As talked about in the initial article, the Fukushima disaster was caused by a killer tsunami wave occurring in the aftermath of an earthquake with a magnitude of 9 on the Richter scale, in 2011.
The corium (i.e., nuclear fuel) contains among other radioactive elements, Cesium-134 and Cesium-137 with a half-life of 30 years. Cesium is water soluble, but it can blend in with the soil particles, posing great risks not only to the environment, but also humans. Exposure to cesium causes nausea, bleeding, loss of unconsciousness, coma, cancer and may even induce death, if the individual is exposed to a high concentration of cesium.
Mr. Robert Alvarez, former Senior Policy Adviser to the Secretary and Deputy Assistant Secretary for National Security and the Environment at the U.S. Department of Energy declared the following:
Based on U.S. Energy Department data, assuming a total of 11,138 spent fuel assemblies are being stored at the Dai-Ichi site […] [these] contain roughly 336 million curies (~1.2 E+19 Bq) of long-lived radioactivity. About 134 million curies is Cesium-137 — roughly 85 times the amount of Cs-137 released at the Chernobyl accident as estimated by the U.S. National Council on Radiation Protection (NCRP). The total spent reactor fuel inventory at the Fukushima-Daichi site contains nearly half of the total amount of Cs-137 estimated by the NCRP to have been released by all atmospheric nuclear weapons testing, Chernobyl, and world-wide reprocessing plants (~270 million curies or ~9.9 E+18 Becquerel).
At the time being, there is still no knowledge on the whereabouts of the missing reactor corium; however, there is still the matter of the cesium isotopes, which have been released into the Pacific at the moment of the explosion and have been carried away by the currents ever since.
However, the oceanographic scientists in Bedford, Canada made an important discovery: just months after the Fukushima calamity, the Pacific Ocean currents they were tracking down diffused and reduced the high radioactive level of the cesium particles to safe water-drinking levels. Specialists also declared that by 2021, these low radioactive levels will completely succumb to the natural radioactivity of the ocean, which contains isotopes of uranium-238, tritium and rubidium-87, among others.
John Smith, one of the scientists working for the Bedford Institute of Oceanography, declared:
We had a situation where the radioactive tracer was deposited at a very specific location off the coast of Japan at a very specific time. It was kind of like a dye experiment, and it is unambiguous – you either see the signal or you don’t, and when you see it you know exactly what you are measuring.
Ken Buesseler, a marine chemist working for Woods Hole and is one of Smith’s research partners stated that:
We detected cesium-134, a contaminant from Fukushima, off the northern California coast. The levels are only detectable by sophisticated equipment able to discern minute quantities of radioactivity. Most people don’t realize that there was already cesium in Pacific waters prior to Fukushima, but only the cesium-137 isotope.
Cesium-137 undergoes radioactive decay with a 30-year half-life and was introduced to the environment during atmospheric weapons testing in the 1950s and ’60s. Along with cesium-137, we detected cesium-134 – which also does not occur naturally in the environment and has a half-life of just two years. Therefore the only source of this cesium-134 in the Pacific today is from Fukushima.
By following the radioactive particles, scientists were able to see the exact moment in which these radioactive currents reached the Canadian, as well as the North American coastlines, which was in June 2012, according to a research paper in the field, written by John Smith in collaboration with other oceanographic scientists.
However, it seems that the Fukushima disaster could have been prevented. A UN report compiled by over 180 IAEA (International Atomic Energy Agency) experts, in 42 countries, criticized the Japanese regulators for not reinforcing better safety protocols and procedures, despite being aware of the fact that the possibility of large tsunami waves hitting the nuclear plant at any time was in the cards, given its location. Please see below an excerpt from the aforementioned UN report:
The Fukushima Daiichi (No. 1) NPP (nuclear power plant) had some weaknesses which were not fully evaluated by a probabilistic safety assessment, as recommended by the IAEA safety standards.
[…] Prior to the accident, there was not sufficient consideration of low probability, high consequence external events which remained undetected. This was in part because of the basic assumption in Japan, reinforced over many decades, that the robustness of the technical design of the nuclear plants would provide sufficient protection against postulated risks.
[…] The operators were not fully prepared for the multiunit loss of power and the loss of cooling caused by the tsunami. Although Tepco [the Nuclear and Industrial Safety Agency overseeing the construction of the Fukushima power plant] had developed severe accident management guidelines, they did not cover such an unlikely combination of events.”
This month, the IAEA board will revise the summary of this UN report, and the paper will be thoroughly examined during the IAEA’s meeting, which will take place in September. The paper includes information on the causes and effects entailed by the Fukushima catastrophe and its aim is to contribute to better reinstatement of the necessary ground rules of nuclear measures.
What are your thoughts regarding the impact of the Fukushima disaster on the environment? Use the comments section below.