Research on the stability of fuel debris consisting of oxides and alloys, 9; Raman microscopic analysis of simulated fuel debris in the UO-Zr-SS system

Kusaka, Ryoji  ; Kumagai, Yuta   ; Watanabe, Masayuki   ; Akiyama, Daisuke*; Kirishima, Akira*; Sato, Nobuaki*; Sasaki, Takayuki*

Fuel debris is considered to alter over time due to the contact with water in the reactors of 1F nuclear power station. The chemical state of the fuel debris is related to its stability, and can be important information for removal, storage, and processing-and-disposal of the fuel debris. Recently, we have conducted immersion tests of uranium-zirconium-stainless steel simulated debris in hydrogen peroxide solution to investigate the reaction with hydrogen peroxide generated by radiolysis of water. As a result, the elution behavior of uranium suggested that the surface of the simulated debris was altered by the immersion. In this study, the chemical state of the debris surface altered by the immersion was identified using micro-Raman spectroscopy. In addition, the existence distribution of the alteration phase near the surface was investigated.