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Fukushima Disaster Likely to Have Limited Impact on Global Push for Nuclear Power, Experts Say
Fukushima: Lessons Learned
The crisis at the Fukushima Daiichi nuclear electricity generating facility, touched off when a tsunami hit northern Japan, has achieved the "key milestone" of cold shutdown where the temperature within the damaged reactors is below the boiling point of water, said Gregory Jaczko, chairman of the U.S. Nuclear Regulatory Commission (NRC).
“There is still some potential for some amount of steam to develop, which can in principle have some very low levels of radioactivity in it,” Jaczko said in a recent appearance at AAAS. “But those pose no real threat to public health and safety.”
The nuclear disaster caused significant nuclear contamination in the area around the reactors, and many years and millions of dollars will be required for clean up. But Jaczko and former NRC Commissioner James K. Asselstine suggested that the long-term impact on global nuclear energy might be limited. While nations may pause in their pursuit of nuclear power, they said, demand for new plants would likely expand in the long term.
Jaczko and Asselstine spoke 24 October in the second lecture in the AAAS Science and Society: Global Challenges forum. The four-part fall series is organized by the AAAS Office of Government Relations and the association’s Center for Science, Technology and Security Policy, and co-sponsored by the American Chemical Society and the Georgetown University Program on Science in the Public Interest.
James K. Asselstine
The crisis began on 11 March when a powerful 9.0 magnitude earthquake offshore sent a tsunami into the coastline of northern Japan. It devastated the city of Fukushima, site of an electrical power generating plant with six nuclear reactors. The nearly 50-foot wave caused minimal damage to the main structures of the power plant but it knocked out connections to the electrical grid as well as backup generators.
Without power to operate the cooling system for the three reactors that were in operation but shut down as a result of the earthquake, their cores began to overheat, boil off the cooling water, and physically melt down. The race was on to restore cooling before the meltdown reached a critical mass. It was touch and go for weeks before the situation was stabilized and the danger receded.
Moderator Richard Harris, a science reporter with National Public Radio (NPR), said the Japanese government initially provided “a very limited amount of information and very limited analysis.” It was “perfectly accurate information,” he added, “but not necessarily very useful.”
Media coverage helped stoke a public perception that Fukushima posed a high risk of contamination that perhaps was not warranted outside the immediate area of the plant. Harris cited as an example the rush to buy iodine tablets by people living on the west coast of the United States.
Jaczko acknowledged that U.S. experts also struggled with a lack of accurate information. “I felt they [Japanese officials] were doing what they could,” he said. In the first phases of such a disaster, he added, “it will always be a challenge.”
Uncertainty remains about the scope of damage because experts still have not gained access to the core of the three failed reactors that were online when the tsunami hit. The assumption is that at least some of the fuel rods melted down, but the extent of that meltdown and exactly where the molten nuclear fuel flowed remains uncertain.
Asselstine served on the NRC in the aftermath of the 1979 Three Mile Island meltdown, the most significant nuclear incident in the U.S. to date. He said it took five years to gather sufficient data and develop the tools and equipment necessary to completely remove the nuclear material from that reactor. However, it may be possible to build upon that experience to move forward more rapidly at Fukushima.
Jaczko said nuclear experts have been modeling core reactor behavior but there are factors that make Fukushima different. One was the use of seawater during emergency efforts to cool down the damaged reactors. The salt remained as the water boiled off, and became more concentrated with time. It is not clear what effect that might have had on the fuel and the materials used in the reactor.
A few hotspots with higher levels of radioactivity have been discovered in the region. Only a few workers at the stricken facility have been exposed to radiation levels that are considered above levels safe for normal operating conditions. There have been no fatalities tied to radiation exposure and no exposures that are believed to put individuals at significantly greater health risk. All persons who worked at the plant are being monitored, according to Jaczko.
Asselstine said movement in U.S. financial markets immediately after the incident “was fairly modest and fairly limited,” in part because of statements by U.S. government officials that there was no need to shut down similarly designed facilities in this country. They also outlined steps that would be taken to review whatever was learned from Fukushima.
The United States strengthened its regulatory approach after Three Mile Island, Asselstine noted. “Neither the NRC nor the Institute for Nuclear Power Operations [which was created after the incident] are infallible,” he said, “but between the two of them not a lot really falls through the cracks.” He thought a similar approach would be useful for the petroleum industry to develop in light of the 2010 Deepwater Horizon/BP oil spill in the Gulf of Mexico.
Jaczko said the initial Russian denials surrounding the Chernobyl disaster—the 1986 explosion and nuclear contamination that led to the resettlement of 350,000 people—resulted in an international treaty that requires better communication and reporting on nuclear incidents. “There is a lot of communication and cooperation among nuclear regulators internationally,” he said, comparing it to a similar information-sharing process developed for commercial aviation worldwide.
Both men anticipate only modest changes in the regulatory environment once review of the Fukushima incident is completed.
Harris noted that the German government announced in June that it would phase out all of its 17 existing nuclear generators by 2022. Those facilities currently produce about 22% of the country’s electricity. Germany already has aggressive programs to conserve energy and develop alternative energy sources, such as solar power, as part of an effort to reduce global warming. He asked if the United States might do the same.
“Each country needs to make its own decisions based upon their situation, the available alternatives, and how comfortable they are with the operation of their nuclear plants…other alternatives, and the economic competitiveness of those alternatives,” said Asselstine.
France, the United Kingdom, and most parts of Asia are likely to move forward with investments in nuclear energy after a short pause triggered by the Fukushima incident, he said. “My sense is that China will look at further steps to strengthen and expand their regulatory framework. I think that is a good approach.”
4 November 2011