| The purpose of this research is to ensure that an MCNP model of the Missouri S&T reactor produces accurate results so that it may be used to predict the effects of some desired upgrades to the reactor. The desired upgrades are an increase in licensed power from 200 kW to 400kW, and the installation of a secondary cooling system to prevent heating of the pool. This was performed by comparing simulations performed using the model with experiments performed using the reactor. The experiments performed were, the approach to criticality method of predicting the critical control rod height, measurement of the axial flux profile, moderator temperature coefficient of reactivity, and void coefficient of reactivity. The results of these experiments and results from the simulation show that the model produces a similar axial flux profile, and that it models the void and temperature coefficients of reactivity well. The model does however over-predict the criticality of the core, such that it predicts a lower critical rod height and a keff greater than one when simulating conditions in which the reactor was at a stable power. It is assumed that this is due to the model using fuel compositions from when the fuel was new, while in reality the reactor has been operating with this fuel for nearly 20 years. It has therefore been concluded that the fuel composition should be updated by performing a burnup analysis, and an accurate heat transfer and fluid flow analysis be performed to better represent the temperature profile before the model is used to simulate the effects of the desired upgrades. |
