Development of the European Activation System

Abstract

The ability to predict the effects of neutron irradiation on an arbitrary material is a fundamental need of fusion technology. The European Fusion Technology Programme has long recognised this fact, and has developed the European Activation System (EASY). This integrated package relies on research in several areas and can be described as an example of successful international co-operation. The areas include: measurements of differential cross sections, evaluation of decay data, theoretical modelling of cross sections, library compilation and evaluation, inventory code development, integral validation, code/data package production and documentation and applications of the package.Modern software tools were used to produce a user-friendly application (SAFEPAQ-II) running under Windows-98 or NT in which all nuclear data are stored in relational databases. Cross section data from almost 50 sources are read and converted from standard formats to databases. By a series of manipulations these data are selected, modified and processed to yield SAFEPAQ-II databases. All reactions can be graphically displayed with experimental data and uncertainty estimates. Following internal validation and processing the data can then be written out in standard EAF format (including a set of nine multi-group files) ready for use by the FISPACT inventory code.The various EAF data libraries have been extensively validated against integral measurements using fusion relevant materials and three complementary neutron spectra. Results from such studies have also been fed back to improve library development. EAF-2001 has been released this year - it is the first library to be produced completely using the SAFEPAQ-II system, which incorporates rigorous QA. FISPACT-2001 also contains some new features, primarily to enlarge the number of output options. New evaluations of decay data remove poor data from some minor nuclides and the use of recent biological hazard coefficients makes potential radio-toxicity estimation more reliable.New user tools allow the graphical viewing of all multi-group cross sections and decay data. User feedback on bugs and new options have been incorporated in EASY-2001 which is fully documented and provides a complete and reliable tool for prediction of activation in fusion and other applications.