NEUTRONIC AND DYNAMIC ANALYSIS OF TMSR-500 REACTOR CORE

• Main Author: Widjati, Alessandro
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55013
• Institution: Institut Teknologi Bandung

TMSR-500 designed by ThorCon is a generation IV nuclear reactor. This reactor has potential to provide energy that are sustainable, safe, and low in CO2 emissions. Therefore study about TMSR-500 will have a significant impact on the development of nuclear energy. Neutronic and dynamic analysis will be conducted in this study. For neutronic analysis, influence of reactor design parameters against neutronic aspects will be evaluated. The design parameters evlauated are fuel composisiton, fuel volume fraction, coolant quantity, and material temperature, while the neutronic aspects are effective multiplication factor (keff), conversion ratio (CR), and delayed neutron fraction (?). Influence of the coolant quantity and the material temperature will only be considered for the keff. For dynamic analysis, response of thermal power, fuel salt temperature, and graphite temperature to positive reactivity insertion will be evaluated. The method used to obtain the neutronic aspects of the reactor is neutronic calculation by computer simulation using the SRAC2006 code system and the JENDL-4.0 nuclear library. While to obtain the dynamic response dynamic calculation is performed by solving the reactor point kinetics equation and the reactor heat transfer equation numerically. The data obtained for neutronic analysis are graph of keff against time, CR against time, ? against time for each fuel composition variation and fuel volume fraction variation. Graph of keff against time for each coolant nuclide density variation and fuel salt-graphite temperature variation, graph of reactivity against relative coolant nuclide density and relative temperature, and coolant nuclide density and temperature reactivity coefficient are obtained too. The data obtained for dynamic analysis are graphs of thermal power against time, material temperature against time, and reactivity against time for each positive reactivity insertion variation. The analysis process of the data shows that if the fissile material is increased, the keff will increase and if the fertile material is increased, the CR will increase. Increasing the fissile material in the form of U-235 will also increase ?. The smaller the fuel volume fraction, the greater the keff in the early reactor operation. The decrease in fuel volume fraction also causes CR and ? to decrease. Coolant nuclide density and fuel salt-graphite temperature are inversely proportional to reactor criticality and reactivity. Positive reactivity insertion causes the thermal power and material temperature to increase, then gradually decrease and become stable. The amount of positive reactivity insertion will be directly proportional to the maximum value of thermal power and material temperature under dynamic conditions. The input of positive step reactivity in the range 50 pcm - 500 pcm can be tolerated by the TMSR-500 because the temperature of the material in its dynamic conditions is still within a safe range. The conclusion of this study is that the concentration of fissile material is directly proportional to keff and ?, while the concentration of fertile material is directly proportional to CR. The fuel volume fraction will be inversely proportional to the keff at the beginning of operation, but will be directly proportional to CR and ?. TMSR-500 requires a minimum U-235 concentration of 1.28% with an optimal fuel volume fraction of 27%. TMSR-500 have a negative coolant nuclide density and temperature reactivity coefficient. TMSR-500 has a good safety response to positive step reactivity insertion in the 50 pcm to 500 pcm range.