Improved multiphysics model of the High Temperature Engineering Test Reactor for the simulation of loss-of-forced-cooling experiments. (1st September 2023)

• Record Type: Journal Article
• Authors: Labouré, Vincent; Ortensi, Javier; Martin, Nicolas; Balestra, Paolo; Gaston, Derek; Miao, Yinbin; Strydom, Gerhard
• Is Part Of: Annals of nuclear energy. Volume 189(2023)
• Publication Date: 2023-09-01
• Subjects: Multiscale heat transfer coupling -- Effective thermal conductivity -- Reactor physics analysis -- High Temperature Engineering Test Reactor -- Loss-of-forced cooling; Nuclear energy -- Periodicals; Nuclear engineering -- Periodicals; 621.4805
• DOI: 10.1016/j.anucene.2023.109838
• Languages: English
• ISSNs: 0306-4549

Abstract

Abstract: We present a multiphysics model of the High Temperature Engineering Test Reactor for comparison with past and predict future loss-of-forced-cooling (LOFC) experiments. The approach selected combines (1) 3-D full-core superhomogenization-corrected neutronics, (2) 3-D full-core homogenized or semi-heterogeneous heat transfer (macroscale), (3) 2-D axisymmetric fuel rod heat transfer (pin-scale), and (4) 1-D thermal-hydraulics channels. Although large uncertainties remain, the time and magnitude of the first power peak after re-criticality is predicted within 1.5 h and 175 kW, respectively. The novelty of our work includes (1) a new macroscale/pin-scale heat transfer coupling approach relying on gap conductance to drastically speed up numerical convergence by two orders of magnitude, (2) determination of a radial effective thermal conductivity, reproducing the semi-heterogeneous re-criticality time within one hour using a homogenized macroscale model, and (3) a preliminary study of the reactor's early behavior following a LOFC event, enabling further assessment of numerical models against fission power measurements. Highlights: A multiphysics model of the High Temperature Engineering Test Reactor is presented. The fission power overall behavior during a LOFC event is successfully reproduced. A novel heat transfer coupling approach is presented, with much faster convergence. A reasonable radial effective thermal conductivity is determined. The reactor's early behavior is investigated.