Component Testing and Materials Development for Fusion Applications Using Materials Test Reactors
Fusion power plant operation will strongly depend on the economy and reliability of crucial components, such as first wall modules, tritium breeding blankets and divertors. Their operating temperature shall be high to accomplish high plant efficiency. The materials properties and component fabrication routes shall also assure long reliable operation to minimize plant outage. The components must be fabricated in large quantities based on demonstrations with a limited amount of test beds. Mock-ups and test loops will, through iteration processes, demonstrate the reliable operation under reference thermal-hydraulic conditions. 14 MeV neutrons escaping the plasma dominate the nuclear conditions near the first wall. Neutron transport analyses have shown that large portions of the components near the plasma have to cope with a neutron spectrum resembling that of a fission core. MTR's, Materials Test Reactors, have been used successfully to test components for fusion power plants. Their space and availability will also ensure their role as future test bed for (sub) components such as blankets, first walls and divertors. The future generation of MTR's will allow faster testing, because of the higher neutron fluxes possible with advanced driver fuels. The strong limitation of MTR's for fusion testing will remain the limited production of helium and hydrogen, because of the lack of 14 MeV neutrons. Though large parts of the fusion components are subjected to nearly fission neutron spectra, in the domain near the burning plasma 14 MeV neutrons are dominant. IFMIF will produce the 14 MeV neutrons to fill that gap by the end of the next decade. In the meantime the MTR's will generate relevant data for fusion power plant component design. After IFMIF is operational the new generation MTR's will still have a function in testing components in a nuclear environment. The new generation test reactors will also be used for the development of component operating at high temperature in the generation-4 fission power plants. The R&D climate will be most stimulating for cross fertilization of fission and fusion component development, leading to more efficient use of the earth's resources.
The IFMIF test facilities design
IFMIF, the International Fusion Materials Irradiation Facility, is being developed by Europe, Japan, USA and Russia under the umbrella of the IEA. As the construction of a fusion demonstration reactor, DEMO, for demonstrating competitive electrical power generation will be the next important program milestone after ITER, the timely availability of a sound materials database has become an indispensable element in international fusion road maps. The primary mission of IFMIF is to generate a materials irradiation database for the design, construction, licensing and safe operation of DEMO. Based on a recently completed comprehensive design report, IFMIF is ready to enter an Engineering Validation and Engineering Design Activity (EVEDA) phase with a subsequent start of construction around 2011. All mayor subsystems of the IFMIF test facility architecture like the Target and Test Cell, the access and maintenance cells as well as the hot cells are fully remote controlled and allow division into radiation zones. Sophisticated remote handling technologies originally developed for fission reactors are inevitably required, especially for assembly and maintenance of the Li-target and test assemblies. The present status of the test facilities is reviewed and major advances during the past few years in the irradiation performance as well as in the nuclear Target and Test Cell design are highlighted.
Nietzsche's Task: An Interpretation of Beyond Good and Evil
When Nictzsche published Beyond Good and Evil in 1886, he told a friend that it was a book that would not be read properly until "around the year 2000". Now Laurence Lampert sets out to fulfill this prophecy by providing a section by section interpretation of this philosophical masterpiece that emphasises its unity and depth as a comprehensive new doctrine on nature and humanity. According to Lampert, Nietzsche begins with a critique of philosophy that is ultimately affirmative, because it shows how philosophy can arrive at a defensible ontological account of the way of all beings. Nietzsche next argues that a new post-Christian religion can arise out of the affirmation of the world disclosed to philosophy. Then, turning to the implications of the new ontology for morality and politics, Nietzsche argues that these can be reconstituted on the fundamental insights of the new philosophy. Nietzsche's comprehensive depiction of this anti-Platonic philosophy ends with a chapter on nobility, in which he contends that what can now be publicly celebrated as noble in our species are its highest achievements of mind and spirit.