28 Août 2013
August 26, 2013
Russia repeated an offer first made two years ago to help Japan clean up its radiation-ravaged Fukushima No. 1 nuclear station, welcoming Tokyo Electric Power Co.’s decision to seek outside help.
As Tepco pumps thousands of tons of water through the wrecked Fukushima station to cool the melted cores of three reactors, the tainted runoff was found to be leaking into groundwater and the ocean. The approach to cooling and scrapping the plant will need to change and include technologies developed outside Japan if the cleanup is to succeed, said Vladimir Asmolov, first deputy director general of Rosenergoatom, Russia’s state-owned nuclear utility.
“In our globalized nuclear industry, we don’t have national accidents, they are all international,” Asmolov said. Since the Liberal Democratic Party took power in December and Shinzo Abe became the prime minister, talks on bilateral cooperation on the Fukushima cleanup have turned “positive” and Russia is ready to offer its assistance, he said from Moscow last week.
After 29 months of trying to contain the radiation from Fukushima’s molten atomic cores, Tepco said last week it will reach out for international expertise in handling the crisis. The water leaks alone have so far sent more than 100 times the annual usual release of radioactive elements into the sea, raising concern it will enter the food chain through fish.
The latest leak of 300 tons of highly radioactive water prompted the Nuclear Regulation Authority to label the incident “serious” and question Tepco’s ability to deal with the crisis, echoing comments Abe made earlier this month. Zengo Aizawa, a vice president at Tepco, made the call for help at an Aug. 21 briefing in Tokyo.
“It was clear for a long time that Tepco was not adequately coping with the situation,” Asmolov said. “It looks like Tepco management were the last to realize this,” he said. “Japan has the technologies to do this, but they lacked a system to deal with this kind of situation.”
The Fukushima crisis, which started in March 2011, is the world’s biggest nuclear disaster since the Soviet Union faced the explosion at Chernobyl in 1986.
Tepco’s solution to cooling melted nuclear rods at No. 1 that otherwise could overheat into criticality, or a self-sustained nuclear chain-reaction, has been to pour water over them. That’s left more than 330,000 tons of radioactive water in storage tanks at the site, and the amount is growing daily. The water is treated to remove some of the cesium particles in it, which in turn leaves behind contaminated filters.
The sheer quantity of water used is the most involving a crippled nuclear plant since the 1972 London convention banned the dumping of waste and radioactive water into the sea, said Peter Burns, formerly Australia’s representative on the United Nations scientific committee on the effects of atomic radiation.
“Until they figure out how to deal with such vast volumes of water, how to manage it, the problem, including leaks, will persist,” Burns, a retired radiation physicist, said from Melbourne.
Retaining thousands of tons of radioactive water in tanks was the wrong strategy from the start and Tepco’s handling of the task is a “textbook picture of a failure of management,” said Michael Friedlander, who has 13 years of experience running U.S. nuclear stations.
The idea of pumping water for cooling was never going to be anything but a “machine for generating radioactive water,” Asmolov said. Other more complex methods, such as the use of special absorbents like thermoxide to clean contaminated water and the introduction of air cooling, should be used, he said.
Russia’s nuclear company, Rosatom, of which Rosenergoatom is a unit, sent Japan a 5 kg sample of an absorbent that could be used at Fukushima almost three years ago, Asmolov said. It also formed working groups ready to help Japan on health effect assessment, decontamination and fuel management, among others, Asmolov said. The assistance was never used, he said.
“Since the arrival of the new Japanese government, the attitude’s changed,” he said. “So far the talks have been on a diplomatic level, but they are much more positive. And we remain open to working together on this issue. To follow developments, I monitor Fukushima news every morning.”
Japan can tap experts in France and the U.S. as well as Russia to help it tackle the situation at Fukushima, he said.
America’s long history with atomic research, including the nuclear weapons site at the Hanford Engineer Works in Washington state, has provided expertise in cleaning up contaminated sites, said Kathryn Higley, who heads the nuclear engineering and radiation health physics department at Oregon State University in Corvallis.
“We have individuals that are working on groundwater contamination and using technology and developing new technologies to clean up strontium in groundwater, for example, at the Hanford site,” she said. “So there are individuals around the world that have been doing this and certainly they would be more than willing to help in this process.”
France’s Areva SA had designed a radiation filtration system that was used for several months at the Fukushima site as temporary cover before Tepco installed its own facilities.
Tepco is in talks with a team of retired U.S. government officials who worked on water management after the Three Mile Island accident in 1979, according to Dale Klein, chairman of an advisory panel to Tepco and a former head of the U.S. Nuclear Regulatory Commission