“…The E-core has attracted a considerable amount of interest in view of the possibility of validating reactor physics and thermal-hydraulics 350 codes in both steady-state and transient conditions. Concerning reactor physics, most of the previous analyses have been carried out by means of deterministic codes, which can be easily coupled with thermal-hydraulics codes, but suffer from various approximations (Kosaka et al, 1988;Ikeda and Takeda, 2001; Ya-355 maji et al, 2014; Grandi and Moberg, 2012;Grandi, 2014;Aoki et al, 2009;Wang et al, 2013). In particular, the modelling of the complex and highly heterogeneous geometry of SPERT-III has been often dealt with by resorting to spatial homogenization methods, which may induce some discrepancies in the estimation of the physical parameters (see for instance the discussion in (Cao et al, 2015)).…”