With the one-year anniversary of the accident at the Fukushima Daiichi nuclear power plant reactor coming up this weekend, three US university professors are calling for a long-term study of how such fuels respond to such extreme environmental conditions.
University of Notre Dame Professor of Civil Engineering and Geological Sciences Peter C. Burns, University of Michigan Earth and Environmental Sciences Professor Rodney Ewing, and Alexandra Navrotsky of the University of California-Davis are calling for a long-term, national research program to study the issue, the Ann Arbor, Michigan-based university said in a Thursday press release.
On March 11, 2011, a magnitude 9.0 earthquake struck the island nation of Japan, triggering a tsunami that, in addition to causing widespread death and destruction, also cut off electricity to the nuclear power station, a second press release, this one from the South Bend, Indiana school, said. Those natural disasters acted as the catalyst for “a series of explosions which released large quantities of radioactive substances into the surrounding environment.”
Three of the plant’s six boiling-water reactors suffered partial core-melt events in the aftermath of the earthquake and tsunami, and several tons of seawater were needed to help cool the overheated reactors. That seawater wound up being directly discharged into the ocean and groundwater for nearly an entire month after the disaster, the University of Michigan said. Now, Burns, Ewing, and Navrotsky have penned a review article, published in this week’s edition of the journal Science are calling on US officials to be better prepared for similar events in the future.
“Reactors are designed to high safety standards, but on the anniversary of the accidents in Fukushima we are reminded that the forces of nature can produce unlikely events that can overcome the safety margins built into the reactor designs,” Burns said in a statement. “A reactor core meltdown releases radioactive material from the fuel. If containment systems fail, as they did at Fukushima, radioactive material is then released into the environment.”
“At Fukushima, a large amount of radioactive material was released when seawater was pumped onto the reactor cores that later leaked into the ocean and groundwater,” he added. “Little is known about how radioactive fuel in a reactor accident interacts with water and releases radioactive material. This paper examines what is known, points to serious shortcomings in our understanding, and proposes a course of research to address the problem.”
The Notre Dame professor and his colleagues believe that some of the information can be gathered by staging simulated core-melt events using fuel analogs containing nonradioactive isotopes. However, they also assert that some of the studies will require the use of actual radioactive materials, making them difficult, costly, and potentially dangerous but nonetheless “essential to reduce the risk associated with increasing reliance on nuclear energy.”
“Nuclear power reactors, of which there are currently 440 operating worldwide, provide about 16 percent of the world’s electricity. They also produce extremely radioactive used fuel,” Burns said. “A growing reliance on nuclear energy in the world over the coming decades will make serious reactor accidents more likely, although they will remain rare events. To better protect humanity when accidents do occur, we need a much improved understanding of how water interacts with damaged fuel, and how the radioactive material is released and transported in water.”
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