New science could make reactors ‘Fukushima proof’

Unit 3 at the Fukushima Daiichi Nuclear Power Plant
Support us and go ad-free

In 2011, the earth shook in Japan – and with it shook the world’s confidence in the safety of nuclear power. The Fukushima Daiichi nuclear reactors exploded following an earthquake, because the cladding meant to protect them reacted with boiling coolant water. Researchers have now figured out a way to make the cladding safer, by combining theoretical models and experimental techniques.

Nuclear power plants produce energy from nuclear reactions. Heat produced by splitting atoms – nuclear fission – is passed through water or gas that runs through turbines. These turbines then turn to power electricity generators.

Guards at whiteboard at Fukushima-1 main gate
Japanese authorities declared a 20km no-go zone around the Fukushima Daiichi Nuclear Power Plant. Image: Steve Herman/Wikimedia Commons

The Fukushima Daiichi Nuclear Power Plant in Japan is one of the world’s 15 largest nuclear plants. It used water for cooling and when a magnitude 9.0 earthquake and resulting tsunami hit the plant on 11 March 2011, the cooling systems failed. This meant the water was no longer cooled and instead boiled. The cladding around the reactors reacted with the boiling coolant water and formed hydrogen gas, which subsequently exploded.

To prevent such a Loss of Coolant Accident (LOCA), the cladding has to be resistant to high temperatures. That’s what two research teams – from the Illinois Institute of Technology and the Institute of Physics Academy of Sciences of the Czech Republic – have been developing. Both teams are presenting their work this week at the AVS 62nd International Symposium and Exhibition in California.

Rethinking cladding

Reactor cladding is designed to provide a barrier between the radioactive material – such as uranium – and the coolant. To be effective and not vulnerable to accidents, it has to withstand extreme heat.

The Illinois Institute of Technology team, led by Dr. Jeff Terry, is investigating silicon carbide as a potential cladding that could prevent hydrogen explosions. To find out whether it’s up to the job, the team analysed the physical and chemical properties of the radioactive elements in silicon carbide under accident conditions. Dr. Terry combined data from several national labs and institutions with predictions made by models and experimental data from earlier experiments to come up with a picture of how the material might behave.

Read on...

Support us and go ad-free

“It is no longer practical to test every element in a nuclear reactor to failure,” he explained. “We need to have models that predict what will actually happen.”

Another approach is to coat the cladding in a protective layer of diamond. A team led by Dr. Irena Kratochvílová from the Institute of Physics Academy of Sciences of the Czech Republic have developed a way of protecting cladding, by coating it with diamond vapour.

“The diamond layer offers many advantages,” commented Dr. Kratochvílová. “In addition to the diamond grains, it contains amorphous carbon, so it is both strong and flexible, providing a cladding that is mechanically durable and can adapt to thermal expansion during reactor operation.”

A team at Texas A&M University tested the new material by irradiating it with an ion beam – even at temperatures above 850 degrees Celsius, the surface was protected against corrosion from steam. The team now plans to test the cladding in real reactors.

Reassuring the public

Several Fukushima reactors were permanently damaged as a result of the tsunami, leading to the release of radioactivity. A 30km evacuation zone was set up and a month later, Japanese authorities declared a 20km no-go zone, which people can only enter with government supervision.

Despite the huge impact the incident had, a BBC public opinion poll carried out in November 2011 suggested that the UK public was more in favour of nuclear power than it was in 2005, with 37% agreeing that “nuclear power is relatively safe and an important source of electricity, and we should build more nuclear power plants”, compared to 33% in 2005.

But the UK is an outlier – virtually every other country saw a significant decrease in public confidence in nuclear power. Post-Fukushima, safety remains one of the key concerns regarding nuclear energy, so ensuring safer reactors – including by developing safer cladding – could overcome a major obstacle to its wider use.

Featured image: IAEA Imagebank/Flickr.

Support us and go ad-free

We need your help to keep speaking the truth

Every story that you have come to us with; each injustice you have asked us to investigate; every campaign we have fought; each of your unheard voices we amplified; we do this for you. We are making a difference on your behalf.

Our fight is your fight. You’ve supported our collective struggle every time you gave us a like; and every time you shared our work across social media. Now we need you to support us with a monthly donation.

We have published nearly 2,000 articles and over 50 films in 2021. And we want to do this and more in 2022 but we don’t have enough money to go on at this pace. So, if you value our work and want us to continue then please join us and be part of The Canary family.

In return, you get:

* Advert free reading experience
* Quarterly group video call with the Editor-in-Chief
* Behind the scenes monthly e-newsletter
* 20% discount in our shop

Almost all of our spending goes to the people who make The Canary’s content. So your contribution directly supports our writers and enables us to continue to do what we do: speaking truth, powered by you. We have weathered many attempts to shut us down and silence our vital opposition to an increasingly fascist government and right-wing mainstream media.

With your help we can continue:

* Holding political and state power to account
* Advocating for the people the system marginalises
* Being a media outlet that upholds the highest standards
* Campaigning on the issues others won’t
* Putting your lives central to everything we do

We are a drop of truth in an ocean of deceit. But we can’t do this without your support. So please, can you help us continue the fight?

The Canary Support us

Comments are closed