Earth Watch Report - Environmental Pollution - Nuclear Plant Incident
Fukushima Dumps 30 TRILLION Bq Radioactive Water, Lower Tuna Catch Quota update 8/22/13
|Environment Pollution||Japan||Prefecture of Fukushima, [Fukushima No. 1 nuclear power plant]|
|Updated:||Friday, 23 August, 2013 at 03:07 UTC|
|Tokyo Electric Power Company workers have detected high levels of radiation in a ditch that flows into the ocean from a leaking tank at the crippled Fukushima Daiichi nuclear plant. Japan’s nuclear watchdog said Thursday the leak could be the beginning of a new disaster – a series of leaks of contaminated water from hundreds of steel tanks holdng massive amounts of radioactive water coming from three melted reactors, as well as underground water running into reactor and turbine basements. Tokyo Electric Power Co. says about 300,000 litres of contaminated water leaked from one of the tanks, possibly through a seam. The leak is the fifth, and worst, since last year involving tanks of the same design at the wrecked Fukushima Dai-ichi plant, raising concerns that contaminated water could begin leaking from storage tanks one after another. “That’s what we fear the most. We must remain alert. We should assume that what has happened once could happen again, and prepare for more,” Nuclear Regulation Authority chairman Shunichi Tanaka told a news conference. “We are in a situation where there is no time to waste.” The watchdog also proposed at a weekly meeting Wednesday to raise the rating of the seriousness of the leak to level three, a “serious incident,” from level one, “an anomaly,” on an International Nuclear and Radiological event scale from zero to seven.The watchdog urged TEPCO to step up monitoring for leaks and take precautionary measures. During the meeting, officials also revealed that plant workers apparently have overlooked several signs of leaks, suggesting their twice-daily patrols were largely just a walk. They have not monitored water levels inside tanks, obviously missed a puddle forming at the bottom of the tank earlier, and kept open a valve on an anti-leakage barrier around the tanks. TEPCO said the leaked water is believed to have mostly seeped into the ground after escaping from the barrier around the tank. It initially said the leak did not pose an immediate threat to the sea because of its distance – about 500 metres from the coastline. But TEPCO reversed that view late Wednesday and acknowledged a possible leak to the sea after detecting high radioactivity inside a gutter extending to the ocean. The company also said the tank may have been leaking slowly for weeks through a possible flaw in its bottom. That could create extensive soil contamination and a blow to plans to release untainted underground water into the sea as part of efforts to reduce the amount of radioactive water. The leaks have shaken confidence in the reliability of hundreds of tanks that are crucial for storing water that has been pumped into the broken reactors to keep melted radioactive fuel cool.|
Latest Radioactive Leak at Fukushima: How Is It Different?
Photograph by Kyodo/Reuters
Published August 21, 2013
In the latest crisis to strike the Fukushima-Daiichi nuclear power plant in Japan, operator Tokyo Electric Power (TEPCO) has discovered that 300 tons (nearly 72,000 gallons) of highly radioactive water has leaked from a holding tank into the ground over the past month.
The development comes on top of TEPCO’s admission last month that an estimated 300 tons of radioactive groundwater, which picks up small amounts of contamination when it flows through the damaged reactor buildings, has been leaking into the Pacific Ocean every day. (See related story: “Fukushima’s Radioactive Water Leak: What You Should Know.”)
The new storage tank leak presents a different and potentially more serious problem than the ongoing groundwater flow leaks. The water from the leaking tank is so heavily contaminated with strontium-90, cesium-137, and other radioactive substances that a person standing less than two feet away would receive, in an hour’s time, a radiation dose equivalent to five times the acceptable exposure for nuclear workers, Reuters reported. Within ten hours, the exposed person would develop radiation sickness, with symptoms such as nausea and a drop in white blood cells.
A More Hazardous Leak
The latest leak comes from one of the massive array of 1,000 above-ground storage tanks built inside the plant by TEPCO, which store water that deliberately has been pumped into the damaged reactors in an effort to cool the nuclear fuel inside and prevent a meltdown. Such water is heavily contaminated and dangerous compared with the larger radioactive groundwater flow problem, which scientists say does not pose an immediate health hazard to humans (though it has made some types of fish from the area unsafe for consumption).
The Japanese government’s Nuclear Regulation Authority is calling the leak a “serious accident” and wants to raise the official threat level from 1 to 3 on the International Nuclear and Radiological Event Scale—the highest level since the level 7 rating given when the March 2011 earthquake and tsunami severely damaged the facility. (See related “Pictures: The Nuclear Cleanup Struggle at Fukushima.”)
While about two-thirds of Fukushima’s storage tanks are welded steel vessels, the leaking tank is one of about 350 improvised temporary tanks that TEPCO has employed to augment its capacity. The temporary tanks are made of steel plates bolted together with plastic packing materials to seal the seams, and apparently are more vulnerable to leaks. A TEPCO official told The Japan Times, an English-language daily, that there have been four previous leaks in the temporary tanks. Unlike the previous ones, this leak somehow went undetected by plant workers for as long as a month. During that time, it leaked an estimated ten tons (about 2,400 gallons) of highly radioactive water per day. (See related photos: “A Rare Look Inside Fukushima Daiichi.”)