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Dr. Xiaoyun Lu of the Bioscience Division at Los Alamos, a member of the team of biochemists, theorists, and engineers who are developing a hand-held biochemistry lab for rapidly detecting the influenza virus

Expanding Nuclear Energy the Right Way

If nuclear is one answer to the world's increasing demand for energy, how does the world deal with the potential proliferation and waste issues and at the same time satisfy individual national interests? Partnership. A global partnership.

nuclear reactor

Global Nuclear Energy Partnership

Vietnam doesn't have an extensive power grid, so the country would like to use small-scale nuclear reactors to feed electricity locally to cities and villages. The Vietnamese, however, don't have the facilities to enrich uranium or contend with the radioactive spent fuel and so are hesitant to invest in reactors.

Japan and France, lacking coal and oil resources, view nuclear energy as vital to their energy security. They have invested heavily in large-scale nuclear power plants and recycle their spent fuel to get the most out of it.

China will need enormous amounts of electricity to power its burgeoning economy. After considering the economic and environmental tradeoffs, it has decided on an 8-fold expansion of its nuclear capacity by 2020, with a 40-fold increase planned by 2050.

Russia intends to have nuclear energy provide 25 percent of its electricity by 2030 and has aggressive plans to establish an international uranium enrichment facility, to build a reprocessing plant to recycle spent fuel, and to market small modular reactors to developing countries.

The United States, the country with the most nuclear power reactors in the world (103), has not built a new plant in three decades. It has a nuclear power infrastructure devoted to the safe and efficient operation of its water-cooled reactors but does not recycle spent nuclear fuel, of which it has accumulated about 50,000 metric tons. It is looking to expand nuclear energy as a means of obtaining clean electricity while reducing its dependence on fossil fuels and is expected to review 30 or more new power reactors for license.

map of thrity countries
Thirty nations, shown in blue and light blue, have commercial nuclear reactors that today supply approximately 16 percent of the world?s electricity.

Australia has abundant uranium ore and is poised to start a uranium enrichment program. Canada would like to sell advanced reactors to the world. India has plans to construct some 25 new nuclear plants, while Poland and Indonesia are exploring going nuclear. Iran is enriching uranium, a capability that can readily be adapted to producing material for nuclear weapons. North Korea, which has extracted plutonium from spent fuel, has already moved in that direction.

The Fast Flux Test Facility
The Fast Flux Test Facility, owned by the U.S. Department of Energy and located at the Handford Site in Washington state, housed a fast-neutron nuclear reactor that tested advanced nuclear fuels, materials, and other aspects of fast-neutron reactor design and operation. This view shows the main equipment air lock leading into the containment building. The reactor ceased operations in 1990, but a similar one would likely be built for the transmutation of spent nuclear fuel. Photo by Mike Cappiello

Get the picture? Faced with dwindling oil reserves and global climate change brought on by fossil-fuel emissions, the world is again looking at nuclear energy. But each nation has a different perspective on this complex energy resource, a unique view that attempts to balance political needs with economic and environmental concerns. If nuclear is one answer to the world's increasing demand for energy, how does the world deal with the potential proliferation and waste issues and at the same time satisfy individual national interests?

A Global Initiative

"We recognize that to realize significant increases in nuclear power," says Dennis Spurgeon, the Department of Energy's Assistant Secretary for Nuclear Energy, "we need a new framework for the utilization of nuclear energy."

That new framework is the Global Nuclear Energy Partnership, or GNEP (pronounced GEE-nep), which the Bush Administration formally unveiled in February 2006. By fostering international cooperation—global partnerships—GNEP hopes to greatly expand the use of nuclear energy around the world while addressing both the proliferation and waste issues.

GNEP plans to reduce nuclear waste through an advanced fuel cycle that recycles spent uranium fuel and reprocesses it into a new type of "transmutation" fuel that would be burned in advanced burner reactors. (See "Advancing the Fuel Cycle.") The result would be a significantly smaller and more easily managed nuclear-waste stream.

fuel cycle


Advancing the Fuel Cycle

Nuclear energy is released when a uranium nucleus absorbs a neutron and fissions into two pieces (fission products) plus two or more neutrons. If the neutrons go on to fission more uranium fuel, a chain reaction can develop—additional fissions release more neutrons, which leads to even more fissions, and so on. A nuclear reactor is designed to sustain a controlled chain reaction and produce heat that can be used to generate electricity.

