Japan: 3 reactors melted down in quake

An aerial view of the damaged Fukushima Daiichi nuclear power plant.Japan's nuclear emergency agency goes further in describing the extent of damageThe Fukushima Daiichi plant was badly affected by an earthquake and tsunami in MarchTokyo Electric Power Co. has avoided calling the event a meltdown

Tokyo (CNN) -- Japan's Fukushima Daiichi nuclear power plant experienced full meltdowns at three reactors in the wake of an earthquake and tsunami in March, the country's Nuclear Emergency Response Headquarters said Monday.

The nuclear group's new evaluation, released Monday, goes further than previous statements in describing the extent of the damage caused by an earthquake and tsunami on March 11.

The announcement will not change plans for how to stabilize the Fukushima Daiichi plant, the agency said.

Reactors 1, 2 and 3 experienced a full meltdown, it said.

The plant's owner, Tokyo Electric Power Co., admitted last month that nuclear fuel rods in reactors 2 and 3 probably melted during the first week of the nuclear crisis.

It had already said fuel rods at the heart of reactor No. 1 melted almost completely in the first 16 hours after the disaster struck. The remnants of that core are now sitting in the bottom of the reactor pressure vessel at the heart of the unit and that vessel is now believed to be leaking.

A "major part" of the fuel rods in reactor No. 2 may have melted and fallen to the bottom of the pressure vessel 101 hours after the earthquake and tsunami that crippled the plant, Tokyo Electric said May 24.

The same thing happened within the first 60 hours at reactor No. 3, the company said, in what it called its worst-case scenario analysis, saying the fuel would be sitting at the bottom of the pressure vessel in each reactor building.

But Tokyo Electric at the same time released a second possible scenario for reactors 2 and 3, one that estimated a full meltdown did not occur. In that scenario, the company estimated the fuel rods may have broken but may not have completely melted.

Temperature data showed the two reactors had cooled substantially in the more than two months since the incident, Tokyo Electric said in May.

The earthquake and tsunami knocked out cooling systems at Fukushima Daiichi, causing the three operating reactors to overheat. That compounded a natural disaster by spewing radioactive material into the atmosphere.

Tokyo Electric avoided using the term "meltdown," and says it was keeping the remnants of the core cool. But U.S. experts interviewed by CNN after the company's announcement in May said that while it may have been containing the situation, the damage had already been done.

"On the basis of what they showed, if there's not fuel left in the core, I don't know what it is other than a complete meltdown," said Gary Was, a University of Michigan nuclear engineering professor and CNN consultant. And given the damage reported at the other units, "It's hard to imagine the scenarios can differ that much for those reactors."

A massive hydrogen explosion -- a symptom of the reactor's overheating -- blew the roof off the No. 1 unit the day after the earthquake, and another hydrogen blast ripped apart the No. 3 reactor building two days later. A suspected hydrogen detonation within the No. 2 reactor is believed to have damaged that unit on March 15.

CNN's Yoko Wakatsuki and Kyung Lah contributed to this report.

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Holes feared in Japan nuclear reactors

An aerial view of the damaged Fukushima Daiichi nuclear power plant.The holes may be as big as 7 to 10 centimetersA hole in the reactor's containment vessel means there is a high probability of leakageThe nuclear plant has suffered cooling problems and radiation leaks since March

Tokyo, Japan (CNN) -- Two of the damaged reactors at the crippled Fukushima Daiichi nuclear power plant in Japan may be riddled with holes, according to the facility's owner.

The holes may be as big as 7 to 10 centimeters ( 2.8- 3.9 inches), Tokyo Electric Power Co. said in a 225-page document submitted to Japan's Nuclear and Industrial Safety Agency.

In the report, Tokyo Electric says the containment vessel of reactor No. 1 may have developed a hole as big as 3 centimeters in diameter 18 hours after the quake.

Fifty hours after the quake, the hole may have widened to 7 centimeters, the report said.

