What is the 'small modular nuclear reactor' that is attracting attention as a power generation method for the new era?

As the realization of a carbon-free society is required as a measure against climate change, nuclear power generation is attracting attention as one of the power generation methods that do not emit carbon dioxide. The Economist, an economic newspaper, describes '

small modular reactors ' that have the potential to replace traditional reactors.

Developers of small modular reactors hope their time has come | The Economist

Nuclear power generation is a power generation method that does not generate carbon dioxide during power generation, and is being constructed in various countries around the world, including Japan. However, due to the Chernobyl nuclear power plant accident in 1986 and the Great East Japan Earthquake in 2011, multiple incidents of radioactive material leaking from the nuclear power plant occurred at the Fukushima Daiichi nuclear power plant, so the 'risk of the nuclear power plant' was raised. It has been attracting attention all over the world. As a result, nuclear power's share of global electricity production fell from 17.5% in 1996 to 10.1% in 2020.

On the other hand, nuclear power generation has been refocused due to the worldwide demand for reduction of carbon dioxide emissions as a measure against climate change, the soaring price of fossil fuels and the destabilization of natural gas supply due to Russia's invasion of Ukraine. I am.

What is happening to the 'nuclear power' debate in Europe, which is shaken by Russia's invasion of Ukraine? --GIGAZINE

Under these circumstances, the small modular reactor (SMR) is attracting attention as a future energy source. In 2020, the SMR of the American private nuclear company NuScale Power was approved by the

United States Nuclear Regulatory Commission, and the British SMR Business Alliance announced a plan to build 16 reactors. The International Nuclear Regulatory Commission (IAEA) estimates that about 50 SMR construction projects are underway worldwide.

'Small modular reactor' that can be operated more safely by natural cooling is finally approved by the regulatory agency --GIGAZINE

As the name 'small size' suggests, SMR is characterized by being smaller than conventional nuclear reactors, so it can be assembled at the factory, unlike conventional nuclear reactors that are assembled at the construction site of a power plant. For this reason, trained workers can work on the construction of reactors one after another in one factory, and moreover, 'the construction period was delayed due to the influence of the weather' which is common when constructing a normal reactor. There is also the merit of avoiding such situations. Chris Colbert, Chief Strategy Officer of NuScale Power, emphasizes the benefits of SMR's factory production, saying, 'Even if the work that takes 17 hours at the construction site of the power plant is completed in 1 hour at the factory.'

The benefits of SMR are not only in terms of manufacturing, but also in terms of safety. The SMR developed by NuScale Power uses a 'passive cooling system' that can cool fuel rods without the need for pumps or moving parts. In addition, because of its small size, it can be cooled with a relatively small amount of water, so even if the cooling system becomes unusable, it can be sufficiently cooled with the water in the water tank.

In addition, SMRs developed by companies such as X-energy and U-Battery are designed to use gas such as helium to cool the reactor, and the helium after cooling the reactor keeps a high temperature of about 750 degrees. And that. For this reason, it is said that the heat emitted can be reused in the same way as power plants that use fossil fuels. 'It may be possible to produce hydrogen by thermochemical cycle using the heat of helium,' said Tim Abram, chief engineer at U-Battery.

As mentioned above, SMR has great advantages in terms of manufacturing cost and safety, but The Economist said, 'Although SMR has been developed since the 1960s, it has not been commercialized due to economic and technical problems. In the light of history, he is skeptical about whether the SMR will replace the traditional reactor. On the other hand, 'Russia's invasion of Ukraine requires a shift in energy policy, which is a great opportunity for SMR.'

in Note, Posted by log1o_hf