Video: As the clean-up continues across the worst earthquake and tsunami hit areas a suspected breach in a reactor core at the stricken Fukushima nuclear plant could mean more serious radioactive contamination. (March 25)
TOKYO — Water used to douse ultra-hot reactors at the Fukushima Daiichi nuclear power complex showed fresh signs of a possible radiation leak from the reactor’s core Friday, as Japanese officials expanded the evacuation zone around the crippled plant.
Water in a turbine building was so radioactive that it gave leg burns to three workers and reignited fears that the hazardous material could only have come from inside reactor unit 3’s primary containment building or through its main steam system.
That plant is of special concern because it uses mox, a fuel that contains extremely dangerous and long-lasting plutonium in addition to uranium. A leak directly from inside the reactor threatens immediate harm to any workers attempting repairs, while raising the prospect of much longer-term contamination of the facility and surrounding area.
The plant’s owner, Tokyo Electric Power Co., also said it was switching to fresh water to cool reactor cores in units 1 and 3 because of worries that salt from the seawater might have formed thick crusts around the nuclear fuel rods. Those crusts could block the cooling water and allow heat to build up again. Two U.S. Navy barges carrying fresh water are heading to the area to help in the cooling efforts, Japanese authorities said; the ships are expected to arrive in about three days.
One nuclear power expert said that iodine-131 and other contaminants were found in water outside units 1 and 2, which could point to leaks from the primary containment buildings there as well. Because of the relatively fast pace of decay of iodine-131, it would most likely be coming from inside the reactor vessels rather than from the used nuclear fuel rods in storage pools, which are older.
Actual conditions inside four of the complex’s six reactors remain murky; the International Atomic Energy Agency said pressure readings at units 2 and 3 were “unreliable,” for example, because of possible damage to the sensors. What was clear was that the battle to regain control of the reactors was far from over.
“The situation at the Fukushima Daiichi power plant is still very grave and serious,” Prime Minister Naoto Kan said in a live television address. “We must remain vigilant. We’re trying to prevent a deterioration of the situation, and we are still not in a position where we can be optimistic. We must treat every development with the utmost care.”
After maintaining for two weeks that it was safe for residents living at least 12.5 miles away from the power plant to stay in their homes, Japanese government officials said those living as far as 19 miles away should consider evacuating voluntarily. They said that radiation fears were making it increasingly difficult to bring in basic supplies.
Those residents had already been advised to stay indoors as much as possible. Officials said the new recommendation was based on concerns about access to safe food and drinking water, rather than specific new information about radiation levels.
The U.S. government has advised American citizens to stay at least 50 miles away from the Daiichi facility.
Loading...
Comments