OECD/NEA BENCHMARK ON PELLET-CLAD MECHANICAL INTERACTION MODELLING WITH FUEL PERFORMANCE CODES: INFLUENCE OF PELLET GEOMETRY AND GAP SIZE

ALEJANDRO SOBA; A. PRUDIL; J. ZHANG; A. DETHIOUX

Congreso; Top Fuel 2021; 2021

The Nuclear Energy Agency (NEA) Expert Group on Reactor Fuel Performance(EGRFP) proposed a benchmark on fuel performance codes modeling of pelletcladdingmechanical iteration (PCMI). The aim of the benchmark was toimprove understanding and modeling of PCMI amongst NEA memberorganizations. This is achieved by comparing PCMI predictions for a number ofspecified cases. The results of the two hypothetical cases (1 and 2) werepresented earlier. The two final cases (3 and 4) are a comparison betweencalculations and measurements, which will be published as NEA reports. Thispaper focuses on Case 3, which consists of eight beginning of life (BOL) subcases(3a to 3h) each with different fuel rod designs that have undergoneramping in the Halden Reactor. The aforementioned experiments are known asthe IFA-118 experiments and were performed in Halden reactor from 1969 to1970. The variations between cases include three different pellets heights (7, 14and 30 mm), two different gap sizes between pellet-cladding (40 and 100microns) and three variations on pellet face geometry (flat, dishing and dishingwith chamfer). Such diversity has allowed exploring the codes? sensitivity tothese individual factors.