Reports from Tokyo Electric Power Co. (TEPCO), operator of the disaster-stricken Fukushima Daiichi nuclear power plant, say that measurements of radioactive tritium in seawater – seeping out of the nuclear complex via groundwater into the sea – show levels at 4700 becquerels per liter, the highest tritium level in the measurement history. The highest tritium levels have come in the past 15 days, the same reports show.
TEPCO also revealed that the highest levels of radiation in seawater were detected near reactor 1. Previous measurements showed the levels at 3800 becquerels per litre near reactor 1, and 2600 becquerels per liter near reactor 2, but the measurements have been showing increased radiation levels in the past 2 weeks. This increase in the harbour’s seawater has been continuously rising since May, reports said.
Also on Monday, another leak of highly contaminated water was discovered from the valve of a tank dike on the premises of the nuclear plant, adding to the multiple leak issues that the plant has had since TEPCO started the cleanup job on the facility. With this leak, radiation levels at the site again increased to 100 millisieverts per hour. The safe level of radiation is 1-13 millisieverts per year. The valve was said to have been left open so that rainwater can flow through, helping the TEPCO workers spot any radioactive leaks. TEPCO has since closed the valve as soon as it was discovered that radioactive water was flowing through it, instead of just surface and rainwater.