Meltdowns Grow More Likely at the Fukushima Reactors

Japan's government and nuclear industry, with help from the U.S. military, is inside a desperate race to stave off multiple nuclear reactor meltdowns -- as well as prospective fires in pools of spent fuel.

As of Sunday afternoon, a lot more than 170,000 individuals have been evacuated near the reactor sites as radioactive releases have increased. The number of military emergency responders has jumped from 51,000 to 100,000. Officials now report a partial meltdown at Fukushima's Unit 1. Japanese media outlets are reporting that there might be a second one underway at Unit 3. Folks living nearby have already been exposed to unknown levels of radiation, with some requiring medical consideration.

Meanwhile, Unit 2 of the Tokai nuclear complicated, which is close to Kyodo and just 75 miles north of Tokyo, is reported to have a coolant pump failure. And Japan's nuclear safety agency has declared a state of emergency at the Onagawa nuclear energy plant in northeastern Japan due to the fact of high radiation levels. Authorities are saying its three reactors are "under control."

The damage from the enormous earthquake and also the tsunamis that followed have profoundly damaged the reactor sites' infrastructure, leaving them with out power and their electrical and piping systems destroyed. A hydrogen explosion Saturday at Unit 1 severely damaged the reactor creating, blowing apart its roof.

The outcomes of desperate efforts to divert seawater into the Unit 1 reactor are uncertain. A Japanese official reported that gauges do not seem to show the water level rising inside the reactor vessel.

There stay quite a few significant uncertainties in regards to the situation's stability and a lot of questions about what may transpire next. In addition to the struggle to cool the reactors could be the possible danger from an inability to cool Fukushima's spent nuclear fuel pools. They include quite huge concentrations of radioactivity, can catch fire, and are in a lot more vulnerable buildings. The ponds, normally rectangular basins about 40 feet deep, are created of reinforced concrete walls 4 to 5 feet thick lined with stainless steel.

The boiling-water reactors at Fukushima -- 40-years-old and created by General Electric -- have spent fuel pools a number of stories above ground adjacent towards the leading of the reactor. The hydrogen explosion might have blown off the roof covering the pool, as it's not underneath containment. The pool needs water circulation to eliminate decay heat. If this doesn't happen, the water will evaporate and possibly boil off. If a pool wall or support is compromised, then drainage is really a concern. When the water drops to around 5-6 feet above the assemblies, dose rates could be life-threatening close to the reactor creating. If substantial drainage occurs, right after many hours the zirconium cladding around the irradiated uranium could ignite.

Then all bets are off.

On regular, spent fuel ponds hold five-to-ten times more long-lived radioactivity than a reactor core. Especially worrisome is the significant level of cesium-137 in fuel ponds, which contain anyplace from 20 to 50 million curies of this harmful radioactive isotope. Having a half-life of 30 years, cesium-137 offers off highly penetrating radiation and is absorbed in the food chain as if it had been potassium.

In comparison, the 1986 Chernobyl accident released about 40 percent of the reactor core's 6 million curies. A 1997 report for the Nuclear Regulatory Commission (NRC) by Brookhaven National Laboratory also identified that a severe pool fire could render about 188 square miles uninhabitable, trigger as several as 28,000 cancer fatalities, and expense $59 billion in damage. A single spent fuel pond holds far more cesium-137 than was deposited by all atmospheric nuclear weapons tests in the Northern Hemisphere combined. Earthquakes and acts of malice are thought to be to become the main events that may result in a main loss of pool water.

In 2003, my colleagues and I published a study that indicated if a spent fuel pool had been drained in the United States, a major release of cesium-137 from a pool fire could render an region uninhabitable higher than developed by the Chernobyl accident. We suggested that spent fuel older than five years, about 75 % of what is in U.S. spent fuel pools, be placed in dry hardened casks -- some thing Germany did 25 years ago. The NRC challenged our recommendation, which prompted Congress to request a evaluation of this controversy by the National Academy of Sciences. In 2004, the Academy reported that a "partially or completely drained a spent fuel pool could result in a propagating zirconium cladding fire and release big quantities of radioactive supplies to the atmosphere."

