The Project focuses on HTR/VHTR technological developments needed for industrial reference designs in the areas of reactor physics, safety, fuel and fuel cycle back end, materials and components . Moreover system integration with the reference designs is carefully checked.  

The overall objectives of HTR/VHTR in the present phase are:

·    Assessing technologies of the first step in advanced HTR development (HTR/VHTR in the range 850-950°C, with a burn-up about 15% FIMA).

·    Exploring promising options for higher performances (VHT above 950°C, higher burnup).

·    Developing technologies for coupling the nuclear reactor with industrial process heat applications

Globally the time frame of FP6 Project corresponds to the period of conceptual of the first large scale demonstrators. The R&D will have to provide relevant results for these phases, that is

·    To confirm that the technologies developed in particular within FP5 for HTR or recovered from the past European developments (fuel, materials, helium technologies, etc.) can actually satisfy the specifications of the HTR/VHTR, or to provide alternative solutions, when necessary for overcoming the possible limits of these technologies, and settle a suitable experimental basis for qualifying these technologies,

·    To assess the different design options in order to provide the basis for the choice of options,

·    To consolidate the qualification of computer tools , mainly:

                o   coupled reactor physics and thermodynamics codes

                o   fuel performance codes

                o   transient analysis

·    To set up the test facilities (helium loops, irradiation facilities…) needed first for the validation of technology and design options and later for the final qualification of the demonstrator components,

·    To provide basic data on the environmental impact of the whole VHTR life cycle (in particular the releases in normal and accident conditions and those of the irradiated fuel in disposal conditions).

In the meantime, an exploratory R&D for longer-term innovations must also be started. 

Considering these boundary conditions, the technical objectives of the Project are:

·    To explore the limits in the performance of the fuel under irradiation in normal operating and accident conditions and to explore the potential of advanced kernel and coating concepts for improving the performance of the fuel for higher temperatures and higher burn-up, 

·    To select materials for high / very high temperature conditions and acquire their properties in normal operating and accident conditions,

·    To develop conceptual designs for key components and to test component mock-ups corresponding to these designs in order to select and validate the appropriate design options,

·    To acquire relevant elements (through experiments and benchmarking) for the qualification of computer codes fitting the HTR/VHTR advanced design needs and to continue the development of advanced models for the behaviour of HTR/VHTR fuel under irradiation,

·    To assess and improve knowledge of HTR/VHTR behaviour in accident conditions,

·    To confirm, complete and extend to VHTR the specific safety approach outlined in FP5 and widen its scope by considering different types of applications,

·    To obtain more precise experimental data on leaching behaviour allowing for a reliable assessment of the suitability of coated particle fuel for direct geological disposal.

Moreover the Project will make a special effort for system integration , to take into account the needs for the VHTR designs developed by the industrial partners of the Project, to assess the benefit from the R&D results of the IP for these designs and to identify the additional R&D needs generated by new issues resulting from R&D findings or required for overcoming limits imposed to the performances by the use of the current technologies. Therefore the system integration tasks will be

·    To provide R&D boundary conditions relevant for application to the industrial partners' designs,

·    To ensure that the technologies and components developed in the Project can be integrated within the whole system from the functional and safety points of view,

·    To assess the viability and performance of systems based on the technologies and components developed in the Project,

·    To evaluate such systems towards the goals and criteria proposed by the MICHELANGELO Network and GIF for nuclear systems of the next generation.