Hitachi-GE developed a 300MWe class DMS (Double MS: Modular simplified & medium small reactor) concept and the DMS was originally designed for generating electricity only. In this study, the feasibility of a cogeneration DMS plant which supplies both electricity and heat is under investigation. The thermal performance of the DMS plant without or with low, medium or high temperature thermal utilization (TU) applications is evaluated by numerical simulations. The results show the electricity generated reduces as the heating requirement of TU application becomes higher. Furthermore, the economic performance of the cogeneration DMS plant is compared with another two integrated systems: (i) DMS plus electric boilers and (ii) DMS plus natural gas boilers, for those three TU applications in Canada. Results illustrate the DMS plus natural gas boilers system is most economic if there is no carbon tax, but with high CO2 emissions (up to 180 Ktons per year). The cogeneration plant performs best as the carbon tax increases up to 40$/ton. The cogeneration DMS plant is a promising scheme to supply both electricity and heat simultaneously in the economic-environmental point of view.