Small Modular Reactors (SMRs)

With the growing demand for energy and global temperature rising there is a continuous struggle for a reliable and green source of energy. Governments are now looking towards nuclear power a non-direct emitter of carbon dioxide, to fulfill the demand and contain the mercury rising. There are challenges to expanding nuclear power – construction bottlenecks and expected time for the construction. Building a nuclear fission reactor (splitting nuclei of heavy elements) is expensive but relatively cheap to run. To cut short the time required for the completion of construction and costs, a kind of nuclear reactor is designed that requires a fraction of the capital costs that of a conventional and a year for it to operate.

These reactors are generally small producing 300 MWe equivalent or less and are designed with modular technology – building part by part and then assembling it at a location, making it less expensive than a conventional nuclear reactor. Such reactors are called Small Modular Reactors (SMRs) having the capability to integrate other modules and expand as demands grow. This reduces the startup costs associated with conventional designs.

SMRs have a much smaller footprint for instance 220 MW to 440 MW Rolls-Royce SMR reactor takes 40,000 m2, 10% of that needed for a traditional plant. Because of their small size and modularity, SMRs could almost be completely built in a controlled factory setting and installed module by module, improving the level of construction quality and efficiency. Lower power production means smaller radioactive inventory making it safer. Like the conventional nuclear power plant placing the reactor unit underground or underwater provides more protection from natural (seismic or tsunami) or man-made hazards (aircraft impact). Furthermore, achieving series production for a specific SMR design will reduce costs.

The applications of SMRs are enormous – they can be used to supply electricity in remote locations, desalinate seawater, power marine propulsion system, provide steam for industrial applications, etc. For instance, electricity needs in remote locations are usually small and variable, making them suitable for a smaller plant. The smaller size may also reduce the need for a grid to distribute its output. Since SMRs are easier to transport after they are complete and ready to provide power, it is suitable for providing power to military bases at an isolated place.

There are at least 50 SMR designs and concepts, most of them are in various developmental stages and some are claimed as being near-term deployable. There are currently four SMRs in advanced stages of construction in Argentina, China, and Russia, and several existing and newcomer nuclear energy countries are conducting SMR research and development. It will be interesting to see how the UN Climate Change Conference (COP26) starting on 31 October 2021 in Glasgow modifies the climate change policy for nuclear to get more attention.

2. Small Modular Reactors – once in a lifetime opportunity for the UK. Rolls-Royce plc. 2017.

Published by Amit K Shah

Nuclear Engineer. Junior Research Fellow at National Institute of Advanced Studies.

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