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FUKUSHIMA, Japan, June 24 (Reuters) - A decade and a half before it blew apart in a hydrogen blast that punctuated the worst nuclear accident since Chernobyl, the No. 3 reactor at the Fukushima nuclear power plant was the scene of an earlier safety crisis.
Then, as now, a small army of transient workers was put to work to try to stem the damage at the oldest nuclear reactor run by Japan's largest utility.
At the time, workers were racing to finish an unprecedented repair to address a dangerous defect: cracks in the drum-like steel assembly known as the "shroud" surrounding the radioactive core of the reactor.
But in 1997, the effort to save the 21-year-old reactor from being scrapped at a large loss to its operator, Tokyo Electric, also included a quiet effort to skirt Japan's safety rules: foreign workers were brought in for the most dangerous jobs, a manager of the project said.
"It's not well known, but I know what happened," Kazunori Fujii, who managed part of the shroud replacement in 1997, told Reuters. "What we did would not have been allowed under Japanese safety standards."
The previously undisclosed hiring of welders from the United States and Southeast Asia underscores the way Tokyo Electric, a powerful monopoly with deep political connections in Japan, outsourced its riskiest work and developed a lax safety culture in the years leading to the Fukushima disaster, experts say.
Special Reports on disaster: r.reuters.com/tec78r
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A 9.0 earthquake on March 11 triggered a 15-metre tsunami that smashed into the seaside Fukushima Daiichi plant and set off a series of events that caused its reactors to start melting down.
Hydrogen explosions scattered debris across the complex and sent up a plume of radioactive steam that forced the evacuation of more than 80,000 residents near the plant, about 240 km (150 miles) northeast of Tokyo. Enough radioactive water to fill 40 Olympic swimming pools has also been collected at the plant and threatens to leak into the groundwater.
The repeated failures that have dogged Tokyo Electric in the three months the Fukushima plant has been in crisis have undercut confidence in the response to the disaster and dismayed outside experts, given corporate Japan's reputation for relentless organization.
Hastily hired workers were sent into the plant without radiation meters. Two splashed into radioactive water wearing street shoes because rubber boots were not available. Even now, few have been given training on radiation risks that meets international standards, according to their accounts and the evaluation of experts.
The workers who stayed on to try to stabilize the plant in the darkest hours after March 11 were lauded as the "Fukushima 50" for their selflessness. But behind the heroism is a legacy of Japanese nuclear workers facing hazards with little oversight, according to interviews with more than two dozen current and former nuclear workers, doctors and others.
Since the start of the nuclear boom in the 1970s, Japan's utilities have relied on temporary workers for maintenance and plant repair jobs, the experts said. They were often paid in cash with little training and no follow-up health screening.
This practice has eroded the ability of nuclear plant operators to manage the massive risks workers now face and prompted calls for the Japanese government to take over the Fukushima clean-up effort.
Although almost 9,000 workers have been involved in work around the mangled reactors, Tokyo Electric did not have a Japan-made robot capable of monitoring radiation inside the reactors until this week. That job was left to workers, reflecting the industry's reliance on cheap labor, critics say.
"I can only think that to the power companies, contract workers are just disposable pieces of equipment," said Kunio Horie, who worked at nuclear plants, including Fukushima Daiichi, in the late 1970s and wrote about his experience in a book "Nuclear Gypsy".
Tokyo Electric said this week it cannot find 69 of the more than 3,600 workers who were brought in to Fukushima just after the disaster because their names were never recorded. Others were identified by Tepco in accident reports only by initials: "A-san" or "B-san."
Makoto Akashi, executive director at the National Institute of Radiological Sciences near Tokyo, said he was shocked to learn Tokyo Electric had not screened some of the earliest workers for radiation inside their bodies until June while others had to share monitors to measure external radiation.
That means health risks for workers - and future costs - will be difficult to estimate.
"We have to admit that we didn't have an adequate system for checking radiation exposure," said Goshi Hosono, an official appointed by Prime Minister Naoto Kan to coordinate the response to the crisis.
'BROAD IS THE ROAD THAT LEADS TO DESTRUCTION'
Fujii, who devoted his career to building Japanese nuclear power plants as a manager with IHI Corporation, was troubled by what he saw at Fukushima in 1997.
Now 72, he remembers falling for "the romance of nuclear power" as a student at Tokyo's Rikkyo University in the 1960s. "The idea that you could take a substance small enough to fit into a tea cup and produce almost infinite power seemed almost like a dream" he said.
He had asked to oversee part of the job at Fukushima as the last big assignment of his career. He threw himself into the work, heading into the reactor for inspections. "I had a sense of mission," he said.
As he watched a group of Americans at work in the reactor one day, Fujii jotted down a Bible verse in his diary that captured his angst: "Wide is the gate and broad is the road that leads to destruction and many enter through it."
The basis for nuclear safety regulation is the assumption that cancers, including leukemia, can be caused years later by exposure to relatively small amounts of radiation, far below the level that would cause immediate sickness. In normal operations, international nuclear workers are limited to an average exposure of 20 millisieverts per year, about 10 times natural background radiation levels.
At Fukushima in 1997, Japanese safety rules were applied in a way that set very low radiation exposure limits on a daily basis, Fujii said. That was a prudent step, safety experts say, but it severely limited what Japanese workers could do on a single shift and increased costs.
The workaround was to bring in foreign workers who would absorb a full-year's allowable dose of radiation of between 20 millisieverts and 25 millisieverts in just a few days.
"We brought in workers from Southeast Asia and Saudi Arabia who had experience building oil tankers. They took a heavier dose of radiation than Japanese workers could have," said Fujii, adding that American workers were also hired.
Tokyo Electric would admit five years later it had hid evidence of the extent of the defect in the shroud from regulators. That may have added to the pressure to finish the job quickly. When new cracks were found, they were fixed without a report to regulators, according to disclosures made in 2002
It is not clear if the radiation doses for the foreign workers were recorded on an individual basis or if they have faced any heath problems. Tepco said it had no access to the worker records kept by its subcontractors. IHI said it had no record of the hiring of the foreign workers. Toshiba, another major contractor, also said it could not confirm that foreign workers were hired.
Hosono, the government official overseeing the response to the disaster, said he was not aware of foreign