Introduction
Test blanket module systems shall allow testing tritium breeding and recovery in the ITER environment with materials and technologies relevant to tritium breeder blankets of future fusion reactors. The test blanket modules are not among the items which are obliged to be provided by Europe to the ITER Organization. Instead the test blanket modules are to be procured separately by the interested parties and installed in ITER whereupon a test blanket module testing programme will be conducted by ITER.
Executive Summary
In 2012 the main achievements in the area of the test blanket modules is as follows:
• Completion of four grants for (i) Study of three
design configurations for HCLL and HCPB test blanket modules; (ii) test blanket modules functional materials (beryllium, ceramic breeder,
Pb-Li) Development/Qualification - screening
of an alternative production route/capacity for Be pebbles; (iii) post-irradiation examination of beryllium pebbles irradiated in the HIDOBE campaign; (iv) determination of the amount of tritium accountable in TBS over a given time period; development of the conceptual design of the tritium accountancy system;
• Completion of a specific contract (TO-04) for
the shielding analysis of the test blanket module systems in equatorial port and improvement of shielding performances;
• Award of a contract (OPE-412) for inspection,
handling and storage of EUROFER-97 batch#3 semi-finished products;
• Signature of a grant action (GRT-410) for the
upgrade of the EUROFER database and appendix for RCC-MRx;
• Signature of five engineering framework contracts
(OMF-331-1/2/3/4/5) for (i) Design of test blanket module sets and analyses including neutronics, shielding, dose rate and waste; (ii) design of test blanket modules ancillary systems and integration in ITER; (iii) nuclear maintenance studies and design of associated equipment; (iv)
TBS transient and accidental analyses & safety studies; (v) development and characterisation of preliminary welding procedure specifications for the test blanket module box assembly by welding and fabrication of feasibility/demonstration mock- ups;
• Award of four R&D framework partnership
agreements (FPA-372, FPA-380-1/2/3) for (i) Experimental Activities in support of the design of HCLL and HCPB-TBS using the TBM-CA experimental facilities; (ii) Experimental Activities in support of the design of HCLL and HCPBTBS using other facilities; (iii) test blanket system instrumentation development; (iv) qualification of functional materials for test blanket module applications.
Progress Report
The development of the European test blanket modules systems conceptual design has progressed in 2012, in particular with engineering contracts dedicated to seismic and electro- magnetic analyses and with the design of a tritium accountancy station (GRT-254). The conceptual design of the seven HCLL/HCPB ancillary systems has been further developed and is now an important reference for many components, in particular in terms of technology selection and preliminary performance evaluation. A systematic review of technical regulatory aspects like the PED/ ESPN classification of the TBS equipment has also been achieved. Integration in ITER has progressed, in particular with the preliminary integration of the plant interlock/safety systems within ITER.
The development and standardisation of fabrication technologies for test blanket module structures with embedded cooling channels (first wall, cooling/ stiffening plates and side caps) have progressed (OPE-305). Within this framework new fabrication benches have been fabricated and detailed fabrication procedure specification is being developed on the basis of codes and standards. As a result of the grant GRT-10, the EUROFER-97 structural material that will be used for test blanket modules has been introduced, for the first time, in a nuclear code: the RCC-MRx Edition 2012. For the time being, EUROFER-97 is introduced under
probationary phase and with partial list of material properties.
Other activities in the area of development/ characterisation of test blanket module functional materials have progressed satisfactorily. For instance the post-irradiation examination of the beryllium pebbles irradiated in the HIDOBE campaign has been achieved (GRT-30-3). In addition, investigation on alternative fabrication routes for beryllium pebbles (GRT-30-2) has shown that the “impact grinding” method is not recommended for a use in test blanket modules in particular because of excessive amounts of impurities. At least, preliminary investigations have showed the advantages of beryllium pebbles with grain sizes ranging from 10 to 30 μm over higher grain size (tritium release measurements, chemical composition and pebble density).
In the area of numerical modelling, a tool able to simulate tritium migration/processing in the test blanket module systems has been developed (GRT-254). This tools is unique in Europe and likely worldwide; it is now used for consolidating essential data for test blanket module safety demonstration in ITER and estimation of radwaste data.
Within the framework of the test blanket module programme committee activities, the following progresses have been obtained (i) the main legal provisions which shall govern the future test blanket modules arrangement to be signed between each ITER member that is planning testing of a test blanket module in ITER and the ITER Organization have been negotiated and endorsed by the ITER Council. They address in particular the role and responsibility of ITER members and ITER Organization, intellectual property rights and nuclear liability; (ii) the radwaste management strategy and updated radiological data for the European test blanket module systems have been transmitted to the Agence ITER France (AIF), as well as a preliminary study on the feasibility of transportation of irradiated TBMs outside ITER site for Post Irradiation Examination in European nuclear facilities.
Mock-up of a helium-cooled pebble bed (HCPB) test blanket module cooling plate (courtesy of KIT/Karlsruhe)
Mock-up of a helium-cooled lead-lithium (HCLL) test blanket module cooling plate (courtesy of ATMOSTAT-CEA)