Most commercial nuclear reactors—so-called light-water reactors—use low-energy neutrons to fission the uranium isotope U-235. But the concentration of U-235 in natural uranium ore is a mere 0.7 percent, the rest being the isotope U-238, which is not fissioned by low-energy neutrons. As a result, uranium ore must be enriched to about 5 percent U-235 before it is turned into fuel. As this fuel fissions, or "burns," in the reactor, the U-235 concentration drops. When it drops too low, the fuel is spent and must be removed.

The spent fuel contains U-235 and lots of U-238 but also small amounts of plutonium, neptunium, americium, and curium— transuranic— elements that are created by neutron capture reactions with the fuel. The uranium and transuranics are radioactive for tens of thousands to millions of years and therefore are a long-term disposal challenge. The spent fuel also contains the intensely radioactive fission products that decay to stable elements within a few hundred to a few thousand years.

In the United States, the spent fuel is simply stored, awaiting final burial in a high-level waste repository such as the one proposed for Yucca Mountain in Nevada. Given the rate at which spent fuel has been generated, the repository's legislated capacity would be reached by 2013, necessitating a new Yucca Mountain-sized repository every 30 years.

GNEP would promote an advanced fuel cycle, wherein the uranium and the transuranics would be recycled. The spent nuclear fuel would be separated into uranium, transuranics, strontium, cesium, and fission-product streams. (Plutonium would never be isolated as it is in traditional reprocessing methods.) The uranium would be either stored or recycled (re-enriched and converted into new fuel), while the strontium and cesium would be stored until their ultimate disposal in a low-level waste facility. The transuranics would be mixed with uranium and fabricated into a —transmutation— fuel that would be burned using high-energy (fast) neutrons in an advanced burner reactor. The use of fast neutrons results in a net loss (rather than creation) of transuranics. The spent transmutation fuel would also be recycled into new fuel.

This advanced recycling extracts more energy from the fuel and significantly reduces the volume of waste that gets sent to a high-level waste repository. It also greatly eases the long-term storage requirements of the repository because the waste is primarily the short-lived fission products.

Proliferation concerns would be addressed by implementing an integrated program that includes the development of international fuel-leasing arrangements. As an incentive for a country to forgo the development and implementation of fuel cycle activities (uranium enrichment and the reprocessing of spent fuel—the two processes that can produce weapons-grade nuclear material), the country would be guaranteed fresh nuclear fuel from a supplier, who would then take the spent fuel back.

transuranic fuel pellets
Transuranic fuel pellets, standing on a test port, are typical of the materials that would be tested in the Materials Test Station and test reactors. Los Alamos Archive

Furthermore, all GNEP facilities—the reactors, plus enrichment and recycling plants—could be designed to facilitate monitoring by the International Atomic Energy Agency (IAEA) through safeguards agreements. Specific features would be incorporated directly into the facilities to make them more intrinsically resistant to the diversion of nuclear materials.

Capiello
GNEP program manager Mike Cappiello is leading the Los Alamos effort to develop the technologies for advanced fuel recycling.

The Bush Administration has requested $250 million to fund GNEP in the 2007 fiscal year, mostly to develop (at an engineering scale) the technologies needed to develop the advanced fuel cycle but also to help foster international partnerships. For example, researchers have little experience in the fabrication of transmutation fuels. While the United States is performing fundamental research to develop the technology, it is also establishing collaborations with other nations to accelerate the process.

Partnership will be of equal importance in designing the advanced burner reactor (a liquid-metal-cooled, fast-neutron reactor). Although the technology is for the most part mature (several prototype liquid-metal-cooled reactors are already in operation in other countries), the burning of transmutation fuel in the reactor needs demonstration. The transmutation fuel and the structures that contain them undergo physical changes within the high-radiation, high-temperature reactor environment, so their overall behavior and performance are unknown. To anticipate all effects prior to designing and building the reactor, GNEP will use a significant computer modeling and simulation effort supported by small-scale experimental work.

