American Scientist

Since the Fukushima Daiichi nuclear power plant disaster in 2011, the nuclear power industry has been in the spotlight worldwide. M. V. Ramana, a physicist with the Program on Science and Global Security at Princeton University, and a Sigma Xi Distinguished Lecturer, studies nuclear power in the wider context of energy production, and looks at public perception of the energy industry. Ramana discussed the future prospects of nuclear power with managing editor Fenella Saunders. (A video of the full interview is available here.)

How did the Fukushima Daiichi incident compare with previous problems at other nuclear power reactors?

On March 11, 2011, a tsunami struck the coast of Japan, and as a result, three operating reactors at the Fukushima Daiichi nuclear power plant lost cooling. One of the problems with any nuclear power plant is that the fuel, even if you shut down the reactor, continues to keep generating heat that has to be continuously transported out of the reactor. Because that was no longer happening, there was essentially a meltdown, and one result was hydrogen gas being produced inside the reactor. Eventually there was a hydrogen explosion that led to the radionuclides generated inside the nuclear reactor being expelled into the atmosphere. This release then contaminated both the surrounding countryside and the Pacific Ocean.

Compared with Chernobyl, Fukushima probably resulted in something like an eighth to a quarter of the amount of cesium-137, which is the most significant long-term radionuclide that contaminates, being released. But most of it was carried over the Pacific Ocean, so there was not much damage to human health. There was much, much less radioactivity released from Three Mile Island.

What is the current state of nuclear power usage in the world?

The International Atomic Energy Agency counts about 450 operating plants, of which 43 are in Japan. Of the latter, only 2 are operating, and it’s not clear how many of the ones that are not operating will ever come back. Most of them were shut down after Fukushima. Likewise, in the United States, although there are 100 plants, quite a few are scheduled to be shut down over the next few years.

How much power is generated by nuclear plants, compared with all sources?

Nuclear power generates about 11 percent of the world’s electricity as of last year, and this number has been declining steadily. The highest it has been was in 1996, when it was about 17.6 percent, so there’s been roughly about a 39 percent decline since then.

Is that because of economics, public perception, or some combination thereof?

I think there are multiple factors going on here. Economics certainly plays a very important part. Nuclear power plants are expensive to construct. They also take a long time to construct, so you cannot quickly build up a nuclear power capacity. Public perception has certainly played a part too, though it’s a much harder thing to quantify. Also, the world has been using far less electricity than had been anticipated in the past. People thought the energy demand would keep growing, and that has not really happened around the world. There are many countries where energy consumption has been fairly stagnant, including the United States.

What safety updates are being built into new reactors, in light of the problems that occurred at Fukushima?

Most countries around the world made some kind of safety assessment of their reactor fleets and of what they were constructing. To the extent that these have been implemented, one assumes that these fleets are going to be safer, as are newer plants. At the same time, I think the question is, can we really be sure that these reactors are not going to have an accident? And there I think the answer is that one just cannot be sure about this. There’s always going to be a possibility of an accident, regardless of what kind of reactor it is.

How are other energy technologies affecting the economic viability of nuclear power generation?

In the United States, except in a few states that have regulated markets, it makes no economic sense whatsoever to invest in a new nuclear plant. A new nuclear plant today, such as the ones being constructed in Georgia and South Carolina, cost around $15 to $20 billion for about 2,000 megawatts of generating capacity, and the cost of electricity from these plants is much higher than one can expect from most of the alternatives. Because of fracking, natural gas prices are very low, but renewables have also become extremely cheap in the past few years. Electricity from a new nuclear plant would cost roughly twice as much as electricity from a photovoltaic farm.

Renewable energy sources are able to have smaller footprints. There has also been some investment in smaller modular nuclear reactors, but is scale a factor?

Wind and solar tend to be much more modular in their nature of construction. Nuclear reactors could also be more modular, and in fact, the oldest nuclear power plants were small ones. But there was a reason why nuclear power plants became big. They were always very expensive, and the only way to lower costs was to take advantage of economies of scale. It doesn’t take twice as much concrete or twice as many workers to operate a plant that is generating twice as much electricity. It’s hard to imagine how a small reactor is going to be economically better off.

How do we compare the risks of a nuclear power plant disaster with, say, less visible but potentially disastrous climate change from fossil fuel use?

Comparing risks is always a very tricky business. Nuclear power suffers from a particular combination of risks that make it very hard for people to come to terms with. It’s an unfamiliar risk. It’s also a risk that is fairly catastrophic at some given point, as opposed to a small number of deaths occurring year after year, as is the case with fossil fuel plants. It’s a risk that probably runs across generations. It’s also a risk over which people have very little control. Comparisons between that and, let’s say, the risks of being in a car accident, cause people to react very differently.

