Climate change is a reality. Every day, the effects of it are visible and one of the main challenges is to achieve carbon neutrality by 2050. With this goal, one increasing technology in clean energy generation is nuclear fusion. Nuclear fusion needs unique working conditions, such as: extremely elevated temperatures, strong electromagnetic fields, and ultra-high vacuum conditions. But another challenging milestone should be taken into account: breeding tritium. Tritium quantity is naturally scarce on Earth and has to be generated, which is costly and currently very limited. One of the missions for the later stages of ITER operation is to demonstrate the feasibility of producing tritium from lithium within the vacuum vessel, making breeding blankets a key component of ITER.
Given its relevance, there are several proposals to breed tritium, from using helium or water as a coolant, or liquid types like lithium-lead (LiPb) alloy or solid types such as lithiated ceramic pebbles as breeder. One of the proposals being currently developed, is the Helium Cooled Ceramic Pebble (HCCP), where lithiated ceramic pebbles are used as breeder and helium, as coolant. HCCP is designed to test tritium breeding, recovery, and withstand reactor loads. A key function is heating removal, with the Helium Cooling System (HCS) essential for ITER's safety and availability.
This paper describes the Reliability, Availability, Maintainability and Inspectability (RAMI) analysis and preliminary risk assessment (HAZOP) performed, together with the proposed design, operation and maintenance suggestions needed to achieve the mail goal: a reliable and safe operation for HCCP-HCS.