Los Alamos Plays Its Part

Los Alamos has years of reactor modeling experience dating back to the 1970s and '80s with the pioneering TRAC code—the first computer code capable of realistic reactor safety analysis—and up to the current Advanced Simulation and Computing program and associated high-performance supercomputing capabilities. Using existing capabilities as a basis, Los Alamos will perform multi-dimensional modeling and simulation of an advanced fast-neutron reactor that will span a dramatic range of physical scales, from the microscale investigation of the fuel cladding materials to the macroscale modeling of the entire facility.

blue light
Blue Cherenkov light, generated by radioactive emissions, illuminates spent fuel held in temporary storage in a water tank. Photo courtesy of Atomic Energy of Canada Limited (AECL)

In addition, Monte Carlo analytical techniques that were developed at Los Alamos will be used to predict the type and amount of radiation emitted by the spent fuel—the so-called radiation signature. By comparing a calculated signature with a measured result, the IAEA is in a position to know if a user is being honest with regard to its fuel inventory.

crystals
Uranium crystals extracted from spent fuel by an innovative carbonate extraction method being developed at Los Alamos by Wolfgang Runde and Gordon Jarvinen. Photo by Wolfgang Runde

But fuel and material behaviors cannot be understood by modeling and simulation alone. The new Materials Test Station, proposed for the Los Alamos Neutron Science Center, will expose candidate fuels and cladding materials to copious amounts of fast neutrons that have nearly the same energy spectrum as that of the proposed reactor. Says GNEP program manager Mike Cappiello, "The Materials Test Station will be the only facility in the United States capable of mimicking the extreme conditions found in the advanced burner reactor."

hotcells
Radiation-proof hot cells in the Chemistry and Metallurgy Research facility will be used to develop the techniques to remotely fabricate transmutation fuel. Los Alamos Archive

To understand how to fabricate robust transmutation fuel, Los Alamos is using the unique resources in its Plutonium Facility and Materials Science Laboratory to develop advanced ceramic fuels. After being tested on a small number of samples, the same processes will be scaled up to higher volumes, using safe remote techniques in "hot cells" at the Laboratory's Chemistry and Metallurgy Research facility.

Los Alamos chemists will also explore advanced chemical separation processes specially designed to implement fuel cycling and address waste management issues. The Laboratory recently marked the 40th anniversary of the U.S. safeguards program, which was started by Los Alamos' Robert Keepin in recognition of the need to develop methods to secure, track, and account for nuclear materials. Los Alamos has continued to be the leader in safeguards systems and technology development ever since—and looks forward to applying these capabilities to the GNEP initiative.

Finally, the Laboratory can lead the nation in establishing technical working relationships with nuclear research labs around the world, as it did with Russian labs after the breakup of the Soviet Union in 1991. Los Alamos worked in partnership with the Russians to enhance the security of their nuclear facilities, installing first physical protection systems and then sophisticated electronic eyes that monitor nuclear materials and track their movements.

Richard Wallace, the Los Alamos project leader for International Safeguards, is enthusiastic about the possibilities of working cooperatively with Russia and other countries to resolve some of the remaining technical issues in a GNEP-type advanced fuel cycle and to find creative solutions to the international engagement issues.

"Through the Department of Energy's program for Materials Protection, Control and Accounting, or MPC&A, we've been able to build a tremendous relationship with the Russians," says Wallace. "We know the people and can work together to achieve results." The Russian cooperation programs could be expanded under GNEP as part of its broader international partnerships.

Similarly, Japan will likely be a key partner in the GNEP initiative, as the country already has a very sophisticated nuclear power industry and is constructing a major reprocessing facility. Los Alamos worked closely with the U.S. and Japanese governments, industry experts, and the IAEA to support the design and implementation of a state-of-the-art safeguards system for the recycling plant at Rokosho. The collaboration illustrated the importance of incorporating monitoring systems into the facility design—a practice that undoubtedly will be followed for future GNEP facilities.

The expansion of nuclear energy is a global issue, which is why global partnerships are the foundation of GNEP's long-term vision and innovative political and technical agenda. Many nations, including Russia, France, and Japan, seem to agree with GNEP's goals and philosophy. In an energy-hungry world, everyone sees the advantages of getting nuclear "right."





Title: Expanding Nuclear Energy the Right Way: Global Nuclear Energy Partnership (GNEP)—a U.S. initiative

Keywords: nuclear energy, recycling, modular reactors, advanced fuel cycle, transmutation fuel, fast neutrons, advanced burner reactor, nuclear-waste stream, transuranics, uranium enrichment, spent fuel, proliferation, fuel-leasing, IAEA, Advanced Simulation and Computing program, Materials Test Station, chemical separations, Materials Protection, Control, and Accounting, nuclear safeguards

Abstract: Los Alamos scientists will contribute to GNEP, the U.S. initiative to expand the use of nuclear energy around the world while addressing proliferation and nuclear waste issues. Modeling and simulation of advanced burner reactors, development and testing of transmutation fuels, and international collaboration on nuclear safeguards are areas of Los Alamos leadership.

Link: http://www.gnep.gov/


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