Findings from stress analysis of pipings

Problems of stress analysis of pipings for Czechoslovak nuclear power plants are discussed with emphasis on the effect of possible earthquakes. For the Mochovce power plant, partial seismic protection measures are planned; for instance, piping systems of more than DN 50 inner diameter, which are classed in the 1st seismic category, must be subjected to stress analysis. In these instances, not only static effects (as with the previous Czechoslovak nuclear power plants) but also seismic effects and transient modes must be considered. The computer time for dynamic calculations is as much as ten times longer than that for static stress analysis. The software for the complex stress analysis of piping systems comprises programs UCELENA2 and JAPAR2; suggestions are made for their extension. (Z.M.). 1 fig