Skip to comments.New Age Nuclear (Thorium is safer & cleaner)
Posted on 06/15/2007 11:33:29 AM PDT by BlackJack
Nuclear energy produces no greenhouse gases, but it has many drawbacks. Now a radical new technology based on thorium promises what uranium never delivered: abundant, safe and clean energy - and a way to burn up old radioactive waste.
What if we could build a nuclear reactor that offered no possibility of a meltdown, generated its power inexpensively, created no weapons-grade by-products, and burnt up existing high-level waste as well as old nuclear weapon stockpiles?
And what if the waste produced by such a reactor was radioactive for a mere few hundred years rather than tens of thousands? It may sound too good to be true, but such a reactor is indeed possible, and a number of teams around the world are now working to make it a reality. What makes this incredible reactor so different is its fuel source: thorium.
(Excerpt) Read more at cosmosmagazine.com ...
Please bump this article so as many Freepers as possible can get a chance to read it!
If what the magazine says is true I’m all for it. But if the piece on thorium reactors is as “accurate” as its comments about Gore”bull” warming I’m afraid I don’t put much stock in it.
Dr. Strangelove knew all about thorium 40 years ago.
We must not allow a thorium reactor gap!
Where does the thorium fuel come from?
Unfortunately, baby seals and spotted owls.
Kewl, I hope this works.
India to build prototype thorium reactor
The Indian Union Cabinet cleared the Department of Atomic Energy’s proposal to set up a 500 MW prototype of the next-generation fast breeder nuclear power reactor (FBR) at Kalpakkam, thereby setting the stage for the commercial exploitation of thorium as a fuel source.
Although uranium is the only naturally occurring fissile element directly usable in a nuclear reactor, the country only has 0.8 per cent of the world’s uranium reserves and may have to depend on imports in the future. On the other hand, India has around 32 per cent of the world’s reserves of thorium, and with a carefully planned program, indigenously available uranium can be used to harness the energy contained in non-fissile thorium to be used in the FBRs. Though the country’s atomic power program had produced only a little over 2,000 MW of nuclear energy over 34 years, the Indian Planning Commission has set an ambitious target of producing around 20,000 MW of nuclear power by 2020.
India has a so-called “three-stage nuclear program”. In the first stage, plutonium is created in its pressurized heavy water reactors (PHWRs) and extracted by reprocessing. In the second stage, fast breeder reactors (FBRs) use this plutonium in 70-percent MOX-fuel to breed uranium-233 in a thorium blanket around the core. In the final stage, the FBR’s use thorium-232 and produce uranium-233 for other reactors.
The first stage has been realized with India’s 10 nuclear power plants. The second stage is only realized by a small experimental fast breeder reactor (13 MW), at Kalpakkam. This reactor has a history with a lot of problems (as has been the case with the 10 nuclear reactors). This reactor is on top of a list of dangerous reactors in the country, according to a safety assessment of India’s Atomic Energy Regulatory Board. The reactor has a lack of safety measures and cooling systems.
Unfortunately the U.S doesn’t really have any. Australia is abundant with it.
|Tarapur units 3 and 4 -PHWR 540 MWE each||2X1000MWE VVER reactors under construction at Koodankulam||
Inside view of Kamini reactor, critical in Sept 96, using U-233 fuel
AEC Chairman Dr. Anil Kakodkar addressing the IAEA
As the US Congress debates the Indo-US agreement on nuclear cooperation, a key aspect from the American viewpoint is that India has certain inherent strengths in the area of nuclear technology, which would enable India to forge ahead, albeit slowly, even without US cooperation.
Central to this argument is the availability of huge reserves of thorium in India. Thorium reserves have been estimated to be between 3,60,000 and 5,18,000 tonnes. The US estimates the economically extractable reserves to be 2,90,000 tonnes, one of the largest in the world. Our uranium reserves, by contrast, are estimated to be at a maximum of around 70,000 tonnes.
