EXPERIENCES AND FIRST RESULTS OF THE OL3 INNER CONTAINMENT IN-SERVICE INSPECTION SYSTEM

摘要

The prestressed Inner Containment of the OL3 EPR in Olkiluoto, Finland is equipped with an In-service Inspection (ISI) system. The inspection plan comprises the schedule for measurements at specified intervals during the containment operation time as well as criteria for assessment. The measurement results of the Initial Structural Integrity Test (ISIT) are decisive as precondition for the plants commissioning. The present paper describes the instrumentation and the evaluation of the measurement results since the installation of the ISI system. Valuable knowledge has already been gained in the prestressing phase by monitoring the containment deformations during tensioning of the different tendon groups. The comparison to precalculated results is illustrated. Since then, the long term deformation development has been pursued. The evaluation permits first assessments of the containment ageing behaviour. The applied prestressing system and the material parameters are elucidated as main influencing factors of concrete creep and shrinkage. Concerning the ISIT the ISI system requirements are illuminated. Results are indicated and compared to design calculation values.