Japan Releases Low-Level Radioactive Water Into Ocean
Tokyo Electric Power Company, via Reuters
In an image provided by Tokyo Electric Power Company,
contaminated water from the crippled No. 2 reactor is seen leaking
through a crack and draining into the ocean at the Fukushima Daiichi
Nuclear Power Station in northern Japan on Saturday.
Published: April 4, 2011
TOKYO — The Tokyo Electric Power Company began dumping more than 11,000
tons of radioactive water from the Fukushima Daiichi nuclear plant into
the Pacific Ocean on Monday, mostly to make room in storage containers
for increasing amounts of far more contaminated runoff.
Shiho Fukada for The New York Times
On Monday, people in Otsuchi, Japan, in Iwate
Prefecture, searched for belongings in homes damaged by the March 11
tsunami.
The water, most of it to be released over two days, contains about 100
times the legal limit of radiation, Tokyo Electric said. The more
contaminated water has about 10,000 times the legal limit.
The effort would help workers clearing radioactive water from the
turbine buildings at the damaged reactors, making it less dangerous to
reach some of the most crucial controls for their cooling systems, which
were knocked out by the 9.0-magnitude earthquake and tsunami that
struck northeast
Japan on March 11. The hopes are that the cooling systems can be revived and bring the plant back under control.
But the pumping effort is not expected to halt, or even alter, a gushing
leak from a large crack in a six-foot-deep pit next to the seawater
intake pipes near the No. 2 reactor. The leak, discovered Saturday, has
been spewing an estimated seven tons of highly radioactive water an hour
directly into the ocean;
attempts to trace and plug it have so far failed.
Tokyo Electric, the plant’s operator, has been pumping hundreds of tons
of water into four of the plant’s six reactors to cool nuclear fuel in
the cores of three and in spent-fuel storage pools at those three and a
fourth.
But leaks whose source is unclear — from the reactor containment units
themselves or from pipes, valves or other connected units — have flooded
areas of the plant, creating new complications in the effort to stave
off full meltdowns of the fuel.
Workers have been pumping the runoff into storage tanks, most urgently
the highly radioactive water flooding the turbine building of the No. 2
reactor. But the storage system is now full, and adding capacity will
take time.
Tokyo Electric is rushing tanks to the plant, though they may not arrive
until mid-April, a company spokesman said. The company also plans to
moor a giant artificial island off the coast to store contaminated
water, though getting the island in place will take at least a week, he
said.
Tokyo Electric said it would dump about 4,800 tons of water a day for
two days. An additional 1,500 tons will also be released from the No. 5
and No. 6 reactors, after runoff was found flooding parts of their
turbine buildings.
The concern there is that the water could damage the backup diesel
generators for the reactors’ cooling systems, said Yukio Edano, the
chief cabinet secretary. That water will be released 300 tons at a time
over five days.
“Unfortunately, the water contains a certain amount of radiation,” Mr.
Edano said. “This is an unavoidable measure to prevent even higher
amounts of radiation from reaching the sea.”
Mr. Edano said he had ordered the company to monitor the effects of
radioactive materials in the water on sea life. Consuming seafood caught
in the area every day for a year would result in the intake of about
0.6 millisieverts of radiation, or about a quarter of the average annual
exposure to radiation in Japan, a company spokesman said at a news
conference.
But the Japanese government has said it could take months to stem the
release of radioactive material from the plant, and marine biologists
expressed concern.
“We’re seeing the levels of radioactive materials in the water increase,
which means this problem is going to continue to get worse and worse,”
said Kenya Mizuguchi, emeritus professor of maritime science and
technology at Tokyo University.
Elements like cesium 137, which has a half-life of 30 years, collect in
larger fish as they consume smaller fish, which means the problem may
grow over time.
Iodine 131 and other elements that have far shorter half-lives are not
as dangerous because it can take weeks for fish to make it to
supermarkets and restaurants, according to Hiroki Otani, who teaches in
the health and welfare department at Tokyo Metropolitan University.
But Mr. Otani said the government needed to share more data on the
impact on shellfish and different types of seaweed that do not move
around the ocean.
Mixing radioactive water with uncontaminated seawater can lead to a
rapid decrease in radiation levels, according to an analysis by the
International Atomic Energy Agency on Friday.
The agency, citing samples taken by the Japanese authorities on March 24
and 27, said radiation levels in the water about 19 miles offshore from
the nuclear plant were only about one-thousandth the level closer in,
at about 360 yards from the shore. Nevertheless, the level of radiation
at 19 miles offshore was still hundreds to thousands of times as high as
levels sampled in the same site in 2005.
The agency said in a different analysis that the short-term concern from
radioactive water would be iodine 131, owing to “possible enrichment in
the marine food chain.”
Seafood businesses are being hurt. The price for some fish like inada,
or young yellowtail, has fallen by half or more in recent days,
according to Seizaburo Tsuruoka, deputy chief of the Isumi-East
Fisheries Cooperatives in Chiba Prefecture, south of Fukushima.
Mr. Tsuruoka said his fishermen tested their fish and had not found that
they were radioactive. He added that the ocean current was traveling
from south to north this season. He worries, though, what will happen
when the tide reverses in autumn.
“While the government says, ‘Don’t worry,’ the company says it will
release water from the plant,” Mr. Tsuruoka said. “I’m sure the general
public feels very uncomfortable, and we get hurt.”
To try to prevent radioactive silt from drifting deeper into the ocean,
Tokyo Electric intends to drape a curtain in the waters off the plant,
Reuters reported, quoting Hidehiko Nishiyama, deputy director general of
Japan’s Nuclear and Industrial Safety Agency.
In Vienna on Monday, Japan’s crisis was a major focus as the
International Atomic Energy Agency began a 10-day gathering of
representatives of dozens of countries on nuclear safety.
Reporting was contributed by Ken Ijichi, Yasuko Kamiizumi, Moshe Komata and Andrew Pollack.
