2011 was in many ways a depressing year for nuclear energy. The Tōhoku earthquake and tsunami that caused the Fukushima accident changed many things. Germany's political leaders went into unreasonable panic and Merkel immediately ordered the shut down of 10 reactors and soon followed that up by a decision to reinstate the previous nuclear phase out plans. With a bit of humor one can state that the Japanese Tōhoku earthquake and tsunami permanently shut down more reactors in Germany than it did in Japan. Switzerland also decided on a phase out plan that is in many ways similar to the phase out plan Sweden was following for many years. Maby the swiss will look at Sweden and learn how badly it worked, only time will tell. Fukushima also temporarily put a break on the rapid nuclear build in China and the future of nuclear in Japan is very unsure.
But this blog post is not about the bad things that happened in 2011, instead we will look at the good things that happened! Here comes a partial list of things that makes us all raise our glasses in cheers of a promising future.
The biggest good news is the rationality that most countries showed after the Fukushima accident. Germany's panic didn't spread and most countries that had plans to expand, renew or start a new nuclear fleet has publicly stated they will stick to the plans. In China, without a doubt the most important country for new nuclear projects, their ambitious program has only been downsized slightly and the focus has been shifted towards generation 3 reactors like AP1000 rather than the indigenous generation 2 designs. Plans in the US seems to be going straight ahead after the recent approval by NRC of the AP1000 design and the developing countries are one by one embracing nuclear as a clean and safe energy source for the future. We applaud the maturity most government have shown despite the, at times, ridiculous media coverage.
The year has been an exciting one for small modular reactors (reactors with an electric power less than 300 MW). NuScale was brought back from the brink of bankruptcy by an hefty investment from the engineering company Flour, one of the largest engineering firms in the US. The NuScale design is quite interesting and innovative and I encourage everyone to check out their homepage and have a look. Babcock and Wilcox and their 125MWe mPower design seems to be steaming on right ahead with a cooperation announced with TVA to build 6 reactors at their Clinch river site. The first unit is supposed to be constructed by 2020 and we hope that ambitious time plan will hold up. All depends on the ponderous NRC review process.
B&W's mPower within its containment structure
Westinghouse doesn't want to be left in the dust on the small modular market and they presented their own design this year, abandoning their earlier IRIS modular project. The new small reactor is about double the size of mPower at 225 MWe. The whole reactor will be sited underground (a common feature of many small modular reactors) and construction time is projected to be 18 months.
China, not surprisingly, also has a modular PWR in the works, a 100-150MWe design, I haven't read much about it but it is going to be an interesting fight on what modular PWR will hit the market first. If I was to make a bet then I bet on the Chinese, due to the slow pace of NRC. But mPower sure looks promising and B&W has long experience with submarine reactors which should speed up their development process significantly.
All modular reactors however aren't light water reactors. There are also several generation 4 designs in the works and news have popped up on several of the during 2011. Bill Gates have several time made the news discussing the traveling wave reactor concept that is being developed by Terrapower, with Gates as one of the biggest investors. The latest information is that Gates was in talks with China about the reactor. The traveling wave concept is a cool one, the basic idea is that one has a fairly large core where most of it is subcritical and composed out of depleted uranium. In the center, or at one edge of the core depending on design, one "ignites" the core with a load of highly enrichment uranium. The area closest to the critical zone will slowly get it is depleted uranium converted to plutonium and become critical while the starting critical zone slowly gets depleted. The whole thing is a fast spectrum reactor with liquid metal coolant so it is capable of breeding. In this fashion a criticality wave travels through the reactor over a time span of say 50 years, continuously producing power. The appeal of the design is that one can basically bury the whole thing, push the on button and then walk away and let it produce power for decades without any need for refueling or major maintenance. The reactor is still in the basic design stage at this point in time and god knows what roadblocks Terrapower will stumble upon. But it is very heartening to see a man like Gates involved and if China gets interesting things can move on quickly.
When talking about China, China is already building a generation 4 modular reactor, the Chinese version of the pebble bed reactor. I worked for a year with Pebble bed reactors and it is a very interesting type of reactor. They don't have the high fuel utilization of fast breeders but they have plenty of other perks, most of all it's passive safety. A pebble bed reactor is as close to idiot proof as even the most gifted idiot can imagine. The fuel in a pebble bed reactor consists of tiny particles of uranium surrounded by thin but extraordinarily sturdy layers of silicon carbide and pyrolytic carbon. All these particles is compressed into a ball together with a bunch of graphite and this ball is then surrounded by another layer of graphite to make a pebble about the size of a tennis ball. To fuel the reactor one throws in a whole bunch of these balls into a cylinder that is made out of even more graphite. The whole thing is cooled by blowing Helium through it. What makes this reactor so safe is the thermal intertia of the whole system, the extreme durability of the fuel particles and the very strong negative feedback.
