Nuclear resilience and reactor design
Posted by Dave Bath on 2011-03-16
In the wake of troubles with Japanese nuclear reactors, opinions about nuclear power are inappropriately polarized. (Links to my most trusted source of technical news on the crisis, Nature Group, over the fold.)
The debate should be less about use of nuclear power as such – more about what reactor designs are appropriate for what situations.
The reliance of Japanese reactors on electricity for cooling, given the geology of the place, is lamentable – and other designs, such as micro-reactors, thorium and pebble-bed reactors are better alternatives, especially for replacing the now useless ones.
Pebble-beds are basically urns of "hot rocks"e; – Homer Simpson could run them safely, bringing down the heat by emptying the hot rocks out of the bottom into a number of lead-lined containers. Not much power required to open and shut a grille at the bottom of the container – a few small generators with a modest amount of diesel would do the trick, then everyone can walk away.
Micro-reactors are small enough to fit in a furniture truck, sealed completely, last for about 10 years supplying power for about 10,000 people without anybody running them – they are quite suitable for remote communities, even a community where the only tertiary educated people specialize in 14th century Japanese accounting systems, as long as you are able to get them there and take them away with a truck or large helicopter.
The resilience to earthquakes of many small reactors is pretty obvious – like the resilience of the internet that doesn't rely on a large central supercomputer. Restoring power to a stricken area is less troublesome – you basically go and put the wires back into the power outlets, one by one, where the distribution network is available.
OK, ok, it’s a little more complicated than that, but not much. Both pebble-beds and micro-reactors are designed to be almost idiot-proof and low-maintenace, even if it means they are a bit less efficient.
If you want to go high-tech, thorium reactors are the way to go, and and I won’t bother going into their advantages so much, as they are well described in this piece over at ABC Drum, but in a nutshell, they are cleaner, and need energy input to keep burning – shut off the "light" and the fire stops.
Now, I’m equivocal about the desirability of nuclear power generally, but if you decide that nuclear power is worthwhile, I think you are better off buying lots of Volkswagon beetles (remember, they had no water-cooling, it’s an appropriate metaphor) than one or two high-maintenance buses that require specialist attention.
See Also:
- "The greener nuclear alternative", Tim Dean, The Drum, 2011-03-16.
A good intro to Thorium reactor advantages.
- Balneus posts (each with quite a few links):
- "Australian nuclear industry: qualified support", (2006-11-07)
My thoughts on nuclear power generally, including pebble-beds
- "Nuclear power options snippet" (2009-07-25)
Includes a brief discussion of microreactors, and a nice graphic showing just how small they are.
- "Australian nuclear industry: qualified support", (2006-11-07)
- Nature News
Probably the most unbiased, technically accurate reporting you’ll get on this issue, with rich linkage.- "The Fukushima Crisis: Anatomy of a disaster" (2011-03-13)
- "Exclusive: Nuclear test ban agency has valuable radiation monitoring data from Japan nuclear accident — but can’t share thEm" (2010-03-14) – An international agency set up to monitor for nuclear tests is collecting extensive data on the levels of radionuclides in the air in and around Japan and the Asia-Pacific and transmitting this daily to its member states. The data would be of enormous public interest as it would provide a far fuller picture of the extent and spread of any current or future radioactive release from the major Japanese nuclear accident now under way. But none of these data are being released to the public, Nature has learned.
- 2011-03-15 Update with this fantastic concise table of technical details.
- "Fukushima spent fuel threat rises/Boric acid shortage" (2011-03-16)
- "The Fukushima Crisis: Anatomy of a disaster" (2011-03-13)



Ann O'Dyne said
I just read at abc.news online about thorium (by Tim Dean)and wish Homer Sim-San every success.
Dave Bath said
Ann O’Dyne: You’re right, Thorium reactors and Homer Simpson don’t mix.
That said… a pebble bed is pretty simple.
The microreactors could be run by Homer and the dog – Homer to feed the dog and the dog to bite Homer if he tries to touch anything but the power outlet. Seriously…