India currently has 15 commercial power reactors in operation, most of which are pressurised heavy water reactors (PHWR) which use natural uranium. Two Tarapur reactors are boiling water reactors (BWR) which need enriched uranium, which has to be imported.
Together they generate about 3300 MWe (Mega Watt Electrical) of power, about 4 per cent of that generated from all sources. Another six PHWRs are in construction, and along with the two VVER Russian built 1000 MWe reactors which use enriched uranium, they would add about 3960 MWe by 2008. The goal is to reach at least 20,000 MWe by 2020.
India's uranium reserves are low. Obtaining enriched uranium for the two Tarapur reactors and VVER type reactors requires the consent of the Nuclear Suppliers Groups countries, including Russia. This is where the agreement with the US is expected to be beneficial to India.
Also central to India's success in achieving these goals, is the harnessing of thorium, for which India has developed a three-stage nuclear programme. India has already developed and tested the technologies needed to extract energy from Thorium, but large scale execution has not yet been possible, mainly because of limited availability of Plutonium.
Stage one is the use of PHWRs. Natural uranium is the primary fuel. Heavy water (deuterium oxide, D2O) is used as moderator and coolant. The composition of natural uranium is 0.7 percent U-235, which is fissile, and the rest is U-238. This low fissile component explains why certain other types of reactors require the uranium to be enriched i.e. the fissile component increased.
In the second stage, the spent fuel from stage one is reprocessed in a reprocessing facility, where Plutonium-239 is separated. Plutonium, of course, is a weapons material, which goes towards creating Indias nuclear deterrent.
Pu-239 then becomes the main fissile element, the fuel core, in what are known as fast breeder reactors (FBR). A test FBR is in operation in Kalpakkam, and the construction for a 500 MWe prototype FBR was launched recently by Prime Minister Dr Manmohan Singh.
These are known as breeder reactors because the U-238 blanket surrounding the fuel core will undergo nuclear transmutation to produce more PU-239, which in turn will be used to create energy.
The stage also envisages the use of Thorium (Th-232) as another blanket. Th-232 also undergoes neutron capture reactions, creating another uranium isotope, U-233. It is this isotope which will be used in the third stage of the programme. Thorium by itself is not a fissile material, and cannot be used directly to produce nuclear energy. The Kamini 40 MWe reactor at Kalpakkam which became critical in Sept 1996, using U-233 fuel, has demonstrated some of these technologies.
India is currently developing a prototype advanced heavy water reactor (AHWR) of 300 MWe capacity. The AHWRs, which use plutonium based fuel, are to be used to shorten the period of reaching full scale utilisation of our thorium reserves. The AHWR is thus the first element of the third stage. AHWR design is complete but further R and D work is required, especially on safety. It is expected to be unveiled soon and construction launched.
In the third phase, in addition to the U-233 created from the second phase, breeder reactors fuelled by U-233, with Th-232 blankets, will be used to generate more U-233.
The Bhabha Atomic Research Centre has estimated that India's thorium reserves can amount to a staggering 3,58,000 GWe-yr (Giga Watt Electrical - Year) of energy, enough for the next century and beyond
BARC scientists are also looking at other designs, like an advanced thorium breeder reactor (ATBR) which requires plutonium only as a seed to start off the reaction, and then use only thorium and U-233. Here the plutonium is completely consumed and this reactor is thus considered proliferation resistant. A Compact High Temperature Reactor also under development at BARC . This reactor is designed to work in closed spaces and remote locations.
Success in harnessing thoriums potential is thus critical for the Indias future energy security.
India has put in place mechanisms for ensuring safety and security of nuclear facilities. The regulatory and safety systems ensure that equipment at India's nuclear facilities are designed to operate safely and even in the unlikely event of any failure or accident, mechanisms like plant and site emergency response plans are in place to ensure that the public is not affected in any manner. In addition, detailed plans, which involve the local public authorities, are also in place to respond if the consequences were to spill into the public domain. The emergency response system is also in a position to handle any other radiation emergency in the public domain that may occur at locations, which do not even have any nuclear facility.