When I drive, I know there’s a risk of an accident, but I also know that if I wear my seat belt, if I drive within the speed limit, if I obey laws, if I don’t try to drive at midnight on a Saturday night when I’m expecting many more drunk drivers, and so forth, my chances of an accident go down. I have no such control over what happens in a nuclear power plant, or for that matter, an airplane, so I am going to treat those kinds of risks very differently. The numbers then do not mean a lot.

With respect to climate change, it and nuclear plants share similarities in the magnitude and lack of control for individual people, but the differences are that the climate is seen as something with multiple possible solutions, and people who are concerned about climate also strongly support things like renewables and energy efficiency. Those kinds of options do not exist with nuclear.

How widespread is support for using nuclear energy to mitigate climate change?

To the extent that people support nuclear power more because of climate change concerns, it’s a very reluctant source of support. The people who are concerned about climate change also tend to be concerned about nuclear waste, the risk of accidents, and so forth, so they say, “If there is no other option, then perhaps we will go in for nuclear, but given that we see that there are rapid advances in renewables and other ways, then we would rather support that.” In the United States, if you look at the people who support nuclear power, it’s correlated very strongly with people who also deny climate change or who think that it is not a big problem.

Is there anything to the argument that renewables will take too long to ramp up, and nuclear is the better option because it’s more established?

I think the argument does not work at all. It takes much less time to ramp up renewable power production, simply because nuclear power plants take a very long time to construct. In California recently there was a decision to shut down the Diablo Canyon plant over the next 10 years. The local utility will replace it with a combination of renewables and efficiency. That kind of a model seems to be much more likely. But build a new nuclear power plant to replace it? I don’t think any utility that has concern about its profitability is going to make that decision.

Does the support of some prominent political leaders for nuclear power change public perception of the technology?

In public opinion polls, if you ask people whether they support new nuclear power construction, their answers very much depend on how you phrase the question or which kind of information you give them beforehand. If you tell people, for example, that “Nuclear power is a well-known way of mitigating climate change. Do you support building nuclear power plants?,” you’re more likely to get the answer yes, as opposed to when you ask them, “Nuclear power plants cost a lot of money to build. Would you support that?” In that sense, if you have a lot of prominent people supporting nuclear power, that’s going to help with public perception, but at the same time, that alone is not going to change the picture fundamentally.

Is there any connection between mistrust of science and experts and criticism of nuclear power?

I think the vast majority of people who are concerned about nuclear power also quite often know a lot about science, and trust science, and it is the results of these science-based studies that lead them to be distrustful of predictions about how safe nuclear power plants are. I think in many cases the nuclear industry has not served itself well. In India, for example, the head of the Indian Atomic Energy Commission, after Fukushima, announced that the probability of a Fukushima-like accident in India is one in infinity—zero, in other words. This is the kind of very overconfident statement that actually leads people not to trust scientists of that sort.

Is such a myth of guaranteed safety being propagated in China as well?

In China, certainly this battle is going on in a big way. China has the fastest growing nuclear power industry anywhere in the world, and yet they are faced with the fairly important decision of where they build their nuclear power plants. So far, all the nuclear power plants in China have been built on the coast. Prior to Fukushima, there were plans to construct nuclear power plants inland as well, near large rivers or lakes, because all nuclear reactors require sources of cooling water. This has been strongly resisted both by the public as well as by fairly high-level decision makers. The nuclear industry in China has been saying, “You don’t have to worry about it. The new designs that we are constructing are perfectly safe,” and on the other side, there are people saying, “We still cannot be sure, and we don’t want to risk contaminating our agricultural land and our rivers with this.”

Is the disposal of nuclear waste taken into account when reactors are built?

Is waste management planned at the beginning of the cycle? I think the answer for that has to be no. Whether it’s in the United States or elsewhere, many countries had assumed that within a couple of decades or when they built their first power plant, they would start having geological waste repositories operating. To date that has not happened. We all know about the Yucca Mountain proposal, which has gone up and down, but it’s not operational. There is in fact no operational underground waste storage facility for permanent disposal of commercial radioactive nuclear waste.

Most people thought the problem of setting up a nuclear waste repository would mean finding a suitable geological site. It turns out that that’s not the main problem. The main problem is trying to find a community that is willing to live near one of these waste repositories, with all the risks that come with it. Now they are saying, “Let’s start with trying to find a community that is willing to do this, and then set up one of these things.”

So is nuclear basically an industry that’s on the way out?

It’s a risky business to predict the future. But if you look at the trends, they do show an industry in decline. At the same time, the nuclear industry has high levels of political support in different countries, so it’s not going to go away any time soon either. I think what we’re going to see is something very slowly running into the sunset, unless there is some dramatic breakthrough in the next decade or two. There are lots of technical challenges still in front of us.