Clearly, the Japanese government didn't understand, didn't know the meaning of, "simulation". The whole point of simulation is to provide possible scenarios based on limited inputs, and that's what SPEEDI was supposed to do. It did exactly that, but the government squashed the simulation results.



In order to be "correct" with only the measured data (which was non-existent at that time), the politicians both in the government and in the Nuclear Safety Commission chose to keep quiet and let the residents of Namie-machi irradiated, their homes, fields contaminated, probably beyond repair. Not only that, they went on the offensive, telling Fukushima residents and the Japanese people that everything was under control, it was safe.



Without any warning or advice from the government or TEPCO based on SPEEDI, Namie residents ended up evacuating to where the radioactive plume went. SPEEDI had correctly predicted that the radioactive plume would go the direction of Namie based on the prevailing wind pattern.



Here's the video news created by Wall Street Journal:





NIHONMATSU, Japan—On the afternoon of March 12, 24 hours after a tsunami crippled Japan's Fukushima Daiichi nuclear complex, some 700 residents of the coastal town of Namie were gathered at an elementary school just outside the government's 6.2-mile evacuation zone. Children played in the schoolyard, adults walked their dogs and volunteers cooked rice balls and soup outdoors. With cellphones knocked out and no television, few had any inkling of the rapidly escalating threat posed by the nearby plant.



Back in Tokyo, however, red flags were popping up inside a nondescript office building outside of the central business district, home to one of Japan's nerve centers for responding to a nuclear disaster. A computer system there, called Speedi, used real-time weather data to predict how radiation would spread in the event of an accident, spitting out maps for the government to use to get people out of harm's way.



That afternoon, the system was generating an ominous forecast for Namie: If radiation were to escape the plant, the wind would blow it straight through the town of 21,000, beyond the 6.2-mile safety perimeter and right over the schoolyard. But that information never reached the townspeople, according to Tamotsu Baba, the mayor.



At 3:36 p.m., the plant's reactor No. 1 blew up, spewing radiation sky-high.



"I heard a tremendous noise from the direction of the nuclear plant and knew right away it had exploded," recalls Toshio Konno, a 60-year-old retail-store worker who was standing in the schoolyard. He says he immediately "jumped in my car and headed off in the opposite direction. No one told me what to do. It was up to me to protect myself."



Many people gathered at the school, however, didn't realize what had happened, and most didn't leave for a few more hours.



The mayor later accused central-government representatives at the disaster-response headquarters in Fukushima of failing to protect Namie residents. "We walked straight into the areas where radiation levels were the highest," he said in a recent interview in Nihonmatsu, a neighboring city that is now home to Namie's town hall and some 3,000 of its evacuees. "I told them it was tantamount to an act of murder."



A Wall Street Journal investigation of Japan's efforts to protect people living around the stricken plant reveals that government officials failed to warn those residents despite projections showing a risk of radioactive contamination—information that wasn't made public until days or weeks later. In addition, the government and the plant's operator didn't provide many nearby residents with promised evacuation assistance, which forced the towns to improvise without any clear idea where the radiation was heading.



The fallout projections "could have been used as a guide for evacuation if they had been shared with people ahead of time," says Yukio Sudo, president of Nuclear Safety Technology Center, the government agency that operates Speedi on behalf of the education and science ministry.



The alarming reports did reach the central government's disaster headquarters headed by Prime Minister Naoto Kan. But bureaucrats there later said they didn't alert the politicians who were making evacuation decisions. The bureaucrats said the government didn't know precisely how much radiation had escaped the damaged reactors, so the forecasts, based on assumptions, weren't reliable enough.



Mr. Kan and top aides have said they weren't even aware of the system in the early days of the crisis. "We are truly very sorry that Speedi's projections weren't in the end shared among the parties who needed them," chief government spokesman Yukio Edano told a parliamentary committee on June 20. He said that would be a key subject for a government commission investigating the many things that went wrong at Fukushima Daiichi.



It is unclear how much radiation those living around the plant absorbed. The government to date has done full tests on just 120 residents of the affected communities, and those results haven't been released. Officials are now promising to survey all of Fukushima Prefecture's two million residents sometime in August, and to monitor over the next three decades the 200,000 considered most at risk.



Some experts say the delays mean it is likely too late to detect the full extent of the exposure and potential harm, since some radioactive elements disappear within weeks, even though any damage to the body triggered by those elements remains.



Back in the 1970s and 1980s, when Japan was ramping up its reliance on nuclear energy, the government and the utilities assured those living near reactors that they were safe. In the event of an accident, emergency evacuation protocols required authorities and plant operators to notify local municipalities and to keep residents informed about the accident and evacuation. The government was required to provide evacuation transportation.



In 1980, the year after the Three Mile Island nuclear accident in the U.S., the Japanese government began developing a computer system to help with evacuation planning. The system—called System for Prediction of Environmental Emergency Dose Information, or Speedi—aimed to predict how released radiation would spread if an accident occurred. When the system was launched in 1986, the government said it could produce a detailed radiation map within 15 minutes of any accident that would show which areas were safe.



The guts of the system, developed with the help of Fujitsu Ltd., are housed in a Tokyo office building, above a bank branch. Computers sit in a cooled room, separated by a darkened glass wall from a team of operators at computer monitors. The system crunches data collected from a government meteorological agency and nuclear facilities around the clock, producing regularly updated maps of potential radiation fallout. At least two operators from the nuclear-safety agency are always manning it, ensuring that data are updated every hour.



