PKL facility. Photo: FRAMATOME, Germany
The Experimental Thermal Hydraulics for Analysis, Research and Innovations in Nuclear Safety (ETHARINUS) project was launched in October 2020 to address knowledge gaps identified from the PKL [Primärkreislauf-Versuchsanlage (Primary Coolant Loop Test Facility)] phase 4 project and other NEA joint projects on nuclear thermal-hydraulic safety, such as the ATLAS project. The project was completed at the end of 2024. It involved 24 partners from 13 countries and included a large scope of experimentation, mainly in the modified PKL facility at Framatome GmbH, Germany. A few additional test series on small break (SB) LOCA were performed at the PACTEL facility at the Lappeenranta-Lahti University of Technology, LUT University, Finland.
The project extended the database on the effectiveness of passive heat removal safety systems, reactor safety during design extension condition (DEC) scenarios, two-phase flows in intermediate break (IB) LOCA transients, core cooling under partial core blockage and cool-down procedures after multiple steam generator tube rupture (M-SGTR) transients.
In 2024, a pressure loss test and a SB-LOCA test to study the impact of a reactor coolant pump trip on peak cladding temperature were performed in the PKL facility. The PKL facility was dismantled after tests completion for the ETHARINUS project.
The data analysis and other analytical activities were also completed in 2024 with the open phase of a benchmark on thermal-hydraulic codes on a test addressing passive heat removal system response in a station black-out (SBO) scenario.
In 2025, one of the M-SGTR tests is the subject of an international standard problem (ISP-52) that is being performed under the CSNI/WGAMA programme of work.
The ETHARINUS and ATLAS phase 3 projects were designed to be complementary in scope and testing. An analytical workshop, common to both projects, was held in Barcelona in November 2023 to discuss the results of the analytical activities of the two projects. The workshop also provided an occasion to discuss the potential for thermal-hydraulic research projects after the ETHARINUS project ends.
A new project proposal, named SYSTHER for system thermal-hydraulics, is proposed for 2025-2028 to address uncovered complex accidents scenarios for operating reactors and the performance of passive safety systems for advanced designs, including SMRs. It would be a joint effort of three operating agents: Framatome, LUT University and CEA. Five experimental facilities would be used in the project. Framatome proposes to include 15 experiments that have already been carried out with the PKL integral test facility. LUT University proposes to perform five tests in the PWR PACTEL integral test facility, the PASI open passive heat removal test facility, and the MOTEL integral test facility. CEA proposes six tests in the MISTRA test facility on large dry PWR containment. The focus of the project will be the performance of passive safety systems.
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Belgium, China, Czechia, Finland, France, Germany, Hungary, Japan, Korea, Spain, Sweden, Switzerland, the United States
October 2020 - September 2024
EUR 4.9 million