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Mar 13, 2011 10:47 AM by Chris Welty

Japan Races to Avert Multiple Nuclear Meltdowns

KORIYAMA, Japan (AP) - Japan's nuclear crisis intensified Sunday
as authorities raced to combat the threat of multiple reactor
meltdowns and more than 170,000 people evacuated the quake- and
tsunami-savaged northeastern coast where fears spread over possible
radioactive contamination.
Nuclear plant operators were frantically trying to keep
temperatures down in a series of nuclear reactors - including one
where officials feared a partial meltdown could be happening Sunday
- to prevent the disaster from growing worse.
Chief Cabinet Secretary Yukio Edano also said Sunday that a
hydrogen explosion could occur at Unit 3 of the Fukushima Dai-ichi
nuclear complex, the latest reactor to face a possible meltdown.
That follows a blast the day before in the power plant's Unit 1,
and operators attempted to prevent a meltdown there by injecting
sea water into it.
"At the risk of raising further public concern, we cannot rule
out the possibility of an explosion," Edano said. "If there is an
explosion, however, there would be no significant impact on human
health."
More than 170,000 people had been evacuated as a precaution,
though Edano said the radioactivity released into the environment
so far was so small it didn't pose any health threats.
"First I was worried about the quake," Kenji Koshiba, a
construction worker who lives near the plant. "Now I'm worried
about radiation." He spoke at an emergency center in Koriyama town
near the power plant in Fukushima.
The French Embassy urged its citizens Sunday to leave the area
around Tokyo - 170 miles (270 kilometers) from Fukushima Dai-ichi -
in case the crisis deepened and a "radioactive plume" headed for
the area around the capital. The statement acknowledged that the
possibility was looking unlikely.
Edano said none of the Fukushima Dai-ichi reactors was near the
point of complete meltdown, and he was confident of escaping the
worst scenarios.
A complete meltdown - the collapse of a power plant's ability to
keep temperatures under control - could release uranium and
dangerous contaminants into the environment and pose major,
widespread health risks.
Up to 160 people, including 60 elderly patients and medical
staff who had been waiting for evacuation in the nearby town of
Futabe, and 100 others evacuating by bus, might have been exposed
to radiation, said Ryo Miyake, a spokesman from Japan's nuclear
agency. The severity of their exposure, or if it had reached
dangerous levels, was not clear. They were being taken to
hospitals.
Edano said operators were trying to cool and decrease the
pressure in the Unit 3 reactor, just as they had the day before at
Unit 1.
"We're taking measures on Unit 3 based on a similar
possibility" of a partial meltdown, Edano said.
Japan struggled with the nuclear crisis as it tried to determine
the scale of the Friday disasters, when an 8.9-magnitude
earthquake, the most powerful in the country's recorded history,
was followed by a tsunami that savaged its northeastern coast with
breathtaking speed and power.
More than 1,400 people were killed and hundreds more were
missing, according to officials, but police in one of the worst-hit
areas estimated the toll there alone could eventually top 10,000.
The scale of the multiple disasters appeared to be outpacing the
efforts of Japanese authorities to bring the situation under
control more than two days after the initial quake.
Rescue teams were struggling to search hundreds of miles
(kilometers) of devastated coastline, and hundreds of thousands of
hungry survivors huddled in darkened emergency centers cut off from
rescuers and aid. At least 1.4 million households had gone without
water since the quake, and food and gasoline were quickly running
out across the region. Large areas of the countryside were
surrounded by water and unreachable. Some 2 million households were
without electricity.
Japanese Trade Minister Banri Kaieda warned that the region was
likely to face further blackouts, and power would be rationed to
ensure supplies to essential facilities.
The government doubled the number of troops pressed into rescue
and recovery operations to about 100,000 from 51,000, as powerful
aftershocks continued to rock the country. Hundreds have hit since
the initial temblor.
Unit 3 at the Fukushima plant is one of three reactors there
that had automatically shut down and lost cooling functions
necessary to keep fuel rods working properly due to a power outage
from the quake. The facility's Unit 1 is also in trouble, but Unit
