What are those radioactive materials leaked out in Japan's Nuclear Reactors? Are they the by products of nuclear fission? Can you help explain the nuclear process?
Cesium,Iodine mostly, but Heat and Oxidation by air has caused various other elements to be vaporised from the spent fuel pools used to keep old fuel rods cool. If the spent fuel rods are melted in to a big pile, there would be various different atomic elements that might have vaporized. The radiations that have escaped will form other radiations, mainly what is called beta radations any where they go or land. DwayneD.L.Rabon
It's very debatable as to whether plutonium is more dangerous than the other known radioactive elements (I'd say radon would be somewhere high on the list myself). The reactor must have something in it's fuel rods, and that could well be plutonium. I don't know but it doesn't matter - no part of the fuel rods have escaped from the reactor. It's the coolant that is escaping which is lower level radioactivity than the fuel rods. Since Chernobyl reactors have been designed so that if there is an accident, as little radiation is released as possible. In particular, if the reactor cracks because the fuel has melted, the resulting liquid falls into a sand pit and you get glass, not like Chernobyl where there was a pool of water underneath that formed steam and caused the explosion. I am of the opinion that the media coverage of this event is stupid because it really will not adversely affect many people in Japan at all, and almost certainly no one outside Japan. On the other hand there have been almost 200000 people killed in the earthquake and tsunami that are being ignored in favour of radiation scaremongering.
Yeah, and headlines like this: 'Fukushima nuclear plant' radiation found at UK sites. But then they say there's no public health risk. So why even mention it? Headlines like that spread panic, and the general public shit their pants whenever they hear the 'N' word, so much so that NMR scans had to become MRI scans. We really need to manage the press better on these occasions.
plutonium was detected in surrounding soil. BTW, the vegetables from the farms there were banned, this had caused a farmer to commit suiside. very pitiful
Plutonium ( /pluːˈtoʊniəm/ ploo-TOH-nee-əm) is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-white appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen and silicon. When exposed to moist air, it forms oxides and hydrides that expand the sample up to 70% in volume, which in turn flake off as a powder that can spontaneously ignite. It is also a radioactive poison that accumulates in bone marrow. These and other properties make the handling of plutonium dangerous. http://en.wikipedia.org/wiki/Plutonium
the news says Japan plans to decommission the nuclear plant, what does it mean decommission? to halt the nuclear fission totally? how to halt it? if they can halt it, why not doing it immediately?
They slowly stop the reaction process by drawing the fuel rods away from each other. The reaction only happens when the rids are close to each other but removing them fast would be a hazzard.
Fission is what we call the nuclear reaction. It comes from the greek meaning "to split". An atom of, say Uranium splits apart forming two new elements, some energy (which we want), and two neutrons. These neutrons hit more Uranium atoms causing them to split, and so-on. The fission process is stopped from getting out of hand by using what we call moderators. Usually graphite. These soak up neutrons and slow the whole reaction down. After a while, the nuclear fuel becomes spent, but the fuel rods are full of bi-products such as cesium, and some remaining Uranium which continues to produce heat and is highly radioactive. They then have to be cooled in ponds of water. The fuel is made of pellets and are held inside of a metal zirconium tube. Zirconium is used as it is virtually transparent to neutrons and doesn't slow the reaction down. However, it will burn if it gets hot enough, like most metals, and can split or melt as has happened in Fukujima. This released the uranium, plutionim, cesium, iodine and other nuclear bi-products into the environment when the containment vessels were breached. That's it in a nutshell I think.
so decommissioning means using graphite to stop fission? but the news are vague, no technical details on solution.
off-topic: Yea, here in Germany, people are panicking too. In the last Sunday's election in one of the state (Baden-Württemberg), for the first time in 58 years the ruling party lost against the coalition of the Green party and one other party. The Green got over 100% voting increase. The chancellor herself mentioned the Japanese earthquake, tsunami and nuclear disaster as a "turning point.". She is now temporarily shutting down the atomic reactors in Germany (for 3 months, with a possible extension or even abolishment). /off-topic
So what fuel is going to be used to replace the ~7,000 MWs of electricity that those Nuclear plants produced? My guess? Germany which used to export electricity will make up most of their shortfall with imports from France...... Of course, she only shut down 7 or 17 plants (pre 1980) and she only did it till June, which means she did it in the Spring when electricity demand is the lowest. Arthur
