24 Jul (NucNet): Tokyo Electric Power Company (Tepco) says it is “working intensely” to speed up contamination prevention measures in an effort to stop the radioactive isotopes tritium and strontium-90 leaking into the sea near the Fukushima-Daiichi nuclear plant.
The plant operator said in a statement that the measured total beta-radiation activity (all-β) at one groundwater monitoring post on the east side of the turbine buildings of units 1 to 4 on 23 July 2013 was 150,000 becquerels per litre (Bq/ℓ). This was higher than the past highest density of 120,000 Bq/ℓ detected in a sample taken at the same monitoring post on 18 July 2013.
Tepco said it is continuing to tackle the problem of radioactive leaks into the groundwater, and potentially into the sea, by speeding up work such as improvements to the foundations of protection barriers and adding additional monitoring posts at water outlets and in the seawater port neighbouring the plant.
Last month Tepco found elevated concentrations of tritium and strontium-90 in the groundwater below units 1 to 4 of the plant. The company said levels of tritium had been detected at 0.5 million Bq/ℓ and of strontium-90 at 1,000 Bq/ℓ.
Tepco said it was likely the radioactive material entered the environment after water poured over the melted fuel in Unit 2 and leaked out via the turbine building, which is between the reactor and the ocean.
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