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Installation of a dome-shaped rooftop cover near completion at Unit 3 reactor

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Japan Fukushima Cleanup
In this Thursday, Jan. 25, 2018 photo, an installation of a dome-shaped rooftop cover housing key equipment is near completion at Unit 3 reactor of the Fukushima Dai-ichi nuclear power plant ahead of a fuel removal from its storage pool in Okuma, Fukushima Prefecture, northeast Japan, during an exclusive visit by The Associated Press. The hardest-hit reactor at the Fukushima plant in the March 2011 disaster is moving ahead of the other two melted reactors seven years later in what will be a decades-long cleanup. (AP Photo/Mari Yamaguchi)

 

January 31, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Test run for Fukushima Daiichi 3 cover installation

Fukushima Daiichi 3 cover test run - 460 (Tepco) june 13 2016.jpg

Sections of the cover upon the base of the fuel removal machine

 

 

In preparation for the installation of a fuel removal machine and a protective cover over unit 3 of the damaged Fukushima Daiichi plant in Japan, workers have carried out a practice run of installing roof modules onto the base of the fuel handling machine.

Plans were announced in November 2012 for a cover to be constructed to encase the unit’s damaged reactor building, protecting it from the weather and preventing any release of radioactive particles during decommissioning work.

The section of the reactor building that sheltered the service floor of unit 3 was wrecked by a hydrogen explosion three days after the tsunami of March 2011 – leaving the fuel pond exposed and covered by debris including many twisted steel beams.

The fabrication of the cover has been under way since November 2013 at the Onahama works in Iwaki city. It has been made in sections so that once it is transported to Fukushima Daiichi, the time to assemble it can be shortened and the radiation exposure to the workers on site can be significantly reduced, Tokyo Electric Power Company (Tepco) said.

A separate structure will be built to facilitate the removal by crane of used fuel from the storage pool. This 54-metre-tall structure will include a steel frame, filtered ventilation and an arched section at its top to accommodate the crane. Measuring 57 metres long and 19 metres wide, it will not be fixed to the reactor building itself, but will be supported on the ground on one side, and against the turbine building on the other.

A detailed replica of a portion of the Fukushima Daiichi site has been created at Onahama to enable workers to train in highly realistic conditions, Tepco said. Training began in May and will continue through June.

On 10 June, workers at Onahama assembled sections of the cover on the base of the specially-made fuel removal machine and slid them into place to make a roof, Tepco announced.

Although the largest pieces of rubble have already been removed, once installed the remotely-operated fuel removal machine will be used to clear the remaining rubble and the 566 fuel assemblies from the unit’s storage pool. The removal of debris and fuel using the system is scheduled to begin in fiscal 2017.

The fuel removed from unit 3 will be packaged for transport the short distance to the site’s communal fuel storage pool, although it will need to be inspected and flushed clean of dust and debris.

http://www.world-nuclear-news.org/RS-Test-run-for-Fukushima-Daiichi-3-cover-installation-1306164.html

June 15, 2016 Posted by | Fukushima 2016 | , , , | Leave a comment

Dry run kicks off to build huge dome over damaged reactor

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a massive cover will be built over the No. 3 reactor building of the Fukushima No. 1 nuclear power plant during a practice run at Onahama port in Iwaki, Fukushima Prefecture, on June 10.

IWAKI, Fukushima Prefecture–A dress rehearsal is under way to install a huge “hat” over a crippled reactor building at the Fukushima No. 1 nuclear power plant.

The bulky dome-shaped cover is meant to stop the spread of radioactive material and protect equipment necessary to retrieve 566 bundles of nuclear fuel rods from a storage pool in the No. 3 reactor building.

The simulation is designed to get workers fully drilled so they can set up the cover quickly, reducing the time they are exposed to radiation.

Tokyo Electric Power Co., operator of the crippled plant, has started simulating the process at Onahama port in Iwaki.

On June 10, TEPCO invited reporters to witness part of the drill in which portions of the cover measuring about 18 meters high were moved on a rail for about 50 meters.

The No. 3 reactor building, where a meltdown occurred after the March 2011 Great East Japan Earthquake and resulting tsunami, still has an extremely high reading of radiation.

TEPCO plans to begin retrieving the fuel rods during fiscal 2017, starting in April next year.

The drill is expected to continue through this month to ensure there are no flaws in the working procedures and safety measures.

TEPCO plans to first decontaminate the No. 3 reactor building and put up shields so that radiation levels drop when the massive cover is installed.

The cover used in the drill will be dismantled and then shipped to the power plant for reassembly and use in the actual retrieval.

http://www.asahi.com/ajw/articles/AJ201606130029.html

dome cover 13 june 2013 b.jpg

Parts of the cover to be placed over the No. 3 reactor building of the Fukushima No. 1 nuclear power plant are shown during a drill at Onahama port in Iwaki, Fukushima Prefecture, on June 10

June 14, 2016 Posted by | Fukushima 2016 | , , | Leave a comment