Engineering design of the EURISOL multi-MW spallation target

The European Isotope Separation On-Line Radioactive Ion Beam project (EURISOL) is set to design the 'next-generation' European Isotope Separation On-Line (ISOL) Radioactive Ion Beam (RIB) facility. It will extend and amplify current research on nuclear physics, nuclear astrophysics and fundamental interactions beyond the year 2010. In EURISOL, four target stations are foreseen, three direct targets of approximately 100 kW of beam power and one multi-MW target assembly, all driven by a high-power particle accelerator. In this high power target station, high-intensity RIBs of neutron-rich isotopes will be obtained by inducing fission in several actinide targets surrounding a liquid metal spallation neutron source. This article summarises the work carried out within Task 2 of the EURISOL Design Study, with special attention to the coupled neutronics of the mercury proton-to-neutron converter and the fission targets. The overall performance of the facility, which will sustain fast neutron fluxes of the order of 1014 n/cm2/s, is evaluated, together with the production of radionuclides in the actinide targets, showing that the targeted 1015 fissions/s can be achieved. Some of the greatest challenges in the design of high power spallation sources are the high power densities, entailing large structural stresses, and the heat removal, requiring detailed thermo-hydraulic calculations. The use of a thin martensitic steel beam-window and a well-controlled mercury flow has been shown to reduce the von-Misses stress in the former below the 200 MPa limit, with reasonable maximum flow rates of ~6 m/s. Alternatively, a windowless target configuration has been proposed, based on a liquid mercury transverse film. With this design, higher power densities and fission rates may be achieved, avoiding the technical difficulties related to the beam window. Experimentally, several tests have been performed at IPUL (Riga, Latvia) in order to study the stability of the liquid metal flow and validate the mercury loop design

Engineering design and construction of a function Hg – loop & Contribution of IPUL in windowless Hg-target feasibility studies

Within EURISOL – DS, a liquid metal /LM/ spallation target with a power of several Megawatt is designed to provide neutrons to a fission target. The target station that allows the full intensity of a 4 MW proton beam to be used for RIB production will require new advanced technology. It is a critical component of EURISOL.For a power density above 103 MW/m3 the windowless, free-surface, molten LM-jet is proposed as a target since it avoids the very serious lifetime – shortening damage caused by the power proton beam in any syste

Mean temperature profile at the entrance of a thermoacoustic stacked screen heat exchanger

The entrance effects at a stacked screen heat exchanger are investigated with two CFD test cases. The first CFD test case models an ideal heat exchanger adjacent to an open space. The influence of the heat conduction on the mean temperature is shown. The second test case models two screens of a stacked screen regenerator as two inline cylinders. The mean temperature profile is compared to the numerical solution of a reduced model equation. It is shown that viscous effects do not influence the mean temperature profile at low amplitude

Computational fluid dynamics analysis of the oscillatory flow in a jet pump: the influence of taper angle

A two-dimensional CFD model for predicting the oscillating flow through a jet pump is developed. Various taper angles are investigated and total minor loss coefficients are derived. A good correspondence is achieved with experimental results from the literature. However, at higher taper angles a dramatic decay in the jet pump pressure drop is observed, which serves as a starting point for the improvement of jet pump design criteria for compact thermoacoustic application

Mock-up testing facilities and qualification strategy for EU ITER TBMs

European test blanket modules (TBM) for both European blanket concepts, namely the Helium Cooled Lithium Lead (HCLL) and the Helium Cooled Pebble Bed (HCPB), and their auxiliary systems have been designed in the last years. This paper presents the experimental facilities available in Europe for the qualification tests of European TBMs. In particular, devices designed to analyze specific technological issues, for example corrosion under strong magnetic fields or tritium management and extraction, as well as large scale facility to perform integral tests are described. A preliminary overview on the qualification strategy is presented and discussed