Comment by dhughes | Hacker News Reader

Comment by dhughes | Hacker News Reader

Earthquakes aside there are so many different types of nuclear reactor both in the way they operate and the fuel used people seem to lump them all together in one hysterical pile.

The Fukushima Daiichi plant in Japan used plutonium from what I have read is unique compared to other plants. Canadian CANDU plants use natural uranium and the way they're constructed is far safer than other types of reactors. Two extremes of fuel used and plant design yet it seems some people see no difference. Of course in any discussion about reactors these days LFTR (thorium) reactors are mentioned too, even safer than uranium/plutonium reactors.

People are entitled to their opinion but it seems the vocal anti-science crowd wins. I'm all for closing bad nuclear power plants but all nuclear plants "just because" they use nuclear fuel?

It would be great if we all lived in sunny countries where solar panels and giant battery packs could supply our power but that's not the situation. I like solar but it's not suitable yet in my opinion due to the storage issues and efficiency of the panels, maybe graphene will solve that soon.

https://en.wikipedia.org/wiki/Nuclear_fuel

https://en.wikipedia.org/wiki/Nuclear_reactor

As I understand it, Edward Teller made sure the current CANDUs and any other designs with a positive void coefficient were illegal to build in the US (this is part of what killed the Chernobyl reactor), see http://en.wikipedia.org/wiki/Void_coefficient for more details, especially:

"CANDU reactors have positive void coefficients that are small enough that the control systems can easily respond to boiling coolant before the reactor reaches dangerous temperatures (see References).

RBMK reactors, such as the reactors at Chernobyl, have a dangerously high positive void coefficient. This was necessary for the reactor to run on unenriched uranium and to require no heavy water. Before the Chernobyl accident these reactors had a positive void coefficient of 4.7 beta and after the accident that was lowered to 0.7 beta. This was done so all RBMK reactors could resume safe operating and produce much needed power for the then USSR and its satellites."

The next generation CANDU addresses this, although one of the costs is requiring 1 to 2% enrichment.

The fuel isn't what caused the problems in Japan, rather, an appalling nuclear safety culture, so bad I don't think I can disagree with their decision to turn them all off, to their using boiling water reactors which don't contain everything inside the classic dome.

The international reactions to Fukushima seem about as absurd as pulling every commuter car off the road because the Pinto was a terrible design.

Japan reprocessed fuel and was using mixed oxide fuel in one of the reactors at that site. The plutonium was processed and mixed with uranium so that it could be used in a reactor that was originally designed for uranium. I'm not familiar with the details, but any design elements put in place for the plutonium fuel would have been retrofits, not extremes.

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