An agreement between Russia and the USA to work together to dispose of weapons grade plutonium has been suspended. The deal dates back to 2000 when both nations agreed to reduce their nuclear weapons by disposing of 34 tonnes of plutonium each, enough to build approximately 17,000 nuclear weapons.The strategy behind the agreement was a good one. Through a ‘sword-to-plough’ approach, the weapons grade material would be reprocessed and turned into clean energy to power homes and industry. The bilateral plan reduced the amount of weapons-grade plutonium and in turn burned it, thus producing vast amounts of carbon dioxide-free energy, whilst also strengthening the relations between the two countries with a very tense geopolitical history.Unfortunately it is a breakdown in these relations that appears to have ended the deal. The annexation of Crimea in 2014 and the ongoing war in Syria have tested the relationship to breaking point. The failure of the recent Syrian ceasefire seems to have been the breaking point, with the US announcing that they will suspend discussion with Russia over Syria. Russia however claims that these are distractions and that the real issue is the USA’s reprocessing is insufficient and bombs could still be made from their plutonium.This claim stems from the fact that Russia dilutes their plutonium and makes it into Mixed-Oxide (MOX) fuel which, in turn, would be used to generate electricity in reactors. This approach would see the plutonium permanently destroyed, whilst the Americans decided to scrap their MOX plant after Fukushima and opted to bury the plutonium instead. This, the Russians argue, contravenes the deal as the plutonium would still be retrievable.Without this deal, the plutonium issue remains a significant one. There are large volumes of the material left over from nuclear weapons production. Plutonium is also produced by nuclear power stations. The UK is far from immune to this problem, burdened with the biggest plutonium stockpile in the world.But with every crisis, there is an opportunity. Advanced reactors have the potential to burn up plutonium much more efficiently and easily. The US, Russia and the UK are all investing in new, Generation 4 designs that can deal with the problem. Plutonium is a domestic security issue and combatting it with advanced nuclear power not only reduces this insecurity but also simultaneously increases energy security.International disagreements, however serious, should not be allowed to stand in the way of national or international actions on turning plutonium from a vice to a virtue. Weinberg Next Nuclear’s will soon be addressing this issue in a new report, discussing how the UK should deal with its legacy waste, including the plutonium stockpile.
The recent agreement between six world powers and Iran has, according to President Obama; “cut off Iran’s most likely paths to a bomb”. The agreement includes many commitments to cease enrichment of uranium above concentrations of 5%, dismantling or halting construction of additional centrifuges and a pledge to not construct a reprocessing facility. Iran will continue to enrich uranium to concentrations of 3.5% to keep its stocks at a constant level as it is consumed in the civilian nuclear power program.
However, much of the discussion about the deal has missed one key question: the extent to which we are made prisoners by the proliferation risks of existing fuel cycles. Could a programme of nuclear R&D, aimed at developing proliferation-resistant nuclear energy, prevent future nuclear crises?
Thorium sits two places down the periodic table from uranium, and while very little of naturally occurring uranium is the U235 necessary for use in a reactor, almost all of naturally occurring thorium is Th232, which is the isotope suitable for use as a nuclear fuel. . Because of this, there is no need for any enrichment of thorium fuel and no need for centrifuges of any kind. The lack of any need for these facilities would certainly change the game in terms of detecting rogue nuclear programmes.
However, there is a “but”: thorium fuels need a “fissile driver” to provide the initial neutrons to start the thorium chain reaction. This can be uranium-233, uranium-235 or plutonium, although for anti-proliferation purposes we should certainly discount the last two.
So that leaves us with U233. Handily, uranium-233 is produced by thorium fuels in a reactor (in a thorium fuel cycle, it is actually uranium-233 that fissions). The rub is that the world has very little U233 available and if we want to develop proliferation-resistant fuel cycles, we’ll need a lot more of it. Currently the only way to make it is to kickstart thorium fuel with…U-235 or plutonium, and then reprocess it (although Accelerator-Driven Systems could help).
While U233 is recognised as a proliferation risk by the IAEA, it is far less suitable for making weapons than highly enriched U235 or Pu239. Indeed, only two nuclear tests have involved U233; the USA’s ‘Operation Teapot’and one 0.2kt experimental design in India’s Pokran-II tests. No nuclear weapons in existence are made with U233. Sadly uranium-235 and plutonium have a well-proven track record of making functioning bombs.
