Nuclear Chemistry- Chernobyl - Harrison
The Chernobyl Incident was a graphically tragic period of time, resulting in a massive fallout and radioactive decay zone. This zone is still radioactive to this day, and as time is passing, only grows worse. However, a new way to contain this leakage of radiation has taken a turn for the better. To understand how it works, however, one must understand how a Nuclear Reactor works. Reactors, in essence, use fission to release energy and split neutrons. The Chernobyl reactor's system failed, as well as the safety protocols, and began to overheat, melting down and releasing those split neutrons and radiation resulting from the fission. Currently, the reactor is shielded with a thick layer of concrete, acting similar to a sarcophagus.
However, this shield is failing, and the radiation is breaking the concrete apart, as the structure wasn't strong or durable to begin with. The radiation levels have expanded, and are listed on the image, along with the effects. It is necessary to know that 50mSv per year is equal to 3-25 uSv/hr. Another common measurement is roentgens, to which 0.00877 Sieverts (Sv) is equal to 1 roentgen. Various conversions are also important:
1,000,000uSv = 1Sv
1000mSv = 1Sv
As these effects are such, the necessary work on the project known as "NSC" or "New Safe Confinement" was begun, and the project will be completed sometime within 2017. NSC is a large steel arch designed in a manner to keep Chernobyl contained for the next 100 years. By hermetically sealing the building, the nuclear materials will remain contained within it, unable to escape. It will act as shielding, preventing the rays of radiation from escaping and effectively containing the radiation. As well as this, since it is made from steel, it is less susceptible to the effects of radiation than the previous coffin.
This new coffin will allow the workers to attempt to remove the nuclear waste from within Chernobyl and prevent radiation from spreading, as well as nullifying the reactor. The reason that they must remove these materials is due to the half-lives of the Cesium within Chernobyl. Some interaction, currently unknown, within the soil of Chernobyl, has expanded the half-lives of the Cesium from the normal 30ish years, to between 180 and 320 years. Cesium may not seem as dangerous as plutonium however, as plutonium can cause much much longer damage. However, the Soviets put a much larger amount of cesium in their reactors compared to the normal amounts of plutonium. If the radiation pertains for its true lifespan, Chernobyl may have a hard time ever becoming habitable again, as the effects from the radiation are already evident in several zones, such as the "Red Forest", which was one of the five most contaminated areas within Chernobyl. In the "Red Forest", deformities are everywhere. The trees, although dead, have barely decomposed and remain black trunks in the midst of the chaos. The radiation had caused the environment to show 40% less decomposition. If these leaves and trees were to burn however, in the case of an event similar to a forest fire, radiation would be spread throughout the zone via the smoke.
- Harrison
This new coffin will allow the workers to attempt to remove the nuclear waste from within Chernobyl and prevent radiation from spreading, as well as nullifying the reactor. The reason that they must remove these materials is due to the half-lives of the Cesium within Chernobyl. Some interaction, currently unknown, within the soil of Chernobyl, has expanded the half-lives of the Cesium from the normal 30ish years, to between 180 and 320 years. Cesium may not seem as dangerous as plutonium however, as plutonium can cause much much longer damage. However, the Soviets put a much larger amount of cesium in their reactors compared to the normal amounts of plutonium. If the radiation pertains for its true lifespan, Chernobyl may have a hard time ever becoming habitable again, as the effects from the radiation are already evident in several zones, such as the "Red Forest", which was one of the five most contaminated areas within Chernobyl. In the "Red Forest", deformities are everywhere. The trees, although dead, have barely decomposed and remain black trunks in the midst of the chaos. The radiation had caused the environment to show 40% less decomposition. If these leaves and trees were to burn however, in the case of an event similar to a forest fire, radiation would be spread throughout the zone via the smoke.
What methods did the construction workers use to hermetically seal the containment structure?
ReplyDeleteVery good question Austin, and honestly I am having a hard time coming up with a good answer. The entire dome is made of triple layered plates, and those plates are useful for sealing. As well as this, they are also implementing a system for air vents that prevent radiation from escaping. The entire structure is huge and had to be divided into multiple sections, so when they are combined, the seal will cover nearly the entire building. I hope this answered your question!
DeleteWhere is the radioactive decay zone that result from the Chernobyl incident? How big is the radioactive zone? How does the new coffin allow the workers to remove the nuclear waste?
ReplyDeleteThe entire zone is within the Chernobyl area. Chernobyl is an area near Pripyat, while the reactor itself was known as the Chernobyl Nuclear Reactor. As for the size, Chernobyl is about 1,000 square miles. The new coffin is effective for nuclear waste removal though, as it allows greater flexibility in how they can go about removing the waste with less effect on the exterior environment via the insulated containment. If it was not in place, the radiation from the removed waste would seep out and affect the environment.
DeleteHey Harrison, this is a very interesting post! One thing that sticks out to me when I think of Chernobyl is the famous Elephant's foot, a molten part of the once active Number 4 reactor's core. The disaster is obviously quite unfortunate, but there are some great pictures of this Elephant's foot, one can be found here: http://static.nautil.us/1931_15d185eaa7c954e77f5343d941e25fbd.jpg. What makes this picture amazing, in my opinion, is that, at the time of the picture, it was giving off enough radiation to kill a person in 300 seconds.
ReplyDelete