[en] The Boundary Sources Method (BSM) is an integral method for solving the one-speed neutron transport equation that makes capital out of the exact knowledge of a transport kernel for the classical geometries: planar, spherical and cylindrical. We have developed a slab (multi-region) BSM code that allows for arbitrary order anisotropic scattering. The basic ingredient of our method is the calculation of (angular moments of) infinite medium Green's functions. We have used the singular Eigen-expansion (SEE) method developed for anisotropic scattering by Mika and Case and have developed a robust and accurate method to calculate its two parts: the discrete and continuum spectrum. We use several one-dimensional neutron transport benchmarks to show its high accuracy. We have treated 3 types of problems: 2-cell (U-H₂O) disadvantage factors, the Reed problem and an extreme scattering problem

[en] MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Application) is a multipurpose research facility currently being developed at SCK CEN. MYRRHA is based on the ADS (Accelerator Driven System) concept where a proton accelerator, a spallation target and a subcritical reactor are coupled. MYRRHA will demonstrate the ADS full concept by coupling these three components at a reasonable power level to allow operation feedback. As a flexible irradiation facility, the MYRRHA research facility will be able to work in both critical as subcritical modes. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material developments for GEN IV and fusion reactors, and radioisotope production for medical and industrial applications. MYRRHA will be cooled by lead-bismuth eutectic and will play an important role in the development of the Pb-alloys technology needed for the LFR (Lead Fast Reactor) GEN IV concept. MYRRHA will also contribute to the study of partitioning and transmutation of high-level waste. Transmutation of minor actinides (MA) can be completed in an efficient way in fast neutron spectrum facilities, so both critical reactors and subcritical ADS are potential candidates as dedicated transmutation systems. However critical reactors heavily loaded with fuel containing large amounts of MA pose reactivity control problems, and thus safety problems. A subcritical ADS operates in a flexible and safe manner, even with a core loading containing a high amount of MA leading to a high transmutation rate. The MYRRHA design has progressed through various framework programmes (FP) of the European Commission in the context of Partitioning and Transmutation. The XT-ADS version was a short-term, small-scale (57 MW_th) experimental facility, and has been developed within the EUROTRANS project in the FP6 (2005-2010). The most recent version FASTEF is a further upgrade of XT-ADS, still conceived as a flexible irradiation facility, now able to work in both sub-critical and critical modes. FASTEF has been developed within the CDT project in FP7 (2009-2012). The MYRRHA design has now entered into the Front End Engineering Design (FEED) Phase. A tendering process has been launched to select a consortium of engineering companies to support the FEED. In this paper, the most recent developments in the design of the MYRRHA facility are presented. (author)