The design of MARS (Multipurpose Advanced “inherently” Safe Reactor) plant started in 1983 at the Department of Nuclear Engineering and Energy Conversion of the University of Rome "La Sapienza", with the aim of proposing a new concept of fission-type nuclear plant to be used for a wide range of applications, including desalination and district heating.
The possibility of utilization of the plant in high-density population areas or in developing areas was the main reason for the search for improved safety requirements: the plant had to be simple, with an easy-to-understand and incontrovertible capacity to avoid any radiological hazards to the population. Typically, the safety approach had to be a clearly understandable, deterministic one. The design was focused on a nuclear power generation capacity of 600 MWth, corresponding to about 170 Mwe in the case of only electrical production, with a modular solution to satisfy progressively increasing power requirements
