March 23, 2011— -- Black smoke emerging from Unit 3 of the crippled Fukushima Daiichi nuclear plant in northeastern Japan forced the temporary evacuation of workers, Tokyo's utility company said Wednesday.
Operators of the power station have been toiling to cool the reactors and spent fuel pools at the plant after it was damaged by the March 11 tsunami, which knocked out power to the cooling systems.
Chief Cabinet Secretary Yukio Edano said today that he regrets that rain and wind have spread radiation from Fukushima.
Earlier today Japanese officials issued a statement advising that tap water in Tokyo not safe for infants as it has tested two times above the limits for radioactive iodine. The Tokyo Water Bureau said that the number of Becquerel per unit detected was 210. The allowable level for infants is 100, while the allowable level for adults is 300.
Officials said that babies in Tokyo should not be fed tap water, but that the level is not an immediate health risk for adults.
Speaking with the press today, Edano said that the Japanese government is looking into what can be done for families with infants.
Radiation has now seeped into vegetables, raw milk, the water supply and even seawater in the areas surrounding the plant.
Broccoli was added Wednesday to a list of tainted vegetables, now including spinach, canola and chrysanthemum greens.
Meanwhile, this morning a spokesman for the nuclear safety agency said that high-level radiation fields of 500 millisieverts/hr were detected at Unit 2's turbine building a few days ago, and that is preventing workers from trying to restore the power at the control room.
At those levels a worker would reach Japan's imposed emergency exposure limit of 250 milliSvr within just 30 minutes.
Exposure of 500 milliSvr is the generally accepted threshold at which individuals would begin to suffer immediate health effects.
The temperature and pressure readings in the core of Unit 1 are also a major concern. The vessel is designed to a threshold of 302 degrees Celsius. Currently its external temperature is now about 400 degrees Celsius.
It has been reported that the unit is not in danger of melting, but seawater is now being injected at nine times the previous rate.
That, too, has to be done very carefully, as adding water increases the pressure inside the reactor vessel. If pressure gets too high, it would likely result in the need to release of radioactive steam to reduce the pressure and avoid damage to the vessel, or even worse, an explosion.
While the hope is that power will be back on soon – which will help re-establish some sense of what is really happening -- the actual conditions of the plant and all these flare-ups present their own unique dangers. This all force workers to focus on mitigating the risks as they emerge.
Additionally, the U.S. Food and Drug Administration said today it will stop all milk products and vegetable and fruit products imported from the Japan's prefectures of Fukushima, Ibaraki, Tochigi and Gunma from entering the U.S. -- a response to public fears about the Fukushima nuclear plant.
This announcement comes despite the agency's repeated assurances that radiation found in foods in Japan was small, and posed no risk to the U.S. food supply.
Economic costs of the catastrophic March 11 earthquake and tsunami could reach $309 billion, according to the Associated Press. Utilities have imposed power rationing, while many factories remain closed and key rail lines are impassable.
The Associated Press estimates the current death toll at over 9,400, with more than 14,700 still missing.