In 2005 it seemed that everything had changed. And then in 2007 it happened again. All of a sudden the only thing to expect was the unexpected. I’m talking of course about the weather, and the changes due to radiation entrapment. The climate seemed like it was dying.

Out of desperation, many prominent environmentalists converted to the religion of nuclear (fission) power between 2008-2011. Each year the news about the climate was (and still is) getting worse. Nuclear seemed to be the only way out. After the Japanese earthquake and tsunami last year, some hedged and others doubled down. Given that the crisis there is ongoing and possible worsening, maybe this is a good time to rethink those deathbed conversions.

There are two broad reasons why the conversion to nuclear doesn’t make sense:

  1. It assumed that nuclear is in fact a safer alternative for current and future energy production.
  2. It assumed that society can’t decrease demands.

I’m going to leave the second point alone for now.

To begin with let’s look at what British environmental writer George Monbiot said in 2009:

It’s true that my position has changed. As the likely effects of climate change have become clearer, nuclear power, by comparison, has come to seem less threatening.

But I have not, as many people have suggested, gone nuclear. Instead, my position is that I will no longer oppose nuclear power if four conditions are met:

1. Its total emissions – from mine to dump – are taken into account.
2. We know exactly how and where the waste is to be buried.
3. We know how much this will cost and who will pay.
4. There is a legal guarantee that no civil nuclear materials will be diverted for military purposes.

None of them are insuperable.

Mark Lynas, author of the excellent book Six Degrees, I was disappointed to discover, took an even bolder stance in How nuclear power can save the planet:

I would take a stronger position myself: that increased use of nuclear (an outright competitor to coal as a deliverer of baseload power) is essential to combat climate change, but clearly there need to be some significant technical advances in nuclear fission if it is to become acceptable to many in the west.

Such “fourth-generation” nuclear power is still a dream, but potentially a much more realistic one than carbon capture and storage. Deployed entirely in tandem with renewables, fourth-generation nuclear could offer a complete decarbonisation of the world’s electricity supply – and on the sort of timetable that Dr Hansen and his fellow climatologists demand.

There are many other prominent environmentalists and scientists who’ve done the same calculation—we need nuclear or we’re doomed. Here’s one accounting of who’s changed their mind on nuclear in the last few years.

For better or worse, when I was in high school I did a summer internship in the nuclear industry, working on a blue sky project (that never ended up becoming reality). I’m not sure that at the time I had strongly held views on the technology, but if nothing else I learned how inordinately complex nuclear power production is; few other human endeavors are of such complexity.

Consider a conventional coal-fired plant. Take some coal, burn it, boil some water, pipe the steam to run a turbine. Afterwards, add more coal.

Consider a conventional nuclear BWR. Take some carefully machined and enriched nuclear fuel, maintain the appropriate level of water moderation, start the reaction, maintain the appropriate level of control, boil some water but not too much water and don’t create too many bubbles, pipe the steam to run a turbine. Afterwards, open up the fuel assembly, move the fuel rods into an on-site spent fuel pool with appropriate water cooling for future transport to a reprocessing or long-term storage facility, with all of these steps done with protective gear.

I’m a fan of technologies that fail well. You can just walk away from most other power plants and not much will happen. Stop putting coal into a coal plant, and it will stop. Nuclear isn’t quite so simple. As we’re seeing with Fukushima, the dangerous plant is the one that wasn’t even operating at the time of the disaster—reactor number 4—simply due to the amount of waste that was held there.

A natural response by many nuclear proponents is that modern designs have a much greater margin of safety. No doubt that’s the case, though a little known fact is that utility companies regularly go to regulators and ask to do power uprates of their nuclear plants—that is, to run the plants above the original maximum power level, on the theory that the original designers built in a safety margin. Consider the huge number of uprates that the NRC has approved in the last decade. I’m reminded of the tradeoff between resilience and efficiency, and when money is involved people opt for short-term efficiency over long-term resilience.

Despite this, nuclear proponents might still be justified in standing their ground: risk is everywhere, and statistically nuclear is much safer than many other things in industrial society. That is, in ordinary times. And if there’s anything that’s clear about the combination of global climate change and peak oil and the many other challenges we face, it’s that we’re not in ordinary times—they are unprecedented in recorded history, and point to harder times ahead.

Specifically, three things strike me as the major reasons to avoid nuclear:

Limits to growth. In a (permanently?) declining global economy, the resources (mostly financial, though military resources are important for nuclear safety) to keep plants well maintained are going to be scarce. Nicole Foss said it well-–-that after studying nuclear safety in Eastern Europe she concluded that nuclear power is incompatible with hard times. It’s these hard times that invalidate assumptions about the safety procedures and other risk modeling, for example, that can cause unforeseen cascading accidents.

Waste storage. I think it is possible for us to store waste for the short term. It’s the longer term that is a bit more doubtful, and regardless of the duration it’s an expensive undertaking. The 2010 documentary Into Eternity on Finland’s waste storage plans reminded me of a few things: a) Finland is a small country, and yet the scale of the waste site is huge, b) planning for the 100 years it’ll take to finish the waste site is hard enough (will there be the money needed to complete it? how is it possible to plan for 100 years when we can’t plan beyond the next congressional election?) let alone the hundreds of thousands of years it needs to survive intact, and c) they’ve been working on this for a decade already, while no other country has even the beginnings of a solution. (The documentary was a bit sad: Finland has assembled a number of expert, sincere people trying to solve a problem that you sense they realize cannot be solved.)

Scale. Nuclear isn’t particularly cheap when you compare it to alternatives (though cost estimates vary wildly) and is difficult to scale up quickly. In my calculations on alternative energy several months back, I found David MacKay’s estimate that the peak rate of nuclear power plant construction ever achieved was 30GW of nameplate capacity per year, globally. At that rate we’d only build 0.6TW in 20 years, a drop in the bucket compared to the ~16TW of primary energy we consume globally today.

The combination of these factors, and the fact that it’s not a technology that fails well means that even barring a catastrophic failure, at some point the whole plant has to be decommissioned and many of its parts stored as waste, at great expense. The nuclear industry itself is old, and most nuclear engineers are nearing retirement, so a lot of institutional knowledge is about to be lost.

It’s for these reasons that I prefer solar thermal power (both for heat and for electricity) for baseload generation. A solar thermal tower with mirrors is about as low-tech as can be. There’s little risk of any sort of disaster—the entire system can be passive if it needs to be—and all the parts can be built using ubiquitous materials and simple technology. With heat storage—again, simple technology—solar thermal can provide stable baseload power in a way that most major renewables (other than hydroelectric) can’t.

Finally, stepping back for a moment, there’s the question of whether it was wise to advocate for a technology from a position of weakness—environmentalists felt they had been backed into a corner, and had to pick something—anything—to get us and the climate out alive. That’s not a frame of mind that leads to good decision making. Post-Fukushima, nuclear is off the table in many countries but the pattern that led to that choice is repeating with natural gas, and may keep repeating until we step back from the premise: that we can’t use less energy.