FUEL AND FUEL CYCLE
Vision products2 June 2006
The Global Nuclear Energy Partnership is the USA’s bold vision of how the nuclear industry should operate in the 21st century.
US president George Bush told the National Defense University on 11 February 2004: “The world must create a safe, orderly system to field civilian nuclear plants without adding to the danger of weapons proliferation.” But he didn’t wait for the world to do it. Instead, in February 2006, his State of the Union address announced the Global Nuclear Energy Partnership (GNEP) as part of the Advanced Energy Initiative.
GNEP is a very ambitious global vision, which is centred on the USA and a small number of trusted states. The scale of the plan is such that only the USA would be capable of proposing it – let alone achieving it – but GNEP has the potential to address four very significant problems that face nuclear power:
- First, that of proliferation of nuclear weapons. GNEP would see fissile material manufacture and processing consolidated into a club of mature nuclear nations.
- Second, security of supply. An impartial global nuclear fuel bank would be developed which would supply fresh fuel to any country wishing to benefit from nuclear energy.
- Third, long-term waste management. A globalised nuclear fuel market would require advanced spent fuel management. With large scale reprocessing and the destruction of fission products in burner reactors, the USA’s proposed Yucca Mountain repository would hold another 100 years of the country’s waste.
- Finally, worldwide access to nuclear energy. The USA would make small integrated power reactors available to developing countries. GNEP literature suggests the small PWR, IRIS (see NEI March 2006, p12), as a potential export in this category. Other small reactors could come complete with fuel to last the lifetime of the reactor, like the lead-cooled, transuranic-fuelled ‘portable’ STAR series (see NEI July 2005, p24).
Described by the US Department of Energy (DoE) as a ‘cradle-to-grave fuel leasing approach’, fuel supplier nations would supply fresh nuclear fuel to conventional nuclear power plants located in user nations. Normally this would be in the form of conventional enriched uranium, but at this stage of planning could almost certainly include MOX (mixed oxide) fuel in some cases. The user nation would operate the reactor under safeguards before returning the used fuel to a fuel cycle nation for reprocessing that addresses proliferation concerns by not separating plutonium (see below). Fuel supplier nations would operate so-called ‘advanced burner reactors’ (ABRs) which would run on the recycled user nations’ fuel.
The USA has already committed 17.4t of highly enriched uranium to be blended down with the aim of establishing a fuel reserve to backup supply assurances, and some nations – France, Japan and the UK – already operate advanced fuel cycles, only the latter of which is not committed to nuclear energy for decades to come. The DoE said that some countries have expressed interest in contributing to a fuel bank, but nevertheless it will take quite some time to develop all the necessary technologies to support the cradle-to-grave leasing approach, not least the ABR stage. The USA is looking to find international partners to establish an interim reliable fuel services approach consistent with GNEP’s objectives.
RECYCLE, REUSE, REDUCE
One of GNEP’s key elements is the adaptation of the fuel cycle to minimise waste for geologic disposal. Reprocessing is an effective way to do this, but this is not currently carried out in the USA.
Military and space programmes under the Atomic Energy Commission (AEC, forerunner of the DoE) reprocessed low burnup (~2000MWd/tHM) metallic fuel elements mainly to separate plutonium, and during the 1960s the AEC encouraged the private sector to establish reprocessing facilities. Three were realised to some extent: a private facility at West Valley in New York state reprocessed 650tHM between 1966 and 1977; GE designed and built a plant at Morris, Illinois that never passed pre-operational tests; and the AGNS consortium built a facility alongside the Savannah River site in South Carolina. President Jimmy Carter’s 1977 decision to indefinitely defer separation of plutonium on non-proliferation grounds saw to it that the AGNS facility never operated.
Since 2003, the Advanced Fuel Cycle Initiative (AFCI) has been working to develop proliferation-resistant spent nuclear fuel treatment and transmutation technologies in order to enable a transition from the USA’s current once through nuclear fuel cycle to a future sustainable, closed nuclear fuel cycle. A significant objective for the AFCI has been to develop technical information to inform a recommendation in the 2007-2010 timeframe on the need for a second repository.
Widely-presented AFCI research shows that many Yucca-equivalent (70,000t) repositories would be needed over the next 100 years if nuclear power increases its generation share, or even remains at 20% on a once through fuel cycle. Considering the time, trouble and money that the DoE has put into the Yucca project it would come as no surprise to NEI readers that US policy has been moving to a stance of minimising waste for geologic storage. Under the GNEP regime, AFCI estimates that the technical capacity of Yucca Mountain could be increased by a factor of 50 – enough to hold all the the USA’s high-level waste generated up to the end of this century. Into the bargain, the USA’s civilian plutonium stocks would be dramatically reduced.
