TEPCO starts dumping radioactive water into Pacific  

东电将福岛第一核电站560吨地下水排入大海

Tokyo Electric Power Co. (TEPCO), the operator of the stricken Daiichi nuclear power station in Fukushima Prefecture, said Wednesday it had started dumping hundreds of tons of radioactive groundwater from its plant into the Pacific Ocean.

TEPCO said the levels of radioactivity of the groundwater being released were within legal radiation safety limits and will follow the World Health Organizations guidelines that groundwater for such releases should contain less than 1 becquerel per liter of cesium-134 and cesium-137, 5 becquerels of beta ray-emitting radioactive material.

The move to dump the huge amount of toxic water was unavoidable, TEPCO said, due to the massive volumes of contaminated water building up and failing to be decontaminated and maintained inside the complex.

The embattled utility has been struggling to deal with a number of problems and human errors at the leaking plant, since its reactors' key cooling functions were knocked out by a huge earthquake-triggered tsunami in March 2011.

The utility is still grappling to deal with the daily accumulation of around 400 tons of highly radioactive water, with the same volume of groundwater seeping into the basement of reactor buildings where it's being mixed with the reactors' highly toxic coolant water.

Following protracted negotiations, local fisherman finally agreed to the release of the contaminated water into the Pacific Wednesday, once they'd been convinced that the contaminated water would not adversely affect their business, but the agreement came as the utility had to deal with a fresh headache involving the breakdown of a water treatment system for the highly contaminated water held in thousands of makeshift tanks.

A water treatment facility called the Advanced Liquid Processing System (ALPS), installed to remove the most dangerous nuclides, was completely shut down again this week and has not been fully operational since it was installed nearly two years ago, causing the manager of TEPCO to state that the repeated leaks and technical malfunctions at the plant have been a constant " embarrassment".

TEPCO has pumped a total of 560 tons of groundwater from wells dug in the mountainside of the plant with the operation beginning on April 9 and finishing five days later, and having confirmed that the radiation levels have met legal criteria and will release into the ocean Wednesday using a bypass system that funnels the contaminated water towards the Pacific.

Similarly, around 790 tons of groundwater collected last year will be also be released imminently, although TEPCO officials have declined to specify exactly when.

TEPCO has confirmed, however, that it plans to dump around 100 tons a day of groundwater from the crippled plant into the ocean, once the bypass system goes fully operational, although concerns remain rife as the trouble-stricken utility has again come under fire Wednesday, following the Asahi Shimbun newspaper reporting that based on official unreleased documents, some 90 percent of all workers, including managers duty-bound to deal with emergencies, refused orders and fled the Fukushima Daiichi nuclear plant, at a critical juncture when the disaster was unfolding in March 2011.

"Amid fears that a reactor containment vessel had been destroyed, around 650, or 90 percent, of the approximately 720 workers at the plant left the premises despite being told to remain at the site by the plant's manager, Masao Yoshida," the newspaper said.

TEPCO, despite receiving a massive injection of capital to bring the crisis in Fukushima under control at the beginning of this year, has also been slammed by Nuclear Regulation Authority ( NRA) Chairman Shunichi Tanaka for incorrectly measuring levels of radioactive materials in groundwater at its Daiichi facility.

Tanaka has said that even though three years has passed since the reactor meltdowns at the plant, TEPCO is still "utterly inept" when it comes to taking accurate readings of radioactivity at and around its facilities and "lacks a basic understanding of measuring and handling radiation."

TEPCO reported in February it had detected a record 5 million becquerels per liter of highly-dangerous radioactive strontium-90. The reading was more than five times the total beta radiation reading of 900,000 becquerels per liter recorded in a well, located just meters from the Pacific.

A spokesperson for the utility said the massive error was due to a "calibration error" on one of the machines giving vital readings on strontium levels in samples of water taken from a well near the ocean.

He added that other machines had also been mistakingly calibrated, specifically involving machines that decipher all-beta- radiation.

TEPCO, since the reactor meltdowns in 2011, has been plagued with problems at the Fukushima plant, located 250 km northeast of Tokyo, many of them "avoidable", according to a number of experts including Tanaka and other regulatory authorities and representatives from the International Atomic Energy Agency (IAEA).

Tanaka has pointed to examples of tanks being overfilled with water by workers causing radioactive water to spew over the tank's top and human error being responsible for a worker mistakenly removing a pipe connected to a desalination treatment system used to treat water housed to keep melted fuel cool. The result caused more than seven tons of radioactive water to leak from the pipe for around 50 minutes.

In addition, a vital pump used to inject water to cool nuclear fuel inside the No.1 turbine building at the Fukushima plant was switched off due to a worker mistakingly pressing a stop button on a switchboard.

The cooling of nuclear fuel was temporarily suspended in two of the complex's containment units and the decontamination of radioactive gases was also halted due to the easily avoidable error.

The overall decommissioning of the plant is expected to take around 40 years, with the removal of all nuclear fuel from the Number 4 reactor building being completed by the end of this year, however TEPCO said it had only successfully removed around 9 percent of more than 1,500 unused and spent fuel assemblies in the reactor building's storage pool.