Wednesday 1 February 2017

What's happening in fusion?

Written by Sam Ha

Some of the questions I had when I began looking into fusion research were surprisingly difficult to get answers for. That's not because the answers are closely guarded (pro tip: they're never closely guarded in fusion). I was just asking the wrong questions or the wrong people. I wanted to put together some of these questions and answers to help any readers that might be curious.

(If people have any questions that this doesn't answer, please please PLEASE ask in a comment or message or e-mail to samuel.ha@ukaea.uk)

I'm going to write this in parts, so if you have any questions, feel free to ask them in comments or e-mails and I'll write a Q&A if there are enough questions.

Part 1: The plan for fusion research
Curious-university-student-Sam wanted to know what the plan for fusion research was: which machines are going to be built, when and why. This part covers some of the information about what research is planned

Q: When will I have a fusion power plant?
A: This question is all too common and there are various answers depending on who you believe, but I'm going to try and keep it simple: in Europe, the plan (or EUROfusion Roadmap) is to begin building a Demonstration Fusion Power Plant (known as DEMO) in the 2030's and put Fusion electricity on the grid in the 2040's; widespread commercial deployment can only come after successful operation of DEMO.




Q: How definite is this?
A: We could have electricity from fusion reactors a long time after or before the EUROfusion roadmap's target of the 2040's. Why is this?

Firstly, the roadmap is a long term goal with a lot of unknowns, and ITER is being designed to eliminate a lot of these unknowns. The long and short of it is that ITER is a really complicated machine being built in an even more complicated way and has been delayed multiple times. This could have a knock on to delay the design of a DEMO reactor and increase the time to fusion electricity.


Secondly, ITER isn't the only reactor that we could use to understand some of these unknowns. There are lots of ideas being tried and some other very advanced reactors being built that can help develop our knowledge.

Thirdly, the EUROfusion roadmap is the research stream representing 26 EU member states (+ Switzerland!), whereas fusion research happens all over the world! Other research is being carried out in Japan, China, Korea (who partner with many US researchers), Russia and India, to name a few countries. Korea want to build their reactor by 2037 and China want to build an electricity generating reactor even sooner, called CFETR (Chinese Fusion Engineering Test Reactor).

CFETR not only generates a lot of fusion power (200MW, compared to 500MW in ITER and a 'measly' 16MW in JET), but it has something called a Breeder Blanket which creates more fuel for the reactor and turns the fusion power into useful heat, which can be used to produce electricity. CFETR isn't intended to be as groundbreaking as a DEMO in some important ways, so could take a lot less time to build. That doesn't change the fact that CFETR could be the first device to be able to produce large amounts of electricity from fusion reactions, and that makes me very excited for this machine in particular.


Q: So who's looking into what?
A: Everyone's looking into everything, more or less. There are many designs of DEMO fusion reactors and everyone has a name for theirs: In Europe, we call ours EU-DEMO and Korea call theirs K-DEMO, other names are similarly imaginative.

As an example, a big area that needs developing is materials (an introduction to the problem was covered by our own Alex and Jim!)

European researchers have been developing a special type of steel for several decades now, called Eurofer, which is a type of Low (or Reduced) Activation Ferritic/Martensitic Steel (RAFM). China have also been developing a similar material, called CLAM (Chinese Low Activation Martensitic steel). India have too. So have Japan.

Obviously, I'm oversimplifying the process of materials research and I'm doing a great discredit to the all of the teams I just mentioned, by implying they're all doing the same thing. The reality is that there are subtle and not so subtle differences and each team's working with their own constraints and goals, but the outcome is that many of the countries contributing to ITER are each researching their own low activation, ferritic/martensitic steels.

And the reason is simple: we're all working towards the same goal and each trying to develop fusion technology in a way that people can benefit from. The developments that each country make are made in the spirit of collaboration.


Next time:
So why is it taking so long?
Tokamaks are cool and all, but what about Stellarators or Laser Fusion?
What about after DEMO?