Interesting topic. But Guys, do you know the damage an atomic bomb can make? Indians and Pakistanis, be mature! This is not a toy! I was astonished by one comment, "whether Th (Thorium) has any military application?" I guess he meant A-bomb. Another comment says, China will strike India in 2017. Guys, take a shower in Himalayan glaciers and cool off your heads.
One thing I can say that, any nuclear bomb in South Asia means, complete destruction of every country in that region. China may escape the nuclear fall out (if its bomb destroys India and India doesn't retaliate). Not by nuclear radiation, but by its after effects. You can see glaciers melt (it is already melting), expansion of Thar desert to the size of bigger than the size of Sahara. In Sahara, the human population is one of the lowest and one of the poorest regions. May be you guys will escape, but think about your coming generations- your children, their children....
Absolutely spot on! But I wouldn't blame the members who raise such questions or make such irresponsible comments. In our part of the world people tend to associate nuclear tech only with A-Bombs and WMDs.
Hence, it was really refreshing to hear from someone who really understands the 'true potential of an atom'! I started this thread with an intention of educating the members on the same and show to them how an atom can change the lives of a billion people.
Coming to the Th Based nuclear reactors- let's talk about the scientific side of this.
Th (for Thorium) is not fissile. So it cannot be used for making A-bombs. And so it is difficult to use as nuclear fuel. However, it is a very good neutron capture and changes to U(233) which is fissile.
There are a lot of advantages for Th based nuclear reactors (NR) than U based NR. Moreover, if I remember correctly, the nuclear wastes will be much easier to clean in Th based (correct me if I am wrong). So nuclear accidents like Chernobyl meltdown can be ruled out!.
For a nuclear reactor to run, the reactor should have some fissionable fuel like U(233, U235, U238). Most of the reactors around the world use U238. U235 is mostly used for bomb making and it is difficult to prepare/separate. Here is the politics of Iran's nuclear program comes. They say they want to build nuclear reactors. For that they need only U238 and little bit of U235. But they installed/made a lot of centrifuges to separate U235 from U238 to make more powerful bomb - enrichment program. So Iranian Govt is doing something fishy out there.
Another important use of Th based NRs (Nuclear Reactors)- the entire cycle of materials DO NOT produce any weapon grade materials.
Again spot on! Just to add to what you said above:
Uranium-235 is the only fissionable material that is observed in usable amounts in nature. Thus pioneering nuclear physicist like Enrico Fermi and Eugene Wigner had no other choice of but to use U-235 to create their first chain reaction under the bleachers of the University of Chicago’s unused football field.
But Fermi and Wigner knew early on that once a reactor was built, it was possible to create other fissionable substances with the excess neutrons produced by a U-235 chain reaction. Thus if U-238 absorbed a neutron, it became the unstable U-239, which through a two stage nuclear process was transformed into plutonium-239. Plutonium-239 is very fissionable. The physicists also calculated that if thorium-232 was placed inside a reactor and bombarded with neutrons, it would be transformed into U-233. Their calculations also revealed that U-233 was not only fissionable, but had properties that made it in some respects a superior reactor fuel to U-235 and Pu-239.
During World War II, Fermi and Wigner, who were geniuses with active and far ranging minds, collected around themselves a group of brilliant scientists. Fermi, Wigner and their associates began to think about the potential uses of the new energy they were discovering--uses that would improve society rather than destroy it.
The capture of nuclear energy and its transformation into electrical energy became a central focus of discussions among early atomic scientists. They were not sure how long the uranium supply would last, so Fermi proposed that reactors be built that would breed plutonium from U-238. Wigner counted that thorium was several times as plentiful as uranium, and that it could produce an even better nuclear fuel than Pu-239.
The first nuclear era was dominated by uranium technology, a technology that was derived from military applications, and carried with it, rightly or wrongly, the taint of association with nuclear weapons. As it turned out, there was far more uranium available than Fermi or Wigner had originally feared, but other rationales propelled scientific interest in developing thorium fuel cycle reactors. First, Pu-239 was not a good fuel for most reactors. It failed to fission 1/3 of the time when it absorbed a neutron in a conventional Light Water Reactor (LWR). This led to the most difficult part of the problem of nuclear waste. Plutonium made excellent fuel for fast neutron reactors, but the fast neutron reactor that Fermi liked used dangerous liquid sodium as its coolant, and would pose a developmental challenge of enormous proportions.
