Objective: Provide comparative data on the irradiation induced creep of current Zr alloys and Cr coated samples
Facilities: LVR-15 Reactor and hot cells (Czechia)
Core Group: CVR, UJV REZ and Alvel (Czechia), VTT (Finland) and CEA (France)
In the INCA experiments, fuel cladding materials coated with chromium (a leading idea for improving nuclear fuel’s accident tolerance) will be irradiated. The creep properties of the coated cladding will be compared to the creep properties of standard claddings to determine if the coating changes anything. Irradiation induced creep has a significant impact on reliable and safe fuel rods performance during operation. Power plant operators and fuel designers need to be able to accurately predict cladding creep and therefore it is essential to investigate whether new creep models are needed for the coated claddings. Within INCA, the irradiation creep properties of standard, optimised zirconium-based alloys and accident tolerant fuel (ATF) cladding materials will be studied in LVR-15 reactor at the Research Centre Rez (CVR) in Czechia.
Within the current programme of work, sixteen unfuelled and pre-pressurised cladding samples will be irradiated in a high-flux position in the LVR-15 reactor. Creep behaviour will be measured with sufficient quality and quantity to qualify ATFs and optimised zirconium-based alloys through accurate and direct comparison. Creep properties will be studied using dimensional measurements and will be complimented by studies of the cladding microstructure through PIE performed in well-equipped hot lab at CVŘ. Additionally, the in-pile data from LVR-15 will be compared with similar optimised Zr-alloys samples irradiated in a commercial nuclear reactor.