Given what's happening at the Fukushima Daiichi nuclear complicated, it is time for a severe evaluation of what our nuclear safety authorities contemplate to become improbable, particularly with regards to reactors operating in earthquake zones.

Explosion at Japan nuke plant

By ERIC TALMADGE and YURI KAGEYAMA, Related Press Eric Talmadge And Yuri Kageyama, Linked Press 1 hr eight mins ago

IWAKI, Japan - An explosion at a nuclear power station Saturday destroyed a building housing the reactor amid fears that it was close to a disastrous meltdown following being hit by a powerful earthquake and tsunami.

Friday's double disaster, which pulverized Japan's northeastern coast, has left 574 men and women dead by official count, even though local media reports mentioned at least 1,300 people might have been killed.

Tokyo Energy Electric Co., the utility that runs the Fukushima Dai-ichi plant, mentioned four workers had suffered fractures and bruises and had been being treated at a hospital. A nuclear expert said a meltdown might not pose widespread danger.

Footage on Japanese Tv showed that the walls of the reactor's constructing had crumbled, leaving only a skeletal metal frame standing. Puffs of smoke were spewing out of the plant in Fukushima, 20 miles (30 kilometers) from Iwaki.

"We are now wanting to analyze what's behind the explosion," said government spokesman Yukio Edano, stressing that individuals need to swiftly evacuate a six-mile (10-kilometer) radius. "We ask everybody to take action to secure safety."

The difficulty started at the plant's Unit 1 after the massive 8.9-magnitude earthquake and also the tsunami it spawned knocked out energy there. In accordance with official figures, 586 folks are missing and 1,105 injured. Furthermore, police mentioned between 200 and 300 bodies were identified along the coast in Sendai, the largest city inside the location near the quake's epicenter.

The genuine scale of the destruction was nevertheless not known more than 24 hours soon after the quake because washed-out roads and shut airports have hindered access towards the location. An untold amount of bodies had been believed to be buried inside the rubble and debris.

In yet another disturbing development that could substantially raise the death toll, Kyodo news agency stated rail operators lost make contact with with 4 trains operating on coastal lines on Friday and nonetheless had not found them by Saturday afternoon.

East Japan Railway Co. mentioned it did not know how several folks had been aboard the trains.

Adding to worries was the fate of nuclear power plants. Japan has declared states of emergency for 5 nuclear reactors at two energy plants soon after the units lost cooling capacity.

The most troubled one particular, Fukushima Dai-ichi, is facing meltdown, officials have stated.

A "meltdown" is just not a technical term. Rather, it can be an informal way of referring to a very critical collapse of a power plant's systems and its capacity to manage temperatures. It's not immediately clear if a meltdown would cause severe radiation danger, and if it did how far the risk would extend.

Yaroslov Shtrombakh, a Russian nuclear professional, said a Chernobyl-style meltdown was unlikely.

"It's not a fast reaction like at Chernobyl," he mentioned. "I feel that anything is going to be contained inside of the grounds, and there will be no big catastrophe."

In 1986, the Chernobyl nuclear reactor exploded and caught fire, sending a cloud of radiation more than considerably of Europe.

Pressure has been constructing up in Fukushima reactor - it really is now twice the standard level - and Japan's Nuclear and Industrial Safety Agency told reporters Saturday that the plant was venting "radioactive vapors." Officials said they had been measuring radiation levels inside the region. Wind within the region is weak and headed northeast, out to sea, based on the Meteorological Agency.

The reactor in trouble has already leaked some radiation: Operators have detected eight times the standard radiation levels outside the facility and 1,000 occasions normal inside Unit 1's manage space.

Ryohei Shiomi, a nuclear official, mentioned that each and every hour the plant was releasing the quantity of radiation a person typical absorbs in a year.

