Tag Archive: Gregory Jaczko


More radioactive water spills at Japan nuke plant

http://news.yahoo.com/s/ap/20110328/ap_on_bi_ge/as_japan_earthquake

By SHINO YUASA, Associated Press Shino Yuasa, Associated Press 48 mins ago

TOKYO – Workers discovered new pools of radioactive water leaking from Japan’s crippled nuclear complex, officials said Monday, as emergency crews struggled to pump out hundreds of tons of contaminated water and bring the plant back under control.

Officials believe the contaminated water has sent radioactivity levels soaring at the coastal complex, and caused more radiation to seep into soil and seawater.

The Fukushima Dai-ichi power plant, 140 miles (220 kilometers) northeast of Tokyo, was crippled March 11 when a tsunami spawned by a powerful earthquake slammed into Japan’s northeastern coast. The huge wave engulfed much of the complex, and destroyed the crucial power systems needed to cool the complex’s nuclear fuel rods.

Since then, three of the complex’s six units are believed to have partially melted down, and emergency crews have struggled with everything from malfunctioning pumps to dangerous spikes in radiation that have forced temporary evacuations.

Confusion at the plant has intensified fears that the nuclear crisis will last weeks, months or years amid alarms over radiation making its way into produce, raw milk and even tap water as far away as Tokyo.

The troubles at the Fukushima complex have eclipsed Pennsylvania’s 1979 crisis at Three Mile Island, when a partial meltdown raised fears of widespread radiation release, but is still well short of the 1986 Chernobyl disaster, which killed at least 31 people with radiation sickness, raised long-term cancer rates, and spewed radiation for hundreds of miles (kilometers).

While parts of the Japanese plant has been reconnected to the power grid, the contaminated water — which has now been found in numerous places around the complex, including the basements of several buildings — must be pumped out before electricity can be restored to the cooling system.

That has left officials struggling with two sometimes-contradictory efforts: pumping in water to keep the fuel rods cool and pumping out — and then safely storing — contaminated water.

Hidehiko Nishiyama, a spokesman for Japan’s Nuclear and Industrial Safety Agency, called that balance “very delicate work.”

Click image to see photos of quake, tsunami damage

He also said workers were still looking for safe ways to store the radioactive water.

“We are exploring all means,” he said.

The buildup of radioactive water first became a problem last week, when it splashed over the boots of two workers, burning them and prompting a temporary suspension of work.

Then on Monday, officials with Tokyo Electric Power Co., which owns and runs the complex, said that workers had found more radioactive water in deep trenches used for pipes and electrical wiring outside three units.

The contaminated water has been emitting radiation exposures more than four times the amount that the government considers safe for workers.

The five workers in the area at the time were not hurt, said TEPCO spokesman Takashi Kurita.

Exactly where the water is coming from remains unclear, though many suspect it is cooling water that has leaked from one of the disabled reactors.

It could take weeks to pump out the radioactive water, said Gary Was, a nuclear engineering professor at the University of Michigan.

“Battling the contamination so workers can work there is going to be an ongoing problem,” he said.

Meanwhile, new readings showed ocean contamination had spread about a mile (1.6 kilometers) farther north of the nuclear site than before but is still within the 12-mile (20-kilometer) radius of the evacuation zone. Radioactive iodine-131 was discovered offshore at a level 1,150 times higher than normal, Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, told reporters.

Amid reports that people had been sneaking back into the mandatory evacuation zone around the nuclear complex, the chief government spokesman again urged residents to stay out. Yukio Edano said contaminants posed a “big” health risk in that area.

Gregory Jaczko, head of the U.S. Nuclear Regulatory Commission, arrived in Tokyo on Monday to meet with Japanese officials and discuss the situation, the U.S. Embassy said in a statement.

“The unprecedented challenge before us remains serious, and our best experts remain fully engaged to help Japan,” Jaczko was quoted as saying.

Early Monday, a strong earthquake shook the northeastern coast and prompted a brief tsunami alert. The quake was measured at magnitude 6.5, the Japan Meteorological Agency said. No damage or injuries were reported.

Scores of earthquakes have rattled the country over the past two weeks, adding to the sense of unease across Japan, where the final death toll is expected to top 18,000 people, with hundreds of thousands still homeless.

TEPCO officials said Sunday that radiation in leaking water in Unit 2 was 10 million times above normal — a report that sent employees fleeing. But the day ended with officials saying that figure had been miscalculated and the level was actually 100,000 times above normal, still very high but far better than the earlier results.

“This sort of mistake is not something that can be forgiven,” Edano said sternly Monday.

___

Associated Press writers Tomoko A. Hosaka, Mayumi Saito, Mari Yamaguchi and Jeff Donn contributed to this report.

