Molten salt modelling in SPECTRA applied to MSRE

Abstract In the Netherlands, NRG has an extensive experimental irradiation program on molten salt technology. In support of this program, also system thermal hydraulic modeling capabilities are being developed in the SPECTRA code. This paper describes the (fueled) molten salt capabilities developed and presently available in the code. These include flexible input of properties and (heat) transport correlations, delayed neutron precursor drift, fission product behavior, noble gas behavior, noble metal behavior, noble metal extraction, and chromium leaching and deposition. The paper introduces the models developed and where possible their application to the Molten Salt Reactor Experiment (MSRE) data. In general, satisfactory agreements were found between experimental data and SPECTRA results, especially taking into account all the uncertainties involved in the data retrieved from MSRE which is a large integrated system test. In the next development stages, the models will be validated using separate effect tests, where clear test definition and relatively few phenomena involved will allow to quantify the accuracy of models.