Rim structure formation and high burnup fuel behavior of large-grained UO2 fuels

Fuel-to-cladding gap evolution and its impact on thermal performance of high burnup fast reactor type uranium–plutonium oxide fuel pins

“…Transverse ceramographs at core mid-planes in the JOYO Mk-II driver fuel pins loaded with different fuel pellet lots. 6 similarly to water reactor fuels reported by Une et al [10]. It is evident that grain diameter influences the JOG evolution.…”

Detailed characterisations of high burn-up structures in oxide fuels

“…In [18], resistance to the formation of HBS in two types of large grain pellets (undoped and alumino-silicate doped) is reported. An explanation designates the grain boundaries as the initial sites responsible for the formation of the HBS.…”

Discussion About HBS Transformation in High Burn-Up Fuels

“…A main conclusion reported by NFD is that a large grain size delays the HBS transformation (K.Une [23]). The explanation proposed is that the HBS transformation is initiated at grain boundaries essentially because vacancies are provided from grain boundaries, therefore a reduction of the grain boundaries surface delays the HBS process.…”