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http://news.yahoo.com/s/yblog_thelookout/20110316/ts_yblog_thelookout/japans-nuclear-crisis-where-things-stand

The ongoing crisis at Japan’s Fukushima Daiichi nuclear plant has turned into what one analyst calls “a slow-moving nightmare,” with fires, leaks of poisonous radiation, and mass evacuations.

With events shifting quickly, and a sometimes confusing succession of announcements coming from authorities, it can be hard to get a clear sense of exactly what’s happening, and of what to expect going forward. So here’s a rundown, based on several recent news reports, on where things stand five days in…

 

What’s at the root of the problem?

Friday’s earthquake and tsunami caused power outages across northern Japan — including at the Daiichi plant, which comprises six separate reactors. That in turn caused a failure of the reactors’ cooling systems, which are needed to keep the nuclear fuel from overheating and melting down and/or triggering an explosion, releasing poisonous radiation into the atmosphere.

What’s the current situation at the plant?

Yesterday, an explosion caused the containment vessel covering the Number 2 reactor to crack, releasing into the air a surge of radiation 800 times more intense than the recommended hourly exposure limit in Japan. One third of the fuel rods at the reactor were reportedly damaged. In addition, another powerful explosion blew a 26-foot wide hole in the side of Number 4 reactor, causing fires to break out and a pool containing spent fuel rods to begin dangerously overheating.

The Japanese military tried to use helicopters to dump water from the air to cool the Number 4 reactor, but that plan was abandoned after a third explosion — this one damaging the roof and cooling system of the Number 3 reactor — because it would have meant flying a helicopter into radioactive steam. Gregory Jaczko, the top U.S. nuclear official, said today that all the water was gone from the pool containing the fuel rods at the Number 4 reactor — an assertion denied by a spokesman for the Japanese power company that runs the plant. If Jaczko is correct, it would mean there is nothing to stop the fuel from melting down, spewing radiation.

Water was also poured into the Numbers 5 and 6 reactors, suggesting that essentially the entire plant could be at risk of overheating.

In what appears to have been an understatement, the plant operator described the situation at the Number 4 reactor as “not so good.” But in some ways the rupture at the Number 3 reactor is especially troubling, because it’s the only reactor that uses plutonium as part of its fuel mix. If absorbed into the bloodstream, plutonium can stay in the liver or bone marrow and cause cancer.

Japanese officials said early Thursday they’re close to completing a new power line which would restore the cooling systems for the reactors, but it’s unclear when the line will be up and running.

How much of the surrounding area is likely to be affected by the radiation?

The government has told the roughly 140,000 people who live within 18 miles of the plant to stay indoors, but has said that people outside that zone can safely go outside. However, some experts have accused the Japanese authorities of underplaying the severity of the crisis. The U.S. embassy has recommended that Americans within 50 miles of the plant evacuate the area or stay indoors.

Tokyo, 180 miles south of the plant, has recorded radiation levels only slightly above normal. Still, both France and Australia have urged their nationals throughout the country to leave, and many Tokyo residents have been staying indoors. One American couple living in Tokyo told family they don’t yet see a need to leave, but are monitoring the situation closely.

What other ideas are being considered?

In what experts describe as a last-ditch effort, police are hoping to use a water cannon — usually used to quell riots — to cool the nuclear fuel. Officials have also proposed using boric acid, which can help slow nuclear reactions by absorbing neutrons.

On Monday, 750 workers were withdrawn from the facility, leaving a core of 50 to battle the crisis alone while exposing themselves to potentially deadly levels of radiation. But even those workers appeared to have been withdrawn today after a surge in radiation caused by new explosions made the area too dangerous.

What are the best- and worst-case scenarios?

The best case scenario is that efforts to cool the fuel rods succeed, and damage to the surrounding environment is limited to an area within about 15 miles of the plant. The worst is a full-scale meltdown of the reactors caused by overheating, which would release much larger amounts of radiation into the air than has yet occurred.  In that case, the damage could potentially approach the level of the Soviet Union’s 1986 Chernobyl disaster, for which estimates of deaths vary from 4000 to close to one million.

How does the crisis rank, in terms of nuclear plant accidents?

On Saturday, Japanese authorities ranked the incident a Level Four on a one-to-seven scale used to rank nuclear accidents. but things have worsened since then, and yesterday France’s nuclear authority said it should be classified as a Level Six. Chernobyl is the only Level 7 accident ever to have occurred.

In this image released by Tokyo Electric Power Co., smoke billows from the No. 3 unit among four housings cover four reactors at the Fukushima Dai-ichi nuclear complex in Okumamachi, Fukushima Prefecture, northeastern Japan, on Tuesday, March 15, 2011.  (AP Photo/Tokyo Electric Power Co.)

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