Evaluation of medium 1000mwth sodium-cooled fast reactor oecd neutronic benchmarks

Within the activities of the Working Party on Reactor and System (WPRS), an interna- tional collaboration is ongoing on the neutronic analysis of several Generation-IV Sodium-cooled Fast Reactor (SFR) concepts. Eleven institutions are participating in the analysis of a set of four SFR cores. Two "large"SFR core designs that were proposed by CEA are included in the set. These large SFR cores generate 3,600 MW(th) and employ oxide and carbide fuel technologies. Two "medium"SFR core designs proposed by ANL complete the set. These medium SFR cores generate 1,000 MW(th) and employ oxide and metallic fuel technologies. This paper summarizes the results obtained by the benchmark participants for the medium cores. Nine participating institutions (ANL, CEA/Cadarache, CEA/Saclay, CER, JAEA, KIT, SCK-CEN, UIUC, and IKE) modeled these two SFR cores while using different calculation methods and systems to estimate the k-effective, reactivity feedbacks, isotopic composition evolution, and power distribu- tion. For the different core concepts analyzed, a satisfactory agreement between partici- pants was obtained despite the different calculation schemes used. A good agreement is generally obtained when comparing the burnup composition evolution, the delayed neu- tron fraction, the Doppler coefficient, and the sodium void worth. However, some no- ticeable discrepancies between the k-effective values were observed and are explained in this paper. These are mostly due to the different neutronic libraries employed (JEFF3.1, ENDF/B-VII.0 or JENDL-4.0) and in a less extend calculations methods.