Drone to Measure Radiation inside Fukushima Daiichi Reactor and Turbine Buildings

n-drone-a-20170910-870x558.jpgThis drone will be used to measure radiation inside the reactor and turbine buildings at the meltdown-hit Fukushima No. 1 power plant.

 

Drone to measure radiation in tainted Fukushima No. 1 buildings

Tokyo Electric plans to measure radiation in heavily contaminated buildings at the Fukushima No. 1 power plant as it prepares to decommission its damaged reactors, officials at the utility said.

The data from the drone is expected to help Tokyo Electric Power Company Holdings Inc. create 3-D maps and identify areas of high radiation that workers should avoid.

The drone, 93 cm wide and 83 cm long, has four propellers and can fly for around 15 minutes. Tepco, as the struggling utility is known, expects to use it in the reactor buildings and the turbine buildings.

In February, Tepco tested a drone in the turbine building for the No. 3 reactor, one of three that experienced meltdowns after the March 2011 earthquake and tsunami.

After improving its performance, it decided to use the drone to gauge radiation but it is still deciding where to start, the officials said.

The government and Tepco want to start debris extraction work in 2021 and are in the process of determining a specific approach for removing the molten fuel from each reactor and updating the decommissioning road map.

https://www.japantimes.co.jp/news/2017/09/09/national/drone-measure-radiation-tainted-fukushima-no-1-buildings/#.WbS8LxdLfrd

Drone to measure radiation inside tainted Fukushima plant buildings

TOKYO (Kyodo) — The operator of the crippled Fukushima Daiichi nuclear power plant is planning to use a drone to measure radiation inside heavily contaminated structures as it prepares to decommission damaged reactors there, according to officials of the operator.

Data obtained from its use is expected to help the operator, Tokyo Electric Power Company Holdings Inc., create 3-D maps and identify areas with high-level radiation inside buildings where workers cannot stay safely.

The drone envisioned for the task is 93 centimeters wide and 83 cm long, and, equipped with four propellers, can fly for around 15 minutes. The operator envisions its use inside buildings that house damaged reactors and inside those housing turbines.

In February Tepco, as it is known, tested a drone inside the turbine building for the No. 3 reactor, one of three reactors that experienced meltdowns in the March 2011 earthquake and tsunami.

After improving its performance, the plant operator has decided to put the drone into use for radiation measurement. But it is still considering where it should begin using the machine, according to the officials.

The government and Tepco are aiming to start debris extraction work from 2021, and are currently in the process of determining a specific approach to removing melted fuel from each damaged reactor and of updating their decommissioning road map.

http://mainichi.jp/english/articles/20170910/p2g/00m/0dm/008000c

 

 

 

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10,000 tons of toxic water pools in Fukushima nuclear plant trenches

drainages aug 22 2016

Drainage chart/map

TOKYO (Kyodo) — Around 10,000 tons of contaminated water have pooled in underground trenches around the Nos. 1 to 4 reactor buildings of the crippled Fukushima Daiichi nuclear power plant, according to the plant operator Tokyo Electric Power Company Holdings Inc.

Tokyo Electric has no immediate plan to remove the water in the trenches where cables run for the nuclear power complex devastated by the March 2011 earthquake and tsunami disaster.

Water that flew into the trenches in the wake of the huge tsunami is believed to have been mixed with highly radioactive water leaking from the basements of reactor buildings and contaminated rain water.

“Compared with around 70,000 tons of highly contaminated water that remain in the basements of the reactor buildings, (the water in the trenches) has a low level of concentration and thus poses little threat in terms of radiation exposure and the environment,” said an official of the utility known as TEPCO.

trench01

 

TEPCO said in a report issued in July — based on research conducted in fiscal 2015 — that it has found around 8,000 tons of toxic water in 17 locations in the trenches that connect with reactor buildings where highly radioactive water accumulates, as well as around 3,000 tons of toxic water at 11 locations in trenches that do not connect with reactor buildings.

Fukushima_trenches_(Tepco)

 

Of the water in the trenches around the Nos. 1 to 4 reactor buildings, a removal procedure was completed by June for around 500 tons of water in a pipe that measured the highest level of radioactive cesium at 500,000 becquerels per liter.

The level of radioactive cesium in water at other locations in the trenches was mostly measured at several thousands becquerels or below.

The level in toxic water in the basements of reactor buildings has been measured at around dozens of millions becquerels at maximum.

TEPCO has said it will continue to monitor and measure the level of contamination in water in the trenches regularly and consider taking measures to remove the water in the future. But no concrete plan has been created yet.

The electricity firm has so far removed a total of around 10,000 tons of highly radioactive water at three locations in the trenches running in the seaside of the complex and completed the procedure to fill locations concerned with cement to prevent water leaks.

Still, the level of radioactive cesium remains unchecked at 40 locations in the trenches due to high radioactive levels as well as debris and other objects blocking the research operation.

Around 8,000 tons of contaminated water, including those with an extremely low level of contamination, have also been found in the trenches running around the Nos. 5 and 6 reactor buildings. The two units have lower levels of radiation doses than the Nos. 1 to 4 units as there were no nuclear meltdowns or hydrogen explosions there during the nuclear disaster.

http://mainichi.jp/english/articles/20160823/p2g/00m/0dm/074000c

Drainage charts/maps.
https://t.co/EIJkR80Biq

Tepcos Reports (PDF)
https://t.co/lTM563FjQe