One of the most important challenges in the nuclear industry is the safe long-term operation of existing nuclear power plants and the development of new, safe, and efficient ones. Ensuring the safe and economically viable long-term operation of Generation II and III light water reactors requires investigating the resistance of metal alloys—particularly those produced using additive manufacturing (AM)—to environmental effects. Since AM methods are relatively new, there is very limited data on the ageing behavior of components manufactured in this way; therefore, it is essential to evaluate the influence of this production method on ageing. This is also important when developing new nuclear power plants and predicting their long-term durability.
The project “Prediction of Environmentally Assisted Crack Initiation Behavior of Materials Manufactured Using Advanced Production Technologies for Safe Long-Term Operation of Light Water Reactors (POEAM)” aims to evaluate the use of laser powder bed fusion and cold spraying for 316L metal components, and to a lesser extent laser powder bed fusion for 718 alloy components, under boiling water reactor (BWR) and pressurized water reactor (PWR) conditions. The POEAM project will also seek to improve environmentally assisted cracking (EAC) initiation testing by assessing new specimen designs and enhancing crack initiation monitoring in components. The applicability of additively manufactured materials (via laser powder bed fusion and cold spraying) for reactor primary circuit components will be expanded, taking into account EAC behavior and comparing it with conventionally manufactured materials.
To determine the conditions for EAC initiation, prototype specimens will be analyzed using the finite element method (FEM) and digital image correlation (DIC) to evaluate stresses and strains at selected surface locations of both conventional and AM materials. The results will enable more accurate determination of the initiation time of environmentally assisted cracks and the associated stress/strain states, thereby improving the understanding of EAC mechanisms and enabling refinement of the corresponding testing methodologies.
To support potential participation in the POEAM project, a laboratory equipment set “HIGH TEMPERATURE Low Cycle Fatigue System” is being acquired.
The acquired laboratory equipment set “HIGH TEMPERATURE Low Cycle Fatigue System” will expand the university’s experimental research capabilities and enable testing at elevated temperatures. The currently available testing machine allows experiments only at room temperature or up to 350 °C, but does not enable load-controlled testing at high temperatures.
Project funding:
The project is financed with the funds of the Economic Recovery and Resilience Facility under the “New Generation Lithuania” plan and with the funds of the state budget of the Republic of Lithuania.
Project results:
Project outcomes:
• To enhance R&D activities and competitiveness through the acquisition of the laboratory equipment set “HIGH TEMPERATURE Low Cycle Fatigue System.”
• To expand the university’s experimental research infrastructure, enabling high-temperature experimental investigations.
The new equipment includes:
• High Temperature Water-Cooled Hydraulic Reverse-Stress Pullrods
• A 1050 °C Three-Zone Split Furnace for Low Cycle Fatigue Testing (compatible with 8802 extra height and 8803 standard height models)
This equipment will be used for experimental investigations of mechanical properties and degradation parameters at elevated temperatures. The obtained experimental data will support the development of material models for finite element simulations and the validation of cracked specimen behavior.
The acquired equipment also has strong applied potential for collaboration with industry. Until now, the lack of appropriate measurement infrastructure has limited the ability to conduct certain complex studies; thus, this acquisition fills a critical technological gap. The chosen approach—functional expansion of the existing INSTRON testing system rather than purchasing entirely new equipment—is both rational and economically justified. It maximizes the use of existing resources, reduces investment costs, and ensures compatibility with the current laboratory infrastructure. The modern equipment meets international research standards and enables high-level experimental research competitive with leading laboratories worldwide.
Period of project implementation: 2026-04-20 - 2027-01-31
Project coordinator: Kaunas University of Technology
