Sunday, January 30, 2011
Annoying, but true...
I know, the GEICO commercial that is similar to this annoys me too. I had to post this video though because it conveys so many of the misconceptions that plague the nuclear industry today. I plan on discussing many of these issues in more depth shortly, but I want you to hear some of them now. The issues of waste and safety are big topics of discussion that everyone is curious about and many are misinformed about. I am sure that if you are not a believer in nuclear power, this video probably just turns you away, but I ask that you just stick with me. I can't say that I can confirm 100% of the facts in this video (such as saying that nuclear power has never hurt anyone, which is obviously false because Chernobyl happened), but I plan on embarking on a journey of discovery to explore these topics. I have to give a h/t to Atomic Insights who posted the video earlier this month.
Thursday, January 27, 2011
Why the Nuclear Option?
Maybe you guys will agree...I have found many of my professors to be really terrible at teaching. I guess it probably comes with the territory of being a physics major, or truthfully it probably comes with the territory of any technical field. I don't want to give the impression that they were not good at presenting the information: they have been (usually) experts at doing that.
Let me give you an idea what I am talking about. Imagine yourself as a student who has the background to understand everything you need to know for the lecture you are attending. Lets say you have have learned all the math and physics required to understand the material that is about to be presented. Now the professor walks in and begins to give a brilliant lecture on "quantum confinement." You understand exactly what he is teaching and you now know all about the subject, but then you then realize that you are in a nanotechnology class and you have no idea how quantum confinement has anything to do with the nano world. It is kind of like giving an axe to a man who has never seen trees before. Or maybe instead of building a man a fire to keep him warm, starting him on first in hopes of keeping him warm for the rest of his life.
The question that we have to ask is "why?" In this case, why is everyone all up in arms about nuclear power? If nuclear power is such a danger and so expensive, then why are we wasting our time arguing about it and promoting it? There must be a reason for this, so what is it?
Nowadays, "going green" is all the rage and therefore we hear a lot about nuclear power being zero emissions. This is a good aspect of nuclear power, but there is a much more fundamental reason to chose nuclear power. Put simply, nuclear power is by far the most bang for the buck of any power source. Many would argue saying the nuclear power is very expensive and that is why we are not building new plants. Well, the fact is that this argument is very misleading. I don't want to get too much into policy here, but one must know that nuclear power is not expensive because of the materials or construction costs. Permitting is by far the most expensive part of a new plant's construction. After construction, nuclear power has been called "too cheap to meter." If you need a little more proof, I will direct you to a post on Rod Adams' blog called "Atomic Insights." This is a great blog for learning about nuclear power and I will probably be referencing it often.
So why is nuclear power the best bang for the buck? Well the answer lies in my last couple posts. Fission fo course! If you need an explanation on what fission means, check out my last couple posts, not that they are any better than sitting through the disconnected lectures of my professors... The nucleus is a source of tremendous energy. When we split the atom, we release this energy.
To get an idea of exactly how much energy, let us first look at a combustion reaction such as the burning of coal. This reaction is what is known as a chemical reaction, meaning that it deals with the exchange of electrons. The stripping of electrons can only release the amount of energy that the electron has while orbiting the nucleus. This is typically on the order of 1-2 electron volts. This is a technical unit, and its meaning is not important to make my point, so bear with me.
Now prepare yourself to be totally amazed. The fission of a Uranium-235 nucleus results in the release of roughly 200 mega electron volts, or 200,000,000 electron volts. Yes, a single fission reaction releases one to two hundred million times more energy than a combustion reaction!
So what does this mean? It means that we can retrieve huge amounts of energy from a very small amount of fuel. As an example, the new Virginia class nuclear submarines will run their entire lifetimes without ever having to be refueled. To further prove the point, the first nuclear power submarine, the USS Nautilus, traveled 62,500 miles on a single Uranium core. A diesel submarine traveling the same distance would consume the equivalent of 2,170,000 gallons of diesel oil! Don't believe me, check it out.
So what is the point of educating on nuclear power? If this doesn't portray its importance, I really don't know what will. Is the argument over nuclear power worth fighting? I think so. Nuclear power? Yes please!
Let me give you an idea what I am talking about. Imagine yourself as a student who has the background to understand everything you need to know for the lecture you are attending. Lets say you have have learned all the math and physics required to understand the material that is about to be presented. Now the professor walks in and begins to give a brilliant lecture on "quantum confinement." You understand exactly what he is teaching and you now know all about the subject, but then you then realize that you are in a nanotechnology class and you have no idea how quantum confinement has anything to do with the nano world. It is kind of like giving an axe to a man who has never seen trees before. Or maybe instead of building a man a fire to keep him warm, starting him on first in hopes of keeping him warm for the rest of his life.
The question that we have to ask is "why?" In this case, why is everyone all up in arms about nuclear power? If nuclear power is such a danger and so expensive, then why are we wasting our time arguing about it and promoting it? There must be a reason for this, so what is it?
