|
lizandrol
|
 |
« Reply #1 on: June 25, 2007, 12:48:14 AM » |
|
MOX versus thorium: According to several highly place US and Russia officials, Minatom's announcement of its long silent thorium research was likely timed to offset the prevalent stagnation of the MOX programme.
The MOX project has cost Congress political embarrassment. And there are some people coming out with criticism. And when they see some people involved with MOX in France through DCS's associations with Cogema it causes more embarrassment, one US nuclear official said.
Secondly, the official added, there are concerns about getting the MOX funding. They're looking to make sure there's something there in return for US government support.
But Seth Grae — president of the private, Washington based company Thorium Power that has funded much of the research — was quick to point out to Bellona Web that the fuel is not meant to compete with or replace MOX — despite the touted safety and speed advantages of the fuel. During his most recent trip to Moscow last month, Grae met with some of the more than 300 researchers from seven institutions — including the Kurchatov Institute — who are now working on the project, which is being coordinated by the Nuclear Power Ministry and monitored by the State Nuclear Inspection Agency
What we have is a technology. The technology is not designed to compete with MOX. It is what it is — whether the government decides to use it instead of MOX, in combination with MOX only, that's up to them, Grae said in a telephone interview from Washington
We do not take a position on whether to fight MOX. Even with both programmes, there will still be a lot of plutonium left, he said.
Just how much plutonium that may be is a government protected secret and a source of wildly conflicting estimates. Official tallies for Russia's plutonium are still being added up at the Obninsk nuclear research facility near Moscow.
Kuznetsov, in his most recent book "Nuclear Danger", estimated that Russia is sitting on several hundred tonnes of weapons-grade plutonium. According to an article published by the scandal -tarred former Nuclear Energy Minister, Yevgeny Adamov, and cited by Kuznetsov, Russia could have as much as 780 tonnes of the nuclear material.
Kuznetsov went on to note that Adamov's estimate conflicts outrageously with the commonly accepted figure of about 150 tonnes of weapons grade plutonium in Russian storehouses. The figure also seemed outrageous to Harvard University nuclear researcher Matthew Bunn, who in a telephone interview put the figure closer to 140 tonnes.
In addition to however many tonnes of the stuff Russia currently has, 18,000 Russian warheads, which have been dismantled since mid 1990s, will produce another 162 tonnes of plutonium — which by itself is 62 percent more than the 100 tonnes of weapons grade plutonium officially declared by the United States.
Thorium and US involvement: The growing Congressional discomfort over the political and technical issues surrounding MOX has mobilized a Congressional fan club for thorium-based fuel led by Curt Weldon, chairman of the powerful House Armed Service Committee. Weldon plans to lobby congress to allocate an appropriation of $3.5m for the 304 budget to being the programme in earnest.
Before that, though Grae said $3.5m will be required in 2003, $25m will be required in 2004 out of a total budget of $200m, to run so-called lead test assemblies in a VVER-1000 in 2006.
Eight of Russia's 30 nuclear reactors are VVER-1000's. Four are located in the Saratov region, two near Tver, and one a piece in Volgodonsk and Novovorornezh. Two more plants with VVER-1000 reactors are being built and another is planned, Minatom officials said.
Preceding this lead test slated for 2006, before which Grae said the fuel will continue to undergo ampoule irradiation tests at the Kurchatov Institute's IR-8 experimental reactor. It also, said Grae, is undergoing thermal-hydraulic, temperature and pressure tests at the institute. Although the DOE budget request for the 2004 fiscal year included no funding for the thorium project, Weldon told The Moscow Times he was confident he could squeeze out the money during September's congressional allocation process — even after the mammoth US expenditures on the Iraqi war. I have strongly supported additional funding to test the thorium process at the Kurchatov Institute in Moscow, Weldon told the Moscow Times. The thorium process provides the double benefit of reducing weapons-usable fissile material and producing advanced, proliferation-resistant nuclear reactor and fuel cycle technologies. As such, it is in the best interests of the United States to provide funding to advance this technology.
A brief history of thorium: Like uranium — and unlike plutonium — thorium is a naturally occurring element. In Russia, it is found near uranium deposits in Siberia, near Tomsk. It can also be mined in Kazakhstan, the United States and China. More thorium in Russia's possession was confiscated during the Soviet invasion of Germany, where the Nazis were experimenting with thorium as a potential nuclear weapon. Although the Nazis never achieved a chain reaction with it, Russian and American scientists eventually did. The victorious Red Army took this nuclear booty home, where it is now kept in dilapidated storehouses in Yekaterinburg and Obninsk.
Part of thorium's appeal in plutonium disposition programmes is that, unlike uranium, its supplies are expected to last for the next 500 to 600 years, as opposed to the century supply of natural uranium, Kuznetsov said.
Using it in the plutonium disposition process could also, according to one industry official, give Russia a bigger role in the plutonium disposition agenda — an agenda that one official said has been dictated by the Americans. MOX, said the official, has been forced down the Russia's throat.
The development of this fuel, which has taken place at the Kurchatov Institute, and has been developed by Russian labs — with US funding — could give Moscow a better more, active position in plutonium disposition, the official said, enunciating a position that has been championed by several high profile, recently published reports on the flagging of US-Russian non-proliferation efforts.
