Jeff-3.1.1 Nuclear Data Validation for Sodium Fast Reactors

The JEFF-3.1.1 Nuclear Data Library is the latest version of the Joint Evaluated Fission and Fusion Library. We present the status of the validation of this library using the Monte Carlo Code TRIPOLI 4.5 and the deterministic code package ERANOS 2.2 for fast reactor calculations. For this purpose, we reanalyze a selected set of integral experiments performed in the MASURCA mock-up (CEA/CADARACHE), in the ZPPR mock-up at ANL (USA), and in the SUPERPHENIX Power Reactor. Furthermore, we also present the analysis of pure sample irradiation experiments PROFIL and PROFIL-2 performed in the PHENIX reactor, as this kind of experiment provides a direct feedback on nuclear capture data. We observe good performances of these calculation tools for criticality calculations and fuel inventory prediction. From this validation work, some required improvements on nuclear data are highlighted, as well as the need for new specific integral experiments. The main trends observed are the following: —Reactivity of clean and fresh cores: the results obtained with JEFF-3.1.1 are consistent with those obtained using JEFF-3.1 within 80 pcm, but there is an overestimation of the calculated reactivity of all the experiments between 40 and 800 pcm depending on the spectrum hardness (Pu content) and fuel composition, the discrepancy being larger in hard spectra. Additional investigations are in progress to understand this behaviour. —Integral capture cross sections (PROFIL and PROFIL-2):/C/E - 1/≤ 3%, except for 241Pu (C/E ≈ 1:08), 242Pu (C/E ≈ 1:18), 237Np (C/E ≈ 0:92), 243Am (C/E ≈ 0:93), 244Cm (C/E ≈ 1:35); impact of the trends observed on the individual fission products put in PROFIL and PROFIL-2 is ≈ 4% on the part of Δρburnup due to fission products.