Posted on 01/07/2011 9:47:41 PM PST by Straight Vermonter
Aker Solutions' Accelerator Driven Thorium Reactor™ (ADTR) has won the prestigious Energy Award at this year's IChemE (Institution of Chemical Engineers) Innovations and Excellence Awards. The Energy Award recognizes the best project or process to demonstrate innovation in renewable energy, alternative energy sources, efficient energy use or the development of energy production methods that reduce energy and water intensity.
More about the ADTR(TM) power station
The Accelerator Driven Thorium Reactor™ (ADTR) power station is the name given by Aker Solutions for the company's new design of a nuclear power station. Given world-wide expansion in nuclear power generation, driven by many countries to combat climate change and meet growth in energy demand, the ADTRTM provides the ideal solution to use thorium as an alternative fuel to uranium.
Aker Solutions has developed the concept design of a 600MWe ADTR™ power station with Nobel Prize winner Professor Carlo Rubbia of CERN. The design is an accelerator driven, thorium fuelled, lead cooled, power producing, fast reactor. Thorium is an abundant mineral deposit; there is 3 to 5 times more thorium in the world than uranium. One tonne of mined thorium produces as much energy as 200 tonnes of mined uranium, or 3,500,000 tonnes of mined coal. Thorium has non-proliferation benefits as it does not require the expensive enrichment process often associated with military use.
The ADTR™ power station can be configured to burn radioactive wastes from current uranium fuelled reactors, thus reducing the long term waste burden and environmental risks with waste storage. The ten year fuel cycle gives the ADTR™ significant economic benefits over current uranium fuelled nuclear reactors.
A key advantage of accelerator driven, sub-critical systems over conventional nuclear reactors, is that the accelerator is the main source of reactor control; turn off the accelerator and the reaction reduces virtually instantaneously. This system also enables simple load following control capability.
"This technology offers the potential to supply even small grids from compact 600MW reactors constructed safely underground," says Gary Mandel, executive vice president of Aker Solutions' Process and Construction business.
The ADTR™ power station is targeted at the global energy market, aligning itself with fourth generation nuclear reactor concepts that will come to fruition by 2030.
That's more than right and we should be going after every energy source available to us on a wartime basis as we speak. Aside from the fact of still having 20 - 30 years of petroleum fueled vehicles in service starting from now, there's the question of how money sent to the opeckers gets used, i.e. to fly aircraft into our taller buildings, i.e. you have to figure that into the cost.
But thorium is a spectacular possibility. It's vastly more efficient for producing energy than uranium is and totally clean, burning down to nothing as it is used. It can't be used to make bombs (which is why nobody was interested in it in previous decades), and is much more plentiful than uranium.
“And unlike uranium-based reactors, a modern thorium reactor ... generates a very tiny fraction of the nuclear waste conventional reactors do.”
How is a thorium fission reactor significantly different from a uranium reactor in the generation of radioactive waste?
The company’s blurb mentions a big reduction in actinide production, but that’s not necessarily significant in terms of overall radioactive waste.
“But thorium is a spectacular possibility. It’s vastly more efficient for producing energy than uranium is and totally clean, burning down to nothing as it is used. It can’t be used to make bombs (which is why nobody was interested in it in previous decades), and is much more plentiful than uranium. “
Can you justify any of these assertions?
Thorium isn’t much good for bombs, but a thorium reactor generates other fissionable isotopes that are good for bombs.
Thorium-fueled reactors don’t “burn down to nothing”. What do you think becomes of the fission products, many of which are radioactive? Or does “burn down to nothing” imply that we’ve waited a few billion years for it to happen?
The design is an accelerator driven, thorium fuelled, lead cooled, power producing, fast reactor. Thorium is an abundant mineral deposit; there is 3 to 5 times more thorium in the world than uranium. One tonne of mined thorium produces as much energy as 200 tonnes of mined uranium, or 3,500,000 tonnes of mined coal. Thorium has non-proliferation benefits as it does not require the expensive enrichment process often associated with military use.
Nuke ping! Have you read anything about this design?
India has the largest reserves of Thorium in the world.
Second I think is Australia and third is the US / Canada.
US resources are concentrated now on the Idaho / Montana border and owned by... Thorium Energy, Inc.
