Microchannel heat exchangers are being considered for use in the Generation IV nuclear reactors for their ability to provide increased thermal efficiency in a small volume relative to other types of heat exchangers via an extremely high surface area-to-volume ratio. Three distinct analysis methods that may be used to evaluate the technology are presented in this work. The finite element method model yields results that agree with those produced using the effectiveness-number of transfer units method. More complex free surface flows are effectively and accurately modelled using smoothed particle hydrodynamics. An initial optimization of a microchannel heat exchanger is performed using the effectiveness-number of transfer units method once more, determining an optimal design with an objective function value of 0.081 that is obtained using 3.29 m long channel, 0.023 m channel width, a 0.0001 m wall thickness between channels, and hot and cold inlet flow velocity of 3.91 m/s.