After being reassured by authorities, media and experts (also intervening on ilfattoalimentare.it) that the Fukushima accident could not be compared to that of Chernobyl, the news arrives that the Japanese accident has been classified at the seventh degree on the Ines scale. , exactly like Chernobyl. So how are things really?
We asked Giuseppe Sgorbati, coordinator of the Arpa Lombardia departments and head of the regional network for detecting environmental radioactivity .
“ The fact that the technicians of the plant carried out exceptional maneuvers, such as the use of sea water for cooling, suggested that the situation was much more serious than initially reported and placed as a level of danger between the 4th and 5th on the Ines scale of the International Atomic Energy Agency, IAEA. Now we have reached the 7th level of gravity, because in addition to the damage to the individual reactors that do not exceed the 5th and 6th, we have considered the sum of the damage caused to the four reactors and the effect on the environment ”.
Puns or real evaluation difficulties? “ The estimates on the amount of radioactivity released by the plant – explains Sgorbati – are controversial. The Organization for the Treaty of Nonproliferation Ctbto had already estimated at the end of March that the release of radioactivity could be of the same order of magnitude as Chernobyl ”. However, this does not mean that the reassurance received from the local and world population were false.
“The amount of radioactivity released is not directly linked to consequences on the environment and people. What was released into the atmosphere was carried by the winds over the Pacific Ocean and did not affect Japanese territory, unlike what happened in Chernobyl. I mean: using comparisons and stereotypes to make comparisons is always dangerous and misleading “.
“The same level of severity between Fukushima and Chernobyl does not place the two accidents on the same level. In Russia a huge fire was created caused by the graphite present in the reactor – repeats Sgorbati – and due to the very high temperature, the smoke column reached 3-5,000 meters in height. This means that huge quantities of radioactive substances were carried by the winds very far away. Furthermore, the explosion, due to the release of hydrogen, was immediate and bursting.
In Fukushima, on the other hand, the hydrogen produced gradually and caused small explosions that released fumes in the lower layers of the atmosphere (practically cold if compared to those of Chernobyl). Without the thrust of the temperature, the radioactive substances do not go immediately to high altitudes and therefore have repercussions on much smaller areas “.
On the other hand, with the passing of the days the possibility of an explosion decreases, even if the situation does not yet appear under control since to limit the damage provisional maneuvers are used such as emptying contaminated radioactive water into the sea ).
Several aspects will have to be clarified in the coming months. For example, why in the United States and in Europe levels of radioactivity higher than those expected were recorded, even if it is lower radioactivity when compared to that of Chernobyl and in any case absolutely below the threshold of health attention.