[en] China has launched the ADS engineering construction project in 2011. The engineering design and related R&D activities are going on in order to finish the construction of the first system around 2017. China has a strong program to support the development of fusion and hybrid concepts and R&D activities in order to initiate the construction of fusion test reactor in the near future. CLEAR may play an important bridge role in the transition period from fission energy to fusion energy, such as to support: • Nuclear waste transmutation, fuel breeding, energy production, for promoting fission industry. • Technology sharing, pre-test platform, tritium supply, for promoting fusion development

[en] Overview of completed and ongoing coordinated research projects which address the following issues: (1) Better understanding of radiation effects and mechanisms of material damage and basic physics of accelerator irradiation under specific conditions, (2) Improvement of knowledge and data for the present and new generation of structural materials, (3) Contribution to developmental of theoretical models for radiation degradation mechanism, (4) Fostering of advanced and innovative technologies by support of Round Robin testing, collaboration and networking

[en] MYRRHA - Accelerator Driven System: Multipurpose hYrid Research Reactor for High-tech Applications (MYRRHA) is a flexible fast spectrum irradiation facility able to operate in sub-critical and critical mode for material and fuel developments for GEN IV and fusion reactors and in a back-up role for radioisotopes production. The following is presetned: Material research for design; Environmental effects - • Liquid metal corrosion; • Liquid metal embrittlement; • Irradiation effects; • How to take them into account

[en] Concluding remarks: • A small LFR may be designed to operate on 100% natural convection; • Sandvik’s 12R72 grade of 15-15Ti delivers high creep resistance; • GESA treatment potentially ensures adequate corrosion protection; • Bulk Fe10CrXAl-RE considered for heat exchangers; • Open issues: – Dose rate dependence of swelling in austenitic cladding materials; – Al-limit for weldability of FeCrAl-RE steels. • Modeling of ELECTRA transients reveals major challenges: – Neutron reproduction time; – Axial expansion coefficient; – Natural convection flow rates

[en] LFR share the main issues of all Fast Reactors, while presenting specific issues due to the use of lead as coolant. A number of constraints impairs the design of a LFR core, possibly resulting in a viability domain not exploitable for producing electricity in an efficient (hence economic) way. In particular, the most restrictive issues to be faced pend on the cladding. The selection of proper cladding materials provides the solution for the issues impairing the resistance of the cladding against stresses and irradiation effects. On the other hand, the protection of the cladding requires surface protections like oxide scales (passivation) or adherent layers (coating). Oxide scales seem not sufficient for a stable and effective protection of the base material. The application of adherent layers seems the only promising solution for protecting the cladding against corrosion. For the short term (i.e.: ALFRED), advanced 15/15Ti with coating is the reference solution for the cladding, allowing a core design complying with all the design constraints and goals. The candidate coatings are already being tested under irradiation to proceed towards qualification. In parallel, new base materials and/or coatings are presently under investigation. For the long term (i.e.: ELFR), the availability of such advanced materials/coatings might allow the extension of the viability domain towards higher and broader ranges (temperature, dpa, etc.), extending the fields of applications of LFRs and resulting in higher performances

[en] The objective of the Technical Meeting is to present and discuss innovative liquid metal fast reactor (LMFR) core designs with special focus on the choice, development, testing and qualification of advanced reactor core structural materials

[en] Outline: • Modeling of SFR cores using the Serpent-DYN3D code sequence; • Core shielding assessment for the design of FASTEF-MYRRHA; • Neutron shielding studies on an advanced Molten Salt Fast Reactor (MSFR) design

[en] The objective of the TM on “Liquid metal reactor concept: core design and structural materials” was to present and discuss innovative liquid metal fast reactor (LMFR) core designs with special focus on the choice, development, testing and qualification of advanced reactor core structural materials. Main results arising from national and international R&D programmes and projects in the field were reviewed, and new activities to be carried out under the IAEA aegis were identified on the basis of the analysis of current research and technology gaps

[en] Scope of this technical meeting: • Within FR development programmes, significant research and development (R&D) efforts are devoted to the design of innovative reactor cores ⇒ intrinsic safety features (enhanced negative reactivity feedbacks, reduced coolant void reactivity effects, etc.), ⇒ high performance (in terms of cycle length, high fuel burnup, breeding gain, etc.), ⇒ Minor Actinide transmutation capability. • The development of high performance in-core structural materials represents one of the most challenging aspects ⇒ high neutron flux, ⇒ liquid metal coolant, ⇒ high temperatures. Objectives and expected outcomes: • Present and discuss results of studies and on-going R&D and design activities in the field of innovative reactor core concepts; • Present and discuss results of studies and on-going R&D activities in the field of advanced reactor core structural materials; • Identification of research and technology gaps to be covered through new R&D initiatives to be carried out under the aegis of the IAEA

[en] For a typical MOX fuelled SFR of power reactor size, Implications due to higher burnup have been quantified. Advantages: – Improvement in the economy is seen upto 200 GWd/ t; Disadvantages: – Design changes > 150 GWd/ t bu; – Need for 8/ 16 more fuel SA at 150/ 200 GWd/ t bu; – Higher enrichment of B₄C in CSR/ DSR at higher bu; – Reduction in LHR may be required at higher bu; – Structural material changes beyond 150 GWd/ t bu; – Reprocessing point of view-Sp Activity & Decay heat increase. Need for R & D is a must before increasing burnup. bu- refers burnup. Efforts to increase MOX fuel burnup beyond 200 GWd/ t may not be highly lucrative; • MOX fuelled FBR would be restricted to two or four further reactors; • Imported MOX fuelled FBRs may be considered; • India looks towards launching metal fuel FBRs in the future. – Due to high Breeding Ratio; – High burnup capability