15/03 Japan Says 2nd Reactor May Have Ruptured With Radioactive Release

DigitalGlobe, via Reuters
Workers are struggling at the Fukushima Daiichi plant, seen in a satellite photo at 9:35 a.m. Wednesday.

March 15, 2011
By HIROKO TABUCHI and KEITH BRADSHER

TOKYO — Japan’s nuclear crisis intensified again Wednesday, with Japanese authorities announcing that a containment vessel in a second reactor unit at the stricken Fukushima Daiichi plant in northeastern Japan may have ruptured and appeared to be releasing radioactive steam. That would be the second vessel to be compromised in two days.

The vessel had appeared to be the last fully intact line of defense against large-scale releases of radioactive materials from that reactor, but it was not clear how serious the possible breach might be.

The announcement came after Japanese broadcasters showed live footage of thick plumes of steam rising above the plant.

Yukio Edano, the chief cabinet secretary, said the government believed the steam was coming from the No. 3 reactor, where an explosion on Monday blew out part of the building surrounding the containment vessel.

The reactor has three layers of protection: that building; the containment vessel, and the metal cladding around fuel rods, which are inside the reactor. The government has said that those rods at the No. 3 reactor were likely already damaged.

A spike in radiation levels at the plant as the steam was rising forced some of the relatively few workers left at the plant to retreat indoors, suspending some critical efforts to pump water into several reactors to keep them cool.

Earlier in the morning, the company that runs the plant reported that a fire was burning at a different reactor, just hours after officials said flames that erupted Tuesday had been doused.

A government official at Japan’s nuclear regulatory agency soon after said that flames and smoke were no longer visible, but he cautioned that it was unclear if the fire, at the Reactor No. 4 building, had died out. He also was not clear if it was a new fire or if the fire Tuesday had never gone out.

There are a total of six reactors at the plant.

The developments are troubling reminders of the difficulties the company is having in bringing the plant, which has suffered multiple explosions since Saturday, under control. And the confusion is emblematic of days of often contradictory reports about what is happening at the plant.

The company, Tokyo Electric Power, says it cannot know for sure what is happening in many cases because it is too dangerous for workers to get close to some reactors.

The situation became especially dire on Tuesday, when releases of radiation led the company to pull most of its workers from the plant.

Among the authorities’ main concerns are pools for spent fuel rods at several reactors at the plant, including Reactor No. 4, where the pool has lost some of the water needed to keep the fuel rods stable. The rods are still radioactive and potentially as hot and dangerous as the fuel rods inside the reactors.

Minoru Ogoda, the official with Japan’s nuclear regulatory agency, said a proposed plan to use helicopters to put more cold water into the pool was looking unlikely.

The hole or holes in the roof caused by an earlier blast did not appear big enough to allow sufficient amounts of water in, he said.

He said Tokyo Electric would probably try to spray water into the reactor building through a gaping hole in the wall blasted open by the explosion.

That explosion on Tuesday was caused by hydrogen gas bubbling up from chemical reactions set off by the fuel rods in the pool, Japanese officials said. Inspectors from the United States Nuclear Regulatory Commission said they had been told by Japanese authorities that what was burning was lubricating oil from machinery near the pool.

Concern remained high about the storage pools at two other reactors, Nos. 5 and 6. None of those three reactors at the plant, 140 miles northeast of Tokyo, were operating on Friday afternoon when an offshore earthquake with a magnitude now estimated at 9.0 shook the site. A tsunami rolled into the northeast Japanese coastline minutes later, swamping the plant.

At least 750 workers were evacuated on Tuesday morning after a separate explosion ruptured the inner containment building at Reactor No. 2 at the Daiichi plant, which was crippled by Friday’s earthquake and tsunami. The closely spaced but apparently coincidental explosions at Reactors Nos. 2 and 4 together released a surge of radiation 800 times as intense as the recommended hourly exposure limit in Japan.

But 50 workers stayed behind, a crew no larger than would be stationed at the plant on a quiet spring day. Taking shelter when possible in the reactor’s control room, which is heavily shielded from radiation, they struggled through the morning and afternoon to keep hundreds of gallons of seawater a minute flowing through temporary fire pumps into the three stricken reactors, Nos. 1, 2 and 3, where overheated fuel rods continued to boil away the water at a brisk pace.

By early afternoon radiation levels had plunged, according to the International Atomic Energy Agency. Workers have released surges of radiation each time they bleed radioactive steam from the troubled reactors in an attempt to manage the pressure inside them, but the reactors are not yet releasing high levels of radiation on a sustained basis, Japanese officials said.

The United States military revised its plans as radiation from the plant worsened. Some American warships that had been expected to arrive at the tsunami-shattered northeast coast of Honshu Island were diverted to the west coast instead because of concerns about radiation, the Navy said.

The Navy also promised to continue relief missions even though several more helicopter crews were testing positive for low-level exposure to radiation, and even as American military personnel and their families at the Yokosuka and Atsugi bases were encouraged to take precautions against radiation exposure.

Late Tuesday morning, Prime Minister Naoto Kan warned in a nationally televised address of rising radiation.

Mr. Edano, the chief cabinet secretary, urged people who live within about 18 miles of the plant to take precautions. “Please do not go outside, please stay indoors, please close windows and make your homes airtight,” he said. Yukiya Amano, the director general of the International Atomic Energy Agency, said at the organization’s Vienna headquarters that there was a “possibility of core damage” at reactor No. 2, but that the damage “is estimated to be less than 5 percent of the fuel.”

The sudden turn of events, after an explosion on Monday at one reactor and then an early-morning explosion on Tuesday at yet another — the third in four days at the plant — had already made the crisis at the plant the worst nuclear accident since the Chernobyl reactor disaster a quarter-century ago. It had become impossible for workers to remain at many areas within the plant for extended periods, the agency said. In Tokyo, the metropolitan government said Tuesday that it had detected radiation levels 20 times above normal over the city, though it stressed that such levels posed no immediate health threat and that readings had dropped since then. The explosion in Reactor No. 2, a little after 6 a.m. on Tuesday, particularly alarmed Japanese officials and nuclear power experts around the world because it was the first detonation at the plant that appeared to occur inside one of the primary containment vessels.

Those buildings are fortresslike structures of steel and reinforced concrete, designed to absorb the impact of a plane crash and minimize radiation leaks. After a series of conflicting reports about how much damage the reactor had sustained after that blast, Mr. Edano said, “There is a very high probability that a portion of the containment vessel was damaged.”

Japanese officials subsequently said that the explosion had damaged a doughnut-shaped steel container of water, known as a torus, that surrounds the base of the reactor vessel inside the primary containment building.

Ruptures in the torus are serious, said Michael Friedlander, a senior nuclear power plant operator for 13 years at three plants in the United States, including three years at a General Electric boiling water reactor very similar to the ones in trouble in Japan. But the torus is not as important as the reactor vessel itself, which has 6.7-inch-thick steel walls and 8.4-inch-thick steel for its roof and floor. The vessel is designed to hold very high-pressure steam as well as the uranium fuel rods.

The reactor vessel has 20 safety valves that during a shutdown of the reactor inject steam into a million-gallon “suppression pool” of water in a steel torus immediately underneath it.

“Imagine if you had a big pressure cooker and you had a tube off the pressure cooker into a big tub of water — the suppression pool is the tub of water,” said Mr. Friedlander, a defender of nuclear power who is now a money manager in Hong Kong.

Steam vented into the suppression pool from the reactor vessel is not supposed to be radioactive. But it becomes radioactive, and potentially very radioactive, if the fuel rods in the reactor vessel above have begun to melt.

The atmosphere in the primary containment building, around the reactor vessel and above the suppression pool, is supposed to consist of inert nitrogen, with no oxygen at all. An inert atmosphere is used in the primary containment building to avoid the risk of oxygen explosions with hydrogen if the reactor starts producing much larger quantities of hydrogen gas than usual. Hydrogen gas is highly combustible with oxygen.


Hiroko Tabuchi reported from Tokyo, and Keith Bradsher from Hong Kong. David E. Sanger and Matthew L. Wald contributed reporting from Washington.

16/03 EU to conduct nuclear stress tests

Xinhua, March 16, 2011

The European Union (EU) would conduct "stress tests" on its member states' nuclear power plants in the wake of Japan's nuclear crisis, the bloc's energy chief Guenther Oettinger said on Tuesday.

The tests would include risk assessments of possible damage by earthquakes and high water levels, Oettinger told the European Parliament's Energy Committee.

The development came as fears of a nuclear meltdown mounted over Japan's Fukushima nuclear plant, which was seriously affected by a 9.0-magnitude earthquake on Friday and the massive tsunami that followed.

The tests would be concluded by the end of the year, Oettinger said, adding that thorough stress tests would also take place in nuclear plants of neighboring countries including Turkey, Russia and Switzerland.

Any decision on the early closure of nuclear power plants or on a moratorium on the construction of future plants, however, lies with national governments and public opinion in the EU member states, he said.

Europe now has about 143 nuclear power plants in 14 countries.

Earlier on Tuesday, Germany announced that it would shut down seven of its oldest nuclear reactors built before 1980 for three months while it conducts a safety probe.

15/03 Wind and Rain Steer Radiation’s Reach

March 15, 2011
By HENRY FOUNTAIN

So, how bad could it get?

Experts say it is impossible to forecast how events at Japan’s stricken nuclear plant will unfold, whether there will be a meltdown or other crisis at one or more of the reactors that results in a large release of radioactivity into the environment. And even if such a release occurred, the impact in Japan and elsewhere would depend greatly on wind and rain and how long the release lasted.

“We’re in uncharted territory here,” said Robert Alvarez, a nuclear expert and adviser to the secretary of energy during the Clinton administration. “But in very general terms, the worst-case scenario would be a catastrophic release of radiation that will not necessarily happen all at once.”

That would make the event similar to, and perhaps worse than, the Chernobyl accident in 1986, in which large amounts of radioactivity were released and hundreds of square miles of land in Ukraine were left uninhabitable. But without such a catastrophic release, the events would likely be closer in scale to the partial meltdown in 1979 at Three Mile Island in Pennsylvania, where the plant’s containment structure held and a relatively small amount of radioactivity was released.

So far, the problems at the Fukushima Daiichi plant in Japan are more severe than at Three Mile Island but less so than in Chernobyl.

The Chernobyl reactor, which caught fire after electrical tests resulted in a series of explosions, was not surrounded by a containment structure, as the Japanese reactors are. So a key factor in Japan is whether, if one or more of the reactors has a full meltdown of its nuclear fuel, the containment barriers hold. Complicating matters is the presence of large amounts of spent fuel — which contain most of the same radioactive elements as the fuel in the reactor — in storage ponds that are outside any containment barrier.

Experts differ as to whether breaching of the containment is likely or not. “There’s quite a lot of redundancy and barriers built into the system,” said Mary Lou Dunzik-Gougar, an assistant professor of nuclear engineering at Idaho State University. “A full-fledged meltdown might result in a breach of the pressure vessel, with the fuel dropping into the lower part of the plant. But it’s not going to go very far.”

But a breach would most likely be catastrophic.

“If there’s a breach of containment and a significant release of radioactivity, I think it’s safe to draw parallels to Chernobyl,” said Kenneth L. Mossman, a professor of health physics at Arizona State University. But he described Chernobyl as an “upper bound” of what might happen in Japan.

Dr. Mossman said the impact of the radiation would be twofold. Workers would be at risk for illness or death because of high levels of gamma rays and other ionizing radiation. But the area around the plant would become a no-man’s land, contaminated with radioactive elements like cesium, plutonium and iodine.

Just how large this area would be would depend on whether the poisons were released slowly and stayed close to the ground or were spewed into higher altitudes by explosions or fire. Wind would push the radiation in one direction, and tend to disperse it over a larger area. Rain would bring much of it to the surface.

The size of the contaminated area would also depend on how much of the radiation escaped. At Chernobyl, where the reactor burned for about a week, no one knows for certain how much of the radiation in the fuel was released — one estimate is about 40 percent. At the Japanese plants, unless the containment vessels were totally destroyed by explosions — which some nuclear engineers said was unlikely — some percentage of the radiation in the roughly 150 tons of fuel in each reactor would still be kept safe.

However large, the contaminated area would be uninhabitable for decades.

The spent-fuel pools represent another risk. They are designed to keep the old fuel rods, which are removed from the reactor regularly, submerged to prevent overheating as the radioactive elements in the fuel decays.

“Any of the pools at units 1 through 4 are problems,” Mr. Alvarez said.

It is not clear how much spent fuel there is at each reactor. At the Vermont Yankee plant, a reactor in southern Vermont that is nearly identical to the crippled ones in Japan, close to 700 metric tons of spent fuel is stored. The Japanese plants probably do not have nearly as much — perhaps tens of tons at each reactor, Mr. Alvarez said.

If they overheat and the rods crack or, worse yet, the fuel burns — again, experts differ as to whether this is likely — radioactivity would be released. Because the fuel is older, iodine, an element with a relatively short half-life, would not be a problem. But cesium, plutonium and strontium would still be present in large quantities.

The plume might even be larger than that from a reactor meltdown, because of the lack of containment. But that is another of many unknowns, Mr. Alvarez said.

“The kinds of things that are happening have in very general terms been vaguely predicted,” he said. “The phenomenon of multiple hydrogen explosions, for example — will there be more explosions, will they damage or otherwise compromise the primary containment?

“There are things we don’t know but things we need to be concerned about.”



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16/03 Last Defense at Troubled Reactors: 50 Japanese Workers

March 15, 2011

By KEITH BRADSHER and HIROKO TABUCHI

A small crew of technicians, braving radiation and fire, became the only people remaining at the Fukushima Daiichi Nuclear Power Station on Tuesday — and perhaps Japan’s last chance of preventing a broader nuclear catastrophe.

They crawl through labyrinths of equipment in utter darkness pierced only by their flashlights, listening for periodic explosions as hydrogen gas escaping from crippled reactors ignites on contact with air.

They breathe through uncomfortable respirators or carry heavy oxygen tanks on their backs. They wear white, full-body jumpsuits with snug-fitting hoods that provide scant protection from the invisible radiation sleeting through their bodies.

They are the faceless 50, the unnamed operators who stayed behind. They have volunteered, or been assigned, to pump seawater on dangerously exposed nuclear fuel, already thought to be partly melting and spewing radioactive material, to prevent full meltdowns that could throw thousands of tons of radioactive dust high into the air and imperil millions of their compatriots.

They struggled on Tuesday and Wednesday to keep hundreds of gallons of seawater a minute flowing through temporary fire pumps into the three stricken reactors, Nos. 1, 2 and 3. Among the many problems that officials acknowledged on Wednesday was what appeared to be yet another fire at the plant and indications that the containment vessel surrounding a reactor may have ruptured. That reactor, No. 3, appeared to be releasing radioactive steam.

The workers are being asked to make escalating — and perhaps existential — sacrifices that so far are being only implicitly acknowledged: Japan’s Health Ministry said Tuesday it was raising the legal limit on the amount of radiation to which each worker could be exposed, to 250 millisieverts from 100 millisieverts, five times the maximum exposure permitted for American nuclear plant workers.

The change means that workers can now remain on site longer, the ministry said. “It would be unthinkable to raise it further than that, considering the health of the workers,” the health minister, Yoko Komiyama, said at a news conference. There was also a suggestion on Wednesday that more workers may be brought to help save the power station.

Tokyo Electric Power, the plant’s operator, has said almost nothing at all about the workers, including how long a worker is expected to endure exposure.

The few details Tokyo Electric has made available paint a dire picture. Five workers have died since the quake and 22 more have been injured for various reasons, while two are missing. One worker was hospitalized after suddenly grasping his chest and finding himself unable to stand, and another needed treatment after receiving a blast of radiation near a damaged reactor. Eleven workers were injured in a hydrogen explosion at reactor No. 3.

Nuclear reactor operators say that their profession is typified by the same kind of esprit de corps found among firefighters and elite military units. Lunchroom conversations at reactors frequently turn to what operators would do in a severe emergency.

The consensus is always that they would warn their families to flee before staying at their posts to the end, said Michael Friedlander, a former senior operator at three American power plants for a total of 13 years.

“You’re certainly worried about the health and safety of your family, but you have an obligation to stay at the facility,” he said. “There is a sense of loyalty and camaraderie when you’ve trained with guys, you’ve done shifts with them for years.”

Adding to this natural bonding, jobs in Japan confer identity, command loyalty and inspire a particularly fervent kind of dedication. Economic straits have chipped away at the hallowed idea of lifetime employment for many Japanese, but the workplace remains a potent source of community. Mr. Friedlander said that he had no doubt that in an identical accident in the United States, 50 volunteers could be found to stay behind after everyone else evacuated from an extremely hazardous environment. But Japanese are raised to believe that individuals sacrifice for the good of the group.

The reactor operators face extraordinary risks. Tokyo Electric evacuated 750 emergency staff members from the stricken plant on Tuesday, leaving only about 50, when radiation levels soared. By comparison, standard staffing levels at the three active General Electric reactors on the site would be 10 to 12 people apiece including supervisors — an indication that the small crew left behind is barely larger than the contingent on duty on a quiet day.

Daiichi is not synonymous with Chernobyl in terms of the severity of contamination. The Ukrainian reactor blew up and spewed huge amounts of radiation for 10 days in 1986. But workers at the plants have a bond.

Among plant employees and firefighters at Chernobyl, many volunteered to try to tame, and then entomb, the burning reactor — although it is not clear that all were told the truth about the risks. Within three months, 28 of them died from radiation exposure. At least 19 of them were killed by infections that resulted from having large areas of their skin burned off by radiation, according to a recent report by a United Nations scientific committee. And 106 others developed radiation sickness, with nausea, vomiting, diarrhea and dropping blood counts that left them highly vulnerable to infections.

The people who had suffered radiation sickness developed other problems later, according to the report: cataracts, severe scarring from the radiation burns to their skin and an increased number of deaths from leukemia and other blood cancers.

Some of those Chernobyl workers were exposed to levels of radiation far beyond what has been measured to date at Daiichi — especially helicopter pilots who flew through radiation-laden smoke spewing from the reactor to drop fire-extinguishing chemicals on it.

Radiation close to the reactors was reported to reach 400 millisieverts per hour on Tuesday after a blast inside reactor No. 2 and fire at reactor No. 4, but has since dropped back to as low as 0.6 millisieverts at the plant gate. Tokyo Electric and Japanese regulators have not released any statistics on radiation levels inside the containment buildings where engineers are desperately trying to fix electrical systems, pumps and other gear wrecked by Friday’s earthquake and tsunami.

But nuclear experts said that indoor radiation levels were likely to be higher because the containment buildings were probably still preventing most radiation from leaving the plant.

The site is now so contaminated with radiation, experts say, that it has become difficult for employees to work near the reactors for extended periods of time. According to one expert’s account of nuclear emergency procedures, workers would be cycled in and out of the worst-hit parts of the plant.

In some cases, when dealing with a task in a highly radioactive area of the plant, workers might line up and handle the task only for minutes at a time before passing off to the next worker, said Katsuhiko Ishibashi, a former professor in the Research Center for Urban Safety and Security at Kobe University.

Tokyo Electric has refused to release the names or any other information about the 50 workers who stayed behind, nor have utility executives said anything about how they are being relieved as they become tired or ill.

Some of those battling flames and spraying water at reactors at Daiichi are members of Japan’s Self-Defense Force, police officers or firefighters.

Defense Minister Toshimi Kitazawa said Tuesday that Self-Defense Force soldiers might be called on to fly the helicopters Tokyo Electric may use to spray water onto the overheating used fuel storage pool at reactor No. 4. The same day, however, members of Japan’s nuclear watchdog group, who had been stationed about three miles from the plant, were moved to a site 18 miles away. (The authorities later said that using helicopters to put spray water on reactor No. 4 might not be feasible.) If the plant operator is limiting the exposure of each worker at Daiichi — and calling on hundreds of volunteers to make up the 50 on site at any given time — then Chernobyl may offer some consolation.

To clean up the Chernobyl site after the accident, the Soviet Union conscripted workers in proportion to the size of each of its republics, and developed a system to limit their exposure.

“They sent up to 600,000 people in to clean up the radioactive debris around the plant and build a sarcophagus,” said Dr. John Boice, an author of the study, a professor of medicine at Vanderbilt and the scientific director of the International Epidemiology Institute in Rockvillle, Md. The workers were sent into contaminated zones for limited periods.


Keith Bradsher reported from Hong Kong, and Hiroko Tabuchi from Tokyo. Denise Grady contributed reporting from New York, and Matthew L. Wald from Washington.


This article has been revised to reflect the following correction:

Correction: March 16, 2011


A news alert associated with an earlier version of this article, relying on an English translation of remarks by Japan's chief cabinet secretary, incorrectly stated that workers had been evacuated from the Fukushima Daiichi nuclear power plant. A core group of workers remained at the plant.




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12/03 Trung Quốc không thay đổi kế hoạch phát triển điện hạt nhân

Thứ bảy, 12/03/2011, 16:46 (GMT+7)

Thứ trưởng Bộ Bảo vệ môi trường Trung Quốc Zhang Lijun, hôm 12-3 cho biết, Chính phủ nước này sẽ không thay đổi kế hoạch phát triển các dự án điện hạt nhân, nhưng sẽ rút ra những bài học sau trận động đất mạnh 8,9 độ richter ở Nhật dẫn đến nguy cơ rò rỉ các chất phóng xạ.

Theo kế hoạch dự thảo 5 năm lần thứ 12( từ năm 2011-2015) vừa được công bố một tuần trước, Chính phủ Trung Quốc sẽ khởi công xây dựng các dự án năng lượng hạt nhân với tổng công xuất đạt 40 triệu Kw. Ngoài việc đẩy mạnh xây dựng các nhà máy điện hạt nhân ở các khu vực ven biển, các nhà máy mới sẽ được Chính phủ Trung Quốc quy hoạch trong các khu vực trung tâm.

Hiện Trung Quốc đang theo dõi gắt gao tình hình động đất và sóng thần ở Nhật Bản xem nó tác động như thế nào đến các nhà máy điện hạt nhân, để trên cơ sở đó rút ra những bài học cho mình trước mắt cũng như lâu dài.

Đăng Hưng (theo Tân Hoa Xã)

Nghĩ gì về nhà máy nguyên tử năng ở Việt Nam?

From: Trinh Lequoc
To: HongLeTho
Sent: Tue, March 15, 2011 8:25:22 PM
Subject: FW: DHN o VN

Gui anh Tho doc va cho cac anh chi trong danh sach.

Cam on,

Trinh

====================================================

Nghĩ gì về nhà máy nguyên tử năng ở Việt Nam?

Khi mới nghe tin nhà máy ĐNH (Điện Hạt Nhân) Fukushima ở Nhật bắt đầu gặp sự cố nghiêm trọng và báo chí Canada đã có bài viết khoa học trả lời những câu hỏi về nguy cơ "nổ lò nguyên tử" tôi đã trích dẫn bài báo này gửi ngay về VN cho tờ báo SaiGon Giai Phong online xem như là một ý kiến đóng góp của một độc giả từ Canada . Thế nhưng qua ba ngày tôi vẫn không thấy động tĩnh chi cả, vào SGGP vẫn thấy chính quyền Hà Nội ra thông báo về ĐHN, xin trích dẫn cho bà con cô bác biết

_______________________________________________


4 lý do để xây dựng nhà máy điện hạt nhân


Thứ bảy, 12/03/2011, 02:02 (GMT+7)

(SGGP). – Ngày 11-3, Trung tâm Nghiên cứu phát triển truyền thông (thuộc Bộ KH-CN) đã tổ chức giao lưu trực tuyến “Hướng tới nhà máy điện hạt nhân đầu tiên của Việt Nam”. Đến thời điểm này, Việt Nam đang trên lộ trình tiến đến xây dựng nhà máy điện hạt nhân đầu tiên.

Thứ trưởng Bộ KH-CN Lê Đình Tiến khẳng định, tại thời điểm này Việt Nam có 4 lý do để có thể xây dựng nhà máy điện hạt nhân gồm: các nguồn năng lượng hóa thạch cũng như thủy điện trong nước cũng như trên thế giới đang cạn kiệt; nhu cầu năng lượng của Việt Nam hiện tại và tương lai ở tình trạng thiếu; năng lượng hạt nhân hiện nay đã đảm bảo tính an toàn cao và hiệu quả kinh tế cũng cao; điện hạt nhân giảm được khí thải nhà kính.



PGS-TS Vương Hữu Tấn, Viện trưởng Viện Năng lượng nguyên tử, cho rằng lợi ích trước tiên của việc phát triển điện hạt nhân là góp phần đảm bảo về an ninh cung cấp điện năng cho đất nước, phục vụ quá trình công nghiệp hóa - hiện đại hóa. Tuy nhiên, theo ông Tấn, vẫn tồn tại những khó khăn đối với Việt Nam. “Điện hạt nhân là một công nghệ mới đối với chúng ta. Chúng ta còn thiếu nguồn nhân lực, đặc biệt những nhân lực có trình độ cao về điện hạt nhân. Chúng ta còn thiếu những khuôn khổ pháp lý cần thiết mà hiện nay vẫn đang phải tiếp tục xây dựng và hoàn thiện. Ngoài ra, năng lực tài chính của chúng ta cũng hạn chế trong khi nhu cầu đầu tư dự án điện hạt nhân rất lớn” – PGS-TS Vương Hữu Tấn khẳng định.



TS Hoàng Anh Tuấn, Phó cục trưởng Cục Năng lượng nguyên tử (Bộ KH-CN) cho biết, diện tích cho mỗi dự án xây dựng nhà máy điện hạt nhân khoảng 500ha. Theo kế hoạch, số hộ dân cần di dời để xây dựng nhà máy điện hạt nhân Ninh Thuận 1 là 156 hộ (khoảng 650 người) và dự án Ninh Thuận 2 là 611 hộ (trên 2.000 người).



Công tác tái định cư, xây dựng cơ sở hạ tầng và giao thông cho dự án đang được tích cực chuẩn bị để đảm bảo tiến độ. Theo kế hoạch, năm 2014 Việt Nam sẽ khởi công xây dựng nhà máy điện hạt nhân đầu tiên và sau năm 2020 tổ máy đầu tiên có thể phát điện.



TRẦN LƯU (SGGP - 12-03-2011)

(www.sggp.org.vn/khoahoc_congnghe/2011/3/252705/)

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Vì vậy tôi đề nghị DanChimViet cho đăng bài này lên Trang Nhà như một chứng cớ cho thấy báo chí "lề phải" và Nhà Nước VN vẫn còn cố tình bưng tai bịt mắt trước những thảm hoạ vô cùng nguy hiểm cho hàng triệu người dân miền Trung nói riêng và cho toàn thể nhân dân VN nói chung, tôi còn giữ E-Mail làm bằng chứng SaiGon Giải Phóng đã chấp nhận thư góp ý của tôi (confirmation).



Theo dõi sát sao những gì đang xảy ra trong các lò nguyên tử của Nhật Bản sau cơn động đất và sóng thần, chúng ta đều thấy hiểm hoạ "bom nguyên tử" đang lơ lửng trên đầu người dân Nhật, toàn thế giới đang nín thở theo dõi và hạm đội Mỹ đã phải rời xa bờ biển Nhật sau khi tham gia cứu trợ vì bị nhiễm phóng xạ, thế mà nhà cầm quyền VN vẫn tiếp tục làm ngơ, giả câm giả điếc.



Trước động thái ngoan cố này, tôi suy đoán ra rằng Nhà Nước VN dưới quyền lãnh đạo của ĐCS đã cố tình đưa đất nước vào con đường chính trị phiêu lưu mạo hiểm. Họ muốn mượn sự hiện diện của Nga Sô (xây lò nguyên tử, cung cấp vũ khí, bảo trì hải cảng Cam Ranh) để làm đối trọng với áp lực của TQ ngoài Biển Đông, trong tương lai (10-20 năm) họ hy vọng sẽ chế tạo được bom nguyên tử để dằn mặt ngoại bang phương Bắc. Đường lối chính trị này, thêm một lần nữa, chứng tỏ ĐCS VN chỉ biết nghĩ đến quyền lợi đảng phái mà bỏ quên sự an toàn của người dân, luôn tìm cách dựa vào thế lực ngoại bang để giữ quyền thống trị độc tài, độc đảng trong nước. Nguy hiểm bậc nhất là VN không hề có một nền giáo dục khoa học kỹ thuật căn bản để đào tạo những chuyên gia kinh nghiệm, kiến thức có khả năng điều hành và bảo trì nhà máy ĐNH. Chỉ cần một sơ suất nhỏ thôi là toàn bộ nhà máy mất kiếm soát gây nên nhiều sự cố dây chuyền cuối cùng dẫn đến thảm hoạ khôn lường, hãy nhớ đến Chernobyl (Liên Xô 26-04-1986), Three Mile Island (Mỹ 28-03-1979) và Fukushima ngày hôm nay để làm bài học để đời.



Nhà nước VN hãy còn thì giờ suy nghĩ và lấy quyết định nhanh chóng trước khi đặt viên đá đầu tiên khởi công xây nhà máy ở Bình Thuận.



Japon : la centrale nucléaire de Fukushima en dix questions
La Presse (Canada) - Publié le 13 mars 2011 à 07h46 Mis à jour à 07h46




Le séisme et le tsunami, qui a noyé les circuits de refroidissement, ont provoqué une crise inquiétante sur les réacteurs 1 et 3 de la centrale nucléaire de Fukushima (Photo AFP)

Le séisme et le tsunami, qui a noyé les circuits de refroidissement, ont provoqué une crise inquiétante sur les réacteurs 1 et 3 de la centrale nucléaire de Fukushima (250 km au nord-est de Tokyo). Quelles sont les causes possibles de cet accident? Les scénarios envisageables ? Et les conséquences?

Q: Comment est protégé le réacteur d'une centrale nucléaire ?

R: La matière radioactive est séparée de l'environnement par trois barrières: le «crayon» qui enveloppe l'uranium (sous forme de pastilles); la cuve et enfin l'enceinte de confinement. Au Japon, elle est constituée d'un «liner», ou «peau métallique», ancré dans des parois en béton et fermé d'un couvercle. Ce liner est muni de capteurs.

Q: Que se passe-t-il en cas de séisme comme au Japon?

R: Dès qu'une secousse est détectée, les capteurs déclenchent des barres constituées de matériaux «neutrophages» qui s'insèrent automatiquement dans le réacteur et évitent la propagation de la réaction nucléaire. Le réacteur est de facto à l'arrêt. Cette première parade a très bien fonctionné au Japon. Cependant, la réaction nucléaire continue à un niveau beaucoup plus faible et il faut alors refroidir le réacteur. Mais le système principal et celui de secours ont été vraisemblablement endommagés par le séisme.

Q: Pourquoi injecte-t-on de l'eau de mer?

R: Le tsunami qui a envahi la région a endommagé les circuits de refroidissement et les circuits de secours (diesel). Les réacteurs ont continué à chauffer, avec des températures de l'ordre de 1.000 degrés. Les barres de combustibles se trouvent alors partiellement émergées (des trois-quarts dans la nuit de dimanche sur le réacteur numéro 3) et ont commencé à se dégrader. Les opérateurs japonais ont alors injecté de l'eau de mer borée - le bore étant un élément chimique qui absorbe les neutrons et freine la réaction nucléaire.

Q: A quoi est due l'explosion du réacteur numéro 1 ?

R: Une réaction chimique due à la dégradation des barres de combustibles et à la baisse du niveau d'eau a provoqué la production d'hydrogène: c'est lui qui a vraisemblablement déclenché l'explosion quand il s'est répandu dans l'enceinte de confinement. Un scénario similaire était susceptible de se reproduire dimanche dans le réacteur numéro 3.

Les opérateurs ont alors libéré une partie des gaz contenus dans l'enceinte de confinement, mélange de vapeur d'eau, d'éléments radioactifs -césium, iode radioactif, crypton...- et d'hydrogène.

Q: A quoi est liée l'explosion survenue samedi dans le réacteur numéro 1?

R: Vraisemblablement, le gaz produit a été évacué dans la partie supérieure du réacteur et a fait sauter un panneau soufflant qui le recouvre. L'explosion aurait donc des causes chimiques (l'hydrogène) et ne serait pas liée à une réaction nucléaire. L'enceinte de confinement est intacte car le taux de radioactivité mesuré est plutôt faible. Il s'agit donc d'une explosion de nature chimique et non d'origine nucléaire.

Q: Qu'est-ce qu'une fusion au sein d'un réacteur ?

R: La fusion correspond à la surchauffe du combustible qui commence à fondre et à couler, comme une bougie. Il devient alors difficile à refroidir et les gaines qui retiennent les produits radioactifs se désagrègent à leur tour. Les produits radioactifs risquent de passer dans l'eau qui circule théoriquement en circuit fermé.

Q: Y a-t-il actuellement fusion au sein du réacteur japonais ?

R: Très probablement dans le réacteur no 1 selon les informations disponibles. Si c'est le cas, elle se traduira par la présence d'un magma appelé corium, qui résulte de la fusion des métaux présents et de l'uranium lui-même.

Le corium risque alors de percer la cuve en la chauffant et de se retrouver directement dans l'enceinte de confinement. Ce qui provoquerait des rejets massifs d'éléments radioactifs dans l'environnement.

Q: Cette situation est-celle comparable à celle de Tchernobyl en 1986?

R: Non, car la centrale de Tchernobyl ne disposait pas d'enceinte de confinement mais d'une simple chappe de béton. En outre, à Tchernobyl, il s'agissait d'un emballement de la réaction nucléaire, avec un réacteur en surchauffe, alors qu'au Japon les réacteurs ont été arrêtés 24 heures avant l'explosion.

Q: Cette situation est-elle comparable à celle de Three Mile Island (TMI) aux Etats-Unis en 1979?

R: En partie, puisqu'il y avait eu fusion, avec du corium retrouvé au fond de la cuve. L'enceinte de confinement avait résisté.

Mais on a déjà dépassé le niveau de la catastrophe de TMI car il n'y avait pas eu là-bas, ou très peu, de pressurisation de l'enceinte de confinement (évacuation de vapeur).

Q: Y a-t-il eu relâchement d'éléments radioactifs?

R: Oui, avec un relâchement volontaire de vapeur pour éviter que le bâtiment ne se fendille, et avec la vapeur d'eau contaminée qui est sortie de la centrale après l'explosion du bâtiment du réacteur. Tant qu'il n'y aura pas de rétablissement du refroidissement, d'autres relâchements de vapeur contaminée seront inévitables pour éviter un accident majeur.

(Sources contactées par l'AFP: Jean-Mathieu Rambach, ingénieur expert en génie civil et Jérôme Joly, directeur de l'expertise nucléaire à l'Institut de Radioprotection et de Sûreté Nucléaire (IRSN); Olivier Gupta, directeur-général de l'Autorité de Sûreté du nucléaire (ASN); et Bertrand Barré, conseiller scientifique chez Areva.)



Le Quoc Trinh, Canada

15-03-2011

16/03 Japan crisis revives global nuclear debate

View Photo Gallery —  Governments around the globe question the use of nuclear power as Japan’s attempts to avert a meltdown at one of its plants erode confidence in nuclear energy.

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By Keith B. Richburg, Published: March 16

BEIJING — The crisis in Japan has revived anti-nuclear passions around the world, putting governments on the defensive and undermining the nuclear power industry’s recent renaissance as the clean energy of the future.

In the most dramatic move, German Chancellor Angela Merkel announced Tuesday that all seven of the country’s nuclear power plants built before 1980 would be shut down, at least for now, as safety checks are conducted. The decision came one day after the government, facing strong public opposition to nuclear energy ahead of upcoming regional elections, suspended plans to extend the life of its aging plants.

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As nuclear radiation fears grow in Japan, the U.S. is urging Americans to evacuate further away from Japan's nuclear plants. All the while, the U.S. Military relief effort is expanding. (March 16)

Switzerland, with five reactors, announced Monday that it would freeze plans to build or replace nuclear power plants, and Austria called for new stress tests on plants across Europe.

Yet other countries, including Italy, where a Franco-Italian partnership is planning to start construction on a nuclear plant in 2013, have called for calm, with authorities saying the crisis should not derail plans to expand nuclear energy.

White House officials defended the use of nuclear power in the United States, which President Obama has embraced throughout his administration. “At this time, we don’t have any information that would cause us to do anything different,” Gregory B. Jaczko, chairman of the Nuclear Regulatory Commission, said at a White House briefing Monday.

In France, where nuclear plants produce 80 percent of electricity, the Japanese calamity reenergized a long-dormant political debate about the country’s heavy reliance on nuclear power.

Government officials sought to reassure the public that France’s more than 50 nuclear plants are safe, and President Nicolas Sarkozy told his political coalition that the plants were among the safest in the world.

The main opposition Socialist Party was divided, with key leaders saying it would be foolhardy to abandon a nuclear energy program that has stood since the 1970s but several Socialist figures demanding a reconsideration of nuclear safety measures.

Europe Ecology-Greens Party activists, long opposed to nuclear power, called for a referendum on whether France should get out of the nuclear business and accused the government of playing down the risks.

“We have to end the myths,” said Cecile Duflot, a prominent Green leader. “Zero-risk nuclear power production does not exist.”

In Russia, Ukraine and Belarus — which will mark the 25th anniversary of the Chernobyl disaster this April — the crisis in Japan has served as a reminder of the dangers of nuclear power, but national leaders say they don’t see any alternative.

Russia is building six new nuclear power plants and has plans for more. It also recently signed an agreement with Belarus to build one there.

Ukrainian Prime Minister Mykola Azarov said Tuesday that Kiev is moving ahead with plans to build two new reactors at the Khmelnytsky power plant. “I believe there is no possible alternative to the use of nuclear energy,” he said at a news conference during a visit to Istanbul, “and only rich countries can afford to discuss the possibility of closing” nuclear plants.

Environmental groups disagree. “The example of Japan vividly demonstrates that even if properly maintained, nuclear power engineering is extremely dangerous,” Greenpeace Russia head Ivan Blokov told Interfax on Monday.

In Britain, where officials have laid out plans for a new generation of 10 nuclear power plants, the government has commissioned a fresh report on nuclear safety, while opponents vowed a new campaign of public pressure.

“The risks from nuclear energy remain unchanged; there were always risks,” said Stephen Tindale, a British environmentalist. “But they will clearly need to be properly reassessed in the light of what’s happening in Japan, and that’s inevitably going to mean that the nuclear renaissance is going to be a smaller renaissance than it would have been.”

Even in tightly controlled China, a debate on nuclear safety seemed to be underway.

According to the London-based World Nuclear Association, China has 13 nuclear power reactors in operation and 27 others under construction. An additional 50 reactors are in the planning stage, and more than 140 others have been proposed, the association says. China, like Japan, is prone to earthquakes.

Government officials have said China’s nuclear program, the world’s most ambitious, will continue unabated, but they have also tried to allay fears about the potential dangers. Officials have said the plants being built here, unlike Japan’s older plants, are new-generation models that do not rely on electrical power for their cooling systems but instead are fitted with large tanks of water operating by gravity in the event of a crisis.

But concern about the possibility of a nuclear leak in China dominated discussions on the country’s burgeoning microblogging sites, the country’s newest forum for the public to voice unfettered views.

“How many nuclear power plants are there in our country? Are they all far away from the seismic zones . . . ?” Zheng Yuanjie, a well-known author of children’s books, wrote on his microblog.

In Taiwan, environmentalists, civil engineers and the opposition party called for the government to immediately halt construction of a fourth nuclear plant, slated to go online in late 2012. Just 100 miles off the coast of China, Taiwan lies on the same arc of tectonic plates as Japan.

Trying to allay public fears, President Ma Ying-jeou ordered safety checks Tuesday of Taiwan’s three existing plants but dismissed calls to put the fourth plant on hold.

In India, activists and villagers who have waged a two-year struggle against a proposed nuclear plant in Jaitapur, in Maharashtra state, said the events in Japan have given them a new tool to fight the government.

“What is happening in Japan has reenergized our opposition to the nuclear plant here,” said Vaishali Patil, an anti-nuclear campaigner.

The proposed plant will be built by the French company Areva. India now has 20 nuclear reactors in seven power plants.

The Indian government set aside sites for American, French and Russian-built nuclear reactors across the country after New Delhi signed a landmark 2005 nuclear accord with the Bush administration.

India’s environment minister, Jairam Ramesh, said Tuesday that “if additional safeguards have to be built in as part of the environmental clearance, we will certainly look at it.”

Staff writer Perry Bacon in Washington, correspondents Anthony Faiola in London, Edward Cody in Paris, Will Englund in Moscow and Rama Lakshmi in New Dehli, special correspondent Amber Parcher in Taipei and researchers Zhang Jie and Wang Juan in China contributed to this report.

15/03 Thế giới khâm phục Nhật Bản

Thứ ba, 15/3/2011, 10:22 GMT+7

Một người đàn ông Nhật tìm thông tin về người thân ở tòa thị chính thành phố Natori, tỉnh Miyagi. Ảnh: AFP.

Bất chấp những cảnh tượng kinh hoàng do động đất và sóng thần, nước Nhật sẽ bước ra khỏi cuộc khủng hoảng với uy tín lớn mạnh hơn bởi sự kiên cường của người Nhật đang được cả thế giới ca ngợi.
> Người Nhật kiên cường
> Khủng hoảng hạt nhân xảy ra như thế nào
> Nóng chảy hạt nhân là gì?

Truyền hình và báo chí khắp thế giới ngày ngày đưa hình ảnh những con sóng khổng lồ cuốn phăng nhà cửa và ô tô tàu thủy như những món đồ chơi nhỏ, hình ảnh những người sống sót thất thần trước cảnh hoang tàn.

Loạt tin và phóng sự cũng cho thấy một nước Nhật Bản khác - người Nhật bình tĩnh và kiên trì đi tìm những người thân hay trật tự chờ đợi đến lượt được nhận nhu yếu phẩm. Không hề có dấu hiệu cướp bóc hay bạo lực.


Một người đàn ông Nhật tìm thông tin về người thân ở tòa thị chính thành phố Natori, tỉnh Miyagi. Ảnh: AFP.

Vô số blog tiếng Anh trên thế giới mô tả những người Nhật là "khắc kỷ", và tự đặt câu hỏi nếu thảm họa như vậy xảy ra ở các nước phương Tây thì không hiểu mức độ thảm cảnh sẽ lên đến đâu.

Giáo sư đại học Havard Joseph Nye nhận xét rằng thảm họa này có thể khiến "quyền lực mềm" của nước Nhật tăng lên. Quyền lực mềm là thuật ngữ ông dùng để mô tả cách mà các quốc gia đạt được mục tiêu của mình bằng cách khiến nước khác ngưỡng mộ.

"Cho dù thảm họa này là to lớn, nó cho thấy một số nét tính cánh tuyệt vời của người Nhật, và sẽ giúp cho quyền lực mềm của họ", Nye viết.

"Họ cho thấy một xã hội ổn định, kỷ luật tốt và được chuẩn bị sẵn sàng cho những thảm họa, một quốc gia hiện đại. Họ đối phó với thảm họa một cách bình tĩnh và trật tự", ông bình luận.

Nhật Bản, một quốc gia với nền hòa bình được quy định trong hiến pháp, vốn từ lâu sử dụng viện trợ như một trong các chính sách đối ngoại quan trọng, nhiều khả năng sẽ phải xem xét lại các ngân khoản một khi họ bước vào giai đoạn tái tiết sau động đất, sóng thần.


Một em bé Nhật đang được soi để phát hiện xem có bị phơi nhiễm phóng xạ, sau các vụ nổ ở nhà máy điện hạt nhân Fukushima I, hay không. Ảnh: AP.

Mỗi khi có thảm họa thiên nhiên, hầu như quốc gia nào cũng đều nhận được sự cảm thông và viện trợ từ cộng đồng quốc tế, nhưng hiếm khi nào được sự khâm phục và tăng uy tín như Nhật Bản.

Một số chuyên gia nhận định rằng kinh tế Nhật có thể thoát khỏi giai đoạn trì trệ sau thiên tai. "Còn quá sớm để đưa ra bất kỳ dự đoán nào. Nhưng tôi nghĩ, cho đến nay, có vẻ như người Nhật đã thể hiện sự kiên cường trong khủng hoảng. Tôi cho là sẽ có nhiều điều để nói trong những ngày tới, tuần tới, về Nhật Bản", Nicholas Szechenyi, phó giám đốc Trung tâm Nghiên cứu Chiến lược Mỹ, nhận xét.

Báo chí thế giới cũng tràn ngập những lời ca ngợi dành cho người Nhật và công tác chuẩn bị đối phó thiên tai của nước này. Tờ National Post của Canada bình luận rằng tầm nhìn xa của Nhật Bản đã cứu "hàng chục nghìn mạng sống".

"Không như Haiti (2010), Pakistan (2005) hay Tứ Xuyên (2008), số người chết không lên cao vô lý như ở những nơi mà các tòa nhà to tướng đổ sập ngay lập tức lên đầu những người trú ngụ bên trong", báo này viết.

Tờ The Wall Street Journal trong phần xã luận viết: "Sau trận động đất kinh hoàng 300 năm mới có một lần, người Nhật đã giữ được bình tĩnh giữa tình trạng loạn lạc, thực hiện nhiệm vụ cứu hộ cứu nạn khổng lồ, và nhận được sự ngưỡng mộ của cả thế giới".

Xem thêm: Độc giả VnExpress tỏ lòng khâm phục người Nhật Bản.

Thanh Mai (theo AFP)

Theo dòng sự kiện:
Sóng thần, động đất ở Nhật Bản (15/03)
Nhiều nước 'lăn tăn' về điện hạt nhân (15/03)
Cháy ở lò số 4 nhà máy điện hạt nhân Nhật (15/03)
Loạt video mới về sóng thần ở Nhật (15/03)
Nổ lần thứ ba ở nhà máy điện hạt nhân Nhật (15/03)
Người Việt Nam ở Nhật đang được lo chu đáo (14/03)

15/03 Japan Confronts Multiple Crises as Death Toll Climbs

March 15, 2011
By MARK McDONALD and MARTIN FACKLER

TOKYO — Japanese authorities struggled to contain new nuclear emergencies on Tuesday — including a possible rupture in a reactor containment vessel — as the death toll continued to climb with search teams reaching towns that were flattened by last week’s earthquake and tsunami.

The National Police Agency said Tuesday afternoon that 2,722 people had died, and many thousands were still missing. Bodies continued to wash ashore at various spots along the coast after having been pulled out to sea by the tsunami’s retreat.

Some 400,000 people were living in makeshift shelters or evacuation centers, officials said. Bitterly cold and windy weather that was pushing into northern Japan was compounding the misery as the region struggled with shortages of food, fuel and water.

An explosion Tuesday morning at the Fukushima Daiichi Nuclear Station — the third reactor blast in four days — damaged the vessel containing the nuclear core at reactor No. 2 , government officials said, and there was a growing fear of a catastrophic meltdown.

The overwhelmed operator of the nuclear plants, Tokyo Electric Power Company, confirmed there had been radiation leaks and that water was being pumped into three overheated reactors in the Fukushima complex.

A fire that broke out Tuesday morning at a fourth reactor was extinguished by midafternoon, although the government’s chief spokesman, Yukio Edano, later said that temperatures were rising inside a fifth and sixth reactor in the complex.

People living within about 12 miles of the reactors at Fukushima were ordered to evacuate, and those within about 20 miles were told to stay indoors and close all windows, doors and vents. If people had laundry hanging outside, the government advised, they should not bring it inside or touch it.

Tokyo-area residents began to buy and stockpile food, water, candles and batteries as shelves at grocery stores became increasingly bare. Prime Minister Naoto Kan went on national television to implore people not to panic.

But there was plenty of panic in the stock market: Fevered selling drove down the Nikkei stock index by 10.6 percent at the close of trading.

There were scattered news reports of some foreigners fleeing Japan, and one Western diplomat said Tuesday night that “anecdotes and rumors” were swirling in the international community.

Still, there appeared to be no mass exodus. The United States Embassy, for example, was not urging resident Americans to leave.

The ambassador, John V. Roos, said that about 1,300 Americans were living in the five northern prefectures most affected by the earthquake and the tsunami. American consular officers were making their way to Sendai and other northern cities on Tuesday to conduct “welfare-and-whereabouts” checks on American citizens there.

“We are encouraging U.S. citizens to heed the instructions of the Japanese civil defense authorities,” Mr. Roos said.

The commander of American forces in Japan, Lt. Gen. Burton M. Field, confirmed that some American troops aboard three helicopters had been contaminated by radiation when they apparently flew through a radioactive plume released from the crippled nuclear complex.

“We found contamination on the clothes of several crew members, and one crew member had some on his skin,” said General Field. “The exposure rate was about the same as you would get over a monthlong period outside in the sun. We assess that as very, very low.”

He added that the crew members got a good scrubbing with soap and water and were back on duty.

Chinese health and environmental officials on Tuesday gathered for emergency meetings on how to respond in case radioactive fallout hit China. The government said it was stepping up monitoring for radiation and would swiftly report results.

China’s Meteorological Administration said prevailing winds would carry radioactive material away from China until Thursday, and possibly beyond. “China will not be affected,” the agency said on its Web site.

Air China canceled all flights to and from Tokyo and Sendai until Thursday.

Nations such as South Korea and Singapore have announced they would bolster inspections of Japanese food imports.

The United States Geological Survey revised the magnitude of the earthquake to 9.0, from 8.9, but it was the subsequent tsunami that did the most damage. The initial wave scoured away entire communities, and desperate survivors searched Tuesday for signs of friends and relatives who remained missing.

There was plenty that was missing in the fishing village of Minamisanriku: the city hall, the hospital, the shipyard, police stations — and 8,000 people.

The tsunami might have crashed most heavily into this town that once was home to more than 17,000. Situated at the back of a mountainous V-shaped cove, the town was swamped by the first surge of muck and seawater that was 30 feet high as it roared between the valley walls.

As the deluge pressed in on them, Sanae Sato, 71, said 400 townspeople rushed to the community center where she worked. They thought the five-story building would be high enough to protect them. But when the water reached the fourth floor, they all sought shelter in the attic.

From the attic window, Ms. Sato said, she saw the floodwaters hurling cars along, with drivers and passengers still inside. Houses broke from their foundations and were carried along, their owners perched on the ridges of the roofs.

“I saw people trying to balance on the rooftops like surfers,” she said. “It didn’t work. It was like hell.”

The Miyagi prefectural government said Tuesday that search teams had located 2,000 people in Minamisanriku who had been missing and presumed dead. They had fled to surrounding towns as the tsunami bashed the coastal areas of the town.

Troopers from Japan’s Self-Defense Forces cleared roadways into the village on Tuesday as a long line of fire trucks waited to enter. Closer to shore, teams of searchers rummaged through the crushed houses and collapsed shops. They peered into cars that had been swallowed by the mud, hoping to find survivors. Searched cars were marked with yellow tape.

One gruesome discovery was a mud-caked woman hanging by her head from the roof of a gas station. She was brought down, covered in a blue plastic tarp, and her body was laid by the station to await collection by another disaster team.

Rescue teams from 13 countries pressed on with the searches in other towns, some assisted by dogs. In the air, helicopters shuttled back and forth, part of a mobilization of some 100,000 troops, the largest since World War II.

Because the Fukushima plants have been lost to the national power grid, Tokyo Electric announced plans for rolling blackouts across the region to conserve electricity — the first controlled power cutbacks in Japan in 60 years.

The first set of blackouts Tuesday morning began in four prefectures outside Tokyo. The utility, which provides service to 45 million people in the region, said the cuts could continue for six weeks.

Public conservation of electricity was significant enough, the company said, that the more drastic blackout scenarios were being scaled back. Still, anticipating deep and lengthy power cuts, many people were stocking up on candles, water, instant noodles and batteries for radios.


Martin Fackler reported from Natori, Japan, and Mark McDonald from Tokyo. Reporting was contributed by Mac Bishop from Fukushima, Japan, Moshe Komata and Hiroko Tibuchi from Tokyo, and Bettina Wassener from Hong Kong.




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15/03 Workers Strain to Retake Control After Blast and Fire at Japan Plant

Digital Globe, via Reuters
The No. 3 reactor building of the Fukushima Daiichi nuclear plant burned Monday after a blast following an earthquake and tsunami in this satellite image.