I don’t understand why we can’t have this and / or the Hyperion reactor design. Like so many things, something too good to be true usually is.
There was a long term Thorium reactor project at Oak Ridge but since it didn’t produce weapons grade material it was scrapped. I think the Peanut farmer got it the same time he killed the breeder reactors.
They were acquired for 5.5 billion British pounds, so there is a good chance that their design is legitimate.
Quantities are therefore, large.
Percentage efficiency depends on when in the cycle you take the fuel out of the reactor and reprocess to separate the U-233. Probably 20-30% conversion is possible under the right conditions.
Time is months to a few years.
Generating U-233 in a Thorium reactor is almost a no-brainer. Handling it afterwards is harder than U-235 or Plutonium, but the critical mass is less than U-235.
This threat is not just idle speculation, and anyone who says that Thorium reactors can not be used to produce weapons is dreaming...
OK, last question.
In a “normal” cycle, is the U-233 consumed, or does it become a waste product requiring disposal?
The article seems to state that there would normally be no waste.
What’s the fission cross section for U-233? IOW, will it burn up in the core along with the thorium?
If the fuel is removed before the optimum time for Thorium consumption, there is more U-233 present. It is possible to operate the reactor to optimize U-233 production, which produces a lot more U-233 than otherwise.
Whether you "burn" U-235, U-233 from Thorium-232, or Plutonium-239 from U-238, there are always fission fragments -- highly radioactive light elements produced by the fission process. These are always nasty. I don't know all the details of the Thorium cycle, but anyone who tells you that there is no radioactive waste is lying, just like they are lying about no bombs.
Do a search for Operation Teapot. Mixed-core of plutonium and U-233.
I know I said last question, but I want to be be clear about this.
“highly radioactive light elements”
Half-life for these?
Sorry, I never was a nuclear physicist, been out of school for decades.
Half-life for these?
There are many of them. Probably hundreds to thousands. They all have different half-lives. I can't possibly name them all here. Some are particularly bad actors.
Longer explanation.
When anything fissions (U-235, U-233, Pu-239) it produces "fission fragments" plus a few neutrons. The neutrons are what make the fission reaction self-sustaining, the fission fragments are the "highly radioactive light elements", or more properly, the nuclei of these elements. Many of these lighter elements are produced, and each fission reaction has its own distribution of relative quantities.
When I say some are "bad actors" what I mean is that they are more biologically active than others. Anything that has a long enough half-life so that it is likely to be absorbed by a human or animal before most of it decays is biologically active. If the half-life is short enough so that a large fraction of it will decay during the lifetime of that human or animal it is going to have bad consequences. You want to minimize the amount of radioactive decay inside your body.
This is the most difficult to handle part of what is called "nuclear waste". The absolute quantity per unit energy produced of this material is very similar from any fission reactor. Now the particular mix produced in the Thorium cycle may be easier to handle than average, but that certainly doesn't mean it is "easy" or that there isn't any.
To use an analogy, would you rather have a lion, a tiger, or a cougar suddenly appear in your living room? None of these would be considered "good" but the cougar would be "less bad" than the lion or tiger.
This is a big deal. At some point the economy will stabilize, and there will be venture capital coming back that will be looking to get behind thorium projects that are really “green”, although I hate to even use that term with thorium.
Let’s just say that from my view, thorium is truly the next generation of nuclear power generation and could solve a lot of problems on a lot of different levels. Couple thorium with the ongoing engineering of smaller nuclear power plants and it’s easy to see why there is so much interest in thorium.
I read an article last year about a company that is going to market mini-reactors. Essentially, they have a complete liquid sodium power module that comes from the factory ready to go, and they install it into a deep concrete pit. They maintain and operate the nuclear parts for you, and your utility company hooks up your heat exchanger and standard turbine generation sets to it, and off you go.
The concept is instead of building a single 1000MW nuclear plant that costs untold billions to build and operate; you build a bunch of smaller 20MW plants for $50 million apiece. Smaller plants mean you can spread them around closer to where people live. It’s cheaper to lease the sealed nuclear unit than it is to build an enormous reactor containment and infrastructure.
When it needs refueling in 20 years, the company comes in and replaces the old reactor with a new one, and you keep on operating. If you need more capacity, add another unit.
Some good concepts out there if we can ever get past the real hazards in the technology.
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