A pseudo response spectrum method for Mark I loads

A ''pseudo'' base motion response spectrum method is developed to uniquely evaluate the periodic condensation oscillation and chugging drag loads that may occur on submerged structures within the Mark I containments. The term ''pseudo'' is used because the spectral responses are artificially determined to produce modal responses equivalent to those caused by applied time varying load distributions. The applied loads result from fluid displaced within the containment vessels due both to discharging air and steam bubbles and to fluid-structure interaction. Generic definitions of the total load time-histories have been expressed by their component harmonics spaced at 1-Hz intervals over a wide range of frequincies. The Pseudo Response Spectrum Method is developed as a means to comprehensively apply these definitions to the analysis of specific submerged structures. By this method, the dynamic effects of all load harmonics can be accounted for in plant unique analyses