Annular Downcomer Research Articles

Response of reactor internals to fluctuating pressure forces

Abstract The response of nuclear reactor internal components to the turbulent coolant flowing through the annular downcomer region is investigated analytically based on a simplified cylindrical shell model. Powell's acceptance approach is used to compute the r.m.s. response as a function of position on the surface of the shell; the virtual mass effect due to fluid loading is included in the analysis. The input forcing function and damping ratios were obtained by experimental measurement in which the r.m.s. displacement was also measured. The theoretical-experimental agreement is very good.