It may sound obvious to anyone who knows me, but “hazardous, tricky clean-up of nuclear sites”:http://www.newscientist.com/news/news.jsp?id=ns99996199 is for me the single compelling reason to avoid nuclear power as a major energy source. I don’t worry nearly so much about Chernobyl-style accidents as I do about subtle, continuous contamination of an ecosystem due to nuclear byproducts.
Note that this does not apply to cases where nuclear power provides a clear advantage, especially when the contamination argument is less prominent. Specifically, interplanetary spacecraft are a good use of nuclear power, because the need for a lightweight power source is so prominent. I tend to balk at the idea of using nuclear engines for propulsion — at least in the long term — but using a nuclear source for electric power makes perfect sense.
Enough of that, though; I’m boring myself.
You don’t bore me, however. I totally agree with you. But what about getting that nuclear material into orbit? Isn’t there a risk there?
That’s my point, though. If you’re using a small amount of fissionable material for a targeted application (like space travel), even the ‘risked’ biosphere contamination is a thousand times better than the assured contamination due to a large-scale reactor in continuous operation for dozens of years.
Think of it this way: the “San Onofre”:http://www.eia.doe.gov/cneaf/nuclear/page/at_a_glance/reactors/sanonofre.html plant near me generates 2,000,000 kilowatts and is set to run continuously for 40 years. A “Mars Direct”:http://www.astronautix.com/craft/marirect.htm mission (which has pretty hefty power requirements, space-wise) would use a 10 kilowatt reactor, probably for 20 years or less. That would actually provide the power needs for the entire mission, including the generation of fuel for the trip home.
From this, I can assume that Onofre is generating 400,000 times the heat, and probably uses at least ten thousand times more fissionable material. That means that if Onofre were to “leak” only 0.01% of that (or the equivalent in contaminated water, soil, etc) it would do as much damage as a complete dispersal of the launched reactor, an event with probably less than 1% chance of occurring. These are all ballpark figures, but I’ve tried to be as conservative as possible, not even mentioning the long-term disposal of Onofre’s reaction byproducts.
Given that, it’s also important to see what each of these reactors gives us. The Mars Direct reactor makes the difference between an attainable mission ($20B, 3 year duration) and a blue-sky mission ($150B, 3 month duration) because there is no reasonable alternative to generate that much power without weighing considerably more. The Onofre plant provides San Diego one extra torchiere lamp per household. Okay, maybe two. It could be replaced entirely by outfitting each home in the city with 2kW of solar panels.
Sure you’re not bored yet? :)
Nope, not bored yet. :) Thanks.