In 80 years of nuclear reactor history two types of reactors were constructed, one leading to energy production and the other one for scientific research. At the moment, the operational nuclear reactors are represented by 440 nuclear power plants and 220 research reactors, therefore it can be easily deducted the high relevance that the scientific community reserves for research reactors. In the early days of the nuclear history, research reactors were used to product fissile isotopes for weapon applications. Nowadays they have several utilities in the medical field, as the production of radionuclides for cancer treatments, and in the industrial field for the recycling of nuclear waste and material testing applications.