Friday 27 February 2015

Can Nuclear Fusion save the world?

When some of the graduates went to the KIT summer school on Fusion technologies last year (see blog post here), David Ward from CCFE gave a talk entitled ‘Future Energy and the Role for Fusion’. As well as leading CCFE’s Power Plant Technology Unit, David works at the Oxford Institute for Energy Studies, so is well placed to give an overview of fusion’s place in the energy market of the future. It was so well packed with interesting facts and figures that I thought I would convert his talk into a blog (with his permission!)
 
Future outlook
 
Most people are aware of the dire consequences facing the world at the moment due to global warming.  We’re beginning to see more and more examples of extreme weather globally and this has been partly attributed to all of the carbon dioxide that developed countries have emitted since the industrial revolution. Unfortunately the areas that usually get hit the hardest by this extreme weather are developing countries: nations that have contributed the least to these effects.

The graph below (Fig 1) shows the HDI (Human Development Index – a measure of GNP, health, education, etc.) for all OECD (developed) and non-OECD (developing) countries.  For all developing countries to reach the same HDI as the UK for example (~0.9), the world’s energy use would need to double, not accounting for any population increase. 

Figure 1


Figure 2 shows a graph of the energy consumption in Germany, China and India from 1965 until 2010. It shows that in just the final two years the growth in Chinese energy consumption has equalled the total energy consumption by Germany since 1965. Developing countries are becoming a match for energy consumption from developed countries. We must reduce emissions if we are to minimise climate change, yet we are faced with a massive increase in demand for energy. Decoupling this paradox will require dramatic changes in energy systems.
 
How can fusion help?
 
Renewable energy is making progress, and is steadily forming a larger proportion of energy production. In 2013 renewable energy contributed 15% to UK electricity compared to 11% the year before. Renewables have an extremely important part to play in our future, but many of them rely on certain weather conditions (solar, wind) and at the moment we do not have a viable energy storage solution (although progress is being made). Nuclear fission provides a reliable baseline energy supply with low carbon emissions, and fusion has the potential to do the same in the future, with even more advantages.
 
One of the fuels used in fusion is deuterium, which occurs naturally in water. A single litre of water contains 0.033g of deuterium, possessing energy equivalent to 10GJ or 280 litres of oil. There is enough deuterium around to provide energy for billions of years. The other fuel is tritium, which can be produced from lithium. The amount of lithium in one laptop battery would be enough for one person’s lifetime of electricity needs (240,000kWh). There are land based lithium reserves for at least thousands of years (from known supplies) to millions of years (from expected but unconfirmed reserves). The bottom line is that fuel reserves for nuclear fusion are enormous and not an issue.
 

Nuclear fusion is inherently safe – there is no chance of a ‘run-away’ reaction. Tritium is radioactive but has a short half-life of 12.5 years, so it decays quite quickly (long-lived fission products have a half-life of up to 200,000 years). It’s useful to put the amount of radioactivity we experience in our day-to-day lives in perspective. Figure 3 shows the amount of radiological exposure arising from activities which give us energy. The two highest doses are from food, and from improved double glazing – both of which go off the scale of the graph. Food is naturally radioactive, and double glazing increases our dose by introducing more radon into our homes. This graph is just to give context, and not compare means of energy consumption. None of these sources give us a damaging amount of radiation.

Figure 4 shows a 2007 prediction of the lifetime of various energy sources, assuming current demand. There is data for oil, gas, coal, uranium (for fission), breeder (for advanced fission) and lithium (for fusion). For each there is a ‘lower resource’ - what we know we have, an upper resource - what we think we may have, and ‘new’ resources - speculative considerations. These data are rather out of date, and do not include shale gas reserves but give a good overall idea of the future we face. Oil, gas and coal are probably going to run out very soon, and even if they don’t we need to curb their usage. Even uranium for fission doesn’t give us a very long outlook. Advanced fission reactors and fusion would see us far into the future, with very low carbon emissions. 


Fusion’s bad press

There are lots of good things about nuclear fusion, and when we get it working, it has the potential to largely solve our energy problems. However, it has had rather a bad press in the last few years. The typical joke is that ‘fusion is always 30 years away’. What rarely gets reported is how much progress we have made in fusion, the technologies that have advanced due to fusion research, and how much we now understand relative to even 10 years ago. What often gets reported is that we have an international project called ITER, which will be the largest fusion reactor so far, and for which construction has overrun and has gone over budget. This is true, and the management of the project is now being reorganised to address these problems. The estimated total cost of ITER is 15 billion euros, which is a huge amount of money, but it’s interesting to compare this to other costs. The total cost of ITER amounts to the same world expenditure on two days’ worth of oil. Figure 5 shows the estimated amount spent globally on different energy sources. Overall, the amount spent on public sector research and development is a negligible fraction, and of that, fusion is a tiny fraction.
 
