SUMMARY

There has been significant interest in the past decade to implement antineutrino detectors as a technology to enhance safeguards. Despite significant progress in the last few decades, many experiments that have measured the antineutrino flux emanating from nuclear reactors have experienced anomalies in the spectrum. Therefore, current efforts focus on high-precision measurements with large, liquid scintillator detectors. The Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment aims to make a high-precision measurement of the antineutrino spectrum from the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) to precisely measure the \uFive{} flux and search for neutrino oscillations.

This work addresses the need to characterize and understand the uncertainty of the antineutrino flux coming from HFIR due to its unique design and missions. This dissertation work focuses on the modeling and simulation of HFIR to quantify uncertainties associated with antineutrino production within a typical cycle of the reactor. In order to maintain the high-precision antineutrino measurement of HFIR, systematic uncertainties associated with the reactor operation need to be understood to a similar degree. The work also broadens the scope of HFIR and the PROSPECT work by comparing to other nuclear research reactors and power reactors.