In reactor No. 2, the containment vessel may have developed a hole as wide as 10 centimeters 21 hours after the quake.

The nuclear plant has suffered cooling problems and radiation leaks since a March 11 earthquake and tsunami.

The hydrogen explosion four days after the crisis began may have led to the formation of a second hole in reactor No. 2, as wide as 10 centimeters in diameter.

"This report is not conclusive. No one has entered these areas and we cannot confirm this as fact," TEPCO said, adding that the report is making preliminary assumptions about what happened inside the reactors.

A hole in the reactor's containment vessel means there is a high probability of the leakage of radioactive material into the reactor building.

The amount of radioactive material in all three of the reactor buildings has hampered TEPCO's ability to build an effective cooling system. TEPCO says a cooling system is a critical step to leading to a cold shutdown, still estimated to be five to eight months away.

Nuclear experts and scientists have long suspected this sort of damage to the containers of the reactors at the crippled plant, as well as a full meltdown of the fuel rods in reactors 1, 2 and 3.

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Japan utility delays decision on halting reactors

TOKYO (AP) — A Japanese power company postponed its decision Saturday on a government request that it halt three reactors at a coastal nuclear plant until safety measures can be improved to guard against future earthquakes and tsunamis.

A woman strolls in a deserted street in Kesennuma, Miyagi Prefecture, northeastern Japan on Friday.

Shutting down the reactors would likely worsen power shortages expected this summer.

On Friday, Prime Minister Naoto Kan said he had asked Chubu Electric Power Co. to suspend operation of the reactors at the Hamaoka Nuclear Power Station in Shizuoka prefecture until a seawall is built and backup systems are improved. Though not legally binding, the request is a virtual order.

The government is reviewing the safety of the country's 54 atomic reactors since a March 11 earthquake and tsunami crippled the Fukushima Dai-ichi nuclear plant in the north. The disaster left more than 25,000 people dead or missing on the northeast coast.

The Hamaoka plant, which is about 125 miles west of Tokyo in an area where a major quake is expected within decades, has been a major concern for years.

Chubu Electric executives failed to reach a decision after discussing the request Saturday afternoon and decided to meet again after the weekend, company official Mikio Inomata said.

At issue is how to make up for the power shortages that would result from the shutdown of the three reactors. Inomata said they account for more than 10 percent of the company's power supply.

Chubu Electric has estimated maximum output of about 30 million kilowatts this summer with the three Hamaoka reactors running, with estimated demand of about 26 million kilowatts.

"It would be tight," Inomata said, adding that officials are discussing the possibility of boosting output from gas, oil and coal-fueled power plants and purchasing power from other utility companies.

Kan said the shutdown request was for the "people's safety."

"If an accident occurs at Hamaoka, it could create serious consequences," he said Friday.

He noted that experts estimate there is a 90%chance that a quake with a magnitude of 8.0 or higher will strike the region within 30 years.

Since the March 11 disasters, Chubu Electric has drawn up safety measures that include building a 40-foot-high seawall nearly a mile long over the next two to three years, company officials said. The company also promised to install additional emergency backup generators and other equipment and improve the water tightness of the reactor buildings.

The plant does not have a concrete sea barrier now. Sand hills between the ocean and the plant are about 32 to 50 feet high, deemed enough to defend against a tsunami around 26 feet high, officials said.

Shizuoka Gov. Heita Kawakatsu called Friday's government request "a wise decision" and vowed to secure alternative sources of energy.

Residents of Shizuoka have long demanded a shutdown of the Hamaoka reactors. About 79,800 people live within a 6-mile radius of the plant.

The Hamaoka plant provides power to around 16 million people in central Japan including nearby Aichi, home of Toyota Motor Corp.

Automakers and other industries have had troubles with interrupted supply lines, parts shortages and damage to manufacturing plants because of the March 11 disasters.

The nationwide newspaper Yomiuri welcomed the government request to shut down the reactors despite concerns about a power crunch.