If the temperature of the reactor goes up all the neutrons getting slowed down in the graphite will get slowed down slightly less, this makes fission a bit less probably for each time a neutron hits a uranium atom and the fission chain reaction dies. However we all know that even though fission has ceased, heat is still being generated by decay products and this is where the thermal inertia comes into play. The reactor is pretty much a immense volume of graphite with some fuel particles in there. All that graphite can soak up huge amounts of heat and the whole core is very large in size so there is a lot of surface area to radiate away the heat. Combined this means that even if the cooling systems fail completely the equilibrium temperature of the system, due to decay heat production, will be far less than the temperature required to compromise the fuel particles. One can pull out all the control rods, shut down the cooling systems, go for a 2 week vacation in the Maldives and then return to a intact and naturally shut down reactor. All that is needed to resume operation is to just turn on the cooling again. No damage to system, no catastrophic meltdown, no electric systems needed at all for emergency situations. If the Fukushima reactors, or Chernobyl, or TMI had been pebble beds nothing at all would have happened. Pebble bed reactors also has more versatility than light water reactors due to the fact that they produce much higher temperature heat. The massive industrial heat market then opens up for nuclear energy and it is a market that is larger than the electricity market. The Chinese pebble bed reactor is a potential game changer that one should follow carefully.
More exciting developments in China is the grid connection of Chinas fast experimental reactor. It is a tiny reactor at 20 MWe but it is a strong sign that China is not leaving any stone unturned in their strive for nuclear dominance. The follow up to this fast reactor will be the construction of two BN-800 fast sodium cooled reactors China is buying from Russia with planned construction start in 2013. All the talk of generation 4 reactors being sci-fi is obvious nonsense.
Perhaps the most intriguing news during 2011, at least to me, was the launch of a very high profile Chinese project to develop a molten salt reactor using a thorium fuel cycle. In 20 years they expect to have a commercial molten salt reactor running. So far China has been very secretive with any kind of details about the project. There are many ways to make a molten salt reactor and we are eagerly awaiting any information. But some industry insider information I have heard tells me the project is a big deal politically and already to big to be allowed to fail. I am greatly looking forward to finding out more about the project and reading the first papers they publish. One can only hope they won't keep it all secret for long but the fact that they dont participate in the generation 4 cooperation regarding the molten salt reactor hints that they want to do this all by themself. The molten salt reactor is perhaps the most promising of all the generation 4 designs, it is however also the design with the most question marks attached to it.
A even more surprising development is the attempts by General Electric to launch their sodium cooled fast reactor design in Sweden and the UK. It is surprising because it shows a lot of confidence in their design and it would be very interesting if one got built in Europe. Sweden is an unlikely market since it would (unfortunately) not fit the general plan in Sweden to treat spent nuclear fuel as waste instead of a resource. For the same reason I doubt the idea will get approval in the UK, but one can always hope.
As far as waste goes developments are happening in Sweden. The company in charge of developing and building a repository (SKB) for the Swedish spent nuclear fuel has progressed to the point that they have handed in an application to start building the repository. If built this would be the first civilian repository in the world and the second repository in operation. The first repository in operation is the american Waste Isolation Pilot Plant that is used to store military transuranic waste (elements heavier than uranium). One can only hope that once the Swedish repository is in action the old mantra "there is no solution to the nuclear waste problem" by the anti nuclear crowd will finally be silenced. But they didn't go silent after WIPP started so I guess that is to much to hope for. The swedish anti nuclear NGO's like Naturskyddsföreningen and MKG are fighting SKB tooth and nail now when they are on the verge of loosing the waste fight. Spreading FUD wherever and whenever they can.
Those are a small selection of the good news from 2011 that I can remember of the top of my head. Many other things have of course happened, like the approval to build one more reactor in Finland and the developments in the Czech republic, Poland and many other countries. If I have missed some big happy news please let me know in the comments!
Hope all readers of this blog will get a splendid 2012!