisorption behavior on the stainless steel surface

Nakajima, Kunihisa  ; Di Lemma, F. G.; Yamashita, Shinichiro   ; Osaka, Masahiko  ; Nagase, Fumihisa 

Knowledge of accurate Cs-deposition properties is essential to evaluate radiation dose of workers at the Fukushima Daiichi Nuclear Power Plants (1F-NPPs), encountered during retrieval of fuel debris from the radioactive Cs deposits onto structural materials and equipments in the RPV and PCV. The Cs chemisorption tests were performed to investigate its behavior on stainless steels. As the results, we observed that Cs congruently distributes with silicon (Si), which agrees with previous studies. But the results of the XRD and EDS analyses suggest that the reaction product is not CsSiO but a new proposed compound CsFeSiO. Further, it was suggested from our XRD analysis and leaching test that the amounts of the Cs deposit at 800C were higher than those of the Cs deposit at 1000C, though the previous studies indicated the reaction rate increased monotonously up to 1000C.