"The idea is to use the lesson we learned (from Fukushima)," the Yomiuri said, urging other utilities to also improve safety. "An accident and subsequent release of radiation could paralyze the entire country."

Thousands of people joined an anti-nuclear march Saturday in Tokyo's crowded Shibuya shopping and entertainment district, chanting "No nuke plants!"

The Fukushima Dai-ichi plant lost its power and cooling systems in the magnitude-9.0 earthquake and ensuing tsunami, triggering the world's worst nuclear accident since Chernobyl.

Radiation leaks have forced 80,000 people living within a 12-mile radius of the plant to leave their homes.

Since the Fukushima crisis unfolded, officials have acknowledged that tsunami safety measures at Japanese nuclear power plants are insufficient.

Tokyo Electric Power Co., operator of the Fukushima plant, has said the tsunami that wrecked critical power and cooling systems there was at least 46 feet high.

It said radioactivity inside the No. 1 reactor building has fallen to levels deemed safe for people wearing protective suits to enter after workers rapidly installed air filtering equipment Thursday — their first entry since shortly after the tsunami. Workers are to begin preparations as early as Sunday to install a cooling system.

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Japan wants 3 reactors closed while seawall built

TOKYO (AP) — Officials at a Japanese power company were finalizing a decision Saturday following a government request that it suspend all three reactors at a coastal nuclear plant while steps are taken to prevent a major earthquake or tsunami from causing another radiation crisis.

A woman strolls in a deserted street in Kesennuma, Miyagi Prefecture, northeastern Japan on Friday.

Prime Minister Naoto Kan said Friday that he had asked Chubu Electric Power Co. to halt its three reactors at Hamaoka nuclear power plant in central Japan until the operator can improve safety measures.Though not legally binding, the request is a virtual order.

The government is wrapping up a safety review of Japan's 54 atomic reactors after a March 11 earthquake and tsunami crippled the Fukushima Dai-ichi nuclear plant. The disaster left more than 25,000 people dead or missing on the northeast coast.

The Hamaoka nuclear plant just off the Pacific coast in central Japan is the only one so far where the government has asked that operations be halted over safety reasons.

Chubu Electric president Akihisa Mizuno said in a statement that the company would "swiftly consider" the government's request.

He was expected to hold a news conference later Saturday to announce a decision.

"It was a decision made after thoroughly considering people's safety," Kan said Friday, citing experts' forecast of a 90 percent probability of a quake with magnitude of 8.0 or higher striking central Japan within 30 years.

The government asked Chubu Electric to suspend two running reactors and a third currently shut for a regular inspection at the plant in Shizuoka, which is around 124 miles (200 kilometers) west of Tokyo. Two other reactors are currently being decommissioned.

"If an accident occurs at Hamaoka, it could create serious consequences," Kan said.

Since the March 11 disasters, Chubu Electric has drawn up safety measures that include building a 40-foot-high (12-meter-high) seawall nearly a mile (1.5 kilometers) long over the next two to three years, company official Takanobu Yamada said. The company also promised to install additional emergency backup generators and other equipment and improve water-tightness of the reactor building.

Chubu also plans to erect concrete walls along 18 water pumps at the plant, to protect them from tsunami or quake damage. It will also install additional backup generators and other emergency equipment to secure cooling capacity, and improve water-tightness of reactor buildings. It will take two to three years to complete the sea wall, Yamada said.

The plant does not have a concrete sea barrier now. Sandhills between the ocean and the plant are about 32 to 50 feet (10 to 15 meters) high, the company said.

Chubu Electric has estimated a tsunami reaching around 26 feet (8 meters).

The company recently said it was considering restarting the third reactor in July, triggering harsh local opposition.

Trade Minister Banri Kaieda said Chubu's safety measures were insufficient. "Until the company completes safety steps, it is inevitable that it should stop operating nuclear reactors," he said.

Tokyo Electric Power Co., operator of the stricken Fukushima plant, has said the waves that wrecked critical power and cooling systems there were at least 46 feet (14 meters) high.

