21 Mai 2014
May 21, 2014
Groundwater release begins at Fukushima Daiichi
Workers at the crippled Fukushima Daiichi nuclear power plant have started releasing groundwater into the ocean as part of the so-called "bypass plan."
The plan is part of Tokyo Electric Power Company's strategy to stem the accumulation of contaminated water on site.
It involves pumping up groundwater before it reaches the damaged reactor and turbine buildings, where it becomes heavily contaminated.
The pumped water is stored in tanks and tested for radiation. The last phase of the plan is to discharge the water into the ocean if radioactive levels are found to be below safety standards.
Government and TEPCO officials say they began releasing the water on Wednesday morning. They say radioactive levels were found to be below TEPCO's own safety target, which is lower than government standards.
A total of 560 tons of water will be released into the Pacific Ocean from an outlet south of the nuclear plant's port. The operation is expected to take more than 2 hours.
TEPCO officials estimate that 400 tons of groundwater seep every day into the basements of the facility.
They hope to reduce this figure by up to 100 tons once the bypass plan is implemented on a full scale.
May 21, 2014 - Updated 03:02 UTC
Groundwater within safety criteria released from Fukushima plant
TOKYO (Kyodo) -- Tokyo Electric Power Co. said Wednesday it started dumping into the Pacific Ocean hundreds of tons of groundwater collected at the crippled Fukushima Daiichi nuclear complex after having confirmed that its radiation level meets safety guidelines.
The groundwater has been pumped out before it approaches the heavily contaminated area of the site. By repeating the pumping and dumping, TEPCO aims to slow the pace of highly radioactive water accumulating at the plant.
The release of groundwater has long been planned as a key measure to address the toxic water buildup at the plant, but the operation has been delayed amid toxic water leaks and other problems that have undermined local people's confidence in TEPCO.
To allay safety concerns, TEPCO and the government have decided to release groundwater only after confirming that its contamination level is far below the legal limit.
Under the criteria, which TEPCO says are below the World Health Organization's guidelines for drinking-water quality, groundwater for release should contain less than 1 becquerel per liter of cesium-134 and cesium-137, 5 becquerels of beta ray-emitting radioactive material, such as strontium-90, and 1,500 becquerels of tritium.
TEPCO pumped a total of 560 tons of groundwater from wells dug in the mountainside of the plant between April 9 and 14 and have confirmed that the radiation levels satisfy the criteria before the planned release on Wednesday.
Some 790 tons of groundwater collected last year is expected to be released next, although a TEPCO official did not make clear on Tuesday when the discharge will take place.
TEPCO plans to gradually increase the volume of groundwater pumped from the wells. If the so-called groundwater bypass system goes into full operation, the official said water discharge could take place around once a week.
Highly radioactive water has been increasing by around 400 tons a day at the plant because the same volume of groundwater is seeping into the basement of reactor buildings and mixing with water used to cool three reactors that suffered meltdowns in the 2011 disaster.
TEPCO is installing more tanks so that it will not run out of water storage capacity, but it also wants to stop the total volume of radioactive water from increasing.
The official said the amount of water seeping into the reactor buildings may be reduced by up to 80 tons per day, but added that the effect of the groundwater bypass system needs to be checked through actual operation.
Suga lauds start of Fukushima bypass plan
Chief Cabinet Secretary Yoshihide Suga has welcomed the start of work at the Fukushima Daiichi nuclear plant to release groundwater into the sea.
Suga said this means the effort to manage the accumulation of large volumes of contaminated water can now be shifted to handling other problems.
He said it is a small step forward but still represents progress in relieving public anxiety over the handling of the cleanup.
Suga said the government is fully aware that local fishermen had no choice but to accept release of the groundwater into the sea.
He said the industry ministry will strictly oversee the work to ensure radioactive levels in the water never exceed safety standards.
May 21, 2014 - Updated 04:38 UTC