He has mentioned that even when there had been a meltdown, it wouldn't impact men and women outside a six-mile (10-kilometer) radius - an assertion that could will need revising if the situation deteriorates. Most of the 51,000 residents living inside the danger area had been evacuated, he stated.

Meanwhile, the first wave of military rescuers began arriving by boats and helicopters.

Prime Minister Naoto Kan mentioned 50,000 troops would join rescue and recovery efforts following the quake that unleashed one of the greatest disasters Japan has witnessed - a 23-foot (7-meter) tsunami that washed far inland more than fields, smashing towns, airports and highways in its way.

"Most of houses along the coastline were washed away, and fire broke available," mentioned Kan right after inspecting the quake region inside a helicopter. "I realized the very severe harm the tsunami brought on."

Far more than 215,000 people were living in 1,350 temporary shelters in five prefectures, or states, the national police agency stated. Because the quake, more than 1 million households have not had water, largely concentrated in northeast.

The transport ministry mentioned all highways from Tokyo leading to quake-hit areas had been closed, except for emergency vehicles. Mobile communications had been spotty and calls to the devastated places were going unanswered .

Nearby Tv stations broadcast footage of people lining up for water and food like rice balls. In Fukushima, city officials were handing out bottled drinks, snacks and blankets. But there had been huge locations that had been surrounded by water and had been unreachable.

1 hospital in Miyagi prefecture was seen surrounded by water. The staff had painted an SOS on its rooftop and were waving white flags.

Kan said a total of 190 military aircraft and 25 ships have already been sent towards the location, which continued to be jolted by tremors, even 24 hours later.

A lot more than 125 aftershocks have occurred, a lot of of them above magnitude 6.0, which alone could be considered powerful.

Technologically advanced Japan is well prepared for quakes and its buildings can withstand powerful jolts, even a temblor like Friday's, which was the strongest the nation has skilled considering that official records started inside the late 1800s. What was beyond human control was the killer tsunami that followed.

It swept inland about six miles (ten kilometers) in some areas, swallowing boats, houses, automobiles, trees and everything else.

"The tsunami was unbelievably quick," said Koichi Takairin, a 34-year-old truck driver who was within his sturdy four-ton rig when the wave hit the port town of Sendai.

"Smaller cars were becoming swept around me," he mentioned. All I could do was sit in my truck."

His rig ruined, he joined the steady flow of survivors who walked along the road away from the sea and back into the city on Saturday. Smoke from a minimum of one particular huge fire could be noticed in the distance.

Smashed vehicles and small airplanes had been jumbled up against buildings near the neighborhood airport, numerous miles (kilometers) from the shore. Felled trees and wooden debris lay everywhere as rescue workers coasted on boats by way of murky waters about flooded structures, nosing their way by means of a sea of debris.

Simple commodities had been at a premium. Hundreds lined up outside of supermarkets, and gas stations were swamped with cars. The circumstance was similar in scores of other towns and cities along the 1,300-mile-long (2,100-kilometer-long) eastern coastline hit by the tsunami.

In Sendai, as in several regions of the northeast, cellular phone service was down, generating it tough for folks to communicate with loved ones.

President Barack Obama pledged U.S. help following what he named a potentially "catastrophic" disaster. He mentioned 1 U.S. aircraft carrier was already in Japan and a second was on its way. A U.S. ship was also heading to the Marianas Islands to help as needed, he said.

Japan's worst prior quake was a magnitude eight.three temblor in Kanto that killed 143,000 individuals in 1923, according to the USGS. A magnitude 7.2 quake in Kobe killed 6,400 people in 1995.

Japan lies on the "Ring of Fire" - an arc of earthquake and volcanic zones stretching around the Pacific exactly where about 90 % of the world's quakes occur, like the one that triggered the Dec. 26, 2004, Indian Ocean tsunami that killed an estimated 230,000 men and women in 12 nations. A magnitude-8.8 quake that shook central Chile in February 2010 also generated a tsunami and killed 524 men and women.