nuclear-news

Cesium 180 times limit found in fish at Fukushima nuke plant 12 years after disaster.

July 19, 2023 (Mainichi Japan)

FUKUSHIMA — Radioactive cesium 180 times Japan’s legal maximum has been found in fish caught in the port at the crippled Fukushima Daiichi nuclear plant, revealing that the March 2011 triple meltdown there continues to impact the local ecosystem.

The cesium in the black rockfish caught in May measured 18,000 becquerels per kilogram. The legal limit under the Food Sanitation Act is 100 becquerels per kg. According to plant operator Tokyo Electric Power Company (TEPCO) Holdings Inc., the fish was captured inside the inner breakwater, close to the No. 1 to No. 4 reactors at the seaside plant, where decommissioning work continues.

When it rains, the rainwater streams into the “K drainage” — one of several drainpipes at the plant — after running through debris and over the ground, both contaminated with radioactive substances. It is then discharged into the station’s small port.

TEPCO claims that it has confirmed the cesium levels in the discharged rainwater are below the government criteria of 60 becquerels per liter for cesium-134 and 90 becquerels for cesium-137. But compared with other drainages at the plant, runoff with higher concentrations of radioactive materials has been discharged within the inner breakwater. The seabed sediment in the area was also found to contain cesium-137 up to 130,000 becquerels-plus per kilogram and cesium-134 up to 3,400 becquerels-plus as of the end of January this year………………………………………………………………..

……………………………………………………….”We urge that TEPCO take thorough measures to prevent radioactive materials from getting into the ocean, even within the port,” a fisheries federation official urged, refering to the black rockfish with more than 100 becquerels per kg caught in May at the nuclear complex’s port.

Toshihiro Wada, an associate professor of fish ecology at Fukushima University, said of the heavily contaminated fish, “It’s likely that cesium was concentrated within the fish from the food chain, confined as it is by the inner breakwater where radioactive substances have accumulated from the drainages flowing into the port.”

He continued, “Unless fundamental measures are taken to lower the concentrations of radioactive materials discharged from the ‘K drainage,’ fish surpassing the maximum will likely keep being found,” even as TEPCO has stepped up measures to prevent fish from getting away…………………………………

Radioactively contaminated water has been swelling daily at the plant as water injected to cool nuclear fuel debris that melted down in the 2011 disaster has been accumulating with groundwater and rainwater mixing into it. TEPCO processes the contaminated water using ALPS, or multi-nuclide removal equipment, and stores the treated water in tanks after reducing the radioactive levels apart from tritium, which is difficult to remove from water.

‘Set treated water aside’

The Japanese government plans to release treated water from the Fukushima plant into the ocean around the summer, after diluting it to get tritium concentrations below 1,500 becquerels per liter, or one-fortieth of the national standard. It plans to release the water about 1 kilometer offshore via an undersea tunnel.

“Unlike cesium, tritium does not concentrate in fish even if they ingest it, according to data,” associate professor Wada said. “Experimental results have shown that if treated water is put into regular seawater, the concentration (of tritium) is reduced. We need to consider (tritium) separately from cesium.”

(Japanese original by Riki Iwama, Fukushima Bureau, and Hideyuki Kakinuma, Iwaki Local Bureau) https://mainichi.jp/english/articles/20230718/p2a/00m/0na/019000c?fbclid=IwAR2R-0GtuaSlHvGQZ13yqRzQdZ1HUr3RNu4yHWzLBLytboJldZs2eMLHmxM

July 24, 2023 - Posted by Christina Macpherson | environment, Fukushima continuing