First images from within Fukushima containment

19 January 2012

Pictures from a remote examination of Fukushima Daiichi 2 have yet to bring new information on the state of the ruined reactor core.   

Fukushima piping support 213  

Vertical piping and associated supports within the primary containment vessel of Fukushima Daiichi 2   

Today, for the first time, engineers from Tokyo Electric Power Company (Tepco) inserted an endoscopic camera on a flexible cable into the primary containment drywell of reactor unit 2. It passed through the thick reinforced concrete in a 13 mm guide pipe. Tepco had previously practised the same procedure on the undamaged unit 5, bringing back fairly clear images and video of the grid-like steel structures and piping that surround the reactor vessel.

The Fukushima Daiichi power plant was wrecked by an accident sequence started by flooding due to the tsunami of 11 March 2011. A prolonged station blackout saw Fukushima Daiichi units 1, 2 and 3 overheat and suffer core melts over several days.

It is believed that the molten core of unit 1 damaged the bottom of the reactor pressure vessel enough for it to pass through to the surrounding drywell. At units 2 and 3, most of the core is expected to have been retained in the pressure vessel, with a far smaller amount passing through, although to confirm this may require visual checks of the drywell. It is this general area that was probed today by Tepco engineers working to understand the exact status of the reactor cores and ultimately aiming to dismantle the plant completely.

However, the images released have so far appeared largely unhelpful and Tepco was only able to give a rough idea of what they even showed. Some images were very highly speckled due to radiation. Further investigation is to follow as Tepco works to get a full understanding of the accident sequence and current status of the plant. 

Fukushima cabling conduit 213   Fukushima grating and PCV wall 213  

'Structures assumed to be small size piping or cabling conduit' (left) and a grating near the inside surface of the primary containment vessel   

Researched and written
by World Nulear News 
 

Filed under: Fukushima accident