Dr. Jim Walsh Explains Nuclear Mess in Japan, and is Therefore Smarter Than All of Us

Dr. Jim Walsh, a research associate at MIT’s Security Studies Program, was recruited late last night to appear this program because Imus needed somebody to explain “what the hell” is going on in Japan.
 
Unfortunately, Walsh, who focuses on nuclear issues, might not be that person. “First of all, no one knows for sure what’s going on, including the government and the utility,” he said. “Secondly, whatever they thought they knew a minute ago seems to be changing all the time.”
 
In the aftermath of Friday’s gigantic earthquake that triggered a powerful tsunami, Japan has been scrambling to avoid nuclear meltdowns at various facilities around the country. Luckily, Walsh was able to explain to Imus—and to countless members of his audience—what a meltdown actually means.
 
“There are fuel rods inside the reactor,” he explained. “If they’re exposed to air for any prolonged period of time, their casing begins to melt.”
 
A partial meltdown would be where only some of the material begins to melt, but that’s not the event often portrayed in blockbuster movies. “The ultimate scenario is a full meltdown,” Walsh said. “Meaning all the fuel rods melt in their entirety, and drip down into the bottom of the reactor vessel, and there they start to mix together.”
 
When highly-enriched uranium mixes with any other highly radioactive material, unless it’s controlled, it can explode. “Sort of a low-level nuclear explosion,” Walsh stipulated. “Not the same thing as an atom bomb, but not far from it.” At that point, the question becomes whether the radioactivity can be contained.
 
In Japan, the nuclear reactors have containment vessels that were built as a last line of defense to keep any meltdown inside the reactor core, but Walsh said it’s unknown yet whether they’ll work. “That’s not an experiment you want to run,” he joked.
 
Most of Japan’s nuclear power plants were built in the 1970s, and it’s unknown what effect the radiation has had, over time, on the concrete walls. While there’s some confidence the containment vessel will hold, it’s impossible to predict. If it does not, Walsh said, “Then you probably have an explosion—not as bad as Chernobyl, but in the Chernobyl neighborhood.”
 
An explosion would disperse intense radioactivity into the air, at which point it’s pretty much Mother Nature’s call what happens next. Walsh believes that, in the event of an explosion, there will be medical consequences, both physical and mental, as people cope with anxiety over their health; debate whether to return to the neighborhood; and try to withstand the economic fallout.
 
Walsh agreed with Imus that the idea of building nuclear plants in a country like Japan, which sits on the Pacific Plate, an earthquake-prone region also known as the Ring of Fire, sounds insane, but noted the country’s severe lack of natural resources.
 
“They made a real commitment to civilian nuclear energy, because they figured they could rely on that, and they built the plants to withstand a major earthquake,” Walsh said. “But this isn’t a major earthquake. This is a massive earthquake, beyond what you might normally expect.”
 
You might also normally expect the Japanese government to be honest with its people about the possible ramifications of this whole mess, but you would be wrong there, too.
 
“The government’s tendency has been to underreport, to not put a lot of information out there,” Walsh said. Though he is sympathetic to the number of challenges presently facing the country, he stressed the need for the government to be forthcoming or risk losing its credibility.
 
“That’s the one thing the Japanese government’s going to need,” Walsh added. 
 
That, and a whole lottta luck.
 
-Julie Kanfer