Post by Ex_Nuke_Troop on Feb 21, 2014 17:19:00 GMT
Mainichi : 100 tons of toxic water leaked at Fukushima plant, no flow to sea
TOKYO (Kyodo) -- Roughly 100 tons of highly radioactive water leaked from one of the huge tanks at the crippled Fukushima Daiichi nuclear complex, plant operator Tokyo Electric Power Co. said Thursday, admitting it could be the worst leakage from such containers since August.
Steps have been taken to stop the leakage of the water, which contains 230 million becquerels per liter of strontium and other beta ray-emitting radioactive substances. The utility believes the liquid has not flowed into the adjacent sea as there is no drainage nearby.
According to TEPCO, a worker on patrol noticed water spilling from the tank's lid area at 11:25 p.m. Wednesday. The water, by passing through a rainwater pipe, escaped outside a concrete barrier intended to block liquid from spreading outside when tanks leak.
TEPCO spokesman Masayuki Ono told a press conference the company suspects that radioactive water was mistakenly directed to the tank because valves that should have been closed were open, causing the container to overflow.
Among three valves, one appeared to have been closed, but may have malfunctioned, while two others had been open.
After closing the two valves, TEPCO said it confirmed the leak stopped at 5:40 a.m. Thursday.
More than nine hours before the leak was recognized, an alarm indicating a rise in the tank's water surface level was issued.
But workers thought the device was out of order and also could not find leaks when they patrolled the area at 3 p.m. and 4 p.m. Wednesday.
Ono said the utility may consider clarifying how valves should be operated and improving the design of rainwater pipes, which are attached to tanks as a measure to prevent rainwater from accumulating inside the concrete barriers surrounding clusters of tanks.
He also said the company must determine if and when the valve and a water level indicator malfunctioned.
The latest incident is another sign TEPCO is struggling to manage a massive amount of radioactive water generated in the process of cooling three reactors that have suffered meltdowns during the nuclear crisis triggered in March 2011.
The water passes through a facility that can reduce cesium, but it contains high concentrations of radioactive substances such as strontium-90. Strontium tends to accumulate in bones and is thought to cause bone cancer and leukemia.
In August last year, TEPCO said 300 tons of highly radioactive water escaped from a different tank, some of which is also believed to have flowed into the ocean.
TEPCO has since been stepping up efforts to detect leak incidents as quickly as possible such as by reinforcing patrolling activities and installing water-level indicators to all of the tanks made of steel sheets joined by bolts.
mainichi.jp/english/english/newsselect/news/20140220p2g00m0dm081000c.html
TOKYO (Kyodo) -- Roughly 100 tons of highly radioactive water leaked from one of the huge tanks at the crippled Fukushima Daiichi nuclear complex, plant operator Tokyo Electric Power Co. said Thursday, admitting it could be the worst leakage from such containers since August.
Steps have been taken to stop the leakage of the water, which contains 230 million becquerels per liter of strontium and other beta ray-emitting radioactive substances. The utility believes the liquid has not flowed into the adjacent sea as there is no drainage nearby.
According to TEPCO, a worker on patrol noticed water spilling from the tank's lid area at 11:25 p.m. Wednesday. The water, by passing through a rainwater pipe, escaped outside a concrete barrier intended to block liquid from spreading outside when tanks leak.
TEPCO spokesman Masayuki Ono told a press conference the company suspects that radioactive water was mistakenly directed to the tank because valves that should have been closed were open, causing the container to overflow.
Among three valves, one appeared to have been closed, but may have malfunctioned, while two others had been open.
After closing the two valves, TEPCO said it confirmed the leak stopped at 5:40 a.m. Thursday.
More than nine hours before the leak was recognized, an alarm indicating a rise in the tank's water surface level was issued.
But workers thought the device was out of order and also could not find leaks when they patrolled the area at 3 p.m. and 4 p.m. Wednesday.
Ono said the utility may consider clarifying how valves should be operated and improving the design of rainwater pipes, which are attached to tanks as a measure to prevent rainwater from accumulating inside the concrete barriers surrounding clusters of tanks.
He also said the company must determine if and when the valve and a water level indicator malfunctioned.
The latest incident is another sign TEPCO is struggling to manage a massive amount of radioactive water generated in the process of cooling three reactors that have suffered meltdowns during the nuclear crisis triggered in March 2011.
The water passes through a facility that can reduce cesium, but it contains high concentrations of radioactive substances such as strontium-90. Strontium tends to accumulate in bones and is thought to cause bone cancer and leukemia.
In August last year, TEPCO said 300 tons of highly radioactive water escaped from a different tank, some of which is also believed to have flowed into the ocean.
TEPCO has since been stepping up efforts to detect leak incidents as quickly as possible such as by reinforcing patrolling activities and installing water-level indicators to all of the tanks made of steel sheets joined by bolts.
mainichi.jp/english/english/newsselect/news/20140220p2g00m0dm081000c.html