Quantification of the Effective Detectable Period for Concrete Voids of CLP by Lock-In Thermography

This study is to inspect the voids between concrete containment building and liner plate (CLP) in light-water reactor type nuclear power plant with lock-in thermography (LIT) inspection technology. For that, a finite element method (FEM) model containing was created, thermal distribution change of CLP surface simulated through numerical analysis simulation various LIT conditions converted real-time data. temperature image amplitude phase images calculated by four-point method, signal-to-noise ratio (SNR) analyzed based on sound area void areas. As result, difference SNR according size remarkable, effective detectable period (EDP), which common each condition, derived. Furthermore, mockup identical shape produced, EDP experiment same technique, results are compared. Although there some differences experimental environments, deduction utilization FEM considered useful approaches applying back CLP.