Six workers at Japan's crippled Fukushima Daiichi nuclear plant were exposed to leaking radioactive water after one of them mistakenly removed a pipe to a water treatment system, the plant's operator said Wednesday.
Tokyo Electric Power Co. (TEPCO) has been battling to contain radioactive water at the plant, which suffered triple meltdowns and hydrogen explosions after a massive earthquake and tsunami damaged the reactor containment and cooling systems in March 2011. Regulators have criticized the utility for its handling of the problems.
In the latest incident, a worker mistakenly detached a pipe connected to a treatment system to remove salt from the hundreds of tons of water that TEPCO pumps over the melted fuel in wrecked reactors at Fukushima to keep them cool.
"Several tons" of water spilled at the treatment facility but were contained within the site, a TEPCO spokesman said.
At least seven metric tons of highly radioactive water may have leaked, according to a Reuters calculation based on the latest figures released by TEPCO. A metric ton of water is equivalent to 264 U.S. gallons.
On Monday, TEPCO said a plant worker had accidentally switched off power to pumps that inject water to cool the damaged reactors. A backup system kicked in immediately, but the event was yet another incident in a long list that serves as a reminder that the Fukushima disaster is a continuing crisis, still far from resolved.
TEPCO said last week that 113 gallons of contaminated water had spilled out of a storage tank at Fukushima and probably flowed to the ocean.
Japan's Nuclear Regulation Authority said on Wednesday that the incident was equivalent to Level 0 on the International Nuclear and Radiological Event Scale (INES), but did not give an official rating.
In August, a leak of 300 metric tons of highly radioactive water from a hastily built tank on the site was given a Level 3, or "serious incident," rating on the INES scale. A maximum Level 7 was declared at the battered plant after explosions led to a loss of power and cooling two years ago, confirming Fukushima as the worst nuclear accident since Chernobyl a quarter of a century earlier.
The contaminated water has been found to contain radioactive isotopes such as tritium, strontium-90 and cesium-137. Elevated exposure to these isotopes has been linked to a number of cancers, birth defects, thyroid disease and immunological disorders.
On Monday, Japanese Prime Minister Shinzo Abe suggested that his country was open to receiving international assistance to contain the ongoing disaster.
Al Jazeera and Reuters