The present publication describes the results of the coordinated research project on Fuel Modelling in Accident Conditions (FUMAC), initiated under the IAEA Action Plan on Nuclear Safety implemented after the accident at the Fukushima Daiichi nuclear power plant. The project, which ran from 2014 to 2018, followed previous projects on fuel modelling: D-COM 1982–1984, FUMEX 1993–1996, FUMEX-II 2002–2006 and FUMEX-III 2008–2012.
The project participants used data derived from accident simulation single rod and bundle experiments, in particular data designed to investigate the fuel behaviour during design basis accident (e.g. Halden, Studsvik and KIT LOCA tests) and design extension conditions (KIT CORA-15 bundle test), to carry out calculations on selected priority cases identified at the first research coordination meeting. These priority cases were designed to support the participants’ individual priorities and were chosen as the best available to help determine which of the many models used in the codes most closely reflect reality. The cases were also used for verification and validation purposes, and for inter-code comparisons.