THE STRUCTURAL ANALYSIS OF THE LOVIISA PLANT STEEL CONTAINMENTS FOR SERVICE LIFE EXTENSION

摘要

This paper reports the activities performed in order to prepare the application documents to extend the service life of the Loviisa nuclear power plant by 20 years. Five key components were selected for detailed analysis process concerning the ageing effects, namely: 1) reactor vessel; 2) primary coolant pump; 3) steam generator; 4) pressurizer; 5) containment. This report concentrates on the containment building. The containment consists of the following main parts: 1) hemispherical dome; 2) cylindrical shell with stiffening and anchoring rings; 3) pre-stressed anchoring bolts; 4) penetrations and openings in dome and cylinder; 5) reinforced concrete base slab and reactor pit; 6) steel lining of the base slab and reactor pit; 7) vertical penetrations and openings in the base slab and reactor pit; 8) columns and walls supporting the base slab. The analysis was based on the results of monitoring the aging of the containment parts during the 30 years operating life of the plant and also on the 3D - structural analysis of the containment taking into account the degradation effects. As a result of the analysis the weakest links of the containment were identified and the remaining lifetime was assessed.