The amount of radioactive tritium in wastewater from Chinese nuclear plants, recorded at 13 of the nation's monitoring points in 2021, surpassed the maximum allowable annual amount of the material contained in treated water set to be released from the Fukushima Daiichi plant, according to public data.

Beijing has been opposed to Tokyo's plan to begin releasing treated radioactive water from the crippled Fukushima plant into the sea and has tightened controls on seafood imports from Japan. Tokyo has not taken such measures despite the high level of tritium found in Chinese waters.

Chinese Foreign Ministry spokesman Wang Wenbin has stressed the difference between the Fukushima water and that released by nuclear plants in normal operations, saying no comparison can be drawn between the two as the former "came into direct contact with melted reactor cores."

The Qinshan nuclear plant in the eastern Zhejiang Province discharged around 218 trillion becquerels of tritium in 2021, roughly 10 times the maximum annual release set for the Fukushima water at 22 trillion becquerels, according to the data from a yearbook on the Chinese nuclear power industry.

File photo shows the Fuqing nuclear power plant in Fuqing, Fujian Province, China, in January 2021. (Kyodo)

The yearbook contains radioactive material monitoring results of water released from 13 nuclear plants at 17 points in the country.

The amount of tritium found in water from the Daya Bay and Yangjiang nuclear plants in the southern Guangdong Province was around five times the maximum annual amount for the Fukushima water, while the Fuqing plant in the southeastern Fujian Province discharged 2.4 times more tritium than the Fukushima upper limit.

Under China's national environmental protection law and related legislation, the maximum annual release of radioactive materials from nuclear plants is determined based on the size of the facilities.

The Haiyang nuclear plant in Shandong Province released 82.6 trillion becquerels of tritium in 2021, close to the upper limit set for the facility.

Before the major nuclear accident in 2011, triggered by a massive earthquake and tsunami, the Fukushima Daiichi plant in northeastern Japan was releasing about 2.2 trillion becquerels of tritium annually, according to Japan's industry ministry.

In July this year, the International Atomic Energy Agency concluded in a report submitted to the Japanese government that the planned Fukushima water release aligns with global safety standards and will have "a negligible radiological impact on people and the environment."

However, China has contended that the IAEA did not adequately represent the perspectives of the participating experts in their review. Consequently, China implemented comprehensive radiation testing on all seafood imports from Japan to guarantee public health and food safety.

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