Nowadays, "going green" is all the rage and therefore we hear a lot about nuclear power being zero emissions. This is a good aspect of nuclear power, but there is a much more fundamental reason to chose nuclear power. Put simply, nuclear power is by far the most bang for the buck of any power source. Many would argue saying the nuclear power is very expensive and that is why we are not building new plants. Well, the fact is that this argument is very misleading. I don't want to get too much into policy here, but one must know that nuclear power is not expensive because of the materials or construction costs. Permitting is by far the most expensive part of a new plant's construction. After construction, nuclear power has been called "too cheap to meter." If you need a little more proof, I will direct you to a post on Rod Adams' blog called "Atomic Insights." This is a great blog for learning about nuclear power and I will probably be referencing it often.
So why is nuclear power the best bang for the buck? Well the answer lies in my last couple posts. Fission fo course! If you need an explanation on what fission means, check out my last couple posts, not that they are any better than sitting through the disconnected lectures of my professors... The nucleus is a source of tremendous energy. When we split the atom, we release this energy.
To get an idea of exactly how much energy, let us first look at a combustion reaction such as the burning of coal. This reaction is what is known as a chemical reaction, meaning that it deals with the exchange of electrons. The stripping of electrons can only release the amount of energy that the electron has while orbiting the nucleus. This is typically on the order of 1-2 electron volts. This is a technical unit, and its meaning is not important to make my point, so bear with me.
Now prepare yourself to be totally amazed. The fission of a Uranium-235 nucleus results in the release of roughly 200 mega electron volts, or 200,000,000 electron volts. Yes, a single fission reaction releases one to two hundred million times more energy than a combustion reaction!
So what does this mean? It means that we can retrieve huge amounts of energy from a very small amount of fuel. As an example, the new Virginia class nuclear submarines will run their entire lifetimes without ever having to be refueled. To further prove the point, the first nuclear power submarine, the USS Nautilus, traveled 62,500 miles on a single Uranium core. A diesel submarine traveling the same distance would consume the equivalent of 2,170,000 gallons of diesel oil! Don't believe me, check it out.
So what is the point of educating on nuclear power? If this doesn't portray its importance, I really don't know what will. Is the argument over nuclear power worth fighting? I think so. Nuclear power? Yes please!
Wednesday, January 26, 2011
Fissioning Grenades?
There is no getting around the fact that nuclear physics is difficult. Fission is a complicated process and is difficult to understand. In my previous post, I presented some of the details of the fission reaction...but maybe it is better to take a step back and think about what fission looks like.
Let's look at it in a large scale situation. Imagine that there is a field in front of you, and in that field, each placed about a foot apart from each other, are live hand grenades. These hand grenades all have had their pins pulled and have been placed in the dirt in such a manner that they do not explode on their own, but if disturbed at all, will explode. In this state, these hand grenades are "unstable" just like the nuclei which undergo fission.
Now, imagine that you are holding a BB gun. You carefully take aim at a hand grenade somewhere in the grid and you shoot it. Assuming that you hit a grenade, it will explode upon the BB's impact. This is how a fission reaction is induced. Think of the neutron as a BB. If the neutron is fired fast enough, it will cause the unstable target nucleus (the grenade) to "explode."
Of course, since this grenade is located in proximity to so many others, its explosion will produce shrapnel and release a large amount of energy. The explosion will cause the surrounding grenades to explode which will then cause the grenades surrounding them to explode, thus starting a chain reaction. The fission reaction in a reactor causes the "exploding" nucleus to release a large amount of energy as well as more neutrons (kind of like the shrapnel). The newly released neutrons go on to cause surrounding nuclei to fission as well, just like the grenades causing each other to explode. Assuming that there are enough nuclei around which are capable of fission, the reaction will continue indefinitely, releasing large amounts of energy, until measures are taken to stop the reaction. This is the basic idea of a nuclear reactor.
Let's look at it in a large scale situation. Imagine that there is a field in front of you, and in that field, each placed about a foot apart from each other, are live hand grenades. These hand grenades all have had their pins pulled and have been placed in the dirt in such a manner that they do not explode on their own, but if disturbed at all, will explode. In this state, these hand grenades are "unstable" just like the nuclei which undergo fission.
Now, imagine that you are holding a BB gun. You carefully take aim at a hand grenade somewhere in the grid and you shoot it. Assuming that you hit a grenade, it will explode upon the BB's impact. This is how a fission reaction is induced. Think of the neutron as a BB. If the neutron is fired fast enough, it will cause the unstable target nucleus (the grenade) to "explode."
Of course, since this grenade is located in proximity to so many others, its explosion will produce shrapnel and release a large amount of energy. The explosion will cause the surrounding grenades to explode which will then cause the grenades surrounding them to explode, thus starting a chain reaction. The fission reaction in a reactor causes the "exploding" nucleus to release a large amount of energy as well as more neutrons (kind of like the shrapnel). The newly released neutrons go on to cause surrounding nuclei to fission as well, just like the grenades causing each other to explode. Assuming that there are enough nuclei around which are capable of fission, the reaction will continue indefinitely, releasing large amounts of energy, until measures are taken to stop the reaction. This is the basic idea of a nuclear reactor.
