Welcome to Bavaria - West Germany to the SECOND EUROPEAN NUCLEAR SIMULATION SYMPOSIUM. That workshop-type meeting is a follow-up of the first Symposium which took place also at Schliersee in October 1987. The objective of gatheri ng together is to cover most of the aspects of Nuclear Mathematical Modelling and Simulation in theory and practice to promote the exchange of knowledge and experience between different national and international research groups in that field taking into con sideration that Nuclear Safety in "United Europe" turned to be a main issue. Furthermore, there is to strengthen the international contact between deve lopers and users of mode 11 i ng and simu 1 ati on techniques consi deri ng the "open" European Community borders of 1992. This triennial International Conference jointly promoted by ASIMUTH - Applied Simulation Technology and the Gesellschaft fUr Reaktorsicherheit (GRS) created an interest to publish new projects including their new results. A large number of contributed papers has been strictly examined and selected by the editorial committee to guarantee a high international technical standard. The book contai ns the accepted papers whi ch wi 11 be presented at the Symposium. The papers have been classified according to the following topics: VI 1. NUCLEAR POWER PLANT SIMULATION 2. SOFTWARE TOOLS 3. ARTIFICIAL INTELLIGENCE 4. COMPUTATIONAL FLUID DYNAMICS 5. NEUTRON KINETICS PLANT ANALYSER 6.