Development of Advanced Technology for Enhancing Long Term Operation Safety of Nuclear Materials

○ Development of safety assurance technology against radiation embrittlement of reactor pressure vessel - Embrittlement database on high fluence neutron irradiation and probabilistic evaluation model of fracture toughness distribution for RPV steels of KSNPP - Development of probabilistic fracture mechanics PTS analysis code by considering the characteristics of domestic reactor materials - Database and evaluation model for analysis of fatigue crack growth rate properties for Type 347 stainless steels under PWR water conditions ○ Evaluation and model development of corrosion cracking of Ni base alloys for nuclear power plants - Development of PWSCC growth rate curve of Alloy 690 based on residual strain, temperature and dissolved hydrogen content - Development of ODSCC susceptibility factor by evaluating effect of Pb, Cl, and S - Development ODSCC evolution prediction by using Weibull distribution ○ Development of advanced technology for early diagnosis of material degradation and damage - Development of advanced eddy current probe for precise diagnosis of u-bend region in steam generator tube, with improved performance of defect detection by 35% - Establishment of non-linear ultrasonic diagnosis system, and successful verification of nonlinear characteristic of signal from micro-crack - Development of guide wave diagnosis system for long range buried pipe, and verification of detection performance for micro-defect of corrosion less than 2% in pipe weld ○ Development of technology for predicting materials damage based on computer simulation - Development of three computer simulation codes for predicting radiation damage to reactor materials, including radiation hardening, segregation and swelling - Establishment of novel technology for analyzing neutron-irradiated materials (Atom probe, micro-mechanical test) - Setup of MD-Portal (Materials Data) site and its open to the public ○ Development of advanced mitigation technology for material degradation in coolant system - Development of SG tube surface modification technology for corrosion release mitigation - Development of fuel tube surface modification technology for crud deposition mitigation - Development of denting prevention technology by Alloy 690 cladding on a tubesheet of SG.