23 Décembre 2013
December 23, 2013
Barriers surrounding storage tanks of radioactive water at the Fukushima No. 1 nuclear power plant were found to have four leaks in two tank areas, operator Tokyo Electric Power Co. said.
The company estimated that a maximum of 1.6 tons and 1 ton of contaminated water leaked from two spots of a barrier at one storage tank area on Dec. 21 and Dec. 22, respectively.
Radioactive strontium measuring 190 becquerels per liter, exceeding TEPCO’s tentative limit of less than 10 becquerels, was detected in water at the location on Dec. 22.
An estimated 0.8 ton of water leaked from two spots at a different barrier surrounding storage tanks located to the southeast. Three becquerels per liter of radioactive strontium were detected from water in this barrier.
TEPCO officials said the leakage was found mainly in the vicinity of concrete joints of the barriers surrounding the storage tanks of highly contaminated water.
Measures to prevent the water from seeping into the ground have already been taken, the officials added.
TOKYO (Kyodo) -- An estimated 1.8 tons of water has leaked through three newly discovered breaches in concrete barriers around clusters of tanks storing radiation-contaminated water at the stricken Fukushima Daiichi nuclear plant, Tokyo Electric Power Co. said late Sunday.
The finding follows a similar leakage of about 1.6 tons found Saturday.
The latest leaks were confirmed at barriers for two tank clusters, with water piling up 6 centimeters deep inside one of the barriers due to several days of rain and leaking through a gap between the barrier and its base, the plant operator said.
The leaked water is not believed to have flowed into the sea because there is no drainage ditch nearby, the utility said.
At the other cluster, water was confirmed to have leaked from below the barrier and also from a crack in the barrier, it said, adding it is investigating the situation.
The barriers, about 30 centimeters high, have been created around each of the 23 clusters of tanks holding highly radioactive water to block the water from spreading outside when a leak occurs in the tanks.
About 1.8 tons of radioactive water has leaked out of three new breaches in the water retention barriers ringing the storage tanks at the Fukushima No. 1 nuclear plant, Tokyo Electric Power Co. said.
The announcement late Sunday followed a report Saturday that 1.6 tons of tainted water had leaked from other barriers set up around the clusters of tanks. The barriers are supposed to prevent any water seeping from the leaky tanks from spreading.
The leaks were confirmed at two tank clusters. Tepco said one of the barriers, holding 6 cm of water augmented by several days of rain, was leaking due to a gap between its wall and base.
The water isn’t believed to have entered the sea because unlike previous cases, there is no drainage ditch nearby, the utility said.
At the second barrier, water was confirmed to have leaked both from the bottom and through a crack.
Water leaks found near Fukushima tank barrier
The operator of the damaged Fukushima Daiichi nuclear power plant says 1.6 tons of radioactive water is estimated to have drained into the ground from the barrier surrounding tanks storing contaminated water.
TEPCO officials said they found water coming from the barrier's foundation joints on Saturday afternoon.
They also said they measured 93 becquerels per liter of strontium 90 in the water remaining within the fence. The radiation level is about 9 times the national limit for water allowed to be released from the barrier.
The officials said they believe cause of the leakage was deteriorated joints.
They also said that, from the radiation level, they believe the leaked water is not radioactive water from the tanks but rainwater that had collected inside the fence.
They added that they think the high level of strontium 90 was detected because the rainwater absorbed radioactive materials that have been spreading in the environment since the March 2011 accident.
They confirmed that no radioactive water leaked into the ocean, as there are no drainage systems leading to the sea near the site.
Dec. 22, 2013 - Updated 08:28 UTC
December 22, 2013
New fix may be needed for leaks from tank barrier
The operator of the damaged Fukushima Daiichi nuclear plant says radioactive water may have leaked through barriers surrounding contaminated water tanks on the plant site.
TEPCO officials say an estimated 2.6 tons of water leaked through two seams on the concrete bottoms of barriers surrounding the tanks. The seams had been sealed with resin.
They say up to 190 becquerels per liter of strontium 90 were detected in the water inside the barrier. That radiation level is about 19 times the allowed national limit for radioactive water to be released from the barrier.
They say leaks were also found seeping through cracks at 2 other locations. Radiation levels in the water inside the barrier were within the safety limit.
The leaks through poorly made joints and from cracks in the barrier, rather than an overflow, may require TEPCO to take new countermeasures.
The utility has been working to raise the barrier after heavy rain in October caused water inside the barrier to overflow.
TEPCO officials confirmed that no radioactive water leaked into the ocean, as there are no drainage systems leading to the sea.
Dec. 22, 2013 - Updated 21:37 UTC