Samples from the crippled Fukushima Daiichi nuclear complex grounds were found to be contaminated with radioactive cesium, prompting utility Tokyo Electric Power Co. (TEPCO) to take back an earlier statement about groundwater safety in the area. Prior to TEPCO’s announcement on Monday, the company said that there’s no need to raise the alarm for any contamination detection. The discrepancy of the findings resulted from a problem of accounting background radiation according to the utility.
The sample obtained by TEPCO was said to be on a level not detected by the Fukushima Daiichi complex instrument. When tested again at the Fukushima Daini plant, which is known to have lower radiation levels, results showed to have 0.22 Becquerel of Cesium-134 and 0.39 Becquerel of Cesium-137 per litre. Cesium-134 is known to have a half-life of 2 years while Cesium-137 has longer half-life of 30 years. There is about 400 tons of groundwater getting in contact with the reactor buildings in Fukushima Daiichi complex every day. It can be said that the same amount of groundwater also becomes contaminated on a daily basis.
TEPCO has developed a system to reverse or at least slow down the contamination brought about by the reactor buildings at the Fukushima Daiichi nuclear plant. It will direct some waters into the ocean without reaching the reactor buildings. The groundwater will then be stored in tanks before release. TEPCO’s system is only one among those that are developed to make Fukushima at least less contaminated given the damage it created after the Tohoku Earthquake and Tsunami in 2011.
Should the discrepancy continue, it is unlikely for Fukushima Daiichi nuclear plant to release the groundwater. Cesium is known to be highly reactive, even with water at low temperatures. It is also known to be very pyrophoric. Cesium-137 is particularly very mobile because of its water-soluble properties, thus imposing greater risk when released in the environment.