Towards improved assessment of safety performance for long-term operation of nuclear civil engineering structures
The purpose of ACES is to advance the assessment of safety performance of safety-critical concrete infrastructure by addressing remaining scientific and technology gaps for the safe and LTO of NPPs. This collaborative project aims to clarify, enhance and unify methods of structural integrity assessment in support of LTO.
The project scope of work focuses mainly on safety critical reinforced and prestressed concrete structures. ACES is aimed at an experimental proof of concepts, and validates the developed methodologies at both a laboratory scale and a quasi-full scale level (mock-ups). 
The proper understanding of deterioration and ageing mechanisms requires a research strategy based on combined experimental and theoretical studies following a multidisciplinary approach, utilizing state of the art experimental and modelling techniques. Material characterization at different length scales is necessary, focusing on the physical understanding of the degradation processes (e.g. radiation effects, internal swelling reactions, liner corrosion, etc.) and their influence on macroscopic mechanical properties and structural/functional integrity of the components.  
ACES aims at having a significant impact on the safety of operational Gen II and III NPPs, and impact the design of next-generation plants. ACES will improve the understanding of ageing and deterioration of concrete, and will demonstrate and quantify inherent safety margins introduced by the conservative approaches used during design and defined by codes and standards employed throughout the life of the plant. The outcomes from ACES will therefore support the LTO of NPPs. 
This will be achieved by using more advanced and realistic scientific methods to assess the integrity of NPP concrete infrastructure. The project will provide evidence to support the methods by carrying out various tests, including large-scale tests based on replicated scenarios of NPPs.