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In this paper, the feasibility of high-level radioactive waste transmutation in accelerator driven system sub-critical reactor assembly, has been studied for two zone's model and with three different core configurations. The inner zone has a fast neutron spectrum and the outer one has a thermal neutron spectrum. The subcritical core is coupled with external neutron source of energy 14 MeV (D-T source). The effects of high level waste isotopes sample (238Pu, 239Pu, 240Pu, 241Pu, 242Pu, 241Am, 243Am, 244Cm, and 245Cm) distribution on the neutron spectrum and burnup performance in the inner zone have been investigated and discussed, by proposed three core configurations non-uniform, uniform, and spiral. The burnup calculations have been performed for one-year operation cycle for all the all proposed models. This work shows that one can effectively transmute most of the actual minor actinides isotopes in the inner fast spectrum zone of the proposed system, with optimal distribution of these isotopes.

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Highlights • Neutron consumption for various designs of a hybrid system for tritium breeding were investigated. • A comparison of neutron economy and tritium breeding performance on location of the fuel zone was conducted. • The use of Li containing coolant for the fuel zone design degrades transmutation and tritium breeding performance. • For the fuel zone design, the softening of neutron flux degrades transmutation and tritium breeding performance Abstract Comparison evaluation of system performance for Fusion-Fission Hybrid System as a tritium supply facility to perform D-T fusion researches was conducted. Performances for neutron consumption as well as k-eff variation, energy multiplication, tritium breeding and waste transmutation were investigated. All neutronics calculations were conducted by MCNPX2.6.0 and MCNP6.1 with ENDF/b-VII.0 neutron cross-section library. Analysis results for tritium breeding modules show that tritium with module using water or FLiNaBe coolant is effectively produced due to softening effect in spite of low 6Li enrichment. When designing hybrid system for tritium breeding, design of the fuel zone between tritium breeding zones is beneficial for tritium breeding. In this case, 7 kg of tritium is more produced without degradation of transmutation compared to the design of fuel zone in front of the tritium breeding zone. In the comparison evaluation of performance on coolants options; PbBi, LiPb, Na and FLiNaBe, tritium with Li containing coolant is produced in the fuel zone, however amount of produced tritium in the tritium breeding zone is reduced due to low neutron economy. Performance of tritium breeding with softening flux is degraded, since neutron economy is reduced by increasing the capture reaction. [ABSTRACT FROM AUTHOR]

Abstract: MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) is the flexible experimental Accelerator-Driven System (ADS) currently under development at SCK⋅CEN and will replace the Material Testing Reactor (MTR) BR2. The MYRRHA facility is currently being developed with the aid of the FP7-project “Central Design Team” and will be as a flexible irradiation facility, able to work in both subcritical and critical modes. In this way, MYRRHA will allow fuel developments for innovative reactor systems, material developments for GEN IV systems, material developments for fusion reactors, radioisotope production for medical and industrial applications, and Si-doping. MYRRHA will also demonstrate the full concept of Accelerator Driven Systems by coupling the requisite three components (accelerator, spallation target and subcritical reactor) at reasonable power level to allow operation feedback, scalable to an industrial demonstrator and allow for the study of efficient transmutation of high-level nuclear waste. Since MYRRHA is based on the heavy liquid metal technology, Lead–Bismuth Eutectic, it will be able to significantly contribute to the development of Lead Fast Reactor (LFR) technology. Further, in critical mode, MYRRHA will play the role of European Technology Pilot Plant in the path forward for LFR. In this paper we present the historical perspectives, international and high profile membership within the consortium of the MYRRHA project and the rationale for the design choices are presented. Also, the latest configuration of the reactor system is described together with the different irradiation capabilities. More specifically, the possibilities and performances for fuel irradiations are presented in detail. [Copyright &y& Elsevier]

One of the outstanding new developments in the field of partitioning and transmutation (P&T) concerns accelerator-driven systems (ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies, nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program on neutron-induced data related to ADS for P&T is running at the 20{180 MeV neutron beam facility at `The Svedberg Laboratory' (TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (n, xn') reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program of development is outlined. [ABSTRACT FROM AUTHOR]

Abstract: The conceptual design of the fusion-driven subcritical system FDS-I with the multifunctional subcritical dual-cooled waste transmutation (DWT) blanket proposed as a middle step toward the final application of fusion energy was presented previously. Safety is a key concern for the innovative conceptual system. The potential safety characteristic is expected as one of the advantages of FDS-I for the transmutation and incineration of nuclear waste compared with the critical reactor. With the intent of evaluating the inherent and passive safety features of FDS-I, the reactivity coefficients (e.g. the coolant density/void effect and the Doppler feedback), which are similar to those in critical reactors, and the kinetics quantities (e.g. neutron generation time and β eff), which are influenced by the external neutron source of the source-driven system, are calculated and analyzed. In addition, the specific transient scenarios for FDS-I, which show the effects of the source power perturbation on the safety parameters, is presented. [Copyright &y& Elsevier]

The fusion-driven hybrid reactor studies have been performed for nearly 20 years in China to seek for early application of fusion energy. The overall progress is presented, including that in conceptual designs and related R&D activities of fusion-fission hybrid reactors for fissile nuclear fuel breeding or so-called fusion-driven sub-critical systems for both nuclear waste transmutation and fuel production. The further prospect of fusion-driven hybrid systems is given. [Copyright &y& Elsevier]