It's been a dozen years since the nuclear mishap at Fukushima's nuclear plant. Now, the cooling water used post-disaster to maintain the nuclear reactor core temperature must be safely discharged into the sea. This crucial step aims to safely decommission the plant. However, queries surface: Is the "radioactive" water from Fukushima perilous? Despite widespread online skepticism, both the Japanese government and the International Atomic Energy Agency (IAEA) reassure that the water poses no danger. They affirm it won't impact the ocean's radioactivity due to the already high decay rates per second, keeping any changes negligible post-discharge.
Unraveling the Fukushima Dai-ichi Nuclear Catastrophe
Fukushima Dai-ichi, located on Japan's eastern coast, was the epicenter of a significant nuclear accident. This mishap marked the second Level 7 incident on the INES scale, following the Chernobyl disaster in 1986.
Triggered on March 11, 2011, by an earthquake followed by a tsunami, this calamity caused the automatic shutdown of reactors via the SCRAM procedure. However, keeping the reactors cool posed a challenge. The tsunami destroyed emergency generators initially supplying power, leading to the shutdown of the cooling systems of reactors 1, 2, and 3.
The cooling failure resulted in nuclear meltdowns between March 12 and 15, with explosions from hydrogen leaks further damaging the reactor buildings. A subsequent investigation revealed that the accident was predictable and preventable with appropriate safety measures.
Post-accident, approximately 154,000 residents evacuated due to widespread radiation and contamination. By 2021, many remained displaced. Unlike Chernobyl, Fukushima’s incident caused radionuclide leakage into the ocean, stirring concerns about water and underwater environment contamination.
Why Spill "Radioactive" Water from Fukushima into the Ocean?
The Tokyo Electric Power Company (TEPCO), responsible for managing the nuclear plant's radioactive wastewater, along with the Japanese government, assert the need to release about 1.37 million tons of water stored in around 1,000 tanks into the ocean to safely decommission the Fukushima plant. Over the years, the water accumulation has intensified, presenting logistical and safety challenges.
Contrary to popular belief, the answer is a resounding no. If skepticism towards the Japanese government or IAEA prevails, let's turn to the decade-long scientific data and procedures.
Fukushima's reactor cooling water underwent two filtration rounds, with the latter as a safety measure. The innovative ALPS (Advanced Liquid Processing System) was implemented to eliminate 64 different radioactive elements in Fukushima's water. ALPS, through its chemical filtration stages, effectively captures a broad spectrum of substances. These filtration procedures have proven successful in virtually eradicating all radioactive elements, save for tritium.
Is the water from Fukushima dangerous? The problem of tritium
This is due to the size of tritium, which consists of one proton and two neutrons. It is a radioactive isotope of hydrogen that occurs naturally in both marine waters and the atmosphere. Its removal from water is complex because of its chemical properties similar to hydrogen, one of its constituents.
The concern related to tritium, similar to that for other radioactive elements, lies in the amount of exposure accumulated in human body tissues. However, it is important to note that the decay period of tritium is considerably longer than the time it remains in the body after absorption. Consequently, no deaths directly attributable to this substance have been reported. The presence of tritium is also accepted in small amounts in drinking water supplies, meeting established limits, such as 100 becquerels per liter (Bq/L) in the European Union. Interestingly, international guidelines even allow concentrations up to 7000 Bq/L.
Another element of concern: carbon-14
The radioactive isotope of carbon known as carbon-14 or 14C consists of 6 protons and 8 neutrons. Both tritium and carbon-14 were detected in analyses performed before and after the second filtering cycle at the Fukushima nuclear power plant. Since both are beta particle emitters, the degree of hazard associated with these elements is limited. The decay process involves the transformation of a neutron into a proton, an electron and an antineutrino. In most cases, the electrons are shielded by the outer layer of the human epidermis. In addition, due to the influence of the electric fields generated by the surrounding nuclei in the emission zone, the electrons lose much of their kinetic energy, resulting in a practically harmless state (Bremsstrahlung phenomenon).
It should be noted that carbon-14 is also present in the human body, constituting 23% of the total carbon. It is important to remember that there is one isotope of C-14 for every million billion atoms of C-12 (stable). A 70-kilogram person can contain more than 3 kBq of radioactivity from carbon-14 alone.
In summary, on October 21, 2020, the Tokyo Electric Power Company (TEPCO) submitted a report to the IAEA based on analyses conducted at Fukushima in September. This report indicates that the residual levels of radioactivity are well below the established targets.
Fukushima "radioactive" water will be diluted with seawater
According to the plan outlined by Japanese authorities, water from Fukushima will be mixed with seawater until it reaches a tritium concentration of less than 1,500 Bq/L before being released into the ocean. This level represents a significantly lower threshold than Japan's legal limit of 60,000 Bq/L.
Once introduced into the ocean, the water will be further diluted to avoid any appreciable impact on the natural concentration of tritium in the marine environment. Another radioactive element that demonstrates limited removability is carbon-14. According to Tokyo Electric Power Company (TEPCO), the water from Fukushima contains a concentration of 2 percent of the limit set by international standards, and this concentration will be further reduced by dilution with seawater.
Tokyo Electric Power Company (TEPCO), in collaboration with the Japanese government, has emphasized an important point: many nuclear power plants around the world release tritium-containing water into the environment, often in higher amounts. The approach to releasing radioactive water has been planned in a phased manner over several decades in order to minimize negative impacts on the surrounding ecosystem.
Japan's decision has been strongly opposed by several Pacific nations, including China and South Korea, as well as other islands in the region, which have raised serious concerns on both safety and political grounds. In particular, China has labeled the plan as "extremely irresponsible" and called on Japan to seriously consider the concerns both internationally and domestically. These concerns also extend to local fishing communities, beach facilities, and tourism organizations, which fear possible damage to reputation and the fishing industry.
South Korea, likewise, has strongly disagreed with the decision to release the waters and has maintained restrictions on the import of seafood not only from Fukushima, but also from other Japanese prefectures. This attitude reflects serious concerns related to food safety and potential health impacts on citizens.
In order to address legitimate international concerns, the International Atomic Energy Agency (IAEA) will have a crucial oversight role in the process of dispersing treated water. The inclusion of the IAEA in this context is welcomed by many nations, as it will ensure independent monitoring and impartial evaluation of the implementation of the release plan.
Quite different are the constant alarmist reports from the media and environmental groups that have always been hostile to nuclear power. This brings direct consequences for Japan's economy and population. In fact, in recent hours the Japanese government is appealing to China to call on its citizens to stop acts of disruption involving Japanese citizens on Chinese soil.
These incidents include insults and throwing of objects, including stones, at diplomatic facilities and educational institutions. These concerns arise after Tokyo announced its decision to release water from the Fukushima nuclear power plant into the ocean. In this context, there was also an incident in which an object was thrown at the Japanese embassy in Beijing.
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