Thorium's advantages: One of the advantages of the thorium-based fuel has on MOX, say US and Russian nuclear authorities, is that spent thorium fuel contains no weapons — or even energy — usable plutonium components that can be separated out in reprocessing.
The plutonium in our fuel cannot be reprocessed for any energy or weapons purpose, said Grae. The fuel could then be stored and buried as standard spent nuclear fuel, Grae said. The thorium fuel produces over 80 percent less plutonium than MOX, and the small amount of plutonium that is produced is denatured and diluted with other isotopes making it unsuitable for use in weapons or for energy use.
The fact that MOX — on which the American public and Congress have spent million, and plan to spend billions of dollars — can, with sophisticated technology, be once again broken down into bomb-grade plutonium, has come as a shock to many in Washington, a government source said.
One of the most surprised officials was the US governments main champion of the MOX programme, US Energy Secretary Spencer Abraham, who while testifying before the House Armed Services Committee in March, 2002, was forced to admit during questioning that he did not know that plutonium was a by-product of spent MOX fuel. We talk to people in congress and they are shocked, they actually don't know that, the government source said. The American people and the Congress are spending billions of dollars to produce something that can still be turned into a weapon — and the technology is out there to do it.
No expensive reactor retrofitting: Another advantage, say Grae and Valery Rachkov — who heads up the Russian side of the thorium project as deputy head of Minatom's scientific research department — is that unlike plans under consideration in the MOX programme, the reactors slated to burn the thorium-based fuel will require absolutely no upgrades.
Rachkov, added in his Moscow Times interview, that the possibility of using thorium fuel in existing reactors is very significant because it means we will not have to change the reactors. MOX related retrofitting projects for VVER-1000s, by comparison, will cost, by most reliable estimates, $200m per reactor. One Russian nuclear regulatory official added that these costs are likely to grow by several million more dollars, because the reactors will have to be restored to their original state after the internationally agreed amount of plutonium is disposed of in MOX.
Grae said that the thorium-based fuel — unlike MOX assemblies — is designed specifically for VVER-1000 reactors, taking into account designs of the standard uranium fuel assemblies these reactors employ. In a standard uranium fuel assembly, said Kuznetsov, there are 163 power producing uranium seed rods, and 61 carbide control rods — a so-called blanket — which control the level of the nuclear reaction. This assembly produced 1000 megawatts of power. For the thorium-based assembly, Grae said, there are some slight modifications to the reactor, to use fuel assemblies with approximately the same number of plutonium and zirconium metal rods, and thorium blanket rods. The reactor would still produce the same 1000 megawatts of electric power.
Scepticism... and support: But Kuznetsov was sceptical of the thorium design, saying that emissions of neutrons from thorium in VVER-1000's increase by ten percent, which jeopardizes the technicians' control over the reaction. You would have to reconstitute the entire system of regulation in the reactor, which could cost even more than the retrofitting costs on VVERs for MOX, he said. He also said that the thorium-based fuel has to undergo several years of trials at the Kurchatov IR-8 reactor before it is used in a VVER-1000. Grae and a Kurchatov researcher, who preferred not to be named in this article, said the fuel has undergone these required tests. Nonetheless, Kuznetsov said that running the thorium-based fuel through a VVER-1000 was tantamount to terrorism.
But because the thorium-based fuel is designed specifically to produce 1000 megawatts of power, Grae said, Kuznetsov's concerns are unfounded. Harvard's Matthew Bunn agreed.
In the post-Chernobyl world, research and development with thorium has been viewed with scepticism. But if anyone could make it work, it would be the Kurhatov institute, Bunn said in a telephone interview. He also concurred that the thorium-based fuel assembly could be used without any special upgrades to the VVER-1000. I'd be pleased if they made it work, by the 2006 deadline, he added.
Tom Cochran, director of the nuclear arm of the non-profit environmental group, the Natural Resources Defence Council, said from Washington that the thorium project has good prospects. I think it's a viable project. It has some technical advantages on MOX for burning up the plutonium. The question really is in the cost, which at the moment is still a matter of speculation. But he said that the thorium approach leaves less plutonium. With MOX in a reactor, in the usual case, you are breeding the plutonium, whereas in the thorium based case you are fissioning the plutonium and producing uranium 233, Cochran continued. So that way you never end up with highly enriched uranium, but you still burn that plutonium. Technically, it's more attractive. But you still have to sort out the safety and the regulatory issues.
Grae said that the last nine years of research on the fuel have been conducted under the scrutiny of GAN. But one possible roadblock to manufacturing the thorium-plutonium fuel, Bunn noted, is that the Elektrostal fuel plant near Moscow — which is viewed by Grae as one of the most likely fabrication sites — does not have a license to produce plutonium fuels. This could not be independently confirmed with Russian nuclear authorities because of state secrecy laws limiting information about what Minatom structures are allowed to deal with plutonium. But Kuznetsov remained sceptical, and called attention to the fact that the United States and Germany had abandoned thorium based fuels as long as 25 years ago. If thorium activists are so excited about it now, why have they been so silent about it for such a long time, he said. The US and Germany conducted high temperature experiments in 300 megawatt reactors and abandoned it. If thorium is so wonderful, why did two countries shut down their programmes?
|