When a mega-quake followed by a massive tsunami struck Japan last March, the country’s defenses were overwhelmed by the scale of the natural disaster. While the earthquake and tsunami caused catastrophic destruction and significant loss of life, radiation released from the Fukushima Daiichi reactors has not caused a single death. In fact, the radiological consequences of the accident to date are negligible, due in large part to emergency response plans that were in place before the incident.
“The reporting of Fukushima was guided by the Cold War reflex that matched radiation with fear and mortal danger,” writes Wade Allison, emeritus professor of physics at Oxford University in the UK newspaper, The Telegraph. “Reactors have been destroyed, but the radiation at Fukushima has caused no loss of life and is unlikely to do so, even in the next 50 years.”
When a significant accident occurs at a nuclear energy facility, conditions inside the reactors usually gradually deteriorate over time thus allowing emergency workers to respond appropriately. When the first earthquake struck off the coast of Japan, government officials and workers at Fukushima Daiichi seized the opportunity to implement and execute emergency response plans, just as they had practiced for years. These carefully designed plans, coupled with the evacuation warning prompted by the tsunami, were instrumental in preventing a widespread radiological hazard to human health. The workers at Daiichi deserve tremendous admiration for working in extreme conditions in those first days after the tsunami. They manually hauled tons of power cable and foraged for alternate sources of battery power in total darkness as they worked feverishly to avert disaster.
Immediately after the earthquake struck, the operating reactors at Fukushima Daiichi automatically shut down as planned. During this time, back-up generators functioned as designed and continued the critical work of supplying cooling water to the reactor. Nuclear reactors need electricity to circulate water through the reactor core in order to keep the uranium fuel cool.
It was not until a series of tsunamis arrived approximately 30 minutes after the earthquake that the plant lost the backup generators needed to power the cooling systems. Until then, the facility’s backup capabilities and its emergency response functioned as designed.
Within seven hours of the accident, Japanese officials, in conjunction with TEPCO, began to:
- Evacuate all citizens within 12.5 miles of the reactor site
- Distribute potassium iodide tablets to protect a person’s thyroid from radioactive iodine
- Monitor radiation levels in the environment, food and water within a 50-mile radius of Fukushima Daiichi
Once the power and cooling systems were knocked out by the tsunami and the core temperature in the reactor began to rise, nearby residents who survived the earthquake, aftershocks and series of tsunamis still had ample time to evacuate safely. By the time the pressure from the build-up of hydrogen gas inside the reactors led to a series of explosions, all but the brave plant workers who voluntarily remained on-site were out of harm’s way.
According to John Boice, Vanderbilt University epidemiologist, “(While) Fukushima is clearly a major reactor accident, the potential health consequences associated with radiation exposures in terms of loss of life and future cancer risk are small.”
Nearly 200,000 members of the public were monitored for radioactive contamination. One hundred and two people were found to exceed the screening level and underwent a non-invasive, but effective decontamination treatment. After this one-time treatment, their levels of detectable radiation returned to normal. Of the 1,080 children under the age of 15 that were tested for thyroid exposure, none exceeded the screening level.
Although a small percentage of the workers who volunteered to stay on-site were exposed to higher levels of radiation, their health has not been significantly compromised by this exposure. Thirty of the 7,800 workers at the site received exposures in excess of their emergency limits set by the Japanese government. Four workers died while performing their emergency duties, but none were caused by radiation.
Japanese officials continue to monitor radiation levels in the air, water, soil, crops and livestock in an ongoing effort to protect public health. This continuous monitoring in Japan, ensures that exposure to radiation is kept well-within safe levels and eliminates any adverse health impact from radiological contamination. Thus far, these monitoring efforts show:
- 95 percent of the 10,000 samples of food and water were found to be safe, below the government’s established radiation limits
- Food and water with elevated levels of radiation were restricted
Though destruction from the earthquake and tsunami will present significant challenges to Japan for years to come, experts believe there will be no health effects from the reactor accident.
“From a radiological perspective, we expect the impact to be really, really minor,” said Kathyrn Higley, professor of radiation health physics in the department of nuclear engineering at Oregon State University, at a recent event. “And the reason for that is we understand how radionuclides move through the environment, how they disperse and how people can be exposed. Because we understand that we are able to make decisions to block exposure.”
Also see videos from Health Physics Society experts: “Impact of Radiation Exposure on Workers and Residents Near Fukushima” and “How Emergency Planning Zones Help Protect Public Health and Safety.”