Recently the prismatic block design has emerged as a preferred concept of gas cooled reactors (GCRs) and is the basis for several proposed small modular reactors (SMRs) worldwide such as Micro Modular Reactor (MMR) in Canada. It uses helium as the primary coolant and the solar salt as intermediate fluid for transporting the heat to gas turbines. The current thermal hydraulic system codes allow to use helium as a dry non-condensable which has been successfully used in modeling helium coolant systems but in most cases solar salt properties are not available in these codes. An effort is made to collect a correct set of thermodynamic and transport properties and the heat transfer correlation for solar salt and incorporate them into the code ASYST4.1. It will allow the code application for design basis safety studies related to MMR primary and intermediate loop. Solar salt (NaNO3-KNO3 in 60:40 ratio by weight) is a very popular heat storage and heat transfer medium in solar thermal plants. The primary advantages are its thermal stability, large temperature range, low cost, high density, and low vapor pressure.Reliable computational tools are required for thermal hydraulics design and accident analysis as well as the associated experimental data for validation. One emerging tool is ASYST (Adaptive SYStem Thermal-hydraulics) - ISA (Integral Simulation and Analysis). It is a new code which combines the capabilities of SCDAPSIM/MOD4 and SAMPSON and is being developed jointly by Innovative Systems Software (ISS), USA and Institute of Applied Energy (IAE) of Japan. The thermal hydraulic module, ASYST-THA, replaces the original US NRC-developed RELAP5 code used in RELAP/SCDAPSIM/MOD3.x and THA code used in SAMPSON with new system level hydrodynamic options that include multidimensional, multi fluid models originally developed by ISS and IAE. ASYST represents an international-level collaboration on system code development and benefits form the expertise and experiments available world-wide.This work will present a benchmarking study on Molten Salt nitrate Natural Circulation Loop (MSNCL) and the results are compared against those reported from experiment. ASYST calculated results are found to be closely matching with the experiment.

Implementation of Solar Salt as Fluid in asyst4.1 and Validation for a Natural Circulation Loop

Paper Proceedings: https://asmedigitalcollection.asme.org/ICONE/ICONE28/volume/85246

2021 28th International Conference on Nuclear Engineering (ICONE28)

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