Fukushima Long Ranked Japan's Most Hazardous Nuclear Plant
July 27, 2011
By Chisa Fujioka and Kevin Krolicki
TOKYO (Reuters) - Japan's Fukushima
Daiichi nuclear plant ranked as one of the most dangerous in
the world for radiation exposure years before it was
destroyed by the meltdowns and explosions that followed the
March 11 earthquake.
For five years to 2008, the Fukushima
plant was rated the most hazardous nuclear facility in Japan
for worker exposure to radiation and one of the five worst
nuclear plants in the world on that basis. The next
rankings, compiled as a three-year average, are due this
Reuters uncovered these rankings, privately tracked by
Fukushima's operator Tokyo Electric Power, in a review of
documents and presentations made at nuclear safety
conferences over the past seven years.
In the United States -- Japan's early model in nuclear
power -- Fukushima's lagging safety record would have
prompted more intensive inspections by the Nuclear
Regulatory Commission. It would have also invited scrutiny
from the U.S. Institute of Nuclear Power Operations, an
independent nuclear safety organization established by the
U.S. power industry after the Three Mile Island accident in
1979, experts say.
But that kind of stepped-up review never happened in
Tokyo, where the Nuclear and Industrial Safety Agency
remains an adjunct of the trade ministry charged with
promoting nuclear power.
As Japan debates its future energy policy after the worst
nuclear accident since Chernobyl, a Reuters review of the
long-troubled record at Fukushima shows how hard it has been
to keep the country's oldest reactors running in the best of
times. It also shows how Japan's nuclear establishment sold
nuclear power to the public as a relatively cheap energy
source in part by putting cost-containment ahead of
radiation safety over the past several decades.
"After the Fukushima accident, we need to reconsider the
cost of nuclear power," Tatsujiro Suzuki, vice chairman of
Japan's Atomic Energy Commission, told Reuters. "It's not
enough to meet safety standards. The industry needs to
search for the best performance.”
In an illustration of the scale of the safety problems at
Fukushima, Tokyo Electric had set a 10-year goal that
insiders considered ambitious in 2007. The plan was to
reduce radiation exposure for workers at Fukushima to bring
the facility from near rock-bottom in the industry's global
safety rankings to somewhere below-average by 2017,
"Severer management than before will be required," Tokyo
Electric safety researcher Yasunori Kokubun and four other
colleagues said in an English-language 2004 report. That
report examined why Japan lagged other countries such as
France and the United States in limiting radiation exposure
for workers during plant maintenance.
The report came from an earlier period of corporate soul
searching by Tokyo Electric, a politically powerful regional
monopoly in Japan that ran the Fukushima power station and
remains in charge of the clean-up work at the crippled plant
expected to take a decade or more.
In 2002, the chairman and president of the utility were
forced to step down after regulators concluded the company
had routinely filed false reports during safety inspections
and hid evidence of trouble at its reactors, including
Fukushima. All 17 of Tokyo Electric's reactors were ordered
shut down. The last of those did not restart until 2005.
As part of a bid to win back public trust, the utility
promised to repair a "safety culture" it said had failed in
the scandal. Teams of newly empowered radiation safety
managers were created and began to audit the company's
nuclear operations, including Fukushima. They also reported
back findings to other nuclear plant operators and
regulators. None of the utility's safety managers who gave
those archived presentations responded to requests for
comment for this report.
One problem, according to one of those early assessments,
was that Tokyo Electric's managers on the ground tended to
put cost savings ahead of a commitment to keep driving
worker radiation doses "as low as reasonably achievable,"
the international standard for safety.
Take maintenance, for instance. Japanese plants are
required to shut down every 13 months for almost four months
at a time -- twice as long as the U.S. average. Tepco was
slow to invest in the more expensive radiation safety
precautions needed during maintenance, thus lowering the
cost of operating Fukushima before the accident.
But that focus on costs also kept Tepco from developing a
more active commitment to worker safety that could have
helped it navigate the March disaster, officials now say.
After the earthquake, contract workers at Fukushima were
sent in without radiation meters or basic gear such as
rubber boots. Screening for radiation from dust and vapor
inhaled by workers was delayed for weeks until experts said
the testing was almost meaningless. At least 39 workers were
exposed to more than 100 millisieverts of radiation, five
times the maximum allowed in a normal year.
