The Spanish Nuclear Safety Council (CSN) is hosting experts from around the world to evaluate advances in the technical simulation of nuclear reactor safety systems during a new meeting of Phase 4 of the international ATLAS project, an initiative sponsored by the OECD Nuclear Energy Agency (NEA).
The meeting was inaugurated by the President of the Spanish nuclear regulator, Juan Carlos Lentijo, who underlined that international collaboration is essential for regulatory bodies to have solid, independent technical knowledge when making decisions. In this regard, he highlighted that the ATLAS project represents "an excellent example of how cooperation helps preserve key research capabilities, maintain technical competence, and generate the necessary knowledge to address current and future challenges in nuclear safety."
The CSN President also valued the great diversity of participating entities —ranging from regulatory bodies and research centres to universities, vendors, and private companies— emphasising that this plural exchange strengthens the scientific basis supporting safety evaluations.
The meeting, coordinated with the Korea Atomic Energy Research Institute (KAERI), enables the sharing of tests carried out at the ATLAS experimental facility to analyse how cooling water circulates and behaves in light water reactors under different scenarios. Highlights on the agenda include the definition of new tests, steam generator replacement, and the manufacture of passive cooling systems designed to cool the reactor containment without requiring an external electrical power supply.
Spanish representation plays a prominent role in the ATLAS project through the contributions of two academic institutions. On the one hand, Universitat Politècnica de València is presenting results derived from coupling various computational tools. On the other hand, the Universidad Politécnica de Madrid is analysing experimental tests focusing on the behaviour of passive safety systems. 

Fourth phase of the ATLAS Project

The ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation) project, promoted by the NEA, investigates complex thermal-hydraulic phenomena to improve the safety of current, future light water reactors, and Small Modular Reactors (SMRs).
One of the main objectives of the Nuclear Energy Agency is knowledge management through joint international research projects. These projects bring together experts from across the globe who contribute to maintaining and enhancing operational experience, technical exchange among specialists, and consensus on approaches to resolving safety issues in participating countries.