nuclear-news

”………..What we know about nuclear disasters at Chernobyl, Fukushima, and elsewhere comes primarily from modelling what is known as the “source term”—the types and amounts of radioactive material that were in a reactor’s core and then released to the environment by an accident. These models are revised as we learn more about the prevailing winds and other factors but are still only models; ideally, one wants to examine the reactors’ cores themselves. Unfortunately, even 10 years later, no one can get close to Fukushima’s reactor cores, and we do not even know precisely where they are located.

As recently as December 2020, Japan’s Nuclear Regulatory Authority (NRA) announced “extremely serious” developments at Fukushima that were far worse than previously thought, the Asahi Shimbun newspaper reported. TEPCO had discovered that the massive shield plugs covering the reactors were emitting 10 Sieverts of radiation per hour—a lethal dose for humans (though it should be noted that reactor cores are normally examined by robots, unless these, too, are destroyed by radiation). Because Fukushima now has more contaminated material at higher doses than previously estimated, “this will have a huge impact on the whole process of decommissioning work,” said NRA chairman Toyoshi Fuketa.

The effective dose of radiation required to sicken or kill you is measured in Sieverts, a unit named after Rolf Sievert, the Swedish physicist who first calibrated the lethal effects of radioactive energy. A dose of 0.75 Sieverts will produce nausea and a weakened immune system. (Sieverts are used to measure the relative biological damage done to the human body, while becquerels and curies are units that describe the amount of radiation emitted by radioactive material.)

A dose of 10 Sieverts will kill you, if absorbed all at once.

A dose somewhere in-between 0.75 and 10 Sieverts gives you a fifty-fifty chance of dying within 30 days.

Guidelines for workers in the nuclear industry limit the maximum yearly dose to 0.05 Sieverts, or 50 milliSieverts—the equivalent of five CT scans, says Harvard Health Publishing. (This is a high figure compared to the 1 milliSievert per year that is considered acceptable for the general public; a physicist familiar with the industry explained that the thinking is that workers in the nuclear energy industry are implicitly being paid to take on the risk.)

So how many Sieverts are currently being produced by Fukushima’s melted reactors? The latest reading from reactor No. 2 is 530 Sieverts per hour. This means that every hour the heart of the reactor is emitting more than 10,000 times the yearly allowable dose for radiation workers……  https://thebulletin.org/2021/03/fukushima-today-im-glad-that-i-realized-my-mistake-before-i-died/?utm_source=Newsletter&utm_medium=Email&utm_campaign=ThursdayNewsletter032021&utm_content=NuclearRisk_Bass_03102021