Fukushima Daiichi, built in a poor region on Japan's
Pacific Coast to supply power to Tokyo, was pushed into
crisis by the massive March 11 earthquake and the tsunami
that hit less than an hour later. The backup power systems
meant to keep its radioactive fuel cool were disabled,
leading to meltdowns, explosions and radiation spewing into
the environment, forcing the evacuation of more than 80,000
Goshi Hosono, the government minister appointed to
coordinate Japan's response to the Fukushima crisis, said he
was not aware of the details of Fukushima's radiation safety
record before March 11 and declined to comment on that
But he said the utility had failed to protect workers in
the chaos that followed the accident, prompting a reprimand
from government officials and a decision by regulators to
take charge of radiation health monitoring at the plant.
"In normal times, radiation monitoring would be left to
the plant operator, but these are not normal times," Hosono
HIGHER RADIATION IN OLD PLANTS
In a June report to the International Atomic Energy
Agency, Japanese officials said basic design failures, a
fatal underestimation of tsunami risk and a chaotic
decision-making process had contributed to the disaster. But
they also said Tokyo Electric's "safety culture" had failed
Outside experts agreed. "The main root causes of this
man-made disaster can be found in (Tokyo Electric's)
ineffective -- exemplary poor -- safety practices and track
record," said Najim Meshkati, an engineering professor at
the University of Southern California and former U.S.
government science advisor.
In response to questions about the radiation safety
record at Fukushima, Tokyo Electric said that radiation
exposure for each individual worker at the plant had been
kept below the regulatory standard. The overall radiation
level remained relatively high because the plant's six
reactors were all between 30 and 40 years old at the time of
the accident, the utility said.
"Because it was an older plant it required longer
maintenance periods and more intensive repair work," Tokyo
Electric spokeswoman Ryoko Sakai said. "For that reason, the
overall radiation exposure was higher than our other
The General Electric-derived design of the reactors at
Fukushima posed a particular safety challenge during routine
shutdowns because radioactive steam is allowed to circulate
through the power-generating turbine. That means that large
parts of the power plant pose a radiation risk during
repairs, experts say.
But even compared to other boiling water reactors,
Fukushima stood out for its risks. At the start of the
decade, each of its reactors had exposed workers to 2.5
times the amount of radiation they would have faced in an
average U.S. reactor of the same design. By 2009, that gap
had narrowed, but exposure at Fukushima was still 1.7 times
the U.S. average and equivalent to subjecting workers on the
site to a collective 1,500 full-body CT scans each year.
Because of Fukushima's high radiation, Tokyo Electric
brought in thousands of workers each year, often to work
just a few days on the most hazardous jobs. The utility
employed almost 9,000 contract workers annually on average
at the plant over the past decade, according to records kept
by Japan's trade ministry.
Those workers were needed in part to allow Tokyo Electric
to meet the international safety standard Japan had
committed to in 2001. Under that standard, workers were
limited to 20 millisieverts of radiation exposure in an
average year, equivalent to getting two CT scans at work.
But even with its extraordinary work force, the average
contract worker at Fukushima was exposed to 73 percent more
radiation than the average nuclear worker at other plants in
Japan over the past decade, according to a Reuters review of
data from Japan's trade and industry ministry. The same
worker was also exposed to almost three times the amount of
radiation that Tokyo Electric's own staff faced. The average
radiation dose ran almost a third higher than for U.S.
workers at similar plants.
The number of Fukushima workers near the annual limit for
radiation also remained troublingly high. Over the past five
years, each Fukushima reactor exposed almost 300 workers to
between 10 and 20 millisieverts of radiation, the Reuters
review of the data showed. The comparable figure for U.S.
reactors of similar design was just 22 workers per reactor
with those kinds of exposure levels.
'THIS SITUATION IS THE WORST'
Part of the reason was that Fukushima maintenance work
took almost three times longer than comparable jobs at U.S.
plants -- more than four months on average. But American
utilities have also spent heavily as a group on steps to
reduce worker exposure, including building mock-up reactors
so workers could rehearse dangerous jobs almost as commandos
"We are ready and willing to spend money to reduce worker
doses," said John Bickel, a nuclear safety expert who has
consulted for the NRC and the IAEA. "I would characterize
that there is an intense competition in the U.S. to be the
By contrast, critics of the Japanese nuclear industry
cite records showing how Tokyo Electric and other utilities
shifted the health risks of operating nuclear plants to a
group of relatively poor and sometimes homeless day laborers
desperate for a quick payday.
