Energy is the backbone of defense and essential for the effectiveness of operations. The archipelago country like Indonesia has a specific characteristic when deploy the army separated over the country will have deep complexity in energy distribution and security. The mobile nuclear power plant is interesting to evaluate, and we interested in heat transfer process in the heat exchanger. The paper presents the potential of the application of a printed circuit heat exchanger (PCHE) on small modular molten salt reactors (MSR) for the military. The Heat exchanger is played a crucial role in the nuclear reactor design where the size compaction and efficiency improvement two issues that must be solved. The PCHE promise some advantages such as high effectiveness, high surface area per volume, light and compact. We evaluate and compare the performance of the heat exchanger of the MSRE ORNL 8 MWTh with PCHE’s design where MSRE a benchmarking. The result shows that low-pressure drops, low-pumping power and high effectiveness and compactness (low-dimension). We recommended that PCHE is applied on MSR than conventional HX like a Shell tube heat exchanger (STHE) of MSRE ORNL.