Physical Models of EULFCI Code

• Published in: Journal of nuclear science and technology Vol. 17; no. 10; pp. 764 - 776
• Main Authors: SHIMEGI, Nobuo, FUJITA, Yoshihisa
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis Group 01.10.1980; Taylor & Francis Ltd
• Subjects: computer codes; coolant dynamics; fuel fragmentation; fuel plating; fuel-coolant interaction; in-cavity dynamics; LMFBR type reactors; marker particle; multi-sized fuel particles; one dimensional model; reactor accidents; TREAT H2
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.1980.9732652

Physical models of the EULFCI code are presented concerning fuel-coolant interaction (FCI) related materials movements in a fuel pin cavity and coolant channel. For the in-cavity dynamics, a model of axially non-uniform mixture between molten fuel and FP gas is employed to take into account of melting of fuel pin cavity wall. In the coolant channel, the ejected fuel is treated as multi-sized particles whose movement are represented by master particles. Though parametric, a fuel fragmentation model is combined with the fuel particle dynamic model. For the coolant dynamics, the cross-sectional changes along the axially direction can be treated, and the marker particle method is applied to trace the interaction (FCI) region boundaries. Calculated results were compared with the results of the TREAT H2 experiment using the multi-sized particle model. The effects of fuel fragmentation time-constant and sodium condensation were parametrically discussed. It is concluded from the results that the EULFCI code could explain the TREAT H2 experiment in the physically reasonable range of parameters.