Transient analysis of the pebble-bed HTGR with the DSNP simulation language. V.1

This is the final report of the first phase of the research contract between KFA-Julich and Soreq NRC covering the period of January 198l to December 1982. During this period most of the components necessary for the dyanmic simulation of the PNP-500 high temperature gas-cooled reactor were developed, tested and included in the DSNP library. Components available in the DSNP simulation language were modified to be applicable to compressible flow systems. The report describes each of these components and provides instructions for their application to system simulation in the DSNP. The primary, intermediate and water-steam heat removal loops were simulated and tested step by step by developing DSNP simulation programs with progressively increasing complexity. The details of each of these simulations is presented together with the partial results obtained. The partial simulations were combined to obtain a full scale PNP-500 simulation. Several accidents were studied with this simulation program particularly a turbine trip, a reactivity accident and a depressurization accident. The major conclusion from the study is that the PNP-500 is inherently a very stable and safe system under a large variety of extreme operating and accident conditions. (author)