Search

This work presents a description of the radiation protection issues impacting on Primary Cooling circuits of the MITICA (Megavolt ITER Injector Concept Advanced) experiment in Padova. MITICA represents the full scale Neutral Beam Injector of ITER; two Heating neutral Beams are planned to be used in Cadarache (F) to reach the plasma nuclear fusion conditions, in addition to other heating systems. Three actively cooled components will be installed in the MITICA Beam Line Vessel, and their surfaces will be impacted by high energy neutral particles produced by an RF Ion Source and accelerated up to 1 MV by a set of five acceleration grids. Ultrapure and deionized water will be used as an insulating coolant to guarantee high voltage holding. Due to the high velocity inside water channels and due to the components materials, the production of activated corrosion products is likely to pose safety concerns in MITICA facility. Considerations about this issue and technical solutions to be adopted for the Cooling Plant are described in this paper.

This paper describes the status of liquid lithium (Li) target facility in Key Element technology Phase (KEP) of International Fusion Materials Irradiation Facility (IFMIF). The IFMIF is being jointly developed by European Union (EU), Japan (JA), Russian Federation (RF) and US to provide an accelerator-based D-Li neutron source for testing the candidate materials for fusion reactor. Key issue of the Li target is to obtain a stable liquid Li flow with a speed of 20 m/s under a deuterium beam deposition of 10 MW. In the KEP, 19 tasks for the Li target are proposed and shared by EU, JA and RF. These tasks are Li flow experiment, Li simulation experiment by water jet, corrosion/erosion, remote handling, and safety analysis. In addition to the KEP tasks, detailed design of the target is being performed on transient thermal analysis of the Li , remote handling of the target assembly and safety analysis of the Li loop.

This paper presents an assessment of ATHENA/Modl, an extension of the RELAP5 code able to represent a number of cooling fluids, on experimental data provided by the helium facility HE_FUS3. The facility was selected to perform experimental campaigns on thermomechanics and thermal-hydrau]ics within the frame of the DEMO HCPB Blanket design programme. As a first step the characterisation tests of the facility have been used to develop an input model for ATHENA. Special models have been adopted in order to simulate some prototypical components for which the generic component models available in the code are inadequate. Later on, a preliminary assessment of this model has been performed, both for steady state and transient conditions, on the first tests conducted in the facility. In spite of the numerical weaknesses detected during the analysis, which have required special caution in the definition of the boundary condetions, the stabilised steady state has been achieved in good agreoment with the experimental data, and two accident transients of LOFA have been qualitatively well reproduced.

Within the European Fusion Technology Programme, for the period 1997-1998, significant R&D activities related to the DEMO Reactor Helium Cooled Pebble Bed Blanket (HCPB) concept are being carried-out. The conceptual design and layout of the Test Blanket Module (TBM) to be tested in the ITER the fabrication of the related test sections and the Out-of-Pile testing activities are performed in the Work Package WP B2.1 and WP B3.2. The reference facility for testing the TBM medium scale mock-ups is the HE-FUS3 facility at ENEA Brasimone. These experiments will have the main objectives to investigate the thermal and mechanical behaviour of the TBM module under steady state, cyclic power and conditions. The paper presents the TBM mock-up design assumptions the preliminary calculations, the envisaged manufacturing procedures and a draft programme for the fabrication and testing of the mock-ups.

Since the 1997 ENEA has launched two out-of-pile experimental activities related to the design of the EU-HT Breeding Blanket (BB) for ITER and the design of the Helium Cooled Pebble Bed Blanket (HCPB) and its Test Blanket Module (TMB) (to be tested in ITER) for DEMO. Both Breeding Blanket designs are characterised for having adopted similar Beryllium binary pebble bed arrangement as reference neutron multiplier material. On the contrary the breeder material and its arrangement in the Blanket module is different.The ENEA out-of-pile experiments have the main objective to investigate the thermo-mechanical behaviour of the blanket modules aiming at obtain the experimental confirmation that the basic lay-out of the module accommodates the Internal heat loads at the reference geometrical and thermal hydraulic boundary conditions.The tests will be carried-out at ENEA, Brasimone Labs in the THESIS apparatus of the CEF1-2 thermal-hydraulic facility and on the HE-FUS3 thermal-hydraulic facility.The paper presents both the designs of the experiments and the related mock-ups.The first thermal-hydraulic and thermo-mechanical calculations with a tentative to adopt a model to simulate pebble beds in a FEM code are also presented.