Mapping Nuclear Fallout After Fukushima

One year after the Fukushima disaster in Japan, the nuclear industry is still grappling with how to handle the risks that come with extreme natural disasters.

What if something similar happened in the United States? According to the Natural Resources Defense Council, there were five nuclear shutdowns in the U.S. last year, all due to natural disasters including two tornadoes, an earthquake, a hurricane and flooding. The group has released a map showing what it says could happen if a disaster like Fukushima occurred at one of the country’s 104 reactors.

The group attempted to model the airborne plumes of radiation that might occur if one of those reactors lost both primary and backup power for even a few hours. The

NRDC’s map, however, is based on the actual weather patterns in the U.S. on March 11 and 12, 2011—not taking into account the high winds that might take place during a severe weather event.

The Fukushima Daiichi meltdowns and radiation leakage came on the heels of the massive 9.0-magnitude earthquake and the resulting tsunami that struck Japan on March 11, 2011.

(See pictures of the cleanup after Fukushima)

Although the NRDC’s model is not based on severe weather, which would change its forecast significantly, Dr. Gerhard Wotawa, a technical expert for the Austrian National Data Center for Nuclear Test Ban Treaty Verification in Vienna, said it could still be useful information.

With Fukushima, nuclear experts put out forecasts for the radiation plume as the international community began to worry about how it might spread. Wotawa said those models “worked fairly well.”

“Prediction is based on the winds forecast for the next few days,” Wotawa said. The models use data from satellites and ships, and the position of the particles. All of the data go into a powerful computer model. “We end up with a timed series of calculations.”

“This is the measurement system that was not available 10 or 15 years ago,” Wotawa said. “It was only a factor of three to four off, which is good based on only a few measurement points.”

Of course, every forecast has its challenges.

“The radiation plume going to Europe after all was more dense than the model thought,” Wotawa said. “More radioactivity came over to Europe than expected before. A few more particles were released into the atmosphere. Some of these are also gases, and gases survive much longer.”

Wotawa said it was actually easier to predict where the plume might go across the Pacific Ocean than to create a local model. “In Japan itself, for example, you have different topography,” he said. “It is more difficult to predict.”

Another challenge for this incident in particular was getting all of the information in a timely manner, due to the Japanese government’s policies.

“It was pretty much live televised, but then it took weeks before it got known publicly how bad it was,” Wotawa said of the Fukushima disaster. “This was the first nuclear accident in the modern age of media. It’s not possible anymore to say that nothing happened.”

While the Japanese government and the energy company that owns the plant took criticism at the time of the event, the NRDC is criticizing the U.S. government now for failing to implement the safety lessons that were learned from Fukushima.

“These important safety upgrades are still years away from being implemented, if ever,” the NRDC said of the Nuclear Regulatory Commission.

Last month, the NRC approved the first new license for a nuclear reactor in 34 years for a plant in Georgia despite the objections of the commission’s own chairman, Gregory Jaczko. Jaczko said he voted against the approval because he wanted Southern Company to commit to changes based on the Fukushima findings.

(Related: Would a New Nuclear Plant Fare Better Than Fukushima?)

The NRDC also said that many reactors across the U.S. are operating at higher power levels than they were initially authorized to use, increasing the radiation hazard in the case of a nuclear accident.

The effort to keep U.S. reactors safe will become even more key in the next few years, as construction moves ahead for the new reactors in Georgia, which are expected to come online by 2016 or 2017.

Meanwhile, the U.S. nuclear industry has stressed that it is moving forward before required by the federal regulators to take steps to back up the safety measures at all plants in the wake of the Fukushima accident. Its new safety strategy, called FLEX, seeks to provide an additional layer of backup power at all 104 reactors by stationing emergency generators, battery packs, pumps, air compressors and battery chargers in multiple locations nearby.  More than 300 pieces of safety equipment already have been installed or ordered, and all operators have committed to station the additional backup by the end of March, says the industry group, the Nuclear Energy Institute.

Tony Pietrangelo, NEI senior vice president, said there was debate soon after Fukushima on whether the industry should have enough power on hand for a four-hour, six-hour, eight-hour loss or more. But the industry decided a more preemptive approach was needed.

“Our goal is to have sufficient equipment so that there is no period of time during which we will experience loss of power,” he said.