This project is helping make NPPs safer and more reliable. NPPs concrete structures age over time. If these structures weaken, it could affect safety. ACES fills important knowledge gaps about how concrete ages under extreme conditions, such as heat, radiation, and chemical reactions, so that operators can make better decisions about maintenance and saftey.
The project has delivered tools and insights that improve how NPPs check the condition of these structures. For example, a robotic system was created that can inspect corrosion inside steel-concrete pipes, saving time and reducing risk. We also developed advanced models to predict how concrete behaves under stress and temperature changes, which helps prevent unexpected failures. By understanding issues like internal swelling and radiation damage, we can extend the life of existing NPPs safely and guide the design of future ones.
Main Objectives: Critical review of ageing management practices for EU NPPs, focusing on ageing in concrete and criteria for LTO decision-making; Improve methods for assessing components under LTO, considering operational demands; Develop innov. quantitative methodologies to transfer laboratory properties to large-scale structural integrity assessments; Advance simulation tools to reflect joined effects of loading/chemical/electrochemical reactions on performance; Enhance understanding of internal swelling reactions and temperature/moisture effects on delayed strains in containment buildings; Improve assessment of prolonged irradiation effects on concrete biological shields combining operating conditions, material degradation, and structural significance; Deepen understanding of corrosion of embedded liners, predict corrosion, and develop innov. inspection tool for early detection.
Main scientific/technical outcomes
WP1 – Completed a SOTA on ageing management approaches for NPP concrete structures. Integrated new knowledge from ACES on liner corrosion, ISR, creep/shrinkage in concrete containment, and irradiated concrete performance.
WP2 – Demonstrated a robotic platform for NDT corrosion inspection of steel cylinder concrete pipes (SCCP). Provided novel insights into crevice corrosion mechanisms of steel liners through extensive experimental and numerical work. Completed two Ageing Management Programs (AMPs) addressing corrosion risks in key NPP structures.
WP3 – Validated coupled TCHM models for ISR in NPP concrete. Advanced understanding of creep and combined pathologies through extensive lower-scale experimental work.
Developed recommendations for EUG on evaluating ISR degradation impact on structural capacity.
WP4 – Completed a comprehensive guidance report on CCB ageing calculations. Assimilated experimental results on concrete creep under LOCA conditions, including destructive post-thermal damage characterization.
Proposed improvements to Fib Model Code 2010 formulas for high-temperature and biaxial loading conditions, offering enhanced accuracy across loading scenarios.
WP5 – Characterized concrete under combined irradiation and temperature effects for European aggregate types, validating numerical models. Benchmarked models for irradiated concrete and its constituents.
Developed a critical tool to support reactor lifespan extension and inform next-generation designs. Assessed structural significance of radiation effects from both shielding and load-bearing perspectives. Provided EUG with a methodology to evaluate LTO of concrete structures exposed to prolonged ionising radiation. Successfully involved university and high school students in research activities.
