Small Nuclear

Brian Wang writes about recent trends in small nuclear reactors. Small fission reactors in the 100 kw to 100 Mw range make it possible for large installations and smaller communities to make their own baseload power, independent of the energy grid or weather patterns. Small reactors are also appropriate for shipboard energy, for water desalination in remote, arid coastal locations, and for combined electricity and heat production--which would come in very handy in arctic or antarctic conditions (not to mention during a little or big ice age or on Mars).

The 200 kilowatt Toshiba designed reactor is engineered to be fail-safe and totally automatic and will not overheat. Unlike traditional nuclear reactors the new micro reactor uses no control rods to initiate the reaction. The new revolutionary technology uses reservoirs of liquid lithium-6, an isotope that is effective at absorbing neutrons. The Lithium-6 reservoirs are connected to a vertical tube that fits into the reactor core. The whole whole process is self sustaining and can last for up to 40 years, producing electricity for only 5 cents per kilowatt hour, about half the cost of grid energy.

Toshiba expects to install the first reactor in Japan in 2008 and to begin marketing the new system in Europe and America in 2009.

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The goal is to produce safe, limited supervision nuclear reactors of the appropriate size for a wide range of uses. These reactors would be built to reliably provide a specified level of power for a specific period of time, before needing service.

Some small reactors are conceived for areas away from transmission grids and with small loads, others are designed to operate in clusters in competition with large units. The cost of electricity from a 50 MWe unit is estimated by the U.S. Department of Energy (DOE) as 5.4 to 10.7 cents/kWh (compared with charges in Alaska and Hawaii from 5.9 to 36.0 c/kWh).

US Congress is now funding research on both small modular nuclear power plants (assembled on site from factory-produced modules) and advanced gas-cooled designs (which are modular in the sense that up to ten or more units are progressively built to comprise a major power station). A US DOE report in 2001 considered nine designs which could possibly be deployed by 2010.

Already operating in a remote corner of Siberia are four small units at the Bilibino co-generation plant. These four 62 MWt (thermal) units are an unusual graphite-moderated boiling water reactor (BWR) design with water/steam channels through the moderator. They produce steam for district heating and 11 MWe (net) electricity each. They have performed well since 1976, much more cheaply than fossil fuel alternatives in the Arctic region.

Encyclopedia of Earth
Read more at Advanced Nano.

Small reactors without on-site refuelling should have the following essential features [1]:

1. • Capability to operate without refuelling for a reasonably long period consistent with the plant economics and energy security;
2. • Minimum inventory of fresh and spent fuel being stored at the site outside the reactor during its service life;
3. • Enhanced level of safety, consistent with the scale of global deployment of such
4. reactors, through wider implementation of inherent and passive safety features and systems;
5. • Economic competitiveness for anticipated market conditions and applications;
6. • Difficult unauthorized access to fuel during the whole period of its presence at the site and during transportation, and design provisions to facilitate the implementation of safeguards;
7. • The capability to achieve higher manufacturing quality through factory mass
8. production, design standardization and common basis for design certification.

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There are many disturbing trends observable in the modern world that should serve as fair warning for forward thinking groups and individuals. The concurrent rise of religious and ideological fundamentalism--both proclaiming that the ends justify the means, no matter what--and the rapid empowerment of individuals of near-average intelligence in the areas of nanotechnology, synthetic biology, autonomous vehicles, explosives technology, genetic modification, sabotage of information and communications systems, biowarfare agents, etc etc, all suggest that the massively interconnected world which we now enjoy may soon be subject to segmentation.

I suggest keeping your eyes open as much as possible.