M Febvre

Status of fabrication development for plasma facing components in the EU

This paper summarises the European R&D efforts for the manufacture of shield modules and divertor cassettes for the International Thermonuclear Experimental Reactor (ITER), including their plasma facing components. The various development steps are described as they had to be taken to resolve the fabrication issues, and to keep track with the evolving design requirements and solutions. For all components, the manufacturing feasibility has been demonstrated on prototype scale which puts Europe in the position to start the procurement as soon as the decision about ITER construction is taken. The time period remaining until then is used to optimise the fabrication processes and to develop more cost effective alternatives.

European achievements for ITER high heat flux components

This paper summarises the main activities carried out by the EU Home Team to develop suitable solutions for the ITER high heat flux components, namely the divertor, the baffle and the limiter. The available results demonstrate that the EU have the capability to manufacture high heat flux components with carbon fibre reinforced carbon, tungsten and beryllium armours which all exceed the ITER design requirements.

European development of prototypes for ITER high heat flux components

The extensive EU research and development, on international thermonuclear experimental reactor (ITER) high heat flux (HHF) components aims at the demonstration of prototypes for the divertor and baffle with challenging operating requirements. The recent progress of this development is summarised in the paper, particularly concerning the manufacture and testing of mock-ups and prototypes. The available results demonstrate the feasibility of robust solutions with carbon and tungsten armour.

European Development of the ITER Divertor Target

Abstract The main European contribution to the ITER divertor project was the development of the divertor target with severe operating requirements such as peak heat loads of up to 20 MW/m2. This development involving EU laboratories and industry included R&D on armour materials, thermo-hydraulics testing, component manufacture, high heat flux testing, design and manufacture of prototypes for later testing. The 4-year EU R&D effort achieved the demonstration of the feasibility of a robust divertor target design based on carbon and tungsten armour. This EU solution has eventually been adopted for the ITER reference design and could be valid also for other ITER high heat flux components such as limiters or baffles.

ITER primary first wall mock-up fabrication and testing for Be/Cu alloy joining development☆

This paper presents the main results obtained so far from the development work performed in Europe to define the joining conditions between beryllium (Be) tiles and the dispersion strengthened copper alloy (DS-Cu) heat sink material for the ITER primary first wall (PFW). Two Be/DS-Cu joining techniques were investigated: hot isostatic pressing and furnace brazing. Six PFW mock-ups have been thermal fatigue tested so far. One PFW mock-up with HIPped Be tile was tested at 2.5 MW/m 2 for 1000 cycles without any indication of failure. On two other mock-ups, Be tiles detached at or above 2.7 MW/m 2 . Two others were tested at 0.7 MW/m 2 for 13 000 cycles also without any indication of failures. A first PFW mock-up with a furnace brazed Be tile was tested at 1.6 MW/m 2 for 1000 cycles. These results should be compared with the operation conditions of the ITER PFW, namely 0.5 MW/m 2 peak heat flux and off-normal events up to 1.4 MW/m 2 . Thermal fatigue testing of other mock-ups is still in progress and the development programme is continuing to further increase the engineering margins while decreasing the fabrication cost of the PFW panels.

Comparison of electron beam test facilities for testing of high heat flux components

Abstract In the last few years, electron beam facilities for the testing of high heat flux components have been erected in Europe, Japan, Russia and in the USA. In principle all the facilities are comparable, but some machine parameters are quite different. These differences include electron beam operation (beam generation, beam diameter, sweeping mode), as well as the temperature measurement devices, calibration techniques and the definition of absorbed power densities. In order to assess the influence of these machine parameters and techniques on the results of high heat flux experiments, a round robin test has been performed in five facilities. In these tests, actively cooled CFC monoblock mock-ups were heated by electron beams using target power densities up to 15 MW/m 2 . Mock-up temperatures and their distribution, measured by different methods (IR camera, pyrometer, thermocouples), have been used as criteria for comparison. The evaluation of data from the different facilities shows good agreement for identical target loading conditions.

Manufacturing of a full scale baffle prototype for ITER with a CFC and W plasma spray armour

Abstract The European contribution to the development of the ITER baffle will culminate with the fabrication of a full scale prototype with a CFC–plasma spray armour. This paper describes the main features of the prototype as well as the extensive R&D carried out to ensure that the component is fabricated with the required quality.

High heat flux behaviour of damaged plasma facing components

A medium scale prototype of the ITER divertor vertical target, manufactured with calibrated internal bonding defects is tested and studied via infrared characterisation, thermal fatigue testing and finite element analysis. Tools for defect detection and behaviour of these defects along in-service lifetime are presented in this document.

EVOLUTION OF FRAMATOME AND CEA HIGH THERMAL FLUX STATION FOR FUSION TECHNOLOGY EXPERIMENTS NEEDS

EB200 High Thermal Flux Station evoluted with the needs of Fusion Technology experiments. The latests improvements of the station used for testing needs in 1995/96 concern: • cooling loop flow rate capacity increase to 6 kg/sec • use of non linear flux shape • cycling tests on several positions • use of pulses with variable length This paper presents these modifications through recent applications on mock-ups.

Main achievements of the EU HT test programme of ITER primary wall small scale mock ups

This paper presents the main achievements of the European Home Team (EU HT) test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show very good thermal fatigue performance and operation margin of the ITER primary first wall concept.