Regulatory and safety functions of Atomic Energy in India are carried out by an independent body, the Atomic Energy Regulatory Board (AERB). The AERB was constituted on November 15, 1983 by the President of India under the Atomic Energy Act, 1962 to carry out certain regulatory and safety functions under the Act. The regulatory authority of AERB is derived from the rules and notifications promulgated under the Atomic Energy Act, 1962 and the Environmental (Protection) Act, 1986. The mission of the Board is to ensure that the use of ionizing radiation and nuclear energy in India does not cause undue risk to health and the environment.
(Source: The Tribune, Chandigarh; Deptt of Atomic Energy)http://www.indembassyathens.gr/India-nuclear%20energy/India_nuclear%20energy_thorium.htm
Yeah it's called a fast breeder reactor. Uses mainly U-238 and "burns" plutonium. If this country wasn't a complete moron when it comes to reprocessing spent fuel rods etc. then Yucca Mtn. wouldn't need to be built to last millions of years. Thank you Jimmah Carter.
Thorium is a mineral in the ground....you mine it.
There is 550 times more thorium in the earth
Yes the US has lots of thorium.
More on Thorium as nuclear fuel:
Cobalt Thorium G.
It hasn't been pursued because those countries that developed enrichment technology already had the means to make a fissile form, 235U, from uranium ore. That was an easier go than breeding 233U from 232Th, for which you need an operating reactor anyway. So it was easier to stick with the uranium fuel cycle than switch over to 232Th-233U. As the article notes, you have other complications, either the need to use Pu and U in a mixture to juice up the neutron population, or one heck of a heavy duty accelerator. Speaking as one who spent a considerable amount of time dealing with accelerator physics in an "earlier life", I can tell you that the headaches associated with keeping a high beam current accelerator running are in some ways worse than dealing with fission products.
Breeder reactors burn U235 and produce plutonium as a by-product.
Thorium burns up the plutonium. No weapons application.
It’s a bi-product of trilithium mining.
Ye gods. The article is mostly bull****. Fission is fission, whether it is U-233 bred from Th-232, U-235 split directly, or Pu-239 bred from U-238. The mix of fission products is virtually the same in all cases. The ONLY significant advantage thorium has is that there is a lot more of it available.
The use of thorium-based fuel cycles has been studied for about 30 years, but on a much smaller scale than uranium or uranium/plutonium cycles. Basic research and development has been conducted in Germany, India, Japan, Russia, the UK and the USA. Test reactor irradiation of thorium fuel to high burnups has also been conducted and several test reactors have either been partially or completely loaded with thorium-based fuel.
Noteworthy experiments involving thorium fuel include the following, the first three being high-temperature gas-cooled reactors:
Between 1967 and 1988, the AVR experimental pebble bed reactor at Julich, Germany, operated for over 750 weeks at 15 MWe, about 95% of the time with thorium-based fuel. The fuel used consisted of about 100 000 billiard ball-sized fuel elements. Overall a total of 1360 kg of thorium was used, mixed with high-enriched uranium (HEU). Maximum burnups of 150,000 MWd/t were achieved.
Thorium fuel elements with a 10:1 Th/U (HEU) ratio were irradiated in the 20 MWth Dragon reactor at Winfrith, UK, for 741 full power days. Dragon was run as an OECD/Euratom cooperation project, involving Austria, Denmark, Sweden, Norway and Switzerland in addition to the UK, from 1964 to 1973. The Th/U fuel was used to ‘breed and feed’, so that the U-233 formed replaced the U-235 at about the same rate, and fuel could be left in the reactor for about six years.
General Atomics’ Peach Bottom high-temperature, graphite-moderated, helium-cooled reactor (HTGR) in the USA operated between 1967 and 1974 at 110 MWth, using high-enriched uranium with thorium.
