It doesn't have to be that way. I'm no great fan of Nuclear power (although mostly because we know it will be privatised and the private company running it will suddenly be bankrupt when it comes to the clean up) but the US and Russia hid a lot of their weapons development behind "too cheap to meter" nuclear power stations.

I wouldn't guarantee they would not do that again, but the incentives are very different this time around, so the design of the power stations shouldn't produce material suitable for modern nuclear weapons as a side effect.