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Small modular reactors an effective tool for climate change mitigation

Antti Rantakaulio 27 February 2020, 14:11 EET

The role of nuclear power has emerged strongly in the discussion around climate change mitigation. Small Modular Reactors (SMRs) and their role in the energy markets are part of this discussion. What are SMRs, and can nuclear power plants really be deployed directly from the factory?

Nuclear power

Same technology and safety requirements as the big plants

Nuclear power plants with an electricity output of 70 - 300 MW are called small modular reactors. Both of Loviisa’s reactors, for instance, have a power output of over 500 MW each, and the Olkiluoto reactors close to 900 MW. By comparison, the power output of the Imatra power plant, Finland’s biggest hydropower plant, is 192 MW.

In terms of technology, SMRs are similar to big plants and require the same level of safety as the current big plants. The big nuclear power plants and SMRs both produce energy efficiently, predictably, stably and without carbon dioxide emissions.

Potential and cost-effective tool in climate change mitigation

The advantages of SMRs are: better adjustability, standardised solutions, advance prefabrication, faster deployment, the potential for more diverse use, and cost-efficiency. In addition to this, the safety properties of small reactors can be further improved with, e.g., passive safety systems that operate without electricity.

As the production of variable wind and solar energy increases, smaller output and adjustable reactors could be a significant balancing factor in the electricity system.

Nuclear power plants directly from the factory?

In the future, small modular reactors will not actually be built on-site; they will be installed from prefabricated modules delivered to the site. One of these modules can be prefabricated at the factory to the extent that the plant just needs to be connected to the rest of the infrastructure, like a power grid or a heating network, and the fuel loaded into the plant.

The goal with standardised solutions and serial manufacturing is for clear cost and timetable benefits. They can help to ensure that a small modular reactor project stays on schedule and within budget.

The cost benefits of factory production aren’t achieved with the first plants; it takes several plants to be manufactured before that happens. The cost benefits of serial production have been seen recently in, e.g., wind and solar power. It isn’t necessarily feasible to have module-producing factories and supply chains in each country; instead, there could be, say, continent-specific factories and the related supply chains.

Small modular reactors enable a carbon-neutral society

SMRs have a smaller level of output, making them perfect for targets where the energy demand is smaller. Thus SMRs might be used as a solution for heating in urban areas and industry, for producing fresh water, or for energy production in isolated locations, like mining towns.

In fact, several Finnish cities have initiatives related to the use of small modular reactors for district heating production. The issue has been studied also in China, where there are several heat reactor concepts under development that would produce heat for a district heating network. With a smaller output, they potentially could be placed closer to cities, for instance in industrial areas. A heating source for industry, in turn, could be the so-called very high-temperature reactors that are under development, as they reach temperatures of over 700 degrees Celsius.

Strong regulatory control associated with nuclear power

At the moment, big nuclear power plants are licensed by each country and, despite collaboration, the regulatory requirements differ from one country to another – even though the top-level requirements are quite consistent.

With small modular reactors, new, more efficient licensing practices must be found, especially if the aim is to move to serial production. Prefabrication in a factory requires standardised structures and systems. In order for the same solution to be used in different countries, either the regulatory requirements have to be standardised or the solution approved in one country must be applicable also in another country.

The oversight focus is probably moving increasingly towards the control of manufacturing and to some sort of type- and factory-approval procedure for concepts. There is still a lot of work to be done here and in the national- and international-level collaboration between plant suppliers, energy producers and authorities.

International race is under way

There are currently multiple small modular reactor development projects around the world. Many of the concepts are still on the drawing board, but the first prototype plants are close to deployment or have already been deployed. The most advanced projects right now are in China, Russia, and the United States. A significant state-driven small modular reactor project is underway in Canada.

Here at Fortum, small modular reactors have been part of the nuclear power R&D programme for several years now. We are continuously developing our own expertise and tools for small reactor plant simulations, for example. We see small modular reactors as part of a nuclear power future, and we are actively monitoring what’s going on around the world. We are involved in various national and international projects to help accelerate the development of and the opportunities to utilise small modular reactors.

Antti Rantakaulio

Project Manager
Small modular reactor research & development project
antti [dot] rantakaulio [at] fortum [dot] com

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