Networking Activities

NA1 : Management

NA2 : Training

NA3 : Manufacturing Practices

NA4 : Measurement Best Prctices

NA5 : Preparation of Transnational Access

          Joint Research Activities

JRA1 : Mechanical Testing Devices

Safety and ageing of light water reactor (LWR) structural materials are major factors to be addressed for guarantying the availability, cost effectiveness and reliability of nuclear power plants. It is known that material irradiation leads to the degradation of their mechanical and fracture properties. As well, irradiation assisted stress corrosion cracking (IASCC) has been identified as an important ageing mechanism of reactor core components.

In order to improve the knowledge on the reactor material ageing under flux, mechanical load or under corrosion, additional experimental data are required. Therefore the MTR experimental capabilities have to be upgraded to meet these objectives.

Two key items have been identified and will be addressed inside the JRA1 activity through dedicated work-packages:

WP1.1 – Mechanical Testing devices under mechanical loads

WP1.2 - Corrosion under Irradiation

JRA2 : Fuel Testing Devices

Fuel testing capability is a key topic with strong impact on strategic items such as:

·       Safety by assessing thermal-mechanical behaviour in normal as well as in non-normal situation. Simulating fast transient experiments is an important MTRs’ feature.

·       Optimisation of existing product and development of new fuels determine for a large part the competitiveness of nuclear energy. This relies on the deeper understanding for example on the fission product dynamics.

·       Transmutation studies and Gen IV fuel definition by assessing the fuel behaviour under a tailored MTR flux tailored so that kinetic rates of nuclear reaction are relevant versus the industrial application.

Enhanced on-line instrumentation (including fission gas measurements) together with advanced modelling is a basic trend and stake for all the above items.

Taking into account the FEUNMARR thematic network (FP5, 2002), the JHR-Coordination Action (FP6, first call) and the broad European expertise present in the present proposal, a short list of key items has been identified as breakthroughs for existing MTRs.

Five key items have been identified and will be addressed through dedicated work package (WP):

WP2.1 – Neutron screen development for advanced fuel and transmutation

WP2.2 -Transmutation

WP2.3 - Power Transient system and neutron screen development for Light Water Reactors

WP2.4 - Water Chemistry

WP2.5 - Fission Gas Measurement

JRA3 : Non-LWR Loop Design

The Generation IV International Forum (GIF), including 10 countries and Euratom, was established in January 2000 to investigate innovative nuclear energy system concepts for meeting future energy challenges. The forum serves to coordinate international research and development on promising new nuclear energy systems for meeting future energy challenges.

Approximately 100 system concepts were analysed and evaluated for their potential to meet the goals of the Generation IV program (ability to fulfil targeted applications, deployment readiness, and development cost). In December of 2002, the GIF selected six systems and describes the research and development pathways for establishing technical and commercial viability, demonstration and, potentially, commercialisation. The six systems are Gas-Cooled Fast Reactor (GFR), Very High Temperature Reactor (VHTR), Supercritical Water Cooled Reactor (SCWR), Sodium-Cooled Fast Reactor (SFR) Lead-Cooled Fast Reactor (LFR) and Molten Salt Reactor (MSR).

Also, fusion reactors and Accelerator Driven Systems (ADS) will be operated at high temperature, and for the ADS in Heavy Liquid Metal environment.

The development of such reactors required selection and qualification of new materials and fuels sustaining high temperature, high dose, and chemical interaction with the cooling medium.

Three key items and one cross topics have been identified and will addressed inside the JRA3 activity through dedicated work-packages:

WP3.1 - Gas loop

WP3.2 - Heavy Liquid Metal Loop

WP3.3 - Supercritical Water Loop

WP3.4 - Miniaturized Components

JRA4 : Safety Test Instrumentation

The design and operation of nuclear reactors calls for justly experiments and studies intended to guarantee reactors safety in normal and accidental operating conditions.

According to the general trends of the designers and utilities to improve the performances of the existing Nuclear Power Plants (e.g. increase of the fuel cycle length, increase of the fuel discharge burn-up,..) and in view of new generations of reactors (HTR, VHTR, GFR..), it is necessary to anticipate and identify the future needs for safety experiments and appropriate experimental facilities, in order to get, in due time, all the information needed to ensure the safety of the plants. In particular, temperature and nuclear conditions and the use of different cooling materials (such as Pb, He, Na) in new reactors require more complicated (or different from the past) testing conditions that mainly focussed on LWR conditions.

Furthermore, the improvement and qualification of safety codes require separate effects tests and more accurate measurements consequently improved instrumentation.