Development of irradiation properties evaluation technique of accident tolerant fuel cladding tube for advanced nuclear system; Outline of research program

Otsuka, Satoshi   ; Onuma, Masato*; Mitsuhara, Masatoshi*; Nakashima, Hideharu*; Toyama, Takeshi*; Yano, Yasuhide  ; Hashidate, Ryuta ; Kaito, Takeji 

Fuel cladding tube takes on an important function in fuel safety by confining the fission products in fuel element and keeping the coolant flow path in fuel assembly. Oxide dispersion strengthened (ODS) steels have excellent mechanical strength and dimensional stability. The application of ODS steel for fuel cladding tube of sodium-cooled fast reactor (SFR) can restrain the rupture and excessive deformation of fuel pin, thus enhancing the fuel safety. For implementation of ODS steel cladding tube to the driver fuel of SFR, it is essential to correctly understand its irradiation performance, and improve the reliability of structural integrity under operation. This study carries out the research towards the development of new technique efficiently evaluating irradiation properties of ODS steel on the basis of correlation between mechanical strength and microstructure peculiar to ODS steels, which has been proved by the authors.