SHANGHAI - A privately held Norwegian company will start burning thorium fuel in a conventional test reactor owned by Norway’s government with help from U.S.-based nuclear giant Westinghouse, the company revealed here recently.
The four-year test at Norway’s government owned Halden reactor could help thorium inch closer to replacing uranium as a possible safer and more effective nuclear power source. Many people believe that thorium is superior because it leaves less long- lived dangerous waste, makes it far more difficult to fashion bombs, runs more efficiently, and can be made meltdown proof.
Oslo-based Thor Energy will deploy a mix of solid thorium mixed with plutonium - a blend known as “thorium MOX” - Thor’s chief technology officer Julian Kelly told the Thorium Energy Conference 2012. I first reported this for the Weinberg Foundation, a London-based non-profit that promotes safe, alternative nuclear power, for whom I covered the conference.
“We don’t often spend a lot of time being excited in the nuclear industry these days, but this is an exciting thing for us,” Kelly told the conference. “We’re ready to go.”
The Norwegian town of Halden looks serene. It also looks like the possible future of nuclear power, as its reactor hosts a thorium trial. The "test" reactor provides steam to a nearby paper mill.
According to some experts, thorium’s advantages are most pronounced in alternative reactor designs such as molten salt reactors and pebble bed reactors, rather than in the conventional solid-fuel, water-cooled reactors in use today.
But other thorium enthusiasts believe that the best way to assert thorium into the energy scene - and thus help deliver CO2-free power - is to first put it to use in reactors that already have regulatory approval.
Thor is testing the thorium fuel in a conventional reactor at Halden cooled by “heavy water” - water that contains an isotope of hydrogen called deuterium. (Although Halden is typically described as a “test reactor,” it also provides steam to a nearby paper mill).
Thor hopes to show that the thorium MOX can operate safely and efficiently in a conventional design.
PROCESSES WASTE, TOO
“We expect this experiment to yield data that will be used to demonstrate the safe, long term performance of ceramic thorium MOX fuels, and that this information will directly support the approval of commercial irradiation of such fuels,” Kelly said.
By including plutonium in the fuel mix, reactors would not only generate power, but they would also eliminate dangerous waste left over from other nuclear operations and thus help address the problem of what to do with that waste. (The uranium community has similar ideas).
Thor will fabricate some of its own thorium MOX in partnership with Norway’s Institute for Energy Technology. Britain’s National Nuclear Laboratory - owned by the UK’s Department of Energy and Climate Change - will also provide some, as will the European Commission’s Institute for Transuranium Elements (ITU).
Westinghouse is helping to fund the project, as are other of Thor’s industrial partners including Steenkampskraal Thorium Ltd., a South African company that is developing a thorium-fueled pebble bed reactor. Other partners include Finnish utility Fortum and French chemicals company Rhodia.
Although Cranberry, Pa-based Westinghouse does not like to discuss its thorium activities publicly - presumably because it could undermine the company’s conventional nuclear business - it has at least a few thorium-connected and alternative nuclear projects in the works.
Besides the Norwegian test, Westinghouse is the commercial adviser on the U.S. Department of Energy’s collaboration with China on developing a molten-salt cooled reactor, for instance. Westinghouse also helped organize many of the alternative nuclear sessions at the American Nuclear Society confab earlier this month in San Diego.
Thor Energy is part of a Norwegian technology incubator called Scandinavian Advanced Energy Technology, whose track record includes the spinout of solar firm Renewable Energy Corp.
In 1999, the Nuclear Nuclear Security Administration (NNSA) signed a contract with a consortium, now called Shaw AREVA MOX Services, LLC to design, build, and operate a Mixed Oxide (MOX) Fuel Fabrication Facility. This facility will be a major component in the United States program to dispose of surplus weapon-grade plutonium. The facility will take surplus weapon-grade plutonium, remove impurities, and mix it with uranium oxide to form MOX fuel pellets for reactor fuel assemblies. These assemblies will be irradiated in commercial nuclear power reactors.
Mox fuel uses depleted uranium, which USEC has in abundance. Plutonium, as an oxide, is then mixed with depleted uranium left over from an enrichment plant to form fresh mixed oxide fuel (MOX, which is UO2+PuO2). MOX fuel, consisting of about 7-10% plutonium mixed with depleted uranium, is equivalent to uranium oxide fuel enriched to about 4.5% U-235, assuming that the plutonium has about two thirds fissile isotopes. If weapons plutonium is used ( 90% Pu-239), only about 5% plutonium is needed in the mix. The plutonium content of commercial MOX fuel varies up to 10.8% depending on the design of the fuel, and averages about 9.5%. Fuel in an EPR with 30% MOX having less than 10.8% Pu is equivalent to 4.2% enriched uranium fuel. An EPR with 100% MOX fuel can use a wider variety of used fuel material (burnup, initial enrichment, Pu quality) than with only 30% MOX.