"Nuclear power is based on discrimination, a system in
which the people who are working to protect nuclear safety
end up on the streets and are given the cold shoulder by
society. All of us who use electricity are responsible for
this system," said Yuko Fujita, a former physics professor
at Keio University who has campaigned for nuclear worker
safety in Japan for over 20 years.
To be sure, Tokyo Electric had taken steps to reduce the
amount of radiation workers faced. It changed the chemistry
of water piped through the reactors to reduce corrosion in
pipes. It developed robots and remote-controlled probes to
inspect hazards rather than sending in workers. And it used
radiation shields such as lead "blankets" wrapped around
pipes during maintenance to limit radiation in places
workers had to be.
Those measures had reduced the overall radiation exposure
for workers at Fukushima to a third of the 1978 peak by the
start of the past decade, the records show.
But by 2006, Tokyo Electric safety managers had decided
that they had to take on a tougher problem to make any more
progress. They needed to reform the basic organization of
the utility, where maintenance managers faced no pressure to
meet targets for reducing radiation exposure for the
thousands of contractors and day laborers, two reports show.
The only more dangerous plants from 2003 to 2005 on that
basis had been the Tarapur nuclear plant in India, where two
reactors shared the basic Fukushima design, and the Perry
nuclear plant on Lake Erie outside Cleveland, Ohio.
Perry, which is operated by FirstEnergy Corp, was cited
by the Nuclear Regulatory Commission for a series of safety
mistakes during a maintenance period in April. In that
incident, regulators said four workers were exposed to high
levels of radiation after being sent to retrieve a radiation
monitor near the reactor's core. The plant has been the
target of NRC safety inspections for more than three years
because of what U.S. regulators call "human performance"
issues in safety management.
COMPLACENCY SETS IN
Tokyo Electric did not come to terms with its own
management and organizational problems related to safety
until recent years, the record shows.
Shiro Takahira, a Tokyo Electric manager in charge of
radiation safety, showed a conference in October 2006 a
chart depicting Fukushima Daiichi as the third-worst nuclear
plant in the world in terms of worker exposure to radiation.
"This graph could be a good driving force to improve our
process," Takahira told the radiation safety conference in
Niigata, Japan, according to remarks posted by the
organizer. Takahira said Tokyo Electric had traditionally
"put more weight on cost effectiveness" than the need to
keep driving radiation exposure down. "There has been no
standard mechanism to promote (the standard of 'as low as
reasonably achievable') systematically and continuously," he
By late 2006, radiation safety managers such as Takahira
had won a seat at the table in planning repair jobs at
nuclear plants including Fukushima. By 2007, the company set
a goal of getting the annual radiation at each Fukushima
reactor to about 2.5 sieverts, a more manageable dose
equivalent to about 250 CT scans for workers. That would
mean Fukushima was still lagging the industry but by a
The full-year radiation for 2008 and 2009 came in just
below 2.5 sieverts of exposure per reactor, just under the
goal managers had set in 2007. On a three-year rolling
basis, the exposure was 2.53 sieverts per reactor between
2007 to 2009.
"We had largely reached our target by 2009," said Tokyo
At that point, some of the urgency behind the safety
campaign appeared to drain. "We'll continue to try to reduce
occupational exposures by every possible measure after cost
performance evaluations," Shunsuke Hori, a Tokyo Electric
safety manager, said at a September 2009 conference in
Hori was one of two Tokyo Electric safety managers who
published what amounted to a declaration of victory after
the nascent effort to improve radiation safety.
"The reliability of Japanese nuclear plants is now quite
high," Hori and another Tokyo Electric manager, Akira
Suzuki, wrote in a radiation health journal. "The Japanese
nuclear industry has over 40 years of radiation protection
experience, and it is believed that more radiation control
will be possible in the future using this experience."
The upbeat assessment was published in a little-read
scientific journal, Radiation Protection Dosimetry, on April
26, 2011, the 25th anniversary of the Chernobyl disaster.
On the ground in Fukushima that day, white smoke was
still steaming off three of the reactors, and residents to
the northwest had started a wider round of evacuations.
(Additional reporting by Scott DiSavino in New York and
Eileen O'Grady in Houston)