Energy amplifier

In

None have ever been built.

History

The concept is credited to Italian scientist

OMEGA project (option making of extra gain from actinides and fission products (オメガ計画)) is being studied as one of methodology of accelerator-driven system (ADS) in Japan.^[6]

Richard Garwin and Georges Charpak describe the energy amplifier in detail in their book "Megawatts and Megatons: A Turning Point in the Nuclear Age?" (2001) on pages 153-163.

Earlier, the general concept of the energy amplifier, namely an

• 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 than uranium — reducing strategic and political supply issues and eliminating costly and energy-intensive isotope separation. There is enough thorium to generate energy for at least several thousand years at current consumption rates.^[7]
• The energy amplifier would produce very little plutonium, so the design is believed to be more proliferation-resistant than conventional nuclear power (although the question of uranium-233 as nuclear weapon material must be assessed carefully).
• The possibility exists of using the reactor to consume plutonium, reducing the world stockpile of the very-long-lived element.
• Less long-lived radioactive waste is produced — the waste material would decay after 500 years to the radioactive level of coal ash.
• No new science is required; the technologies to build the energy amplifier have all been demonstrated. Building an energy amplifier requires only engineering effort, not fundamental research (unlike nuclear 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, and has the potential to load-follow by modulating the proton beam, making it more suitable for countries without a well-developed
  power grid
  system.
• developing countries
  as well as in densely populated areas.
• Desired
  minor actinides) into less harmful substances, for producing radionuclides for use in nuclear medicine or to produce precious metals
  from low-priced feedstocks.
• The lower fraction of
  delayed critical
  ), is of no concern as no criticality of any kind is achieved or needed
• While
  fast breeder reactors

• Each reactor needs its own facility (particle accelerator) to generate the high energy proton beam, which is very costly. Apart from linear particle accelerators, which are very expensive, no proton accelerator of sufficient power and energy (> ~12 MW at 1 GeV) has ever been built. Currently, the Spallation Neutron Source utilizes a 1.44 MW proton beam to produce its neutrons, with upgrades envisioned to 5 MW.^[8] Its 1.1 billion USD cost included research equipment not needed for a commercial reactor. Economies of scale might come into play if particle accelerators (which are currently only rarely built to the above mentioned strengths and then only for research purposes) become a more "mundane" technology. A similar effect can be observed when comparing the cost of the Manhattan Project up to the construction of Chicago Pile-1 to the costs of subsequent research or power reactors.
• The fuel material needs to be chosen carefully to avoid unwanted nuclear reactions. This implies a full-scale nuclear reprocessing plant associated with the energy amplifier.^[9]
• If, for whatever reason, neutron flux exceeds design specifications enough for the assembly to reach criticality, a criticality accident or power excursion can occur. Unlike a "normal" reactor, the scram mechanism only calls for the "switching off" of the neutron source, which wouldn't help if more neutrons are constantly produced than consumed (i.e. Criticality), as there is no provision to rapidly increase neutron consumption e.g. via the introduction of a neutron poison.
• Using lead as a coolant has similar disadvantages to those described in the article on
  lead cooled fast reactors
• Many of the current spallation-based neutron sources used for research are "pulsed" i.e. they deliver very high neutron fluxes for very short durations of time. For a power reactor a smaller but more constant neutron flux is desired. The European Spallation Source will be the strongest neutron source in the world (measured by peak neutron flux) but will only be capable of very short (on the order of milliseconds) pulses.

See also

• Accelerator-driven sub-critical reactor
• Alternative energy
• Thorium fuel cycle
• Breeder reactor, another type of nuclear reactor that aims for an energy profit by creating more fissile material than it consumes.
• Thorium-based nuclear power
• Muon capture
• Nuclear transmutation

References

• 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, Emerging Nuclear Technologies: The Example of Carlo Rubbia's Energy Amplifier, International Network of Engineers and Scientists Against Proliferation

External links

Wikimedia Commons has media related to Thorium.

Look up thorium in Wiktionary, the free dictionary.

• New Age Nuclear: article on energy amplifiers | Cosmos Magazine