STRESS TEST EVALUATION OF REFUELING AND STORAGE POOLS FOR LOVIISA NPP

The paper will describe the following analysis of Loviisa plant's spent fuel pools. As a consequence of stress tests for the existing NPP's in Finland after the experiences gathered from the Tohoku -Taheiyou-Oki event in Japan in March of this year Fortum Power and Heat Oy (Fortum) has initiated the following analyses of the Loviisa power plant's refueling pools and spent fuel intermediate storage pools for the combined cooling loss and the earthquake loads. The following loads will be analyzed: 1) The spent fuel pool and refueling pools water temperature is 100 degrees Celsius. The heat load duration is undetermined; 2) The earthquake ground motion applied simultaneously with the thermal load is defined as follows: (ground motion response spectrum is defined in Guide YVL 2.6), the maximum horizontal acceleration is assumed to be 0.1g, 0.2g, 0.3g and 0.4g, respectively; 3) Own weight; 4) The pool of water, hydrostatic pressure load plus the sloshing load because of earthquake motion. Te analysis is aimed to demonstrate the structural integrity and leak-tightness of the pools under the effect of above loads. The analysis is nonlinear taking into account the cracking of the concrete. As a result of the analysis the maximum strains will be determined in the pool stainless steel liner as well in the pool concrete walls.