We really need a new Cold War
Not just because it guarantees a ready supply of lovely Pu238, but because it means we'll get more cool-looking hardware.
NASA's future solar system exploration programme could be threatened by a shortage of plutonium-238, New Scientist reports. Many of the agency's spacecraft rely on the nuclear fuel, but the US no longer produces the stuff, and despite previous estimates that the lack of plutonium-238 wouldn't bite until 2020, NASA is "already …
...as they cannot even enrich Uranium to nuclear bomb levels in any reasoanble timeframe in spite of regular fantastic and breathless "reporting" from the Murdoch paper empire. I would say that breeding Plutonium, and even more, extracting Pu 238 of a batch is right out.
"Oh no, we dont have anymore. What ever will we do? Oh we can buy it from Russia, you say? Well no we cant be reliant on those commie buggers. We must start producing some ourselves and in the meantime we'll cut back on using it in our projects instead of just buying what we need on the world market, because that would be wrong and unamerican..."
Essentially, yes. Pu-238 only makes up a few percent of the plutonium output of a normal reactor - too little to make extraction practical. And military reactors are more interested in Pu-239 (Pu-238 is too stable to sustain a chain reaction). Therefore, the only way to produce it is through neutron bombardment of Neptunium-237(itself an expensive-to-extract reactor byproduct). After the US fell out of love with nuclear power, the demand for radioisotopic generators dropped so precipitously that it wasn't worth producing the stuff any more. That and the fact that the US hasn't actually been in the business of reprocessing waste nuclear fuel for some years.