 
The Future
 
If we consider hypothetical future energy scenarios, in a world where there is no constraint on carbon emissions, we are totally dependent on coal and fission. In a low carbon future – fission and renewables provide the growth needed for about 50 years. After that, fission needs to be replaced by ‘advanced nuclear’ which includes fast breeders and fusion. Alternatively, fission may be constrained due to public concerns and fusion may be required earlier. However, if fission is rejected by the public, it is uncertain whether fusion will be more or less likely to contribute meaningfully.

World energy consumption is likely to more than double, even with a cap on it. There is therefore an enormous potential market for low pollution, low carbon energy sources. Fusion has huge benefits in terms of resources, environmental impact, safety and waste materials. Those doing research into fusion power must focus on demonstrating its potential as a power source, ensuring the benefits are optimised and keeping costs reasonable. If we are to achieve the transformation required in energy markets, the world needs to invest much more in fusion and in energy research and development as a whole.

For more information please see David Ward’s publication

Thursday 5 February 2015

Inspiring the ITER generation - CCFE's Fusion Workshop

by Sarah Medley

It’s a really exciting time for fusion research right now – we’re building the next-generation tokamak ITER and we’re working towards a demonstration power station (known as DEMO), to put fusion electricity on the grid before 2050. However, the dream of fusion as the ultimate energy source will never become reality without one essential ingredient: people! We need people to continue the research, to operate ITER and design DEMO! So it is essential that the fusion community considers how to inspire this next generation of fusion scientists and engineers - often referred to as “the ITER generation”.

Fortunately, CCFE already has a strong outreach programme dedicated to this goal. We give tours of our JET and MAST fusion experiments to A-level and university students, and we take the Sun Dome science roadshow into primary schools. However, the graduates realised that there was a ‘gap in the market’ when it comes to secondary school students, so we decided to develop something specifically aimed at inspiring GCSE-age students to pursue Science, Technology, Engineering and Maths (a.k.a. STEM) subjects to A-level and beyond!

And behold, the CCFE Fusion Workshop was born. Developed entirely by CCFE graduates, the Fusion Workshop is an interactive activity session that uses hands-on science and engineering demonstrations to bring the real-world applications of STEM subjects to life in the context of fusion research. What exactly does that mean, you ask? Well basically we assemble a crack team of graduates, pile them into a van with a load of demonstration kits and send them off to a local school to invade a GCSE physics lesson.
 

The Fusion Workshop team. From left to right: Jim (materials scientist), Alastair (physicist), Greg (mechanical engineer), Kim (control engineer), Sarah and Alex (physicists).

 School lessons only last for an hour, so the Fusion Workshop is designed to be a snappy and exciting insight into the world of fusion research and why it’s so awesome, all delivered in less than 60 minutes. We kick off the session with a short intro to fusion and CCFE, before diving into the best bit – the demos! This is where the students get to have a great time playing with lasers, magnets, expanding marshmallows, and not forgetting the robotic arm chocolate relay race! Of course, it’s not just about having fun, as the graduates are on hand to provide easily understandable explanations of how each demo relates to a particular element of fusion research, whether it’s plasma diagnostics or vacuum technology. So the demos all aim to show how the science taught at school is actually applied in the real world of fusion research! We wrap up the workshop with a quick chat about how to become a scientist or engineer - and why it’s such an exciting career choice! - then we pack up the van and drive off into the sunset (or back to CCFE), happy in the knowledge that the students all had fun and are hopefully now considering STEM career routes as a result of the session.

Of course, this is how we see it, but what do the students think? Well, the feedback speaks for itself – after trialling the workshop with a local year 10 class, we received comments such as “I loved it and it just made me want to go to university and be an engineer” and “I am hoping to become a physicist when I'm older and this has really enthused me”. One member of the class has even applied for work experience at CCFE, as a direct result of our workshop.

So you put a marshmallow inside a vacuum chamber, switch on the pump, and then….? Greg and Sarah show these two year 10 students what happens and why.
 

Future remote handling engineers?
Unsurprisingly, adults enjoy the workshop session just as much as school students. We witnessed this first hand last month at a networking event that we co-hosted with Science Oxford, where 25 teachers and STEM Ambassadors from across the country came to CCFE to experience the workshop for themselves! This was an excellent opportunity to give us invaluable feedback, which we can now use to refine the workshop and develop it further.
The plan is to continue to work closely with teachers and schools to make sure that the students really are getting the most out of the workshop, and then it can be officially rolled out later this year!


Jim explains to teachers how the GCSE physics concepts of reflection and refraction are applied to JET’s essential laser diagnostics.
Alex explains to teachers how we use ferrofluids in the workshop to illustrate magnetism to students. Magnets are the most essential part of any tokamak!

So, what started out as an enthusiastic group of graduates with a vision is now a very real project with a lot of momentum, and we’re super excited about it. The workshop also has great potential to incorporate other demos in future, for example other graduate projects such as the table-top plasma device or RIFT, so watch this space! Whatever happens, we hope that the CCFE Fusion Workshop will continue to inspire young scientists and engineers for years to come!