The technological challenge for current generation nuclear reactors

Innovation needs in nuclear reactor safety and risk

After three quarters of a century using nuclear fission to produce energy, Nuclear Reactor Safety and Risk constitutes an established technological sector. A key feature is continuous updating following new discoveries and progress in knowledge, resulting in extensive and elaborate safety methodologies, which are still not internationally accepted, generally applicable or technically consistent. Each country developed its own methods, guides, traditions and requirements to deal with evolving design, safety, siting and licensing issues. There is a clear parallel in societal risk perception between nuclear radiation exposure in accidents and viral infection in pandemics and the fear of the “unknown”. Unfortunately, over the last 20–30 years the declining introduction of electricity by nuclear fission in the countries that contributed most to its earliest development also has broken the bond between new scientific advancements and improvements of existing safety methodologies. By looking at the origins and fundaments of nuclear technology, we consider the following topics of both deterministic and probabilistic interest: a) Loss of Coolant analysis; b) nuclear fuel accident performance weaknesses; c) role of containment and ultimate heat sinks; d) residual risk and emergency system deployment, and e) independent and risk informed decision making assessment. As a key outcome, we propose modifying the traditional licensing methodology, and the use of active and/or passive systems by being subsumed into a broader Engineered Safety Features Management process. Furthermore, we emphasize the need of connecting the As Low As Reasonably Achievable principle with the analyses to demonstrate the safety of nuclear installations minimizing the need for excessive “paper” safety analyses and licensing efforts.

Current Status of Reactors Deployment and Small Modular Reactors Development in the World

Due to emerging climate change concerns coupled with increased global energy demand, eventually the world needs to move to low-carbon-emission electricity-generating sources—nonrenewables, such as nuclear power, and renewables, as hydro, wind, geothermal, solar, and tidal. The only source is nuclear power that is reliable, concentrated, and can be of large installed capacity and operate with high capacity factors. This paper updates and presents the current status of nuclear-power deployment and small modular reactors (SMRs) development in the world. Unfortunately, within last 9 years, electricity generation with nuclear power has decreased from ∼14% before the Fukushima Nuclear Power Plant (NPP) severe accident in March of 2011 to about ∼10%. Therefore, it is important to follow up with and understand the latest trends in nuclear power including SMRs development.