About SEARCH

Latest News

Upcoming Events

Concept

With the growing scarcity of fossil fuels and the problem of CO2 emissions, energy is one of the critical problems society faces. Nuclear fission can be a part of a sustainable energy mix provided that due attention is given to safety aspects and waste. Presently, the European Union produces 35% of its electricity via nuclear fission in so-called second and third generation light water reactors (LWR). In this process about 2500 tons of spent fuel is generated that contains 25 tons of Pu, 3.5 tons of minor actinides (MA) like Np, Am, and Cm and 3 tons of long-lived fission products (LLFP).

Nuclear waste must be dealt with in an appropriate way. The current adapted approach is geological disposal, possibly preceded by used fuel reprocessing. The latter depends on fuel cycle choices and waste management policies of individual member states. In any case, the time scale involved in geological disposal exceeds that of the history of accumulated technological knowledge. As a result geological disposal of nuclear waste does suffer from public acceptance problems.

In various studies, partitioning and transmutation (P&T) in critical and/or sub-critical fast spectrum transmuters has been identified as a way to lessen the volume and to lower the decay time of nuclear waste. This reduces the required monitoring period to technologically feasible and manageable time scales. Also in the framework of the GEN IV initiative this approach has been put forward.

At European level a collaborative effort supported by the European commission and leading European research institutes and industries was started to bring advanced fuel cycles and the P&T strategy together in order to investigate its economic and technical feasibility. The exploratory research done in the field and the launch of the Sustainable Nuclear Energy Technology Platform (SNE-TP) in 2007 lead to a joined effort from the European nuclear fission research community to issue a Strategic Research Agenda (SRA) that describes the roadmap towards sustainable nuclear fission energy. Here, the SNE-TP community identifies the sodium fast reactor technology as the reference but also highlights the need for the development of an alternative track with lead or gas cooling. In addition, the need for R&D activities in support of accelerator driven systems (ADS) was stressed to allow the demonstration of ADS technology by the construction of the first ADS Demo facility (MYRRHA).

With regard to alternative fast reactor technologies as described in the SRA, lead cooled fast reactor (LFR) systems are very promising in meeting the Gen IV requirements in terms of sustainability, economics, safety and reliability and proliferation resistance & physical protection. This assessment is based on inherent properties of the reactor coolant and on design choices made.

In the European Strategic Nuclear Infrastructure Initiative (ESNII) Implementation plan, the roadmap for the development, design construction and operation of a lead cooled fast reactor is laid out. The conceptual design of a LFR Demonstrator (ALFRED) is foreseen for 2012. The roadmap also identifies the need for a European Technology Pilot Plant (ETPP) that should be operational by 2023. As a result a priority action must start to complete the design and to support the licencing procedure.

In this context MYRRHA (Multi-Purpose Hybrid Research Reactor for High-Tech Applications) will play a key role as the LFR-ETPP. MYRRHA is a flexible fast neutron irradiation facility that is designed to be able to operate as an accelerator driven sub-critical system (ADS) and as a critical liquid metal cooled reactor. In this latter mode the facility will be operated as a research and test facility to support fast neutron reactor development. All critical components of a lead cooled reactor including the core configuration, the cooling system, control system and instrumentation can be tested in this configuration. In sub-critical mode MYRRHA will serve to demonstrate the feasibility of an ADS at sizable power levels which is crucial for the development of dedicated sub-critical transmuter systems. MYRRHA is designed with a compact high flux core so that the machine can function as a fast spectrum neutron irradiation facility for tests of advanced fuel, structural materials, MA transmutation experiments and medical isotopes production. The high power density of the core dictates the use of lead bismuth eutectic (LBE) rather than pure lead as coolant because with the higher melting point of pure lead, the hot spot temperatures on the reactor fuel get too high. Because MYRRHA is primarily a research facility it is the main ESNII infrastructure that is promoted within the European Strategy Forum for Research Infrastructures (ESFRI).

In March 2010 the Belgian government decided to support the MYRRHA project with an engagement to cover 40% of the costs whereas the other 60% should be invested by a consortium of international partners to be built by 2014. In addition, the decision requires the preliminary environmental impact assessment report (EIAR), the front end engineering design (FEED) and the preliminary safety assessment report (PSAR) to be delivered to the Belgian safety and licencing authorities by 2014. The documents are a first necessary step in obtaining the construction permit and licenses. The deadline set is consistent with the ESNII goal to have the facility operational by 2023.

In particular with regard to the FEED and the PSAR there are a number of technological challenges to be met. A support R&D programme to respond to these challenges is absolutely necessary. Whereas in the past R&D work was mainly focused on feasibility studies, here there is more need for safety and reliability related R&D.