By Michele Lent Hirsch
A response to a public conversation with Allison Macfarlane on March 28, 2012.
Listening last week to Allison Macfarlane, Harvard-affiliated member of the White House’s Blue Ribbon Commission on America’s Nuclear Future and author of Uncertainty Underground: Yucca Mountain and the Nation’s High-Level Nuclear Waste, one got the impression that if anyone could explicate the quagmire that is nuclear-waste safety, it’d be this woman. An MIT-trained geologist who went on to study nuclear reactors and their radioactive byproducts, she has a dazzlingly thorough knowledge of both nuclear power and the geological constraints on underground waste disposal.
And so when she said our grasp of nuclear safety is a joke, I didn’t find myself laughing.
“There’s no operating repository anywhere in the world for high-level waste,” Macfarlane said. (“High-level,” she explained, means the most dangerous forms, including the spent fuel rods that can no longer provide power at plants but are still very radioactive.) Sweden, Finland, France, and Canada are trying to create underground repositories, though none of these countries are close to finished.
Meanwhile, here in the United States, Macfarlane explained, “We’re not doing anything.”
Right now, nuclear plants are each outfitted with a deep pool in which used fuel rods are submerged. The idea is that once placed in the pool, the hot unstable byproducts can cool down away from substances with which they’d react. But they aren’t meant to hang out there forever. Though Macfarlane said that radioactive rods take about five years to cool, most pools are cluttered with rods that have been taking decades-long dips. There are now more than 65,000 metric tons of spent fuel being stored.
What’s more, when storage pools were built decades ago, they were placed precariously on the fourth or fifth floors — not the ground floor — of each plant. The incredulous laugh Macfarlane gave with that fact was none too reassuring.
But the funny part isn’t just that engineers forty years ago made structures that look absurd to experts today. The real kicker, if we listen to Macfarlane, is that the more permanent choices we have to make about storage will be based on murky science at best. As a believer in human error, I wasn’t shocked to learn about the possibility of inaccuracies. But when Macfarlane explained the issue further, I realized just how dicey it was for even top experts to make sound decisions.
Geology is not predictive, Macfarlane said. It looks backwards in time. So when we think about taking those fuel rods out of crowded pools and burying them in the earth, we really can’t know what conditions will prove safe. Some geologists use elaborate computer modeling to “test” future repositories and answer questions like, “If we were to bury radioactive rods in this rock formation, what are the odds of something dangerous occurring?” If geologists think they can predict quakes, floods, and chemical reactions, Macfarlane said, “they’re fooling themselves.” If Fukushima is any indication, we’re not great at predicting the weather.
It’s probably wise to heed an expert who admits that her own field is fallible. When that field is nuclear waste, it’s also a bit disturbing. As Klaus Lackner, the Columbia geophysicist who moderated the discussion, pointed out, carbon capturing (in which CO2 is trapped as a gas, turned into a liquid, and injected into rocks underground) is a parallel procedure to burying of nuclear waste. Both practices are intended to store harmful materials far from us and in places from which they ostensibly shouldn’t escape.
However, the comparison ends there. Once liquid carbon is sequestered, an accidental leak is not a disaster. Scientists can release the underground well back into the environment as carbon gas. While letting out tons of CO2 is not ideal, it is also not a life-threatening proposition. At least at the moment it isn’t. But if radioactive waste leaks, “Oops, better luck next time” doesn’t quite cut it.
Once we bury our waste permanently, we can’t just start anew. Yet until we find the right geological site, the radioactive byproducts stay in those aging, crowded pools. Yucca Mountain, which for a long time had been considered the permanent site of choice, was never the safest option, Macfarlane said. A clear enough risk of chemical reaction betrays that it was chosen more for its middle-of-nowhere-ness than geological suitability. Other, better choices were dismissed too early on.
When reactors were built forty years ago, the long-term storage problem should have been considered. More recently, the chair of the House Energy and Commerce Subcommittee on Environment and the Economy said that Yucca Mountain is the “most shovel-ready” site and that “there are possibly no other 230 square miles in the world that have been examined and reexamined more by America’s greatest scientific minds.” He said we’ve already funneled money into it, so we shouldn’t consider other options.
My question is, how did we let that happen? Politicians love showing that they’re solving a problem, but here the problem is that they made a choice without enough comparison. Given that we can’t choose again once it’s done, that sounds like a joke to me.