Experimental programme within the IAEA ATF-TS - separate effect and bundle tests with ATF cladding materials

Since 2021, the IAEA has been organising a Coordinated Research Project (CRP) on Testing and Simulations of Accident-Tolerant and Advanced Technology Fuels (ATF-TS). A work task (WT1) is dedicated to the experimental programme with various ATF cladding materials. The task was designed to complement the other work tasks and support their results. The strategy of the task is as follows: 1. ATF fabrication = collect priority candidate ATF materials for testing; 2. Define the test matrices based on the needs of modelling and simulation work tasks taking into consideration the limitations of respective laboratories; 3. Collect and combine the experimental data from members and derive correlations; 4. Provide the correlations for the benchmark exercises (both separate effects and bundle) to validate the codes and 5. Provide inputs for the open-source ATF MATPRO-like database.
In total, eight institutes either manufactured or provided their candidate cladding materials for the ATF. The coated cladding concepts are based on various Zr based alloys (Opt. ZIRLO, E110, Zircaloy-4) with different coatings (Cr, CrN, TiAl, SiC, Cr/CrN) deposited by different methods (arc ion plating, magnetron sputtering, PVD with plasma treatment). ... mehrIn addition, FeCrAl cladding materials were tested as well. Those 12 types of candidate ATF cladding materials were tested in 16 laboratories/institutes. The experimental testing was divided into several groups: 1. HT creep/ballooning/burst (5 institutes), 2. HT oxidation (9 institutes), 3. Autoclave corrosion tests (5 institutes), 4. Mechanical tests (5 institutes), 5. Other tests/characterization (JRC – thermophysical properties, UPM, hydrogen charging, INCT, neutron activation analysis) and 6. Bundle tests (CODEX-ATF at EK, Hungary; DEGREE tests at CRIEPI, Japan, and QUENCH-19 at KIT, Germany). This paper summarises the materials tested within the project and their fabrication details, the results of the ballooning/burst test series with coated Zr-based cladding and FeCrAl, as well as the main findings from all the other experimental subtasks performed within Work Task 1. This paper will be further complemented with separate detailed presentations on the CODEX-ATF results, DEGREE bundle tests, and coated cladding post-quench ductility tests by other ATF-TS Work Task 1 members.