5 Juin 2013
June 5, 2013
Tokyo Electric Power Co. has detected radioactive cesium in groundwater previously deemed clean at the stricken Fukushima No. 1 nuclear plant, dealing a blow to plans to dump the water into the ocean.
TEPCO, the plant’s operator, on June 3 acknowledged that it miscalculated the influence of background radiation when it measured radioactivity levels of the groundwater in storage tanks in mid-April. At that time, the company said contamination of the water was negligible.
However, new measurements found a low level of cesium at 0.61 becquerel per liter, a TEPCO official said.
Although that level is still lower than the utility’s standard for dumping the water into the ocean, fishermen operating in the area of the plant were furious about TEPCO’s latest mistake.
“(Our approval for the plan to) discharge groundwater into the sea has certainly taken a step backward,” Masakazu Yabuki, who heads the Iwaki city fisheries cooperative, said angrily.
The Fukushima prefectural government has instructed TEPCO to take thorough and proper measurements of the water.
Groundwater continues to pour into the basement levels of damaged nuclear plant buildings that are already flooded with contaminated water. TEPCO is running out of storage space for the water used to cool the reactors, and some of its underground tanks have been leaking.
To alleviate the water-storage problem, TEPCO plans to pump up the groundwater from wells on the plant’s premises, confirm the safety of the water, and dump it into the ocean.
The central government and TEPCO on May 30 said the groundwater contamination was negligible in a meeting with local fishermen.
June 4, 2013
TOKYO (Kyodo) -- Tokyo Electric Power Co. said Monday that it has detected radioactive cesium in groundwater samples taken from the premises of the crippled Fukushima Daiichi nuclear complex, reversing an earlier announcement that any contamination was negligible.
The announcement came as TEPCO is trying to secure the understanding of local fishermen over the dumping in the Pacific Ocean of groundwater that has been pumped out from wells at the site, saying it has confirmed that concentrations of radioactive substances are sufficiently low.
TEPCO had said radioactive cesium in the groundwater was at a level that could not be detected by an instrument at the Fukushima Daiichi complex. But the same sample was found to contain 0.22 becquerel of cesium-134 and 0.39 becquerel of cesium-137 per liter when checked at the Fukushima Daini plant, where radiation levels are lower.
According to the utility, there was a problem in accounting for background radiation.
The revised amount of cesium-137 is still below the level that TEPCO views as the upper limit for releasing groundwater, which is less than one becquerel.
Currently, about 400 tons of groundwater seeps into the crippled reactor buildings every day, where it becomes contaminated with radioactive substances. This means that the total volume of toxic water is increasing by the same amount daily.
To slow the rate of accumulation of polluted water, TEPCO has created a system to direct part of the groundwater into the ocean by pumping it out before it flows into the reactor buildings. The groundwater is stored in tanks before it is discharged.
But the utility has not been able to fully operate the system amid concern from local fishermen that dumping groundwater may affect the marine environment.
The latest revelation could undermine the credibility of related data presented by TEPCO, possibly making it hard for the utility to get the nod to discharge the groundwater and standing in the way of the overall plan to tackle the massive amounts of radioactive water at the plant.