Shizuoka Gov. Heita Kawakatsu called the government's request "a wise decision" and vowed to secure alternative sources of energy.

Residents in Shizuoka have long demanded suspension of the Hamaoka reactors. About 79,800 people live within a 6-mile (10-kilometer) radius of the plant. Some residents have filed a request to a regional court to suspend the Hamaoka plant.

The Hamaoka plant provides power to around 16 million people in central Japan, including Aichi, home to Toyota Motor Corp.'s headquarters and an auto plant. Faced with a possible power crunch due to the shutdown, Kan sought public understanding.

Automakers and other industries have had troubles with interrupted supply lines, parts shortages and damage to manufacturing plants since the March 11 disasters.

The Fukushima Dai-ichi plant lost its power and cooling systems in the magnitude-9.0 earthquake and ensuing tsunami, triggering fires, explosions and radiation leaks in the world's second-worst nuclear accident.

Radiation leaks have forced 80,000 people living within a 12-mile (20-kilometer) radius of the plant to leave their homes.

Since the Fukushima crisis unfolded, nuclear safety officials have acknowledged that tsunami safety measures at Japanese nuclear power plants were insufficient.

In 2001, TEPCO told Japan's Nuclear and Industrial Safety Agency that waves would not exceed 18 feet (5.7 meters) at the Dai-ichi plant, based on an anticipation of a magnitude-8.6 quake. It assumed the backup power generators, which were stored in basement areas, would stay dry in a tsunami triggered by a magnitude-9.0 quake.

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Japan seeks to halt 3 nuclear reactors

TOKYO (AP) — Japan urged a power company Friday to suspend all three reactors at a coastal nuclear plant while safety measures are taken to ensure damage from a major earthquake or tsunami does not cause a second nuclear accident.

Prime Minister Naoto Kan asked Chubu Electric Power on Friday to suspend nuclear reactors for earthquake safety measures.

Prime Minister Naoto Kan said at a news conference Friday evening the shutdown was requested for safety reasons, citing experts' forecast of a 90 percent probability of a quake with magnitude of 8.0 or higher striking central Japan within 30 years.

"It was a decision made after thoroughly considering people's safety," Kan told a news conference.

The government asked operator Chubu Electric Power Co. to suspend two running reactors and a third already shut for a regular inspection at the Hamaoka nuclear plant in Shizuoka, 155 mileswest of Tokyo.

"If an accident occurs at Hamaoka, it could create serious consequences," Kan said.

A safety review of all Japan's 54 nuclear plants was prompted by the radiation crisis at the Fukushima Dai-ichi nuclear plant, which was crippled by the March 11 earthquake and tsunami that also left more than 25,000 people dead and missing on the northeast coast.

The Hamaoka plant is the only one so far where the government has asked that operations be halted until the utility can implement safety measures. Officials estimate the shutdown could last two years.

Trade Minister Banri Kaieda said Chubu Electric has yet to say whether it would accede the government's request. But Kyodo news agency, quoting sources at the plant, said Chubu Electric had agreed to halt operations at the three reactors.

Since the March 11 disasters, Chubu Electric has drawn up safety measures that include building a 1.5-kilometer-long seawall along the nuclear plant over the next two to three years. The Hamaoka plant is just 100 meters off the Pacific coast.

"The height of the seawall is at least 12 meters. We have come up with this safety measure after the March quake and tsunami," said Takanobu Yamada, an official at Chubu Electric.

Kaieda said the utility company should halt operating its nuclear reactors while implementing such safety measures.

"Until the company completes safety steps, it is inevitable that it should stop operating nuclear reactors," Kaieda said.

Shizuoka governor Heita Kawakatsu called the move "a wise decision."

"I pay my respect for the decision. We must do our utmost to secure alternative sources of energy," the governor said in a statement.

The plant serves around 16 million people in central Japan. Faced with a possible power crunch due to the shutdown, the prime minister sought public understanding.

"We will experience some power crunch for sure. But we can overcome this with public support and understanding," Kan said.

The region powered by the plant includes Aichi, where Toyota Motor Corp.'s headquarters and an auto plant are located.

The March 11 earthquake and tsunami damaged the Fukushima Dai-ichi nuclear plant, which lost its power and cooling systems, triggering fires, explosions and radiation leaks in the world's second-worst nuclear accident.

Radiation leaks from the Fukushima plant have forced 80,000 people living within a 12-mile (20-kilometer) radius to leave their homes. Many are staying in gymnasiums and community centers.

Residents in Shizuoka have long demanded suspension of the Hamaoka reactors.

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Five U.S. nuclear reactors in earthquake zones

By Mark Ralston, AFP/Getty Images

Aerial view of the Diablo Canyon Nuclear Power Plant which sits on the edge of the Pacific Ocean at Avila Beach in San Luis Obispo County, California, is an at-risk reactor like those in Japan.

EnlargeCloseBy Mark Ralston, AFP/Getty Images

Aerial view of the Diablo Canyon Nuclear Power Plant which sits on the edge of the Pacific Ocean at Avila Beach in San Luis Obispo County, California, is an at-risk reactor like those in Japan.

The at-risk reactors are the Diablo Canyon Power Plant and San Onofre Nuclear Generating Station in California; the South Texas Project near the Gulf Coast; the Waterford Steam Electric Station in Louisiana; and the Brunswick Steam Electric Plant in North Carolina.

They appear in an analysis by the mapping and geographic data firm ESRI Inc., based in Redlands, Calif. The online map, the first of its kind to let the public search potential danger zones by address, includes U.S. Geologic Survey (USGS) seismic information and earthquake history for every nuclear plant in the USA.

After the Fukushima disaster, President Obama ordered the Nuclear Regulatory Commission to evaluate the earthquake risk of every nuclear plant in the nation, said Victor Dricks, an NRC spokesman. Dricks said NRC regulations require companies that build nuclear plants to take into account local seismic history and fortify the plants against the largest quake that is likely to occur.

Dricks said the U.S. has taken proper precautions to ensure the safety of its plants. San Onofre, for instance, is built to withstand a magnitude-7.0 earthquake within 5 miles of the site, he said. In addition, the plant is 30 feet above sea level and has a reinforced concrete sea wall that is 30 feet tall and could withstand a 27-foot tsunami.

Japan's Fukushima Dai-ichi plant suffered major damage from a magnitude-9.0 earthquake and 46-foot tsunami that hit March 11. The disaster triggered nuclear radiation leaks and an extensive evacuation in the region around the plant, which was built to withstand a 19-foot tsunami.

The ESRI map aims to help Americans determine their risk. It allows users to plug in their location and find the five nearest nuclear plants.

INTERACTIVE MAP: Find out how close you are to a nuclear plantUsers can also determine whether they live within 10-mile or 50-mile U.S. evacuation zones of any nuclear plants and whether the region around the plant has been jolted by any major earthquakes, measuring magnitude-7.2 or higher, in the past 30 years.

"All of the earthquakes on this map are significant," said ESRI analyst Bronwyn Agrios, noting that the analysis was eye-opening for those on ESRI's staff. "We found that we're just on the cusp of the evacuation zone of the San Onofre plant, just down the coast on the ocean side. Right around our area there have been three earthquakes. We're in a highly dense area for faults. We can feel that. We can feel tremors every week."

William Leith, acting associate director for natural hazards at the USGS, said it's impossible to predict the precise timing, location and magnitude of an earthquake, in part because quakes have been measured in the USA only for a century.

Although most nuclear plants are in the central and eastern USA, where earthquakes are rare, the USGS ranks 39 states as having a high or moderate earthquake risk, Leith said. New studies have shown that at least 20 magnitude-9.0 earthquakes have struck off the coast of Northern California, Oregon and Washington in the past 20,000 years, most recently in 1700, he said.

"We don't want to alarm anybody," he said, "but it can happen here."

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