A PHWR with slightly enriched uranium. About the first core

Many different studies have been performed in Argentina regarding the use of slightly enriched uranium in PHWR nuclear plants. These referred mainly to operating plants so that a transition had to be considered from the current natural uranium fuel cycle to the slightly enriched one. The first argentine NPP, Atucha I, commissioned in 1974 and designed to operate with natural uranium was converted to slightly enriched uranium in a process that was initiated in 1995 and culminated in 2001. In this analysis, where new PHWR plants are considered, technical and economical arguments are presented which favor the use of a natural uranium initial core. The levelized fuel costs are shown to be practically insensitive to the first core and a fast transition between the two cycles is more influential than an initial enriched core.