February 21, 2013 | 1 Comment
The National Research Council has published its unclassified report that determined the potential benefits of successful development of an inertial confinement fusion-based energy technology justify investment in fusion energy research and development as part of the long-term U.S. energy R&D portfolio. A pdf file copy is available for download.
The report is about the Lawrence Livermore National Laboratory’s National Ignition Facility and the University of Rochester’s Laboratory for Laser Energetics, as well as the krypton fluoride gas lasers at the Naval Research Laboratory. Particle beams, being explored by a consortium of laboratories led by the Lawrence Berkeley National Laboratory; and pulsed magnetic fields, being explored on the Z machine at Sandia National Laboratory.
The report is not looking at the non Department of Energy supported efforts such as Dr. Robert Bussard’s EMC2 effort, Dr. Eric Lerner’s Focus Fusion program and the others. The report does offer than the laser driving programs are getting close to ignition, something Farnsworth accomplished 60 years ago.
The report offers a contrast in the major conclusions. The potential benefits of inertial fusion energy production justify more research and development at the same time a nationally coordinated program should wait until ignition is achieved. One wonders how much of that is bureaucratic setup speak for a future program.
Ronald Davidson, professor of astrophysical sciences at Princeton University’s Plasma Physics Laboratory and co-chair of the committee that wrote the report said for the press release, “The realization of inertial fusion energy would be a tremendous achievement capable of satisfying the world’s ever-growing need for power without major environmental consequences. These possibilities form an extremely compelling rationale to continue R&D efforts toward this goal.”
On the plus side Inertial Fusion Energy technology (IFE) would provide an essentially carbon-free energy source with a practically unlimited supply of fuel. IFE relies on a process in which a fuel pellet the size of a pinhead is compressed by an external energy source, raising the temperature and density enough that the nuclei of some of the fuel atoms fuse together, releasing nuclear energy. The aim is ignition, in which the fusion energy produced by the initial compression causes the remaining fuel to undergo fusion.
Gerald Kulcinski, associate dean for research and director of the Fusion Technical Institute at the University of Wisconsin, Madison, who served as co-chair of the report committee explains further with, “The fuel used in the fusion process is tritium and deuterium; deuterium is derived from water and therefore virtually unlimited. And unlike nuclear fission plants, it would not produce large amounts of high-level nuclear waste requiring long-term disposal. The potential is for a sustainable energy source that could power the Earth for millions of years.”
To initiate fusion, the deuterium and tritium fuel must be heated to over 50 million degrees and held together for a long enough time for the reactions to take place. The prospects for making inertial fusion a commercial energy source depend on the ability to implode a fuel target to a high enough temperature and pressure to initiate a fusion reaction that releases on something of the order of 100 times (plus or minus) more energy than was delivered to the target.
What remains unknown is the cost of targets that would have a major impact on the economics of inertial fusion energy power plants. Very large extrapolations are required from the current state-of-the-art for fabricating targets for IFE research to the ability to mass-produce inexpensive targets for IFE systems.
The other great unknown is an IFE power plant would have a high capital cost. Therefore such plants would have to operate with a high availability. So far, achieving high availabilities is a major future challenge for fusion energy systems. That suggests substantial testing of IFE plant components and the development of sophisticated remote maintenance approaches would be needed.
IFE does have the potential for a fusion future. If the innovation, intuition and intellect can master the technology, electric power would a sure thing for millions of years or until the next better thing comes along. So it’s worth the pursuit.
The report, nearly 240 pages long is a veritable gold mine for understanding the proposed IFE effort and a great deal of spillover for competing technologies. Your humble writer strongly urges a download, save to file for a long and leisurely look, perhaps several times and as questions come up in the coming years.
The gem for today is the committee concluded that a range of driver technologies should continue to be pursued, rather than choosing a single technology at this time. After a disaster of the “one horse technology” now being seen decades later of dropping alternative fission technologies back in the 1970s leaving huge opportunities and solutions to gather dust, perhaps the bureaucrats are coming to see that keeping all the doors open and the competition hot is the best thing for the future.
The report also puts some heat on the private and other government supported technologies. If the report does anything, it will help keep the money flowing to IFE.
We’re getting closer to practical fusion. What technologies appear that will offer the lowest risks, lowest investment, operating costs and the most versatility is yet to be known. Lets hope that with the wide range of possible power generating situations that several technologies get to market. When that story starts it will get very exciting around here.