“Everyone knows that midday desert sun can be harmful if you live in it without protection,” wrote David McKay, the late scientific adviser to the UK energy department, “And everyone knows that moonlight is essentially harmless.”
Yet moonlight and sunshine are made up of the same photons. The former is simply harmless because it is 400,000 times less bright than sunshine.
“Nuclear radiation can be like sunlight, and it can be like moonlight,” Prof McKay noted. “There are levels of radiation that are lethal, and levels of radiation that are essentially harmless.” The key lies in discerning which is which.
This may seem uncontroversial; a mere recital of well-worn scientific fact. But you won’t find much trace of it in the public debate about nuclear power. Here, radiation is always “harmful” or “toxic”, and the risks and liabilities associated with handling such material seen as prone to balloon without control.
Hence the gnawing worries about the back-end costs of dismantling old facilities and the risks associated with storing spent fuel for substantial periods. These threaten to stifle future investment in nuclear technology. But how realistic are these fears?
Let’s start with the costs of cleaning up old facilities. Admittedly, Britain’s record in this area is poor. The estimated cost of decommissioning the first generation of facilities — a task far from complete — stands at about £120bn. That is a pretty vast bill when you think the Magnox stations only generated about a tenth of the UK’s electricity in those early years.
But it is worth also looking at where this number comes from. About three-quarters relates to the experimental and military facilities constructed at Sellafield in Cumbria in the 1940s and 1950s. These used processes that left big nuclear messes and were built without much thought to how they would ever be dismantled. The priority was manufacturing fissile material for nuclear bombs.
Britain also provided for this obligation in the most expensive manner possible. Rather than create a sinking fund to pay for the clean-up, it left the tab for future taxpayers to meet.
Future decommissioning will be done more rationally. The switch from idiosyncratic early reactor designs to widely used ones makes the facilities more dismantlable. The UK’s next planned reactors — at Hinkley Point in Somerset — will have a sinking fund from day one to provide for the clean-up — a job its owner, French state-backed energy utility EDF, estimates can be done for about 3 per cent of revenues (£2 to £3 per MWh) over their 60-year life.
Sceptics may quibble that we can’t know that this can actually be done. But a glance at the US (where 14 plants have now been decommissioned) suggests it is not unreasonable.
Despite collecting between just $1 to $2 per MWh — less than the Hinkley number — utilities have assembled two-thirds of the sum needed to decommission the entire US fleet over the next two to three decades. An industry has sprung up competing to pull down old reactors. In a recent deal, a decommissioning company, Holtec, took over a plant at Oyster Creek, New Jersey, lock stock and barrel, on the basis that the accumulated fund would pay for the job.
Of course, decommissioning is only one part of the story. In many ways the bigger barrier to a sustainable nuclear industry is the absence of somewhere to put the high-level waste. Many countries, including Britain, have failed to persuade local communities that depositaries buried deep underground can be safe in the long term. That is because of fears about storing material that could remain radioactive for hundreds of thousands of years. But without such facilities, it is hard to see the industry surviving in the long run.
And here is where McKay and the science come back in. It’s one of nuclear’s paradoxes that the most dangerous radiation comes from isotopes with very short half-lives that hence decay rapidly. Those that last longest don’t emit much radiation.
To see how little, take some analysis the Finnish authorities did when they did secure agreement for a national depositary a few years ago (the first country to do so).
The Finns looked at the impact of waste leaking from the facility after 1,000 years on someone living directly above it, whose food and water all came from the most contaminated plot of land. The conclusion? That person was likely to receive a dose of 0.00018 millisieverts per year; equivalent to the radiation from eating two bananas.
Nuclear power may not be without risk. But it remains one of the few technologies the world presently has for reliably generating zero-carbon electricity. Even renewables generate their own pollution. And unlike radioactive isotopes, the harmful chemicals in solar panels do not quickly decay.
Decommissioning and storage should be manageable problems. It would be bizarre to scrap nuclear over what are prejudices, not real costs and risks.