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NRA rebuts claim that Fukushima cleanup affected faraway rice paddies

November 01, 2014AJ201411010038M

Japan’s nuclear watchdog disputed the farm ministry’s assertion that radioactive substances churned up by debris removal work at the Fukushima No. 1 nuclear power plant contaminated distant rice paddies last year.

The Nuclear Regulation Authority announced at a commissioners’ meeting Oct. 31 its estimate that 110 billion becquerels of radioactive materials spread as a result of cleanup at the No. 3 reactor building on Aug. 19, 2013.

This figure is lower than the 130 billion to 260 billion becquerels estimated by the plant’s operator, Tokyo Electric Power Co., in August.

Radiation readings rose significantly during debris removal that day, with radioactive substances found to have contaminated plant workers about 500 meters from the reactor building.

However, NRA Commissioner Toyoshi Fuketa emphasized, “The affected area of the fallout was within the nuclear plant compound.”

“While it is difficult to simulate the spread of radioactive substances (outside the plant), it is unlikely that the debris cleanup caused the contamination (of the rice paddies),” Fuketa said.

The nuclear facility was ravaged by the March 2011 Great East Japan Earthquake and ensuing tsunami, triggering a triple meltdown.

The NRA arrived at the figure of 110 billion becquerels by analyzing radiation levels recorded at monitoring posts north-northwest of the plant on the day in question.

Radioactive fallout on this scale constitutes a Level 0 incident on the International Atomic Energy Agency’s International Nuclear and Radiological Event Scale.

Earlier, the farm ministry pointed to the possibility that radiation from the plant had spread to rice paddies in Minami-Soma more than 20 kilometers away, and called on TEPCO to take preventive measures in its debris removal work.

During the NRA meeting, some experts noted that despite the NRA’s estimate, it is unlikely that factors other than debris cleanup at the plant could have caused such high levels of radioactive fallout at the rice farms.

“From a broader perspective, the Fukushima No. 1 plant is responsible for the contamination,” one participant said.

Source: Asahi Shimbun

November 2, 2014 Posted by | Japan | | Leave a comment

TEPCO removes section of radiation cover above Fukushima reactor building

oct 31 2014 reactor 1A panel is lifted by crane at the No. 1 reactor building of the Fukushima No. 1 nuclear power plant

in Okuma, Fukushima Prefecture, on Oct. 31

November 01, 2014

OKUMA, Fukushima Prefecture–Tokyo Electric Power Co. has removed part of the canopy above a reactor building at the crippled Fukushima No. 1 nuclear power plant to gauge the effects of anti-scattering agents pumped inside.

It was the first time in three years that debris inside the No. 1 reactor building was visible from the outside. The structure, which was destroyed in a hydrogen explosion a day after the Great East Japan Earthquake and tsunami on March 11, 2011, was covered with the canopy in October of that year.

The removal on Oct. 31 of one of six panels that make up the canopy is the initial stage in work to remove debris and nuclear fuel from inside the structure.

TEPCO drilled holes into the panel, which measures 42 meters by 7 meters and weighs 32 tons, on Oct. 22. It then sprayed anti-scattering resin inside to prevent radioactive substances from stirring up into the air.

The panel was removed to survey the effects of the resin.

The work was performed by a large crane that slowly hoisted the panel and lowered it to the ground, taking about one hour and 40 minutes.

The panel is scheduled to be returned by the end of November. TEPCO plans to start dismantling the entire canopy on a full-fledged basis in March 2015.

Source: Asahi Shimbun

November 2, 2014 Posted by | Japan | | Leave a comment

Japan’s Sendai nuclear restart in final stage: local governor

Oct 31 (Reuters) – The governor of Kagoshima prefecture, home to Kyushu Electric Power Co’s Sendai plant, said restarting the nuclear facility was in its “final stage” in a positive sign for the industry, as the trade minister reiterated support for reviving idled reactors.

All 48 of Japan’s nuclear reactors remain offline more than three years after an earthquake and tsunami set off meltdowns at the Fukushima Daiichi plant, but Prime Minister Shinzo Abe’s government is pushing to restart reactors that meet new regulatory guidelines.

Kyushu Electric’s two-reactor Sendai plant, located 1,000 km (600 miles) southwest of Tokyo in Satsumasendai, was the first to pass the independent regulator’s safety guidelines last month.

“We are in the final stage on the issue of the Sendai plant’s restart,” said Kagoshima governor Yuichiro Ito during a meeting with newly appointed trade minister Yoichi Miyazawa on Friday.

Japan has said it would defer to local authorities to approve any restart.

The city assembly of Satsumasendai voted in favour of restarting the plant this week and Kagoshima’s prefectural assembly is expected to vote to finalise the restart next Friday, local politicians say.

Only eight lawmakers out of 49 state assemblymen are opposed to restarting the plant.

Ito did not give a timeline for a possible restart of the plant, but any return to operations is seen as unlikely until next year.

Miyazawa, who was appointed to head the powerful trade ministry after the sudden resignation of his predecessor over a political funds scandal, said he planned to tour the nuclear plant and talk to local politicians in Kagoshima next Monday, Nov. 3.

Source: Reuters

November 2, 2014 Posted by | Japan | , , | Leave a comment

Removal of melted fuel from Fukushima No. 1 reactor delayed until 2025

October 31, 2014

The government and Tokyo Electric Power Co. (TEPCO) announced on Oct. 30 that removal of melted fuel from the No. 1 reactor at the disaster-hit Fukushima No. 1 Nuclear Power Plant would be delayed by five years, until fiscal 2025.

They also announced that work to remove spent fuel from a cooling pool will not begin until fiscal 2019, two years later than originally planned. The delays are the result of the removal of debris and the installation of cranes taking longer than expected.

The announcement marks the first delays in the decommissioning schedule. TEPCO said, however, that the move would not result in an overall delay to the decommissioning process, which is expected to take 30 to 40 years.

The No. 1 reactor houses 392 fuel rods in its cooling pool, while melted fuel remains in the nuclear pressure vessel and reactor containment vessel. In a meeting on Oct. 30, the government and TEPCO decided to adopt a two-step process with separate measures to remove fuel from the cooling pool and melted fuel. First, a cover will be installed on the top floor of the reactor building. After a special crane for the fuel pool removes fuel, then workers will use a container and crane setup to remove melted fuel. The government and TEPCO say that they chose this method because there are many unknown factors in the removal of melted nuclear fuel, and because they hope to remove the fuel from the cooling pool at an early stage.

At the No. 1 reactor, preparations began this month to remove a cover designed to prevent the spread of radioactive materials, so that debris could be removed from the top floor. This process itself was delayed by six months. Because of this, and the fact that the two-step process is laborious, it is believed the government and TEPCO decided to delay the start of fuel removal work.

At the No. 2 reactor, meanwhile, since radiation levels are high and decontamination of the reactor building is difficult, officials have decided to reconsider the method of removing nuclear fuel. Officials are set to decide on a method in fiscal 2016, but there is a high possibility that removal work will fall behind schedule.

In August, work at the No. 3 reactor was suspended after a large piece of debris fell into the cooling pool while debris was being removed from around the pool’s edge. Officials plan to remove fuel from the pool next fiscal year, but the outlook for this work is unclear.

It is expected that work to remove fuel from the No. 4 reactor pool will be completed this year.

The decommissioning schedule was established under the Democratic Party of Japan-led administration in December 2011. It was revised in June last year, accelerating the removal of melted fuel by up to a year and a half.

The disaster at the Fukushima No. 1 plant, triggered by the March 2011 Great East Japan Earthquake and tsunami, resulted in core meltdowns at reactor Nos. 1-3. Nuclear fuel has passed through the reactor pressure vessels, and caused damage to the containment vessels. The government and TEPCO plan to fill the containment vessels with water and remove about 450 metric tons of melted fuel. But it remains unknown where the melted fuel actually lies. Furthermore, officials have located only two damaged areas in the containment vessels of the three reactors.

In the Three Mile Island meltdown in the United States, it took six years before the removal of melted fuel was begun, though the pressure vessel was not damaged. Fukushima presents conditions that are far more difficult, and it is unclear when the work can be completed.

Source: Mainichi

November 2, 2014 Posted by | Japan | | Leave a comment