Fukushima Unit 1 Had Part Of Cover Removed

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Oct 31, 2014

Tepco on Friday cracked open the cover over the reactor 1 building at the Fukushima No. 1 nuclear plant.

The covering was installed in a bid to contain radioactive dust after a hydrogen explosion shattered the building’s exterior structure in March 2011.

Dismantling it is a first step toward removing spent fuel rods stored in a cooling pool above the reactor. That, in turn, must be completed before the reactor core can be opened to remove the melted-down fuel, according to Tokyo Electric Power Co.

On Friday morning, plant workers used a crane to remove a huge panel to see whether anti-dispersal agents are taking effect. They were inserted last week to reduce the risk of radioactive dust blowing out.

No changes in radiation levels have been observed around the plant so far, the company said.

Tepco will continue observations for a month to make sure radioactive materials are not emerging and then put the panel back again. It plans to begin full-fledged work on dismantling the cover next March.

Once the whole cover is removed, Tepco hopes to be able to clear debris lying on the structure’s upper levels.

The company then plans to begin removing spent fuel rods from the pool — in 2019 at the earliest — and later to try to extract the melted fuel from the reactor itself.

The reactor 1 building cover was installed in October 2011 as an emergency response to the rain sluicing radioactive materials down and the wind picking up contaminated dust.

Tepco initially planned to begin removal preparations by the end of last March but was forced to delay the schedule after local residents voiced concern about the contamination of rice fields nearby.

Sources:

Tepco: http://photo.tepco.co.jp/date/2014/201410-j/141031-01j.html

Japan Times: http://www.japantimes.co.jp/news/2014/10/31/national/tepco-cracks-open-weather-shield-covering-reactor-building-fukushima-1/#.VFOkP_nF8rk

Yomiuri Shimbun:  http://the-japan-news.com/news/article/0001684852

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Plans to remove cover over damaged Fukushima reactor draws concern

unit one oct 2014The cover over the No. 1 reactor building of the Fukushima No. 1 nuclear power plant in June 2014

October 16, 2014

Amid local concerns of the further spread of radioactive materials, Tokyo Electric Power Co. announced plans to start dismantling the canopy installed over the destroyed Fukushima No. 1 nuclear plant’s No. 1 reactor building.

The operation, announced by TEPCO on Oct. 15, will remove the cover that was erected in October 2011 over the building to prevent radioactive materials from entering the atmosphere.

The structure’s walls and roof were destroyed in a hydrogen explosion that occurred after the plant was struck by the 2011 Great East Japan Earthquake and tsunami.

The process, which will begin Oct. 22, is a necessary step in removing the vast amounts of highly contaminated debris, rubble and dust that remain inside the building.

However, as the work to clear debris at the plant’s No. 3 reactor building in August 2013 spread radioactive materials in the area, the Fukushima prefectural government and experts are calling for careful measures to be taken in the dismantling.

The utility plans to monitor closely the radioactivity levels and dust within the plant’s grounds during the operation.

According to TEPCO, the company has informed the prefectural government and 13 nearby municipalities that it will release the detailed schedule for the work before actually dismantling the canopy.

In the removal, the utility will drill 48 holes in the roof of the cover, each 30-centimeter squares. From the holes, synthetic resin will be sprayed as anti-scattering agents inside the building to minimize the possibilities of radioactive materials rising.

Starting from the end of this month, two of the six roof panels will be removed to install a camera to monitor the status of the debris inside.

Once the condition of the rubble is better understood, a specific schedule for the dismantling process will be created. The utility plans to begin major operations in March 2015 in hopes of starting the removal of debris in fiscal 2016.

Source: Asahi Shimbun

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201410160049

Radioactivity spikes in No. 1 reactor well water

Oct 15, 2014

Tokyo Electric Power Co. said there has been a sharp spike in the radioactivity of water samples taken from an observation well built by the sea at the crippled Fukushima No. 1 nuclear power plant.

The samples, collected from the well on Monday, contained a record 251,000 becquerels of radioactive cesium per liter — 3.7 times the amount recorded in a sample collected last Thursday.

The observation well, located to the east of the damaged No. 2 reactor, is one of several installed close to the seawall in the plant’s port. Monday’s reading was the highest recorded in water samples from any of the wells.

The samples also contained 7.8 million becquerels per liter of radioactive beta particle-emitting substances, such as strontium-90, an almost fourfold increase from Thursday’s level.

The amount of gamma ray-emitting substances, such as cobalt-60 and manganese-54, included in the samples was also at a record high.

The well is positioned close to an underground trench by the sea that is connected to the No. 2 reactor building.

Speaking at a press conference on Tuesday, Tepco official Isao Shirai told reporters that the increased radioactivity in the water could be due to higher levels of groundwater caused by recent typhoons mixing with radioactive elements left in the soil after the triple reactor meltdowns at the plant.

Source: Japan Times

http://www.japantimes.co.jp/news/2014/10/15/national/radioactivity-spikes-1-reactor-well-water/#.VD8DBFSUezc