Structural response analysis of the confinement system of the Ignalina nuclear power plant

Presented is a study of the accident confinement system of the Ignalina nuclear power plant (NPP) with Russian acronym for 'channelled large power reactor' (RBMK)-1500 reactors for the ultimate design basis accident. The computation techniques described pertain to the strength analysis of the accident confinement system (ACS): the design of the ACS compartments, materials, and manner of reinforcement. In strength predictions of reinforced concrete to evaluate the carrying-ability of the structure and its performance by the technique of limit analysis. The ACS analysis with finite elements (FE) of several types yielded instantaneous reserve strength factors for static loads. Numerical results of dynamic effects to the strength evaluation for compartment which houses the downcomers of drum separators are presented. The behaviour of pressure and temperature were taken from the results of thermal hydraulics models. Because of the relatively slow rate of loading, the investigation has confirmed that dynamic effects do not contribute additional insight to regular static analysis. (orig.)