By Benoît Hopquin

Posted today at 7:00 p.m.

On Friday, March 11, 2011, at 2:46 p.m. local time, an earthquake measuring 9.1 on the Richter scale struck 130 km off the northeast coast of the Japanese archipelago. A powerful tsunami then hit the Pacific coast. A blade reaching up to 30 m in height causes the death of 18,000 people. Nature once again sends our societies back to their fragility and their unconsciousness. At 3:41 p.m., when the sea invaded the Fukushima Daiichi nuclear power plant, the defenses considered solid, even unstoppable, jumped one by one. Scientists lose all control of their creature. The catastrophe this time places the human being in front of his morgue.

At the time of the earthquake, the three reactors in service, the oldest of the six in the plant, were complying with the safety plans. They switch off automatically. General Electric’s Mark 1 boiling water reactors (BWRs), inaugurated in 1971 by the private Tokyo Electric Power Company (Tepco), prove to be far more reliable and docile than the Soviet equipment at Chernobyl which failed twenty-five years earlier, in April 1986.

Article reserved for our subscribers Read also “We arrived in the epicenter of the Japanese disasters shortly after midnight”: March 2011, on the road to Fukushima

The resistance of the installations to this mega-earthquake even exceeds the expectations and calculations of engineers. It fully justifies the confidence of the knowledgeable and discredits those who are so quick to mouth the trumpets of Revelation. What do they know, these narrow-minded activists or these frightened residents? Moreover, in 1992, a judgment of the Supreme Court of Japan wisely denied citizens the right to challenge the installation of power plants. Given the complexity of the subject, only experts and the government are able to judge the relevance of a reactor, ruled the court.

Short-lived serenity

In the control room of Fukushima Daiichi, the serenity lasts only half an hour. When a 15 m high tidal wave submerges dikes designed for maximum waves of 5.70 m, seawater floods the installations. It cuts off the power supply and floods the standby diesel generators, causing the cooling system to fail. The temperature then begins to rise rapidly in the reactor vessel 1, 2 and 3, but also on the floor above. There, in the pools where used fuel is stored, evaporation threatens to release highly contaminated materials.

At the Takata Matsubara site, the Tsunami Memorial, in Rikuzentakata, March 1, 2021.

Barely five hours after the flooding, the core of reactor number 1 partially melted. Mixed with the zirconium in the supply sheaths, it forms a magma brought to 2000 degrees, called corium, which attacks the steel and concrete containment enclosure. In the following three days, reactors 2 and 3 in turn melt. However, it will be necessary to wait until the end of May to have official confirmation of this sequence that most international specialists feared from the outset.

You have 82.2% of this article to read. The rest is for subscribers only.

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *