By Mark Halper
Posting in Design
Mark Halper's thorium trail winds back to London, where Japan's Chubu Electric reaches him to confirm it does indeed regard the long neglected nuclear fuel as a 'future possible energy resource.'
Yesterday, I wrote that Japanese utility Chubu Electric Power Co. is investigating the possible use of thorium as an alternative form of nuclear power that would be safer, less weapons prone and more efficient than conventional uranium fueled reactors.
That report came from my trip to the Thorium Energy Alliance Conference in Chicago, where Takashi Kamei from the Research Institute for Applied Sciences in Kyoto showed delegates a May 31 video clip from Japanese TV. Serving as the translator, Kamei said the video stated that Chubu was starting a research program at its conventional Hamaoka nuclear station to look into deploying thorium in liquid form, in a type of reactor known as a molten salt reactor.
I had every confidence in Kamei’s presentation, which is why I ran with it. But it’s always good to hear these things straight from the source. Kamei is not a Chubu employee, so, as I indicated yesterday, I had sent Chubu an email last Friday seeking confirmation and elaboration.
They had not replied by the time I wrote my story. But when I landed at Heathrow Airport in London this morning and fired up my BlackBerry, there it was - a statement from Chubu's investor relations department saying they regard thorium as "one of future possible energy resources."
Maybe yesterday’s ditty prompted their response, or maybe it was just the usual international, big company lag time from Friday. Whatever, here’s word-for-word what Chubu sent me. Thank you Chubu. I’ve added the boldface:
"Thank you for contacting us concerning thorium molten salt reactors. We announced our plan of stepped-up efforts for nuclear R&D on May 31st. Our plan consists of two parts; １．We will establish "Nuclear Safety R&D Center" at Hamaoka nuclear power station on July 1st to promote R&D using Nuclear Power plants as R&D fields. ２．Regarding R&D subjects which need broad cooperation between external institutions, we will promote and implement joint research and publicly offered research with institutes and universities. Subjects of research will include future nuclear energy like thorium rectors. This program will start in 2013. Our main activity will be to support institutions and universities financially. We consider thorium as one of future possible energy resources, but there are many challenges to be solved toward actual utilization. Therefore we considered basic studies to be very important from a long-term view point and decided to support institutions' basic study on thorium utilization.Regards,Chubu Electric Power Co., Inc. June 7 2012"
Some thorium experts regard liquid thorium in a molten salt reactor (MSR) as the optimal way to deploy the fuel, although some people advocate using it in solid form in a more conventional, water-cooled reactor.
Oak Ridge National Laboratory developed a thorium molten salt reactor in the 1960s, when the U.S. was deciding between uranium and thorium as a nuclear fuel.
Under President Richard Nixon, the U.S. abandoned the Oak Ridge project and charted a uranium future, in part because uranium, yielded weapons-linked waste desirable in the Cold War arms build up. Thorium is not as proliferation prone
Flibe Energy in Huntsville, Ala., is developing a thorium MSR based on the Oak Ridge design, and including a failsafe plug that allows the liquid fuel to drain into a tank in an emergency, averting the possibility of a reactor meltdown such as what happened at Japan's Fukushima Daiichi nuclear plant last year.
In Japan, Kamei himself is working on different thorium reactor designs, including an MSR as well as one that uses a particle accelerator to trigger a nuclear reaction. More on that another time.
Photo: Thorium Energy Alliance via wn.com.
Walk the thorium trail, with SmartPlanet:
- Japanese utility mulls thorium
- Safe nuclear: UK eyes thorium
- Safe nuclear: Let the thorium debate begin
- Safe nuclear: India’s thorium reactor
- Fukushima’s lesson: ‘Alternative’ nuclear, not ‘no’ nuclear
- Watch replay of nuclear’s future, with dash of rare earth
- Why safe nuclear will rely on rare earth minerals
- Meet the future of nuclear power: 8 guys in China
- How nuclear will make oil greener
- The new face of safe nuclear
Jun 6, 2012
There have already been many thorium prototype reactors built over the past 50 years. (http://en.wikipedia.org/wiki/Thorium_reactor#List_of_thorium-fueled_reactors) In almost all cases the reactors tested were safer than uranium reactors, cheaper to build and operate (thorium being 400 times more abundant than uranium) than uranium based reactors, feasible at smaller scales, and without melt down risks of uranium reactors. We don't need more R&D, we need commercial deployment and optimization. The only thing that has kept thorium reactors from replacing nuclear reactors - is an the influence (ownership) by the uranium industry and the military industrial complex of our governmental decisions making bodies. Thorium reactors are long past the R&D stage and it's time to hold the US Congress and the Executive Branch responsible for the uranium liabilities it has created - not only in the US, but globally.
It's not quite as simple as that. Uranium contains a small fraction of fissile U235, while thorium contains no fissile isotope. As a result, a thorium reactor must be a *breeder* reactor, a uranium reactor does not have to be. This is the main reason uranium was used for nuclear weapons (instead of thorium) and it is the same reason why uranium reactors got a head start over thorium reactors. To put it simply, a uranium reactor must recycle 45% of its neutrons to maintain the chain reaction. A breeder reactor (including any thorium reactor) must recycle 90% of its neutrons-- because for every fissile atom destroyed, one neutron is needed to convert another thorium atom to fissile material, and one more neutron is needed to maintain the chain reaction. This is a significant engineering challenge. Solutions to this challenge were known as early as 1950 but there were always drawbacks slowing the engineering development and causing the proposed thorium reactors to be more expensive, not less expensive than the uranium reactors. Even today it is not obvious that the thorium reactor will actually be cheaper-- it is the cost of the power plant, not the cost of the fuel, that determines 90% of the cost of nuclear energy. And since a commercial thorium power plant has not yet been built and operated, (Germany built one but decommissioned it immediately) it is hard to "prove" that a thorium reactor will be any cheaper. Thus private companies are reluctant to gamble on this technology-- it will take strong government leadership to move it forward.
I have read the Wikipedia articles, and agree with you completely, except in one respect -- let us forge ahead with rigor, vigor, and forgiveness. The future will happen faster this way.
Well, cold fusion is still controversial-- *some* strange reaction is occurring, but it is not highly reproducible, is not supported by any well-understood theory, and there is so far no evidence that the Pons-Fleischmann effect can be scaled up since nobody can explain it (if the effect is even real). Cold fusion requires discovery of "new physics" probably involving metal lattice interactions with bound nuclear states. Thorium reactors on the other hand involve no new physics. All the ideas are 30 to 50 years old and there are enormous databases of information allowing every detail of a thorium reactor to be modeled in the computer. There are however still some economics and chemical engineering issues to be worked out for the molten salt reactor-- how to remove the fission products from the liquid fuel in the most cost-effective manner, and how to guarantee the molten salt reactor will be as safe as a Generation III conventional reactor is now. These are expensive questions but not "deal-breakers." A truly determined advanced nation could solve these problems in one or two decades, if not for political opposition. So thorium reactors appear to have a huge head start over cold fusion reactors, or any kind of fusion reactors (hot fusion) for that matter.