## 4 Discussion  
The primary loop components have lower significance for the neutron kinetics calculation, and hence, the neutron flux is smaller by several orders of magnitude compared to the core region. The neutron flux is concentrated in the energy groups 2, 3, and 4, with the maximum in energy group 3. The flux concentration depends on the salt composition and the energy boundaries used. Most prompt fission neutrons of U-235, U-238, and Pu-239 isotopes appear in the 0.7 MeV energy range, while the average prompt neutron energy is around 2.2 MeV. Also, for the molten-salt mixture in the energy range given by three energy groups, fewer absorptions occur as a result of a bigger neutron population. The group 1 precursors can live long enough to move through the whole system many times, and their fraction is low (\(\beta_{1}\) = 6.186 \(\times\) 10\({}^{-5}\)). Their concentration does not depend anymore on where the precursors are generated, and it becomes relatively homogeneous compared to, e.g., the group 8 precursor concentration. The concentration of group 1 is higher at the core's upper region because of the vicinity of the generation area and the direction of flow. Group 8 will mostly decay in the place where it is generated, and as a result, its concentration is proportional to the neutron flux. GeN-Foam lacks a mathematical steady-state modeling feature, and all the results obtained for the steady simulation are with a time-dependent solver and a system that is not perturbed. In the reactor system after the pump is turned off, the difference in density is what drives the flow of fuel salt and helps the system attain natural circulation, thereby dictating the temperature distribution. When the flow is driven by pump momentum, the effect of \(\beta_{th}\) is suppressed as pump momentum is the dominant factor that influences the velocity and temperature of the fuel salt. To understand the significance of specific heat capacity correlations with input parameters, it is important to understand the differences between single side (\(Q_{s}=mC_{p}\Delta T\)) and total heat transfer (\(Q_{MX}=UA\Delta T\)). The stable nature of these transient results may be due to the simplified geometry and the fact that symmetry boundaries were used on the cell faces that would connect adjacent loops in the actual design. The symmetry boundary condition enforces a zero gradient, so a periodic boundary or a model of two or more adjacent loops may show oscillatory behavior. The heat gained or lost in the fuel salt depends on the inherent characteristics of the salt such as specific heat; as a result, it would affect the outlet temperature of the primary fuel salt exiting the heat exchanger and in general the overall temperature of the salt. After the transient is initiated, specific heat ceases to be a dominating factor and its effect on temperature is suppressed as soon as density and thermal expansion take over as they start  
Figure 21: Three-dimensional SRCC of heat transfer coefficient with (**a**) temperature and (**b**) velocity. dictating the temperature of the fuel salt in the reactor system. Since specific heat still has impact on temperature, it is just not very pronounced; this impacts the velocity as density and temperature difference drive the flow upon attaining natural circulation. This suggests specific heat capacity correlation with velocity increases after initiating the transient. Parameter dependence on temperature decreases upon initiating the transient. As soon as the transient is initiated, it becomes a density-driven flow, and specific heat capacity and the thermal expansion coefficient start dictating the temperature and velocity of the system, whereas the velocity correlation with the heat transfer coefficient increases after initiating the transient.