[en] Full text: Main Challenges in Research for LTO – Cooperation Between EPRI and IAEA on the IGALL Programme This paper will identify the major technical challenges and research needs for long-term operations, highlights of EPRI research in these areas, and how EPRI subject matter experts are working in corporation with the IAEA on technical contribution to the IGALL Programme. Abstract Long-term operations is defined as safe, reliable and economic operation of an existing nuclear power plant beyond its original licensed life. The duration of the operating license varies based on each countries regulation, but is typically limited to 30 or 40 years. To extend the license the plant owner needs to go through a rigorous license renewal process. Globally plant owners are interested in license renewal due to the large number of plants reaching the end of their current licensed life. See the figure below: Effective aging management is necessary throughout the plant life for systems, structures and components (SSCs) important to safety, and in scope for license renewal, to ensure plant safety and compliance with the current licensing bases. The aging management programs are a set of activities related to understanding, detecting, assessing, monitoring and mitigating the effects of aging on SSC in scope of license renewal. This is depicted below: The four key research topics for extended plant operations are: • Reactor pressure vessel (RPVs) neutron embrittlement • IASCC of reactor internals and primary system components • Concrete and containment degradation • Electrical cable qualification and condition monitoring EPRI, in coordination and collaboration with research partners, has conducted decades on research on these main technical research areas. This works forms the basis for the aging management programs and are incorporated by reference in the GALL and IGALL. Research to further enhance aging and asset management continues. This includes, but is not limited to: 1) Improved modeling 2) Improved inspection technologies 3) Advances in assessment and evaluation methodologies, and 4) On-line monitoring and diagnostics In addition, we also evaluate opportunities to harvest materials from decommissioning plants, when we feel this data will added value. EPRI has been working in cooperation with the IAEA to support the IGALL programme. EPRI subject matter experts in the areas of reactor pressure vessels, reactor coolant system metals, reactor vessel internals, electrical cables and concrete degradation are participating on the sub-working groups to update the IGALL AMPs, TLAAs and AMRs. This work includes updating the IGALL to include references to recent EPRI reports and research, current positions and practices in the US, and operating experience. This will help improve the value of the IGALL for all member states to use for their LTO programs, specifically the Ageing Management Reviews (ARMs), the Time Limited Ageing Analysis (TLAAs) and Ageing Management Programmmes (AMPs). (author)