Published: March 21st, 2012 at 4:30 am ET
Title: Podcast Interview with Peter Burns, an author of Nuclear Fuel in a Reactor Accident
Source: Science Magazine podcast
Date: March 9, 2012
From the Science Podcast: an interview with Peter Burns about the properties of damaged nuclear fuel and developing better models for nuclear reactor accidents.
Abstract: Nuclear Fuel in a Reactor Accident
Stream the broadcast here
More on Burns and the Study
The research described in the Science paper was conducted under the auspices of Notre Dame’s Energy Frontier Research Center (EFRC), a U.S. Department of Energy-funded initiative established to pursue advanced scientific research on energy. Burns serves as director of the center.
Burns: [...] In terms of the damaged fuel, there’s been really very limited studies. Basically several groups have studied fuel that actually has been melted in a controlled environment and its reconfiguration from a kind of physical point of view and the release of gaseous fission products from it. But what has not really been studied is the longer-term fate of that material. So after the fuel has melted and it’s mixed with various containment devices and so on – everything has been melted into a big blob – we know very little about what that blob looks like from a chemistry and heterogeneity point of view and material science point of view, and we know very little about how water or even just the air will interact with that over time. And that, of course, other than the gaseous fission products, which are basically released upon meltdown, everything else is presumably still more or less in that big unknown blob. And it’s the interaction of the water and the air with that that is going to control the release of radioactivity to the environment. [...]
In Fukushima, the meltdowns were somewhere in the range of partial to complete depending on the reactor. Hydrogen explosions did cause breaches in containment. Volatile fission products, the gaseous things, probably were largely released early in the accident. But what’s different about Fukushima relative to the earlier events is the vast quantities of water that were pumped into the reactor cores and into the storage pools in order to try to cool them. And that created a whole new release pathway for radionuclides out of the reactors into the environment. We don’t know how much radioactivity was released through the water flow, and we don’t know very much about how the water interacted with the fuel and other structure materials. [...]
I think we need to take very seriously the development of knowledge about how damaged and destroyed and melted nuclear fuel moves in a reactor containment vessel and then how it interacts with the environment, especially water that we might use in an emergency to cool it. Studies that have been done to date really haven’t looked at the longer-term interactions of water and the atmosphere with these damaged materials. They’ve focused mostly on the very short-term release of the gaseous and different volatile fission products. Those ones pose a lot of short-term risk, but the risk is relatively short term because those fission products typically have very short half-lives in the minutes to days kind of range; some are years. But the fuel itself – as it interacts with water or whatever over time – has a potential to release radionuclides that have much longer half-lives and they pose a much longer environmental threat. [...]
Listen to the report here
Here is a shorter video of Burns, also from March 9:
“Seawater is then interacting with this bizarre material at the bottom the reactor vessel and it has the potential to dissolve a lot of radionuclides and transport them out. And that’s exactly what happened at Fukushima.”
And we’re going to probably learn to design reactors better over time, and we’re also going to get a better understanding of the actual low probability events that are going to occur. Because these are the ones that get you – in the end, it’s the things that are really unlikely, but if you have enough reactors operating in the world, sooner or later some of these things will happen. And the number of reactors operating now is about 440, but that’s going to steadily increase, and one could imagine it being perhaps a thousand or more in not too many years.
[Meltdowns are] not as rare as a lot of people would think. There’s been around 20 core-melt accidents in the world to date that we know of [...]
Published: March 21st, 2012 at 4:30 am ET