But to achieve GNEP’s goals, America will have to restart commercial reprocessing, and rapidly accelerate its development in the country to the point that the nuclear club as a whole would be able to reprocess all the world’s spent nuclear fuel.
Because it is still US policy to “discourage the accumulation of separated plutonium worldwide,” it was an important consideration for AFCI to find a reprocessing technique that made such a separation impossible even to a capable nation with ill intent.
AFCI’s separations technology research has identified the Urex+ advanced aqueous processes as being the most promising for proliferation-resistant reprocessing of spent LWR fuel, and in particular, Urex+1A which extracts all transuranic elements as a single group. Laboratory-scale hot testing is underway to evaluate aqueous chemical treatment methods to separate selected actinide and fission product isotopes from the Urex+ stream after uranium has been removed. Long-lived fission products, iodine-129 and technetium-99 could also be separated for transmutation, or incorporated into new waste forms for disposal. In FY2007, a baseline Urex+ modular flowsheet will be selected for scale-up as the Engineering-Scale Demonstration (ESD) plant. Some $155 million is budgeted for ESD in FY2007 for completing the conceptual design, initiating an environmental impact analysis and cold testing of centrifugal contractors, advanced dissolvers, precipitators and calciners.
$20 million has been allocated to develop an integrated Advanced Fuel Cycle Facility (AFCF) in FY2007 meant to improve separations and fuel fabrication technologies up through to engineering-scale. The current vision of the AFCF includes distinct modules for aqueous separation and fuel fabrication, an R&D module for separations processes, waste and storage form development, control and monitoring for advanced safeguards and a pyroprocessing development module. The facility would provide the technical basis for the final design of commercial-scale integrated fuel cycle facilities, including separations plants with capacities of the order of 2000tHM/y and fuel fabrication capabilities of at least 400tHM/y. AFCF would be expected to make significant contributions to worldwide fuel research for 50 years or more.
An Advanced Simulation Laboratory, slated for operation in 2008, would immediately support robust research through computer simulation and visualisation, thereby decreasing testing costs by advancing computer simulation. It is thought that work could start at the AFCF by 2010. The ESD is expected to operate by 2011 and the first AFCF modules should begin operation by 2016. The DoE expects progress to a commercial scale plant soon after that. At 2000tHM/y, such a plant would be capable of recycling all the spent fuel produced by the USA’s LWR fleet.
ADVANCING BURNER REACTORS
The development of pyroprocessing methods at AFCF would be a key step towards the GNEP vision: spent nuclear fuel from commercial reactors worldwide would be reprocessed at a few huge fuel service centres built on research at AFCF. The transuranics will be separated, along with proliferation risks like plutonium, and formed into fuel for the ABRs operating in fuel cycle nations. Pyroprocessing is the final recycle stage, removing the waste products from spent ABR fuel into a form suitable for final disposal.
ABRs are the magic bullet of the GNEP scheme. Not only will they destroy the most difficult to handle wastes, but in doing so will increase the recovered energy value of spent nuclear fuel up to 100 times. However, the ABR is still some way from reality.
In FY2006, a reference fuel for an ABR is to be selected, as are parameters for function and operating requirements for an Advanced Burner Test Reactor (ABTR) demonstration unit, which would be able to generate about 100MWe. The ABTR would be expected to prove the concept of effectively burning transuranics, support development and qualification of fuels and materials, and test safety to support regulatory design certification of the final ABR. The DoE hopes the ABTR could operate by 2014, followed by the first-of-a-kind ~1000MWe ABR standard plant in 2023 and commercial units after that. It is hoped that by that time an international licensing scheme would be in place to speed ABR deployment in fuel cycle nations.
International and industrial collaboration is currently being sought for development of the ABTR as the DoE refines the GNEP scheme. One topic under discussion is the suitability of a sodium-cooled design.
In FY2007, plans should be a little more firm and site selection will begin. A fuel fabrication facility will be established at Idaho National Laboratory to perform a comprehensive study of oxide, metal and nitride fuels. $25 million has been allocated for this work.
DoE chief Samuel Bodman said: “GNEP brings the promise of virtually limitless energy to emerging economies around the globe, in an environmentally friendly manner while reducing the threat of nuclear proliferation.” Certainly, the benefits of making another Iranian situation impossible – or at least removing any reasons for a nation to develop enrichment – would be significant to Washington. So too would be the strategic benefit of cementing the USA into the very centre of a new globalised nuclear industry.
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