The Tokyo Electric Power Company (TEPCO), operator of the crippled Fukushima Daiichi Nuclear Power Plant, admitted this week that it had known since last April that radioactive water was leaking at the plant, but had not reported it until now.
The announcement comes after another highly contaminated leak was found in a gutter that pours rain and groundwater from the plant into a nearby bay.
The leak found last April contained cesium levels as high as 23,000 becquerels per liter, more than 10 times the level seen in other water samples taken from the same roof.
TEPCO said it will prevent this leak from contaminating other water sources by placing absorbent sandbags in the area, while also covering the drains that lead to the sea. These measures are expected to be in place by the end of March.
The utility claimed monitoring systems in nearby ocean waters never showed an increase in radiation levels.
TEPCO has been criticized for its handling of the plant’s closure and cleanup since the March 2011 earthquake and tsunami that devastated it.
Fukushima Prefecture Governor Masao Uchibori told Nippon TV that “It is extremely regrettable the swift release of information and the importance of that awareness -- these basic things were not carried out.”
Local fishermen also expressed concern about the failure to report the leaks, which could affect their livelihoods.
Handling contaminated wastewater at the plant has been one of TEPCO’s biggest problems. Every day, more contaminated water is produced by the cooling process at the plant, and by groundwater and rainwater seeping into damaged sections.
The company is storing the wastewater on site until it can be treated and released into the Pacific Ocean. However, it has encountered a number of difficulties, including running out of space for more storage tanks, leaks of several hundred tons of wastewater, as well as the ongoing problems with the treatment system, which has often been non-operational for long periods of time.
TEPCO had previously set a deadline for having all wastewater treated by the end of March, but announced earlier this year that it would miss its self-imposed deadline by at least two months.