Six years after the power plant accident at Fukashima, in which an earthquake and tsunami knocked out the vital cooling systems of the plant, scientists were able to pilot a small robot into the heart of the nuclear plant. The “Manbo” used tinay propellers to hover and glide through water and avoid dangerous hot spots in the flooded reactor building unlike previous attempts. The robot was able to successfully send back pictures of a hole at the bottom of the reactor that scientists believe to be melted uranium fuel. Researchers are unable to predict the fate of this fuel, but are confident that they can move from a “contamination” phase to a “cleanup” phase. Nuclear plants produce steam to convert into electricity through the process of fission in which uranium atoms are split in a nuclear reactor to provide the heat energy to produce steam. When neutrons hit other atoms, those atoms split, releasing neutrons of their own with heat. These neutrons hit other atoms, splitting them. One fission triggers the next until there is a chain reaction. When that happens, fission becomes self-sustaining. The earthquake that knocked out the cooling system of the plant occurred as a result of subduction from the Pacific Ocean plate pressing down under the continental plate carrying the islands of Japan. When tension caused by subduction was released, an earthquake occurred. Along the fault, the two plates of Earth’s crust slid past each other up to 260. The Tohoku quake lifted the seafloor by 30 feet and the vertical displacement of seawater was the cause of the tsunami that expanded away from the earthquake site. The Fukushima Daiichi nuclear power plant was damaged by tsunami flooding, causing multiple meltdowns and a massive release of radioactivity.

 

The earthquake, tsunami and power plant accident caused many effects on the people living in Japan and the environment. The earthquake and tsunami destroyed several buildings which led to a large amount of falling debris as well as flooding throughout the island. Many people lost their homes and even their lives. The magnitude 9.0 Tohoku-Oki quake was the most powerful earthquake known to hit Japan and the fifth-most powerful quake ever recorded, and coupled with the tsunami, killed thousands of people. The cooling system collapse of the power plant caused three of the reactors to melt which released a plethora of radioactivity. Radiation contaminated a large portion of marine animals as well as soil and water samples. In addition, radioactive isotopes emitted by the power plant affects many people living in Japan today as they are at an increased risk of developing cancer or other radioactive-related diseases.

 

Fackler, Martin. “Six Years After Fukashima, Robots Finally Find Reactors’ Melted Uranium Fuel.” The New York Times, The New York Times, 19 Nov. 2017, www.nytimes.com/2017/11/19/science/japan-fukushima-nuclear-meltdown-fuel.html?rref=collection%2Fsectioncollection%2Fscience&action=click&contentCollection=science®ion=rank&module=package&version=highlights&contentPlacement=1&pgtype=sectionfront.

 

“Fukushima Accident.” World Nuclear Association, World Nuclear Association, 12 Oct. 2017, www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/fukushima-accident.aspx.

 

Aldrich, Daniel P., et al. “Triggers for Policy Change: The 3.11 Fukushima Meltdowns and Nuclear Policy Continuity.” SSRN Electronic Journal, 2015, doi:10.2139/ssrn.2679587.

 

-Rasman Rayyan