Wednesday, February 9, 2011

The global pursuit for nuclear fuel

Brazil plans expansion to uranium enrichment

Brazil nuclearBrazil plans to invest $1.8 billion to expand its capability to enrich uranium for commercial nuclear reactors. A conservative estimates is this level of investment could add at least 1-1.5 million SWU/year to its production rate.

Brazilian Energy minister Edisao Labao told local news media the country has 1.1 million tons of uranium to draw on to supply the plant. He said the objective of the new uranium enrichment facilities is to make Brazil self sufficient in its supply of nuclear fuel.

Brazil has manufacting capabilities to take the enriched uranium, as UF6, covnert its to solid powder, and complete production of fuel pellets and assemblies for commercial nuclear reactors. The intial conversion of Yellowcake to UF6 is carried out for Brazil by Areva in France.

Brazil is completing its third reactor, Angra 3, which is expected to enter revenue service in 2015. The government plans to build another four reactors in the next 20 years,

Brazilian nuclear trade press also reported that Brazil plans to export some of its enriched uranium to China and South Korea. Brazilian officials are especially interested in China's market given its ambitious plans to build at least 40 GWe of new nuclear energy power stations in the next 10 years,

UK Proposes using plutonium stocks for MOX fuel

mox fuel(NucNet) The UK government has proposed using the country’s civilian separated plutonium stocks in mixed-oxide (MOX) fuel for nuclear reactors.

As part of a consultation that was launched on 7 February 2011 the government proposed long-term management options for the country’s civil plutonium stocks.

The three options are:

  1. to reuse it in MOX fuel;
  2. to immobilize it and dispose of it as waste; and
  3. continued long term storage.

The government said its “preliminary view” is that the best option is to reuse the plutonium in MOX fuel.

It said MOX fuel fabrication is a proven and available technology that offers greater certainty of success, while allowing use of the inherent energy resource of the plutonium.

The UK is storing about 112 tonnes of civil separated plutonium. This amount includes about 28 tonnes of material belonging to overseas customers.

In the 1950s plutonium separation was carried out in the UK for defense purposes. In the 1960s when it was thought that fossil fuels would run out, this plutonium was made available as fuel for fast reactors.

Eventually, in 1994, the UK abandoned almost all research into fast reactors because it decided they would not be commercially viable in the foreseeable future.

South Korea pursues spent fuel reprocessing

A contentious negotiation with the U.S. is easing as South Korea agreed to a 10-year joint study to develop spent fuel reprocessing capabilities. It would modify a 1974 accord South Korea signed with the U.S. to not develop this technology.

Since then South Korea has developed a growing fleet of successful nuclear power plants and also entered the global market as an exporter of its designs.

In the latest round of talks, South Korea is said to be proposing development of pyro- processing methods for recycling its spent fuel. The extracted uranium and plutonium would be fabricated into MOX fuel.

(Update 02/11/11: While there is nothing in the news from South Korea about fast reactors, it would seem more likely the output of pyroprocessing would be to produce a new uranium oxide fuel for this type of reactor rather than MOX for an LWR.)

The method does not produce a pure stream of plutonium which makes it attractive in terms of nonproliferation objectives. The Korea Atomic Energy Institute is providing the technical development of the method.

The U.S. contribution will likely come from Argonne National Laboratory which has done R&D work on a pyro-processing technology. (image below via ANL)

ANLpyroprocessing

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3 comments:

donb said...

I fail to see how pyro-processing will help with providing fuel for light water reactors. As I understand the process, it is able to separate out fission products. What is recovered is uranium, plus plutonium and other transuranics. This recovered material mix would be useful for uranium-fueled breeder reactors. But since a large portion of the mix is U238, I don't see what the contribution is here for light water reactors. There is no shortage of U238 in the world, and it is the major component of enriched uranium fuel for light water reactors.

The only use in light water reactors where I see some positive value is in blending down highly enriched uranium from nuclear weapons. The mix out of pyro-processing could be used instead of blending down with natural uranium or depleted uranium. However the stocks of highly enriched uranium are not all that large.

One could "over-enrich" uranium and then blend it down with the mix, but that is so much more effort than just enriching to the desired level.

Sanatanan said...

@donb
Fission products in the spent fuel would compete for neutrons (and hence would tend to deprive the number of neutrons available for fission) in a chain reaction. Thus removal of fission products from spent fuel would itself tend to add some positive reactivity in the reprocessed fuel. Further more, presence of Pu isotopes (239, 241 etc), and some of the transuranics, taken together, might also be somewhat equivalent to the presence of U235 in Natural/enriched U. Of course exact numbers on concentration of each fissile isotope in the product after reprocessing would be important in determining whether it can go back into an LWR or not. I feel, a PHWR, being more neutron economical, might find such a mix, more acceptable. A question that I feel might be important is the quantity of tramp fission products (which are highly radioactive) that might be present in the reprocessed spent fuel and the consequent difficulty it might present in manufacture and handling of the fuel elements for the "downstream" LWR/PHWR reactors.

djysrv said...

(Update 02/11/11: While there is nothing in the news from South Korea about fast reactors, it would seem more likely the output of pyroprocessing would be to produce a new uranium oxide fuel for this type of reactor rather than MOX for an LWR.)