Record high levels of radioactive tritium have been observed in the harbor at Fukushima.
Japan Times notes:
The density of radioactive tritium in samples of seawater from near the Fukushima No. 1 nuclear plant doubled over 10 days to hit a record 1,100 becquerels per liter, possibly indicating contaminated groundwater is seeping into the Pacific, Tokyo Electric Power Co. said.
Tepco said late Monday it was still analyzing the water for strontium-90, which would pose a greater danger than tritium to human health if absorbed via the food chain. The level of cesium did not show any significant change between the two sample dates, according to the embattled utility.
On June 19, Tepco revealed that a groundwater sample taken from a nearby monitoring well was contaminated with both tritium and strontium-90.
During a news conference Monday in Tokyo, Masayuki Ono, a Tepco executive and spokesman, this time did not deny the possibility of leakage into the sea, while he said Tepco is still trying to determine the cause of the spike.
A sample collected Friday contained around 1,100 becquerels of tritium per liter, the highest level detected in seawater since the nuclear crisis at the plant started in March 2011, the utility said Monday.
The latest announcement was made after Tepco detected high levels of radioactive tritium and strontium in groundwater from an observation well at the plant.
Indeed, the amount of radioactive strontium has skyrocketed over the last couple of months at Fukushima.
The New York Times writes:
Tokyo Electric Power, the operator of the stricken nuclear power plant at Fukushima, said Wednesday that it had detected high levels of radioactive strontium in groundwater at the plant, raising concerns that its storage tanks are leaking contaminated water, possibly into the ocean.
The company has struggled to store growing amounts of contaminated runoff at the plant, but had previously denied that the site’s groundwater was highly toxic….
Very high radioactivity levels were detected in groundwater from an observation well at the crippled Fukushima Daiichi nuclear plant, said the plant operator Tokyo Electric Power Co. (TEPCO) Wednesday.
The observation well was set up on the Pacific side of the plant’s No. 2 reactor turbine building last December to find out the reasons why radioactivity levels in seawater near the plant remained high. The company said the sampled water could be from the contaminated water that seeped into the ground.
Reuters points out:
Testing of groundwater showed the reading for strontium-90 increased from 8.6 becquerels to 1,000 becquerels per litre between Dec. 8, 2012 and May 24.
High levels of a toxic radioactive isotope have been found in groundwater at Japan’s Fukushima nuclear plant, its operator says.
Strontium-90 is formed as a by-product of nuclear fission. Tests showed that levels of strontium in groundwater at the Fukushima plant had increased 100-fold since the end of last year, Toshihiko Fukuda, a Tepco official, told media.
Other types of radioactive materials will continue to pose a hazard for decades. As nuclear engineer Arnie Gundersen explains:
The radiation exposures are going up. What you’re seeing is a lot of this stuff is getting revolitalized. It’s in the first couple of inches of dust, and when the wind blows it moves into areas that have been previously cleaned.
This will go on for decades, as the cesium goes down in to the soil, the roots bring it back up and into the plant structures and the leaves fall on the ground and the cycle continues.