March 15, 2011
By HIROKO TABUCHI, DAVID E. SANGER and KEITH BRADSHER

TOKYO — Japanese officials and safety workers struggled to reassert control over badly damaged nuclear reactors and avert calamity on Tuesday after the situation at the stricken Fukushima Daiichi plant appeared to verge toward catastrophe with a huge spike in radiation levels after a new explosion and fire.

Though the situation remained dangerous there were signs that workers had, at least for the moment, contained some of the danger. The higher radiation levels of earlier in the day — possibly from a fire in the No. 4 reactor — stabilized and then declined toward evening, according to the Japanese authorities.

Engineers at the plant, working at tremendous personal risk, on Tuesday continued efforts to cool down the most heavily damaged unit, reactor No. 2, by pumping in seawater. According to government statements most of the 800 workers at the plant had been withdrawn, leaving 50 or so in a desperate effort to keep the cores of three stricken reactors cooled with seawater pumped by firefighting equipment. Crews battled to put out the fire at the No. 4 reactor, which they said they had done just after noon on Tuesday.

But late Tuesday Japan’s nuclear watchdog said a pool storing spent fuel rods at that fourth reactor had overheated and reached boiling point and had become unapproachable by workers. The fire earlier Tuesday morning was sparked by a hydrogen explosion caused by rising temperatures at the fuel pool, which released radioactivity directly into the atmosphere. The government said late Tuesday that radiation levels at the plant also appeared to be falling sharply from levels earlier in the day.

The fourth reactor had been turned off and was under refurbishment for months before the earthquake and tsunami hit the plant on Friday. But the plant contains spent fuel rods that were removed from the reactor. If these rods had become dry, they could overheat and catch fire. That is almost as dangerous as the fuel in working reactors melting down because the spent fuel can also spew radioactivity into the atmosphere.

In a brief morning address to the nation Prime Minister Naoto Kan pleaded for calm but warned that radiation that had leaked earlier had already spread from the crippled reactors and that there was “a very high risk” of further leakage.

The sudden turn of events, after an explosion Monday at one reactor and then an early-morning explosion Tuesday at yet another — the third in four days at the plant — already made the crisis at the Fukushima Daiichi Nuclear Power Station the worst nuclear accident since the Chernobyl reactor disaster a quarter century ago. It had already become impossible for workers to remain at many areas within the plant for extended periods, the nuclear watchdog said.

Shigekatsu Oomukai, a spokesman for the Nuclear and Industrial Safety Agency, said the substantial capacity of the pool at reactor No. 4 meant that the water in it was unlikely to evaporate soon. But he said workers were having difficulty reaching the pool to cool it because of the high temperature of the water.

Worryingly, temperatures appeared to be rising in the spent fuel pools at two other reactors at the plant, No. 5 and No. 6, said Yukio Edano, the chief cabinet secretary.

Earlier Tuesday the Japanese government told people living within about 20 miles of the Daiichi plant to stay indoors, keep their windows closed and stop using air conditioning. More than 100,000 people are believed to be in that area.

Mr. Kan, whose government was extraordinarily weak before the sequence of calamities struck the nation, told the Japanese people that “although this incident is of great concern, I ask you to react very calmly.” And in fact there seemed to be little panic but huge apprehension in a country where radioactivity brings up memories of Hiroshima and Nagasaki, the haunting images of post-war Japan.

Radiation measurements reported earlier Tuesday showed a spike around the plant that revealed that the leakage was significantly worse than it had been, with radiation levels measured at one point as high as 400 millisieverts an hour. Even seven minutes of exposure at that level will reach the maximum annual dose that a worker at an American nuclear plant is allowed. And exposure for 75 minutes would probably lead to acute radiation sickness.

By late Tuesday the measurements at the main gate of the plant were down to 0.6 millisieverts per hour, a drop from the 11.9 millisieverts per hour observed six hours earlier, Japanese officials told the International Atomic Energy Agency.The extent of the public health risk depends on how long people are exposed to such elevated levels — they may have declined because the fire at the No. 4 reactor was extinguished — as well as how far and fast the radioactive materials spread, and whether the limited evacuation plan announced by the government proves sufficient.

In Tokyo, 170 miles south of the plant, the metropolitan government said Tuesday it had detected radiation levels 20 times above normal over the city, though it stressed that such a level posed no immediate health threat and that readings had dropped since then.

Japan has requested assistance from the United States Nuclear Regulatory Commission, as well as the International Atomic Energy Agency. The succession of problems at Daiichi was initially difficult to interpret, with confusion compounded by incomplete and inconsistent information provided by government officials and executives of the plant’s operator, Tokyo Electric Power Company.

But industry executives in close contact with officials in Japan expressed extreme concern that the authorities were close to losing control over the fuel melting in three reactors at Daiichi, especially at the crippled No. 2 reactor where the containment vessel was damaged.

Tokyo Electric Power said Tuesday that after the explosion at the No. 2 reactor pressure had dropped in the “suppression pool” — a section at the bottom of the reactor that converts steam to water and is part of the critical function of keeping the nuclear fuel protected. After that occurred radiation levels outside No. 2 were reported to have risen sharply.

“We are on the brink,” said Hiroaki Koide, a senior reactor engineering specialist at the Research Reactor Institute of Kyoto University. “We are now facing the worst-case scenario. We can assume that the containment vessel at Reactor No. 2 is already breached. If there is heavy melting inside the reactor, large amounts of radiation will most definitely be released.”

Another executive said the chain of events at Daiichi suggested that it would be difficult to maintain emergency seawater cooling operations for an extended period if the containment vessel at one reactor had been compromised because radiation levels could threaten the health of workers nearby.

If all workers do in fact leave the plant, the nuclear fuel in all three reactors is likely to melt down, which would lead to wholesale releases of radioactive material — by far the largest accident of its kind since Chernobyl.

Even if a full meltdown is averted, Japanese officials have been facing unpalatable options. One was to continue flooding the reactors and venting the resulting steam, while hoping that the prevailing winds did not turn south toward Tokyo or west, across northern Japan to the Korean Peninsula. The other was to hope that the worst of the overheating was over, and that with the passage of a few more days the nuclear cores would cool enough to essentially entomb the radioactivity inside the plants, which clearly will never be used again. Both approaches carried huge risks.

While Japanese officials made no comparisons to past accidents, the release of an unknown quantity of radioactive gases and particles — all signs that the reactor cores were damaged from at least partial melting of fuel — added considerable tension to the effort to cool the reactors.

“It’s way past Three Mile Island already,” said Frank von Hippel, a physicist and professor at Princeton. “The biggest risk now is that the core really melts down and you have a steam explosion.”

The sharp deterioration came after a frantic day and night of rescue efforts focused largely on the No. 2 reactor. There, a malfunctioning valve prevented workers from manually venting the containment vessel to release pressure and allow fresh seawater to be injected into it. That meant that the extraordinary remedy emergency workers had jury-rigged to keep the nuclear fuel from overheating no longer worked.

As a result, the nuclear fuel in that reactor was exposed for many hours, increasing the risk of a breach of the container vessel and more dangerous emissions of radioactive particles.

By Tuesday morning, Tokyo Electric Power said that it had fixed the valve and resumed seawater injections, but that it had detected possible leaks in the containment vessel that prevented water from fully covering the fuel rods.

Then an explosion hit that reactor. After a series of conflicting reports about what level of damage was inflicted on the reactor after that blast, Mr. Edano, the chief cabinet secretary, said, “there is a very high probability that a portion of the containment vessel was damaged.”


Hiroko Tabuchi reported from Tokyo, Keith Bradsher from Hong Kong, and David E. Sanger from Washington. Matthew L. Wald contributed reporting from Washington.