U232 is produced in smaller amounts alongside the U233, which is a hard gamma ray emitter. This gives the material a strong and easily detectable radiation signature. The material has to be handled very carefully, and fuel fabrication for example has to be done remotely with sophisticated equipment. These increased difficulties have long been cited as properties that would hinder weapons proliferation.
Hans Blix, the former head of the International Atomic Energy Agency has recently called for the development of nuclear energy from thorium, citing a lower risk of weapons proliferation from reactors as well as benefits including reduced waste. He wrote in the Guardian newspaper that the commitments were “constitute substantial bars to any bombmaking” without curtailing the civilian power program. I’m sure he would agree that if Iran was pursuing thorium-fuelled reactors, the barriers to a weapons program would be even higher.
Of course, how any future international thorium fuel programme would obtain and distribute the “fissile drivers” would be very sensitive, needing just the kind of increased transparency and oversight that has just been agreed. What is certain is that proven thorium fuels, started with U233, would give the international community new diplomatic options in future nuclear disputes.
Thirty-one of the world’s countries currently use nuclear power to generate over 11% of global electricity. Over forty-five countries are considering embarking down the nuclear route, with the front-runners after Iran and UAE including Lithuania, Turkey and Belarus. It is important to stress that thorium is not a magic bullet to weapons proliferation– but it can be a part of the solution to future international proliferation disputes, alongside appropriate regulatory regimes and oversight mechanisms. Given the pressing need for low-carbon energy it seems only prudent to support a more proliferation-resistant route for nuclear energy.
The MegaTons to MegaWatts program which saw almost 20,000 Russian warheads dismantled and used as fuel in American nuclear power plants has recently come to an end, providing almost 10% of US electricity for 15 years. A similar amount of warheads remain in existence. In 1953, Eisenhower’s ‘Atoms for Peace’ speech carefully tried to open the eyes of the world to the positive benefits of nuclear energy, after the horrors of the nuclear bomb had become clear. He urged that “the miraculous inventiveness of man shall not be dedicated to his death, but consecrated to his life”. Perhaps it is time for that speech to be revisited, starting with a massive push to develop proliferation-resistant nuclear energy.
GENEVA – Hans Blix, the disarmament advocate who famously found no weapons of mass destruction in Iraq a decade ago, said today that thorium fuel could help reduce the risk of weapons proliferation from nuclear reactors.
Addressing the Thorium Energy Conference 2013 here, Blix said that nuclear power operators should move away from their time-honoured practice of using uranium fuel with its links to potential nuclear weapons fabrication via both the uranium enrichment process and uranium’s plutonium waste.
“Even though designers and operators are by no means at the end of the uranium road, it is desirable today, I am convinced, that the designers and the others use their skill and imagination to explore and test other avenues as well,” Blix said.
“The propeller plane that served us long and still serves us gave way to the jet plane that now dominates,” said the former United Nations chief weapons inspector who also ran the International Atomic Energy Agency from 1981 to 1997. “Diesel engines have migrated from their traditional home in trucks to a growing number of cars and cars with electric engines are now entering the market. Nuclear power should also not be stuck in one box.”
Blix rattled off a list of thorium’s advantages, noting that “thorium fuel gives rise to waste that is smaller in volume, less toxic and much less long lived than the wastes that result from uranium fuel.” Another bonus: thorium is three to four times more plentiful than uranium, he noted.
“The civilian nuclear community must do what it can to help reduce the risk that more nuclear weapons are made from uranium or plutonium,” Blix said. “Although it is enrichment plants and plutonium producing installations rather than power reactors that are key concerns, this community, this nuclear community, can and should use its considerable brain power to design reactors that can be easily safeguarded and fuel and supply organizations that do not lend themselves to proliferation. I think in these regards the thorium community may have very important contributions to make.”
Blix described the obstacles that are in the way of a shift to thorium and other nuclear alternatives as “political” rather than “technical.”
Not everyone agrees that thorium is a proliferation cure for the nuclear power industry. Even some supporters of thorium note that thorium fuel cycles yield elements such as uranium 233 that groups could use to make a bomb if they were able to get a hold of it.
The lively discussions surrounding these and other thorium issues will continue tomorrow at the conference, which is taking place at CERN, the international physics laboratory. Earlier at the gathering today, conventional nuclear giant Areva announced a thorium collaboration with Belgian chemical company Solvay. Yesterday, Nobel prize-winning physicist Carlo Rubbia lauded thorium for its “absolute pre-eminence” over uranium.
Photo of Hans Blix by Mark Halper