- Energy amplifier
In
nuclear physics , an energy amplifier is a novel type ofnuclear power reactor, a "subcritical reactor ", in which an energetic particle beam is used to stimulate a reaction, which in turn releases enough energy to power theparticle accelerator and leave an energy profit for power generation. The concept has more recently been referred to as an accelerator-driven system (ADS).History
The concept is credited to
Carlo Rubbia , a nuclearphysicist and former director of Europe'sCERN internationalnuclear physics lab. He published a proposal for a power reactor based on a protoncyclotron accelerator with a beam energy of 800MeV to 1GeV , and a target withthorium as fuel andlead as a coolant.Principle and feasibility
The energy amplifier uses a
synchrotron accelerator to produce a beam of protons. These hit a heavy metal target such as lead, thorium or uranium and produceneutron s through the process ofspallation . It might be possible to increase the neutron flux through the use of aneutron amplifier , a thin film offissile material surrounding the spallation source. The use of neutron amplification inCANDU reactors has been proposed. WhileCANDU is a critical design, many of the concepts can be applied to a sub-critical system. [http://www.tfd.chalmers.se/~valeri/Mars/Mo-o-f10.pdf] [cite web|title=Neutron amplification in CANDU reactors|url=http://canteach.candu.org/library/20041209.pdf|publisher=CANDU] Thorium nuclei absorb neutrons, thus breeding fissile uranium-233, an isotope of uranium which is not found in nature. Moderated neutrons produce U-233 fission, releasing energy.This design is entirely plausible with currently available technology, but requires more study before it can be declared both practical and economical.
Advantages
The concept has several potential advantages over conventional nuclear
fission reactor s:* Subcritical design means that the reaction could not run away — if anything went wrong, the reaction would stop and the reactor would cool down. A meltdown could however occur if the ability to cool the core was lost.
*Thorium is an abundant element — much more so thanuranium — reducing strategic and political supply issues and eliminating costly and energy-intensiveisotope separation. There is enough thorium to generate energy for at least several thousand years at current consumption rates.
* The energy amplifier would produce very littleplutonium , so the design is believed to be more proliferation-resistant than conventional nuclear power (although the question ofuranium -233 asnuclear weapon material must be assessed carefully).
* The possibility exists of using the reactor to consume plutonium, reducing the dangerously large world stockpile of the very-long-lived element.
* Less long-livedradioactive waste is produced — the waste material would decay after 500 years to the radioactive level ofcoal ash.
* No new science is required; the technologies to build the energy amplifier have all been demonstrated in the laboratory. Building an energy amplifier requires only someengineering effort, not fundamental research (unlikenuclear fusion proposals).
* Power generation might be economical compared to current nuclear reactor designs if the total fuel cycle and decommissioning costs are considered.
* The design could work on a relatively small scale, making it more suitable for countries without a well-developedpower grid system
* Inherent safety and safe fuel transport could make the technology more suitable fordeveloping countries as well as in densely populated areas.Disadvantages
* General technical difficulties.
* Each reactor needs its own facility (particle accelerator ) to generate the high energy proton beam, which is very costly.
* No proton accelerator of sufficient power and energy (> ~12 MW at 1GeV) has ever been built. Currently, theSpallation Neutron Source utilizes a 1.44 MW proton beam to produce its neutrons, with upgrades envisioned to 5 MW. [http://accelconf.web.cern.ch/AccelConf/e04/PAPERS/TUPLT170.PDF]ee also
Breeder reactor , another type of nuclear reactor that aims for an energy profit by creating more fissile material than it consumes.References
* [http://preprints.cern.ch/cgi-bin/setlink?base=preprint&categ=.&id=CERN-LHC-96-001 A PRELIMINARY ESTIMATE OF THE ECONOMIC IMPACT OF THE ENERGY AMPLIFIER] - An in-depth review of the Energy Amplifier co-authored by Rubbia (pdf download available from the CERN document server)
* Christoph Pistner, " [http://www.inesap.org/bulletin17/bul17art25.htm Emerging Nuclear Technologies: The Example of Carlo Rubbia's Energy Amplifier] ", International Network of Engineers and Scientists Against ProliferationExternal links
* [http://www.cosmosmagazine.com/node/348/ New Age Nuclear: article on energy amplifiers | "Cosmos Magazine"]
Wikimedia Foundation. 2010.