Nuclear: Small is beautiful?

We are very proud to share with you today the third part of a set of 4 documents that present a great overview of the nuclear landscape. Epsiloon, a French magazine that reinvents the scientific press and that is independent, high-standard, committed and sincere. All traits that are also at the core of inTechBrew.

In this series of blogs, originally published (in French) in December 2022, we will go through nuclear’s new golden age, the challenge of long-term maintenance, the SMRs race and finish by presenting you the other potentially game-changing innovations of our nuclear future. Although some examples given in this specific article of our Epsiloon series refer to the French sector, the points made can easily apply to the global nuclear landscape.

This third instalment will give an overview of the current SMR race.

Importantly, and before we start, we would like to thanks @Herve Poirier for trusting us with Epsiloon’s work. The set of articles was originally written by @Vincent Nouyrigat, @Pierre-Yves Bocquet, @Xavier Boivinet and @Muriel Valin for the December 2022 issue of Epsiloon. 

Originally written in French, the translation and revision for an international audience was completed by @Xavier Poteau for inTechBrew.

Nuclear: Small is beautiful?

Two are already operational, three are under construction, and the number of concepts under study is growing year after year: 48 in 2016; 56 in 2018: 72 in 2020; 83 in 2022. The race for mini-nuclear reactors is on.

“There is growing interest from nuclear stakeholders, governments and even other industrialists», says Stefano Monti, head of the nuclear technology development section at IAEA. “The subject has been on the table for years, but there has been a clear acceleration in the last year or two” said Michel Berthélemy, an analyst at the OECD NEA.

A new trend

These “Small Modular Reactors” (SMR) with a power of less than 300 Megawatts of electricity (MWe), or sometimes 50 – compared to the 1600 MWe of EDF’s EPR – have been used in submarines and military vessels for decades, but the objective today is to integrate them into the electricity grids. “China is investing massively in its decarbonization and is trying by all means, including SMRs, to do without coal” says Emmanuelle Galichet, a professor and researcher in nuclear physics at the CNAM (French public higher education institution) “In the United States, the financing of SMR concepts has changed by order of magnitude compared to a few years ago” notes Michel Berthélemy.

“In France, the strong support from the state is transforming Nuward from a research project to an industrial project,” explains Valérie Vandenberghe, a researcher at the French Alternative Energies and Atomic Energy Commission (CEA), which is developing this reactor project consisting of two 170 MWe modules in partnership with EDF, Naval Group, TechnicAtome, Framatome and Tractebel.

Even if for the moment in Europe, no real strategy is emerging, the craze is there. “When it comes to implementing concrete decarbonisation strategies, the agreement is that we lack solutions” says Michel Berthélemy. There is a painful awakening in the face of the climate emergency. “SMRs appear to be a path within our reach, in addition to renewable energies and high-power nuclear».
SMRs advantages are well identified: smaller, these reactors are easier to operate – the risk of chain reaction is undeniably reduced. They can also cool themselves in the event of an incident. They promise to be easier to protect (they can be buried easily). And above all, easier to build. The idea is to reproduce the production system of aeronautics: manufacturing the main parts in the factory, in series and in large quantities, before sending them for assembly on site. “This could be a game changer by simplifying manufacturing, quality control and reducing construction time” Stefano Monti says. Certainly a strategic shift from the economies of scale on which high-power reactors have long relied on.

A complementary technology

Essentially, however, this is not about replacing these large reactors. “There will be overlap areas, but this will not concern most of the market” says Michel Berthélemy. SMRs are here rather to replace coal-fired power plants, whose power range is similar, or to provide electricity or heat to energy-intensive industries, isolated localities or non-nuclear countries. “They can meet needs that large reactors and renewables do not meet” says Valérie Vandenberghe.

Still, the technology has yet to prove itself. Mini-reactors may be more difficult to inspect (because they are very compact), more difficult to monitor (with a risk of nuclear dissemination). And “the advantages of series production have yet to be demonstrated, we must wait for it to actually happen, in the course of the 2030s” warns Stefano Monti. “The next decade will be key; it will be the demonstration of safety and performance for several of these concepts.”

Even if some manufacturers rely on innovative technologies such as molten salts or fast neutrons (still in the R&D phase), the majority of SMR concepts are based on pressurized water technology similar to that of existing high-power nuclear reactors. “It’s a mature technology, so we could get there faster” says Valérie Vandenberghe.

No doubt, the trend is there. It won’t be long before we know if the small reactors are delivering on their promises.