Nuclear power and Fukushima Daiichi – the grave warning not to be ignored, environmental catastrophe
The nuclear disaster at the Fukushima Daiichi nuclear power complex in northern Japan in March, 2011, was largely preventable. Poor plant design appears to have been responsible for loss of cooling to the various reactors in the complex when the earthquake and subsequent tsunami waters knocked out electric power to the complex and shut down and damaged the backup coolant pumps. A backup set of cooling pumps servicing the plant from the landward side of the site combined with separate backup power generators (for the cooling pumps) also located behind the plant and further from the sea would have prevented, or at the very least, greatly mitigated this disaster. Japan has been prone to earthquakes and tsunamis for the thousands of years it has been inhabited. These risks of earthquake and tsunami were well known at the time of the nuclear complex’s design and construction. (Beyond the scope of this blog post, there is some history of original design specifications being abandoned or circumvented during final application for, and construction of, the complex.)
The human reaction to the tsunami’s damage to the multi-reactor nuclear complex was also baffling and perhaps inexplicable. From news reports we were receiving in the US at the time, plant managers did not seem to be moving quickly and decisively to restore cooling to the various reactors. In the first few days, their attempts at restoring cooling to the reactor cores – and thereby preventing damage – seemed to be hit and miss.
Yes, the managers of the nuclear complex had the fuel rods pulled out of the reactor cores so that the self sustaining chain reactions ceased. However, this is not enough to protect the reactor cores from serious damage. Decay heat must be removed from the cores via the cooling systems. There are various fission by products in the reactor cores with varying half lifes. (If you hear of anyone claiming that there are nuclear wastes that are highly radioactive for millions of years, be aware that they do not know what they are talking about. Highly radioactive means a rapid rate of decay and that is the same as saying a short half-life.) One such fission by-product, the radioactive isotope of iodine (I-131), decays very rapidly with a half-life of about 8 days. These decaying radioactive isotopes produce heat called decay heat. This means that even after the fuel rods were pulled out of the cores to stop the ongoing fissioning process, decay heat was still accumulating inside the reactor cores.
This problem of the decay heat was known to Tokyo Electric Power‘s engineers and technicians. We cannot be sure that the news reports and updates we received coming out of Japan during those first few critical days of the emergency were accurate and complete. Restoring cooling to all of the reactor cores needed to be top priority and needed to be acted upon immediately and aggressively once the tsunami knocked out the seaward side backup cooling systems. But, Tokyo Electric Power attempted to cool the reactor cores using isolation condenser systems and using them intermittently. These isolation condensers were not as effective, nor were they designed to be as effective, as true backup cooling systems are. Proper actions not being taken in those early days resulted in massive core damage to 3 of the 6 reactors in the nuclear complex and this was responsible for the not insignificant releases of radiation to the environment.
Nuclear power is inherently dangerous. It allows for no safe margin of human error(s) at all. This fact needs to be appreciated and weighted properly in any decisions as to building new nuclear plants and needs to be factored into both plant design and plant operating procedures.
The legacy of Fukushima is a very poisonous, toxic one and not just for Japan, but also for the western United States. We may not have been told the truth about just how much radioactivity was released from the various damaged reactors at the crippled nuclear complex. We are hearing critics and skeptics of nuclear power asserting that the amounts of radiation reported to have been released were significantly lower than what actually escaped into the air and waters around the nuclear complex. We hear of contaminated waste from Fukushima being dumped into Tokyo Bay thereby spreading the radioactive poisons into the most densely populated part of southern Honshu Island.
But this catastrophe is potentially global in scale, or at the very least international in scope.
The western states of the United States received some of this fallout via the prevailing winds above the northern Pacific Ocean. Some of the other radioactive fission by products, such as Cesium 137 and Strontium 90, have longer half-lives than Iodine 131. (Cs-137 has a half-life of 30 years and Sr-90 has a half-life of 28 years.) These isotopes get into and remain in the soils they are deposited on and get taken up by plants and enter the food chain. Dairy cows then are exposed and humans when they consume contaminated milk and related dairy products.
Now that manmade global warming is being recognized as at worst a hoax, and at best bad science, the world would be better served and protected by pushing ahead with more non-nuclear power sources. There is still much oil, lots of natural gas, and yes, even coal, that can be utilized to meet our electric power generation needs. Clean coal technology has made great strides in the past 30 years as well.