Comment Re:Two sides (Score 1) 292
We know sodium reactors don't go critical even when there's a total coolant failure.
Yeah, except that coolant spontaneously catches fire when exposed to air, spreading radioactive dust all around. Monju is an expensive failure that showed how sodium fares in practice. Sorry, but in my back yard I will only allow a coolant/moderator that is chemically inert when exposed to air : no graphite, no sodium. It must also not seep into the food chain, so water is out also.
You are only left with lead/tin/bismuth alloys which have sufficiently low absorption cross sections, but relatively high melting points when compared with sodium/watter. Lead coolant has been used on Russian subs so we know it works.
All this adds cost, yes, but so does leaving a reactor unused for 20+ years
Most likely, it's much more expensive to handle hot fuel. As you probably know but some readers might not, freshly depleted fuel is extremely hot, both in the thermal and radioactive sense, and continues to generate about 7% of the nominal output of the reactor. This residual heat caused the Fukushima disaster. So by leaving the reactors on standby a few decades most short lived products have decayed and the clean-up is cheaper and safer.