At 3:42 p.m. on Friday, March 11, about an hour after the tsunami hit the Fukushima Daiichi plant, its operator, Tokyo Electric Power Co., declared a nuclear emergency. Speedi was switched into emergency mode. The system began forecasting how radiation, if released from the plant, would spread, and producing detailed weather reports for surrounding areas.



More than 130 miles away in Namie, residents focused first on escaping the giant waves that washed over parts of the town. Many left the town center for evacuation centers at higher elevations, located about 4.4 miles from the plant.



At 5:44 the next morning, a Saturday, the government said conditions at the plant were deteriorating and ordered the evacuation of everyone within 6.2 miles of it—including those gathered at the town's initial evacuation centers.



In addition to Namie, three other towns fell within that 6.2-mile radius. By prior agreement, all four were entitled to special assistance in the event of an emergency. In two of those towns, Futaba and Okuma, the government arranged for buses to transport residents.



Namie and Tomioka were left to fend for themselves. Namie officials began telling residents to get out immediately. They delivered their message over loudspeakers installed around town and from fire trucks driving block to block.



Without access to government buses, most residents left in their own cars, jamming the highway leading away from the coast. Residents say some people were stuck in traffic for hours. Most headed for the town's evacuation centers outside of the 6.2 mile zone, including the school in the neighborhood of Karino.



Back in Tokyo, government officials were using Speedi to forecast radiation fallout from such potential emergencies as venting radiation-laced steam to relieve reactor pressure, or, worse, an explosion at the reactor. That Saturday afternoon, at 12:36, the ministry of education and science received a simulation showing what would happen if reactor No. 1 exploded at 1 p.m. The conclusion: it would carry immense amounts of radiation well over 6.2 miles in a northwest direction, right over Namie, the Karino school and other evacuation sites. A 3 p.m. simulation reached a similar conclusion: any radiation released at about 4 p.m. would be blown in the same direction.



As many as 2,000 residents had fled to areas that Speedi projections showed would be covered by a radioactive cloud if reactor No. 1 was vented that afternoon. The residents were clueless about that danger. At about 2:30 p.m., the venting started.



At one evacuation site about 15 miles from the plant, a community center in Tsushima, dozens gathered in a parking lot to watch clouds of steam shoot up from behind a range of mountains. They knew what they were witnessing. They had heard on television that the plant was going to be vented.



"It never occurred to us radiation would come our way," says Hidehiro Asada, a 43-year-old owner of a lumberyard who was in the crowd. "We assumed the folks from the town or the prefecture would tell us if it was dangerous for us to be there."



At the school in Karino, evacuees also were in the dark about the risk. Many of them had no idea that reactor No. 1 had exploded in the middle of the afternoon until a volunteer fireman arrived about two hours later and told them about it.



That set off a panic. Some evacuees hurried to shut the wide-open sliding doors of the gym. Others started yelling at Tokyo Electric employees who were also taking shelter there, demanding information.



Before long, a Tokyo Electric employee arrived in a company car wearing full protective gear and toting a dosimeter, according to two people who were there. It beeped steadily, indicating high levels of radiation, these people say. He told the evacuees that they were safe because they were outside the official evacuation zone, they say. He left after a few minutes. A Tokyo Electric spokesman confirmed the incident.



That evening, the government expanded the evacuation zone to 12.4 miles, from 6.2, and asked people within 18.6 miles of the plant to stay indoors.



At about 6:30 p.m., a pair of military trucks arrived to pick up people from the school. It was nearly 11 p.m. when the last of evacuees left.



Ryuji Ohura, a town official who spent the day at the school looking after evacuees, locked up the school and headed northwest to another evacuation center. "We felt completely abandoned," recalls the 32-year-old father of two. "As I was driving, I just felt a sense of defeat. I kept thinking how I would get leukemia and die young."



In the wake of the bungled evacuation, government officials have been struggling to explain why the maps and forecast being churned out by Speedi didn't wind up in the hands of the people who needed them most.



Speedi is designed to produce two types of forecasts. Every hour, year-round, it maps where radiation would spread if released, using hypothetical release amounts. In the event of an actual emergency, the system is supposed to use actual radiation-release data collected from the plant.



Following the explosions, Fukushima Daiichi's system for sending real-time radiation-release data wasn't working. Mr. Kan's cabinet, in a report submitted to the International Atomic Energy Agency in June, said complete data on radiation emitted from the crippled plant weren't available in real time. The release of radiation-fallout projections based on estimates, which Speedi produced, could have caused "unnecessary confusion," the report said.



But Japan's emergency law requires Speedi projections to be used even under such circumstances. The overseers of the system say it worked just fine. "Speedi has functioned just as it was always intended, with no error or delay," says Mr. Sudo.



Toshiso Kosako, a nuclear-safety expert at Tokyo University, stepped down as a nuclear adviser to Mr. Kan in late April. In his resignation statement, he blamed government agencies for their "inadequate initial responses" that prevented effectively using Speedi, thus "subjecting residents to unnecessary radiation exposure." In an interview, he said that the system offered useful information for planning evacuations, but that "nobody wanted to be associated with such fearful decisions."



As for the government's failure to communicate effectively with the people of Namie, deputy chief cabinet secretary Tetsuro Fukuyama blames a breakdown of emergency-phone systems.



Today, nearly all of Namie remains closed due to contamination, and residents have no idea when if will be safe to return. Reconstruction is under way in other tsunami-damaged towns, but Namie's coast is still covered in debris. Workers aren't allowed to go near it.