In India, the Kamini 30 kWth experimental neutron-source research reactor using U-233, recovered from ThO2 fuel irradiated in another reactor, started up in 1996 near Kalpakkam. The reactor was built adjacent to the 40 MWt Fast Breeder Test Reactor, in which the ThO2 is irradiated.
In the Netherlands, an aqueous homogenous suspension reactor has operated at 1MWth for three years. The HEU/Th fuel is circulated in solution and reprocessing occurs continuously to remove fission products, resulting in a high conversion rate to U-233.
There have been several experiments with fast neutron reactors.
Much experience has been gained in thorium-based fuel in power reactors around the world, some using high-enriched uranium (HEU) as the main fuel:
The 300 MWe THTR reactor in Germany was developed from the AVR and operated between 1983 and 1989 with 674,000 pebbles, over half containing Th/HEU fuel (the rest graphite moderator and some neutron absorbers). These were continuously recycled on load and on average the fuel passed six times through the core. Fuel fabrication was on an industrial scale.
The Fort St Vrain reactor was the only commercial thorium-fuelled nuclear plant in the USA, also developed from the AVR in Germany, and operated 1976 - 1989. It was a high-temperature (700°C), graphite-moderated, helium-cooled reactor with a Th/HEU fuel designed to operate at 842 MWth (330 MWe). The fuel was in microspheres of thorium carbide and Th/U-235 carbide coated with silicon oxide and pyrolytic carbon to retain fission products. It was arranged in hexagonal columns (’prisms’) rather than as pebbles. Almost 25 tonnes of thorium was used in fuel for the reactor, and this achieved 170,000 MWd/t burn-up.
Thorium-based fuel for Pressurised Water Reactors (PWRs) was investigated at the Shippingport reactor in the USA using both U-235 and plutonium as the initial fissile material. It was concluded that thorium would not significantly affect operating strategies or core margins. The light water breeder reactor (LWBR) concept was also successfully tested here from 1977 to 1982 with thorium and U-233 fuel clad with Zircaloy using the ‘seed/blanket’ concept.
The 60 MWe Lingen Boiling Water Reactor (BWR) in Germany utilised Th/Pu-based fuel test elements.
In India, both Kakrapar-1 and -2 units are loaded with 500 kg of thorium fuel in order to improve their operation when newly-started. Kakrapar-1 was the first reactor in the world to use thorium, rather than depleted uranium, to achieve power flattening across the reactor core. In 1995, Kakrapar-1 achieved about 300 days of full power operation and Kakrapar-2 about 100 days utilising thorium fuel. The use of thorium-based fuel was planned in Kaiga-1 and -2 and Rajasthan-3 and -4 (Rawatbhata) reactors.
With about six times more thorium than uranium, India has made utilisation of thorium for large-scale energy production a major goal in its nuclear power program, utilising a three-stage concept:
Pressurised Heavy Water Reactors (PHWRs, elsewhere known as CANDUs) fuelled by natural uranium, plus light water reactors, produce plutonium.
Fast Breeder Reactors (FBRs) use this plutonium-based fuel to breed U-233 from thorium. The blanket around the core will have uranium as well as thorium, so that further plutonium (ideally high-fissile Pu) is produced as well as the U-233. Then
Advanced Heavy Water Reactors burn the U-233 and this plutonium with thorium, getting about 75% of their power from the thorium.
The spent fuel will then be reprocessed to recover fissile materials for recycling.
This Indian program has moved from aiming to be sustained simply with thorium to one “driven” with the addition of further fissile uranium and plutonium, to give greater efficiency.
Another option for the third stage, while continuing with the PHWR and FBR programs, is the subcritical Accelerator-Driven Systems (ADS).
One place: Nuclear Waste. It’s a byproduct of current power reactors.