2 has been less affected.
On Saturday, an explosion destroyed the walls of Unit 1 as
operators desperately tried to prevent it from overheating and
melting down.
Without power, and with its valves and pumps damaged by the
tsunami, authorities resorted to drawing sea water mixed with boron
in an attempt to cool the unit's overheated uranium fuel rods.
Boron disrupts nuclear chain reactions.
The move likely renders the 40-year-old reactor unusable, said a
foreign ministry official briefing reporters. Officials said the
sea water will remain inside the unit, possibly for several months.
Robert Alvarez, senior scholar at the Institute for Policy
Studies and former senior policy adviser to the U.S. secretary of
energy, told reporters that the sea water was a desperate measure.
"It's a Hail Mary pass," he said.
He said that the success of using sea water and boron to cool
the reactor will depend on the volume and rate of their
distribution. He said the dousing would need to continue nonstop
for days.
Another key, he said, was the restoration of electrical power,
so that normal cooling systems can operate.
Edano said the cooling operation at Unit 1 was going smoothly
after the sea water was pumped in.
Operators released slightly radioactive air from Unit 3 on
Sunday, while injecting water into it hoping to reduce pressure and
temperature to prevent a possible meltdown, Edano said.
He said radiation levels just outside the plant briefly rose
above legal limits, but since had declined significantly. Also,
fuel rods were exposed briefly, he said, indicating that coolant
water didn't cover the rods for some time. That would have
contributed further to raising the temperature in the reactor
vessel.
At an evacuation center in Koriyama, about 40 miles (60
kilometers) from the troubled reactors and 125 miles (190
kilometers) north of Tokyo, medical experts had checked about 1,500
people for radiation exposure in an emergency testing center, an
official said.
On Sunday, a few dozen people waited to be checked in a
collection of blue tents set up in a parking lot outside a local
gymnasium. Fire engines surrounded the scene, with their lights
flashing.
Many of the gym's windows were shattered by the quake, and glass
shards littered the ground.
A steady flow of people - the elderly, schoolchildren and
families with babies - arrived at the center, where they were
checked by officials wearing helmets, surgical masks and goggles.
Officials placed five reactors, including Units 1 and 3 at
Dai-ichi, under states of emergency Friday after operators lost the
ability to cool the reactors using usual procedures.
An additional reactor was added to the list early Sunday, for a
total of six - three at the Dai-ichi complex and three at another
nearby complex. Local evacuations have been ordered at each
location. Japan has a total of 55 reactors spread across 17
complexes nationwide.
Officials began venting radioactive steam at Fukushima
Dai-ichi's Unit 1 to relieve pressure inside the reactor vessel,
which houses the overheated uranium fuel.
Concerns escalated dramatically Saturday when that unit's
containment building exploded.
Officials were aware that the steam contained hydrogen and were
risking an explosion by venting it, acknowledged Shinji Kinjo,
spokesman for the government's Nuclear and Industrial Safety
Agency, but chose to do so because they needed to keep circulating
cool water on the fuel rods to prevent a meltdown.
Officials insisted there was no significant radioactive leak
after the explosion.
If a full-scale meltdown were to occur, experts interviewed by
The Associated Press said melted fuel would eat through the bottom
of the reactor vessel, then through the floor of the containment
building. At that point, the uranium and dangerous byproducts would
start escaping into the environment.
Eventually, the walls of the reactor vessel - six inches (15
centimeters) of stainless steel - would melt into a lava-like pile,
slump into any remaining water on the floor, and potentially cause
an explosion that would enhance the spread of radioactive
contaminants.
If the reactor core became exposed to the outside, officials
would likely began pouring cement and sand over the entire
facility, as was done at the 1986 Chernobyl nuclear accident in the
Ukraine, Peter Bradford, a former commissioner of the U.S. Nuclear
Regulatory Commission, told reporters.
Another expert, physicist Ken Bergeron, told reporters that as a
result of such a meltdown the surrounding land would be off-limits
for a long time and "a lot of first responders would die."

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