After all, despite the expert's protests, we know that nuclear power stations over their life subtract value from the economy: they cost more to build, run and (crucially) decommission than the power they generate is worth. This might change, of course, but buying an out of the money option is a gamble on the underlying going up, and the government doesn't have a hedge.
What I really worry about, though, is the ongoing costs and risks of dealing with the waste. U235 has a half life of 700 000 000 years. For U238 it's 4 billion years, or roughly the age of the earth. The most permanent structure man has made has lasted less than 10,000 years, yet we are taking on liabilities 700,000 times longer. We are going to produce tonnes, perhaps hundreds of tonnes, of material so toxic that ingesting a microgram is likely to be fatal, and it will remain dangerous for billions of years. Put that way is there anyone who honestly believes it's a sensible idea?
Update. The house of Lords clearly have concerns too.
What particularly troubles me about all of this is that fusion research has slowly been making progress and with more funding, goodness knows how quickly we could get there. In the context of the sums at risk from climate change, a few tens of billions on fusion research would be infinitesimal. Yet this is an order of magnitude less than we are spending. That seems like a bad strategy to me.