The company that operates the Fukushima nuclear reactors crippled by the March 2011 earthquake and tsunami started dumping groundwater into the Pacific Ocean on Wednesday (May 21).
And the facility used to treat the most contaminated water shut down this week after repeated breakdowns and leaks.
In a Tokyo Electric Power Company (TEPCO) release dated May 21, managing executive officer Nachiro Masuda wrote that the so-called groundwater bypass “plays an important role among the countermeasures to suppress the increase of contaminated water” building up daily at the damaged and highly contaminated nuclear power station.
Radiation said to be below safety thresholds
TEPCO previously stated that the May 21 release would consist of 560 tons of groundwater contained before it could enter highly radioactive basements of reactor buildings at the Fukushima No. 1 complex and become more contaminated.
The power utility said all groundwater pumped from wells uphill from the reactors and released will be checked for radiation levels, including confirmation tests by “independent” parties, as demanded by an association of local fishermen as a condition for implementing the controversial bypass and dumping program.
Prior to the first release, TEPCO said that strontium-90 levels in the water were undetectable, and that cesium-134 and -137 levels were below safety thresholds. Asahi Shimbun reported on May 15 that tritium levels were well below threshold levels.
Since the March 2011 disaster, TEPCO has admitted that it has previously underestimated radiation levels at the stricken site, blaming faulty equipment.
Regular releases planned
According to the Japan Times on May 21, TEPCO has announced that a further 790 tons of groundwater stored in makeshift tanks in 2013 may be the next release. No date was given for that dump.
Previously, the power company has announcd that if the bypass is successful, it plans to release groundwater pumped from uphill wells on a regular basis, perhaps weekly, in an attempt to reduce the huge amounts of water being stored in more than 1,000 tanks in makeshift tank farms.
According to the utility, 400 tons of water daily seep into the basements of the destroyed reactor buildings, where it mixes with the extremely radioactive cooling water. The bypass could reduce the amount of water reaching the buildings by up to 80 tons per day.
Specialized water-treatment facility shut down
Meanwhile, the Times also reported on May 21 that the manager of the “advanced liquid processing system”, used to treat water with the most dangerous radionuclide contamination, called its latest closure “embarrassing”.
The system has never operated at full capacity since its installation in 2012.