Nuclear reactors inherently safe design

Concerning the operability concept in the previous list of principles of more inherently safe design in the process industry, it seems worth noting that, in the parallel field of nuclear plants, designers tend now to provide a longer grace period in case of mistakes or accidents (e.g. an increase of the water inventory in water reactors, and so on). 

The MARS (Multipurpose Advanced Reactor, inherently Safe) plant is a nuclear plant designed for electric power generation and/or for industrial heat generation. 

The MARS (Multipurpose Advanced Reactor, inherently Safe) is a 600 MW(th), single loop, pressurized light water reactor (PWR). The design was developed at the Department of Nuclear Engineering and Energy Conversion of the University of Rome La Sapienza [IV-1],... 

Reactors are designed to be inherently safe based on physical principles, supplemented by redundant equipment and special procedures. Nuclear power benefits from the appHcation of the concept of defense in depth, ie, by using fuel form, reactor vessel, building containment, and emergency backup procedures to ensure safety. 

Early studies concluded that the nuclear heat transport systems of a small reactor could not operate significantly above atmospheric pressure, if all design requirements were to be satisfied. It was noted that all of the very small reactors currently available, and generally regarded as inherently safe (SLOWPOKE, TRIGA, MAPLE-X) are pool type reactors. 

CINOTTI L., RIZZO F.L. - "The Inherently Safe Immersed System (ISIS) reactor". Nuclear Engineering and Design 143 (1993), pp. 295 - 300. 

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