information about Fukushima published in English in Japanese media info publiée en anglais dans la presse japonaise
5 Décembre 2013
December 5, 2013
A visiting team of IAEA experts said Japan should weigh the possibility of discharging part of the growing stockpile of contaminated water at the crippled Fukushima nuclear power plant to the sea.
Its recommendation came with the caveat that radioactive levels would have to be below safety standards.
"It is necessary to find a sustainable solution to the problem of managing contaminated water at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power station," the International Atomic Energy Agency team said in its preliminary summary report released Dec. 4. "This would require considering all options, including the possible resumption of controlled discharges to the sea."
At the Fukushima No. 1 plant, the stockpile of radioactive water is growing by 400 tons every day as groundwater flowing into reactor and turbine buildings keeps adding to and mixing with water used to cool melted nuclear fuel. TEPCO is using an Advanced Liquid Processing System (ALPS), a purifier touted as capable of removing 62 types of radioactive substances, to treat the contaminated water.
But that does not help reduce the total amount of water that needs to be managed, because the ALPS cannot remove tritium, a radioactive isotope of hydrogen.
TEPCO said it was holding 390,000 tons of radioactive water in storage tanks as of Dec. 3, including 31,000 tons that have been treated with the ALPS.
Juan Carlos Lentijo, leader of the IAEA expert team, held a news conference in Tokyo on Dec. 4, where he said controlled discharges of contaminated water are a common practice around the world. He added that TEPCO should gather data on treated water for safety screenings by Japan's Nuclear Regulation Authority, and release the water to the sea if it is found to have cleared regulation standards.
Lentijo, at the same time, emphasized the importance of gaining understanding from the general public and the parties involved, and said controlled discharges should be allowed to take place only after discussions are held with relevant stakeholders and their approval is obtained.
The 19-member team of IAEA experts was visiting Japan from Nov. 25 to review Japan's effort to decommission the devastated Fukushima plant, including the removal of nuclear fuel from the No. 4 reactor's spent fuel storage pool and the monitoring of seawater. The preliminary summary report praised Japan for achieving "good progress" in preparing for the decommissioning process.
The team is expected to submit a final report to the government of Japan by the end of January.
Shunichi Tanaka, chairman of the NRA, reiterated his support for controlled discharges of treated radioactive water.
"I don't believe the technology is available for easy removal of tritium," Tanaka told a news conference Dec. 4. "The amount is not particularly mind-boggling from a global perspective. We can't help discharging water once it has cleared safety levels."
(This article was written by Akira Hatano and Ryuta Koike.)
Staff Writer
A team of experts sent by the International Atomic Energy Agency suggested Wednesday that Tokyo Electric Power Co. should consider discharging toxic water from the Fukushima No. 1 plant into the ocean after lowering the level of radioactive materials to less than the legal limit.
The proposal by the international nuclear watchdog was part of its call on Tepco to improve its management of the increasing amount of radioactive water at the crippled facility and ensure a safe decommissioning process.
Such a step would draw an angry reaction from people, including commercial fishermen, worried about further contamination of the Pacific.
Controlled discharge is a regular practice at all nuclear facilities in the world,” Juan Carlos Lentijo, director of the IAEA Division of Nuclear Fuel Cycle and Waste Technology, told a news conference in Tokyo as the team wrapped up its inspection of the plant.
Lentijo headed the team of 19 experts that arrived Nov. 25 to check the decommissioning efforts, including the radioactive water problem and the removal of fuel rod assemblies from the spent fuel pool high in the reactor building 4.
The team, which also inspected the plant in April, submitted a preliminary report Wednesday to the government.
If Tepco intends to implement the water discharge, the report says, it should conduct safety and environment assessments that would have to be reviewed by the Nuclear Regulation Authority.
There are about 1,000 tanks at Fukushima No. 1 storing a massive amount of tainted water, while another 400 tons of groundwater is seeping into the reactor buildings every day.
Tepco has been running a test operation of a high-tech water processing machine called ALPS that can remove all radioactive materials except tritium from the tainted water.
The utility hopes to discharge the processed water after diluting the level of tritium below the legal limit, but local fishermen are against this, as it would damage the public image of their catches and harm their business.
“Of course . . . public acceptance for this purpose is necessary,” said Lentijo, adding strict monitoring of the impact of the discharge would also be essential.
The IAEA’s report also points out that Japan should look into waste management solutions, such as creating facilities to store radioactive waste from the plant to support the decades-long decommissioning process.
The team will submit a final report in about two months.
http://mainichi.jp/english/english/newsselect/news/20131205p2g00m0dm062000c.html
TOKYO (Kyodo) -- Japan's central government said Thursday it will carefully consider discharging into the sea some of the radioactive water accumulating at the site of the crippled Fukushima Daiichi nuclear power plant, as proposed by the U.N. watchdog.
"We will respond by considering the advice" from the International Atomic Energy Agency, Chief Cabinet Secretary Yoshihide Suga told a press conference. But the top government spokesman also said such a decision must follow careful consultations with relevant bodies.
The IAEA proposed Wednesday the so-called "controlled discharge" as one of options with which plant operator Tokyo Electric Power Co. would dispose of less harmful toxic water into the nearby ocean.
The agency, which had dispatched a mission to review Japan's ongoing efforts to scrap the damaged reactors at the plant impacted by the 2011 earthquake and tsunami, told a press conference in Tokyo the measure is regularly used in nuclear facilities around the world.
Tokyo Electric has been struggling to manage a massive amount of radioactive water that is increasing daily at the plant site, with groundwater seeping into the plant site mixing with water used to cool the three stricken reactors.
The utility has set up hundreds of tanks at the site to keep the highly radioactive water and is planning to significantly reduce the radiation level of the liquid by running a water treatment system, as accidental leaks from those tanks have been feared.
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