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Japan's Big Event - Before and After
Tuesday night's ScienceNow forum on the devastation in Japan after the March 11 earthquake and tsunami served to inform the public about potential long-term risks and implications around the globe.
It took an earthquake-triggered tsunami 150 seconds to lay waste in Japan, eventually resulting in the deaths of an estimated 11,000 people and causing hundreds of billions of dollars in damage.
Yet the aftermath of the March 11 disaster has not had significant impacts in the U.S., though it has resulted in heightened demand for improved reactor facilities and energy policy, experts on a five-member panel said during a University of Arizona-sponsored discussion about the event.
The College of Science's ScienceNow forum held Tuesday night was organized to provide the general public with a synthesized discussion about what led to the earthquake and tsunami, what happened after the tsunami hit and what the future holds for the country and rest of the world."This is a very significant earthquake because of its size and the damage it caused," UA geosciences professor Susan Beck said, speaking to an audience of about 400 people at the UA's Centennial Hall.
Beck noted estimates indicating the wall of water that arrived on Japan's shores was up to 25 feet in certain areas, also resulting in tremendous damage to a number of reactors.
She also said the tsunami's accleration reached a g-force of more than 2.7 in certain areas, "the largest acceleration that has ever been recorded." Also, Japan's landmass is estimated to have moved about 4 meters to the east, sinking about 1 meter as well.
Overall, panelists said that while concerns about radiation, particularly along the coastal and western region of the U.S. have proliferated media reports, there is not much to fear.Some said what is necessary now more than ever is a heightened emphasis on improved reactor construction and design, a heightened focus on renewable energy sources and efficient energy and better public policy.
In emphasizing those claims, the panelists detailed what happened and what comes next.
The four reactors nearest the epicenter and 11 in total went into automatic shutdown when the earthquake hit – as emergency plans required – but the tsunami caused the optimal damage.
The problem with one nuclear power plant in particular, Fukushima Daiichi, is that it was designed to withstand about a 18-foot wall of water but estimates put the massive tsunami at up to 30 feet in certain areas, said John Williams, a UA nuclear and energy engineering professor.
Williams noted another problem: While the design basis for that particular reactor was set at a g-force of .47, the tsunami arrived at an acceleration of .53.
This resulted in the diesel generators designed to cool the reactors in an emergency to lose power, resulting into a blackout, said Williams who, as the UA Reactor Lab director, coordinated last year's decommissioning of the UA's 52-year old TRIGA nuclear reactor.
"Then we got some interesting and surprising piece of news 24 hours later," he said, referencing reports of emergency radiation levels in parts of Japan, with a sizable plume bound for the states.
"My worst fear is that much of the emissions will end up in the Pacific," Williams said. "But given the hugeness of the Pacific, the serious effects will be localized."
That was one of the major points of the discussion.
Beck affirmed that seismic activity as a result of the March 11 earthquake did reach the Pacific Coast and parts of Arizona. And Eric Betterton, UA professor and head of atmospheric sciences, said the plume did reach the western U.S. about one week after the disaster.
But cause for concern about major adverse effects in the U.S., such as radiation poisoning or a heightened risk for cancer, have been largely diminished.
"That plume did reach the West Coast, but at very low concentrations, at background levels," Betterton said.
"There is no need to panic," he added. "The plume grazed Arizona and will continue to move across the U.S. and to Europe," taking four to five weeks in the process.
This is a critical point, Betterton said, adding that by the time the radiation particles reached this part of the world they were highly dispersed so that "there was no significant impact" in the U.S. as a result.
"Plumes spread and dilute naturally in the atmosphere. It's not as though there were a continuously plume," Betterton said.
"Whatever amount of iodine left Japan, we got about half of it. The ocean helped scrub out these gas particles," he said, adding that "whatever rain and snow storms the plume encountered "would have cleaned them out as well."
Even with the low levels of radiation that arrived, Baldassarre Stea said they did not outweigh the amount people generally are exposed to in their daily activities.
A UA professor and head of radiation oncology, Stea said he hoped to "alleviate the fears" associated with potential radiation contamination in the U.S.
Stea, who treats patients with lung cancers, melanoma, brain tumors and pediatric cancers, said "we are constantly exposed to radiation in our daily activities. Radiation is a part of life."
People who receive chest and dental X-rays, mammograms even travel long distances by air are exposed to varying levels of radiation, Stea said, noting that the risk for people outside of the epicenter in Japan are at very minimal risk.
But there was another lingering question: Could such a disaster happen again? Yes.
"So we need to be prepared for that," Beck said. "Hopefully this is a bit of a wakeup call. We cannot prevent earthquakes but I hope we can do more to prepare for them,"
But the predictable impact such a plume would have on the U.S. and other parts of the world would largely depend on a very complicated picture, one shaped by the size and location of the explosion, wind speeds and direction and the plume's altitude, among other variables.
Several panelists said the greatest concerns now are for the health of the initial rescue workers and emergency personnel in Japan, for possible contamination of vegetation and soil, for the stabilizing and rebuilding of reactors and the repopulation of the region.
And for the rest of the world, one of the major implications is the need to develop stronger policy around meeting demands for energy, said Paul Bonavia, chairman, president and CEO of UniSource Energy Corp.
Bonavia noted the U.S. Energy Information Administration's International report indicating that major sources would continue to include coal, natural gas, renwerables and also nuclear power at least through 2035.
This brings him to four conclusions: The level of demand will continue to rise; There is no one answer to all energy demands; Each energy source carries its own set of challenges; and the energy policy decisions of today will linger and manifest for generations to come.
"Decisions that look good today will be tested by the realities of the future," Bonavia said, adding that particular emphasis should be spent on improving renewable energy sources and energy efficiency.