BUT, there is a problem, big problem. Na (for Sodium) is highly reactive with water. So imagine a situation where the molten Na pass through a tube (non-reactive with Na) and accidentally one drop of water falls in molten Na. BHOOOM!.. which is almost equivalent to a small nuclear explosion, which can result in bigger nuclear explosion. Also, normal Na is reactive to many metals; so forget about the reaction between molten sodium with other metals. So a great care and a lot of scientific research is needed to avoid such situation.
Some countries have been using Sodium as coolant in Fast Breeder reactors for some time. There is a lot of technology required to use molten sodium in reactor - like non-reactive carrier/materials, sensors etc. So India has been running these type of reactors for some time means, they are really masters in this field. As of now, only India has an active Fast Breeder Reactor program. Their experimental reactor has been running for the last 15-20 years successfully!. France was the latest nation to shut down FBR. BTW, 2004 tsunami almost created a nuclear accident at Kalpakam, home of India's FBRs. But they saved!
India has mastered the liquid sodium usage and related technologies. We build our own sodium tanks, sodium pumps, associated safety valves, special materials etc. IGCAR has designed the PFBR. It will use plutonium-uranium oxide as fuel, and liquid sodium will be the coolant. Four more FBRs, of 500-MWe capacity each, are also going to be built by 2020. Beyond 2020, breeder reactors of 1,000-MWe capacity will come up and they would use metallic fuel.
But India doesn't possess sufficient amounts of sodium. This is where the nuclear deal comes in. Recently after signing of the nuke deal with the US and with France and Russia thereafter, we have managed to import about 175 tonnes of solid sodium from France.
China is building a 25/60MW experimental FBR. I guess it should be commissioned sometime in 2010. But they need to go a long way! Especially, considering the view that they are immature in Th based NRs. I am not sure whether they have any secretive FBR or Th based NRs. But I guess, there is no need of secrecy in FBRs, unlike nuclear weapons research. Any, positive results will be well appreciated by Nuclear world. Since there were not many significant research articles related to FBR or Th based NRs from China, I guess their research in these fields are in nascent levels. May be I am wrong, but atleast that is what is seen to nuclear research world.
China has sufficient amounts of conventional Uranium fuel to power her reactors. Moreover unlike India China doesn't possess vast reserves of Thorium. Hence, building Thorium based reactors is not a priority for China. Nevertheless, any breakthrough in FBR tech from any part of the world will be appreciated by the international community.
But not many countries have tried liquid Na as coolant in Fast Breeder reactors. France, India and Japan are strong in FBR and use of Na as coolant. Recently France and Japan signed some agreements on future to involve in FBRs using Na as coolant. I think these FBRs are not based on Th based, though.
In this scenario, the nuclear agreements India signed with other countries such as US, France, Canada and Russia are really significant. But I think, those agreements are related to U-based nuclear reactors where India needs U from other countries for their reactors.
France is top in Nuclear Research. So any nuclear agreement between France and India on Th based and FBrs would be mutually beneficial to both the countries. Consider the cost of production of FBR is down to 1/3 of the present PHWR and FBR being more energy efficient, then future FBRs would be really good for human kind.
The Nuke deal has considerably hastened the process of technology development for indigenous FBRs. Though the deal was for largely conventional uranium based reactors and fuels, it has several add on benefits for the indigenous program. This is primarily because, India does not have sufficient uranium to build enough thermal reactors to produce the plutonium needed for more FBRs of the Kalpakkam type.
This is the sole reason why India insists on getting the right to reprocess, which was eventually granted by means of the nuke deal. Apart, from this India can now import sodium from other countries too.
If India succeeds in Th Based NRs, then they can sell this technology to other nations and it can be rich. But I guess, it will take another 20 years at least. Good Luck India!