Even so, there is enough U-238 mill tailings sitting around that don’t need to be mined at further expense that could be used to fuel a fast breeder liquid metal reactor. Reprocess all of the spent fuel rods, glean the Pu and U in those instead of burying them. Lots of energy not being produced.
This article is largely puffery. The thorium-232 -> uranium-233 fuel cycle produces only marginally less dangerous fission products than the uranium-238 -> plutonium-239 fuel cycle, and uranium-233 is very dangerous and difficult to work with. Nor is the thorium-232 -> uranium-233 fuel cycle new. There have been several developmental nuclear reactors pointed toward this as a commercial goal over the past forty years or so. Gas-cooled, solid fueled reactors have been developed by the US and Germany, among others toward tis goal. And a molten salt cooled and fueled reactor was operated in the US at Oak Ridge National Laboratory in the late 60s and early 70s. This reactor successfully bred uranium-233 from the thorium-232 in the fuel salt. The fuel salt was processed successfully to separate uranium and fission products, and the remaining fuel salt was quite low in radioactivity. Then, this reactor was successfully fueled and operated with uranium-233. This molten-salt cooled and fueled reactor was ‘intrinsically safe’ in that, if the reactor started to ‘run away’ and overheat, the molten salt fuel expands and reduces the reaction rate and thus lowers the temperature without requiring any action by operators or control systems.
Despite all of this, the concept did not appear to be as commercially attractive or close to commercial deployment as the liquid metal cooled fast breeder reactor concept. The molten salt reactor concept was dropped and several countries developed and operated liquid metal breeder reactors. This concept has been pursued by other countries but also dropped by the US. The main reason it hasn’t been a commercial success is that there has been a global glut of enriched uranium as a result of disarmament and it doesn’t make commercial sense, in these conditions, to build breeder reactors of any kind.
Great post carrot....thanks!
I am also interested in the PBMR design....I see atomics is
using thorium...thanks again.
Why do you say that?
Can you explain?
Because it gives off a lot more radiation.
Not only that, but I suspect it is quite feasible to build a fission bomb and/or fusion bomb trigger with U-233. Fission is fission, after all. So even the non-proliferation "advantage" is bogus.
Thanks will look into that.
I was just working today with activated aluminum, 28Al, with a 2.3 minute half-life. A 50 mg total mass (stable 27Al plus activated 28Al) sample, and you wouldn’t want to hold it in your hand, it was reading tens of R/hr on contact. An equal mass of natural uranium, however, you could hold in your hands for the rest of your life and it wouldn’t hurt you. Big difference between a 4.5 billion-year half-life and one of a few minutes.
Come to Northern NJ, exit 63 on Route 80, go up 17 a bit and roll in the dirt on the eastern side of the highway. When you're done, you'll be just positively glowing, thanks to Thorium!
Not really ... fission byproducts are all radioactive.
It’s also the type of radiation. Shorter lived nuclides tend to emit gamma radiation, highly energetic, highly penetrating type of radiation as compared to alpha emitters. Alpha particles are in essence a helium atom and thus is non-penetrating. Gamma rays in theory could zip right through a concrete wall 9’ thick, while an alpha particle could get bounced back by a sheet of toilet paper.
Uhm .... why?? You working for Putin BTW? :)
Maybe making some pellets to be shot from umbrellas?
Don’t they prefer Polonium????
A slightly simplistic explanation would be this: the number of radioactive particles emitted by a gram of radioactive element, over its lifetime, is roughly the same for different elements. And, if the one element stays radioactive for 100 years and the other for 100,000 years, then the first one must be emitting 1000 times more radioactivity per hour, so that the total amount of radiactivity in its lifetime is the same.
28Al wouldn't be a very effective radiological weapon. Doesn't last long enough.
I still think that storing waste for 100 years is a lot less
complicated and less expensive than trying to build
safe storage for 10,000 years.
This fuel cycle starts and ends with uranium. I don't see what's so superior about it.
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