Fast Reactors and Accelerator Driven Systems Knowledge Base

Conference Article: MYRRHA: A multipurpose accelerator driven system for research & development

Abstract

SCK•CEN, the Belgian Nuclear Research Centre, and IBA s.a., Ion Beam Application, a world leader in accelerator technology, are designing an ADS prototype, the MYRRHA Project. The partners are foreseeing MYRRHA as a first step towards the European ADS-Demo facility. The MYRRHA system should become a new major research infrastructure for the European partners presently involved in the ADS Demo development. The MYRRHA concept, as it is today, is based on the coupling of an upgraded commercial proton accelerator with a spallation target surrounded by a subcritical neutron-multiplying medium. A cyclotron, based on positive ion acceleration technology brings the protons up to an energy level of 350 MeV. The nominal current is 5 mA of protons. The spallation target system is a circuit with, at the upper part, a free surface in contact with the incoming proton beam. This windowless concept distinguishes MYRRHA from other ADS designs. The subcritical assembly consists of fuel rods of fast breeder type, with Pu contents between 20 and 30%, in a Pb­Bi environment. This zone is very suitable for material testing and transmutation studies due to the high fast flux attainable. The desired performances in the fast core in terms of the fast flux are 1015 n/cm²·s, for a total power output of 25 MW. The reactor presents itself as a single vessel of about 4 m diameter and 5 m high. The primary heat exchangers, the primary pumps, the spallation loop are also vertically inserted in cover penetrations, at the vessel periphery, very much like it is done in fast reactors. Smaller penetrations are foreseen at different radial positions, in order to provide irradiation positions. This paper will present the current status of the MYRRHA project, the problems identified so far in the design. It will describe the hardware (pumps, heat exchangers, spallation loop, handling tools) as they are now foreseen, and list the cooperations which will be needed in those developments.

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Reference:

Advisory Group Meeting on “Design and Performance of Reactor and Sub-critical Blanket Systems with Lead and Lead-Bismuth as Coolant and/or Target Material” , Moscow, Russian Federation, 23-27 October 2000

International Atomic Energy Agency, Vienna (Austria)

IAEA-TECDOC--1348, pp:173-194