Small modular reactors (SMRs) have emerged in the past especially in the attempt to use nuclear energy as a propulsion technology for military equipment.
What is a Small Modular Reactors
SMR as a group of small power reactors with lower power than today’s nuclear power plants from up to under 10 MWe (micro reactors) up to a power of typically 300 MWe. In contrast, the usual conventional reactors have an output in the order of magnitude of over 1000 MWe.
They are designed to be manufactured at a plant and transported to a site to be installed. Modular reactors will reduce on-site construction and increase containment efficiency and are claimed to enhance safety.
The mode of operation of this reactor group is very diverse: in a number of concepts it corresponds to the mode of operation of today’s light water reactors. These types of SMR are therefore subject to lower development risks, and the developers can draw on operational experience.
On the other hand, the SMR are also based on new concept ideas with little or no prior industrial experience.
Is the SMR Worthing?
Thanks to their modularity, SMR promise shorter production times and lower production costs. Individual components or the entire SMR are to be (mass) industrially manufactured and, if necessary, transported to the selected locations for installation. Comparable to a modular principle, a single reactor with low power or a larger system from several small reactor modules can be set up on site in a short time from the components (modules).
Due to the low electrical output, the specific construction costs are higher than with large nuclear power plants due to the loss of economies of scale . According to this, an average of three thousand SMRs must be produced before it is worth starting SMR production would. It is therefore not to be expected that the structural cost disadvantage of reactors with low power can be compensated for by learning or mass effects. As with high-capacity nuclear power plants, SMR is mainly provided by the state.
Another essential justification for the development of SMR concepts is the expectation of shorter time horizons, in particular shorter construction times.
Can SMR to Damage Climate?
If SMRs are also proposed as a solution in the context of combating the dangers of climate change and the associated reduction in greenhouse gas emissions for global electricity supply, the electricity production achieved with them is relevant.
The SMR provide for planned electrical outputs of 1.5-300 MWe.
Accordingly, a factor of 3-1000 more systems would be required to provide the same electrical power. Instead of around 400 high-power reactors today, this would mean the construction of several thousand to ten thousand SMR plants.
That goal is a long way off.
How secure is SMR?
With a planned, worldwide distribution of SMR, completely new questions arise for the responsible approval and supervisory authorities.
So far, there are no SMR-specific national or international safety standards.
Overall, SMR could have potential safety advantages over nuclear power plantswith high performance, since they have a lower radioactive inventory per reactor and strive for a higher level of safety through targeted simplifications and increased use of passive systems.
Due to their smaller size, developers promise a lower safety risk for the reactors. However, the high number of reactors to provide significant amounts of electrical power and their planned worldwide use will in turn increase the risk many times over.
Many SMR concepts also aim for reduced security requirements, for example with a view to diversity in security systems. These security concepts, which are also pursued for cost-efficiency, contribute to an increase in risks.
The Small Modular Reactors comes as a response to past nuclear disasters.
This strategy was introduced aiming at building smaller reactors, faster to realize, more safely and at lower costs for a single reactor. Despite the loss of scale advantages and considerably less power output, funding was expected to be easier thanks to the introduction of modular construction and projects with expected shorter timescales.