Left alone, these safety devices would have prevented the development of a larger crisis. However, human operators in the control room misread confusing and contradictory readings and shut off the emergency water system.
The reactor was also shut down, but residual heat from the fission process was still being released. By early morning, the core had heated to over 4, degrees, just 1, degrees short of meltdown. In the meltdown scenario, the core melts, and deadly radiation drifts across the countryside, fatally sickening a potentially great number of people. As the plant operators struggled to understand what had happened, the contaminated water was releasing radioactive gases throughout the plant.
The radiation levels, though not immediately life-threatening, were dangerous, and the core cooked further as the contaminated water was contained and precautions were taken to protect the operators. Shortly after 8 a. Pennsylvania Governor Dick Thornburgh considered calling an evacuation. Finally, at about 8 p. The temperature began to drop, and pressure in the reactor was reduced. The reactor had come within less than an hour of a complete meltdown.
More than half the core was destroyed or molten, but it had not broken its protective shell, and no radiation was escaping. The crisis was apparently over. Two days later, however, on March 30, a bubble of highly flammable hydrogen gas was discovered within the reactor building.
The bubble of gas was created two days before when exposed core materials reacted with super-heated steam. On March 28, some of this gas had exploded, releasing a small amount of radiation into the atmosphere.
At that time, plant operators had not registered the explosion, which sounded like a ventilation door closing. A study suggesting a correlation between radiation exposure at Three Mile Island and a type of thyroid cancer only heightened the debate.
With each passing year, the stories have been woven into a seeming collective consciousness, a lore of personal testimonies and anecdotes that bind the men and women who made their homes in the shadow of Three Mile Island. Could a Three Mile Island-related mass evacuation happen today? Over , hit the road when the TMI accident occurred 40 years ago. Emergency personnel are far more prepared today, but there are also a lot more people living in central Pennsylvania than in Longnecker, whose children were eight and 10 at the time of the accident they evacuated , is among the legions of families who hold on to the conviction that exposure to Three Mile Island radiation had short and long-term adverse effects on the nearby population, as well as the plant and animal world.
Over the years, she witnessed a number of relatives, friends, neighbors, and men who worked at the plant succumb to leukemia, cancers and other diseases.
Every parent either for themselves or their children being diagnosed with cancer immediately wondered was it TMI? We are 40 years out and you still hear that comment. No studies have conclusively linked cancer rates to exposure to radiation from Three Mile Island.
The narratives from some residents in the area, however, stand in sharp contrast. Dan Gleiter dgleiter pennlive. Among the oldest surviving witnesses to the accident is Helen Hocker, who at 92, strolls up the hill behind her Fairview Township home from where she can see the iconic cooling towers.
Hocker remembers the crisis in bits and pieces, so much of it now faded with time in her memory, but she has clear recollections of the friends, neighbors and family that she lost to cancer over the years. Among them were daughter, Patty, her oldest, who died of cancer at 40 in ; and her youngest, Chris, who died in To this day, Hocker said she was never satisfied with the response from authorities.
Science and oral histories have not gelled with these narratives, though. Few, if any, studies have corroborated the claims from residents. Most of these studies have been assailed for their methods and conclusions. In fact, the general dearth of conclusive scientific studies has, at times, made the residents the target of skepticism and led to failed lawsuits against Three Mile Island owners.
Some of the studies have had little impact. A study in the American Journal of Public Health, for instance, found a percent increase in infant deaths in Dauphin County in a time frame corresponding to the accident. The deaths could not be linked to radiation, however, and researchers noted they could have been associated with maternal stress and the use of sedatives.
Even the most comprehensive studies have fallen short of drawing conclusive verdicts on the ongoing debate. In the mids, the University of Pittsburgh released what seemed compelling findings linking cancer rates to exposure to Three Mile Island radiation. But in , the university released findings from a more longitudinal year study that concluded that exposure to radioactivity released in the accident did not appear to have caused an increase in cancer mortality among people living within a five-mile radius of the nuclear plant at the time of the accident.
The university study found a higher than expected number of deaths among people who lived near the plant at the time, but many of the deaths were attributed to heart disease, not cancers associated with radiation exposure. And beginning in the late s, a researcher out of the University of North Carolina-Chapel Hill found that cancer rates in the Harrisburg vicinity had spiked in the aftermath of the TMI meltdown. Steven Wing, an epidemiologist, believed that people who lived downwind of Three Mile Island had higher cancer rates and showed signs of genetic damage associated with high doses of radiation.
Wing died in To date, one of the most compelling studies looking at Three Mile Island radiation exposure to cancer rates was conducted by researchers at Penn State College of Medicine. In , Dr. David Goldenberg, the lead researcher, found that a certain type of thyroid cancer was common to people who had been near the nuclear plant in the aftermath of the partial meltdown.
Goldenberg, armed with developments in the medical field and knowledge gained from extensive studies of the Chernobyl nuclear disaster, followed up. He recently found a possible link.
Note the difference between American deaths and the rest of the world for coal, hydro and nuclear, for which data exists, the result of strong U. Note also that the U. No health or environmental effects have ever been found to have occurred as a result of the TMI accident. More than a dozen major, independent studies have assessed the radiation releases and possible effects on the people and the environment around TMI since the accident.
Their research tracked 32, people who lived within five miles of the plant when the accident occurred. Several independent groups also conducted studies. The approximately 2 million people around TMI-2 during the accident are estimated to have received an average radiation dose of less than 1 mrem above the annual background dose of about mrem, less than eating a bag of potato chips a day. Yes, potato chips are the most radioactive food because of the beta-emitting K that is concentrated when you dry out the chip during cooking.
On the other hand, the TMI accident was a cultural hallmark for the nation and a turning point for the industry. Things like stationing dedicated NRC inspectors at each plant, constant inspection of all safety systems and equipment, redundant back-up safety systems, constant interaction and sharing of lessons among every plant in America and the world, and many other upgrades and actions that have made nuclear first in safety and the U. It has added a lot of cost, but safety is worth it.
The rest of the world learned from us as well, although Japan and the Soviet Union decided to ignore some of it, which gave the world Chernobyl and Fukushima. This is important. Nuclear turns out to be the safest form of energy there is. By any measure - rate of human error, worker injury or death, equipment failure, effects on surrounding populations and the environment, number of unplanned shutdowns and level of occupational exposure.
Including all nuclear accidents in history, even wind and solar still kill more people per MWh of electricity produced than nuclear, although all non-fossil deaths involve accidents like falling off a ladder, roof or turbine.
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