Friday, January 21, 2011
Once More from the Top
I figure that before one can make an accurate judgment about the benefits of nuclear power, one should know the fundamentals behind how it works. I don't want to get into to much technical depth (if you want that, you should enroll in a nuclear engineering program), but I do want to walk through the basics so that those reading this have a basic understanding of a reactor when I talk about them at future times in this blog.
In reality, a nuclear power plant is fundamentally the same as any coal-fired power plant. In essence, the process is just boiling water to make steam, which is then pressurized and used to turn a turbine. The turning of the turbine is what creates the electricity. Below is a diagram depicting the basic process by which power is produced by the means of nuclear power. Interestingly enough, the blue system consisting of the steam generator, turbine, generator and condenser is exactly the same for coal-fired power plants.
The difference between the two types of plants is how the water is heated. A coal-fired power plant burns coal to heat the water (I know, the name gives it away). In a nuclear power plant though, the heating of the water is some what more technical, but much more powerful than the burning of coal. At the heart of the nuclear power plant is the nuclear reactor.
The idea of a nuclear reactor is quite intimidating to most people. It conjures images of immense power and to most, it brings thoughts of nuclear explosions. So what does the phrase "nuclear reactor" actually mean? Put simply, it is a concentration of special radioactive materials placed into an environment where a fission reaction is sustained in order to produce large amounts of heat. This brings me to my next point...what is fission? At this point, an awesome picture can explain better than I ever could, so here it is:
In reality, a nuclear power plant is fundamentally the same as any coal-fired power plant. In essence, the process is just boiling water to make steam, which is then pressurized and used to turn a turbine. The turning of the turbine is what creates the electricity. Below is a diagram depicting the basic process by which power is produced by the means of nuclear power. Interestingly enough, the blue system consisting of the steam generator, turbine, generator and condenser is exactly the same for coal-fired power plants.
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| Image borrowed from the NRC |
The difference between the two types of plants is how the water is heated. A coal-fired power plant burns coal to heat the water (I know, the name gives it away). In a nuclear power plant though, the heating of the water is some what more technical, but much more powerful than the burning of coal. At the heart of the nuclear power plant is the nuclear reactor.
The idea of a nuclear reactor is quite intimidating to most people. It conjures images of immense power and to most, it brings thoughts of nuclear explosions. So what does the phrase "nuclear reactor" actually mean? Put simply, it is a concentration of special radioactive materials placed into an environment where a fission reaction is sustained in order to produce large amounts of heat. This brings me to my next point...what is fission? At this point, an awesome picture can explain better than I ever could, so here it is:
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Ok, so maybe the picture is not self explanatory, but I do maintain that the concept of fission is quite simple. To start, there is a parent nucleus (target nucleus in the picture) which has special properties that allow it to fission. In general, this usually means that it is a large nucleus containing many protons and neutrons. It is hard to make generalizations about what numbers of protons and neutrons make a nucleus more or less stable. In other words, it is hard to define what numbers of protons and neutrons give the nucleus the ability to fission. There seem to be several magic numbered isotopes of various elements, but I can discuss later.
Fission is induced in the target nucleus by adding another neutron to it. Simply put, this causes the nucleus to become extremely unstable and to split into two pieces known as the fission products. Also a product of the fission reaction is the release of several more neutrons in the system. It is important to note these neutrons because they are what go on to cause more fission reactions with other nuclei in the reactor. They are what enable the chain reaction in the reactor resulting in usable power from the reactor.
So great, now we have a process to split atoms by bombarding them with neutrons...the question is how do we get power from this? The answer lies in the produced fission products (remember the two nuclei formed after the splitting of the target nucleus). When the fission reaction occurs, the fission products move away from each other at high speeds. Their rapid movement means that they carry a large amount of energy, and as they move through the reactor and slow down, they deposit this energy in the form of heat. Thus, the reactor heats up providing a good source of heat to boil water.
Obviously, this is a very simplified version as to what happens in a reactor, but it is important to understand the basics of fission for nuclear power. One must note that there are many types of reactors all inducing this reaction differently and taking the power from the reactor differently. I will be commenting on different types of reactors in the future to showcase different safety features as well as which ones are more efficient and why, but for now I will leave it simple. If you are interested now in learning about new types of reactors or just seeing the differences between them, I recommend this paper which does a good job introducing the different generations of reactors.
Also, there are many more details to learn about inducing fission reaction and what types of materials require what conditions to undergo fission. If there is interest in this subject, I will be happy to delve into the subject on my blog in the near future.
On that note, impress your friends at the bar this weekend with what you just learned...never mind, it has yet to work for me. But if it does work, fill me in!
Thursday, January 20, 2011
A Long Time Coming
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| Picture taken from http://thebattleoftours.blogspot.com/2010/03/nuclear-power-yes.html |
First thing you need to know about me as far as this blog goes is that I am going to school for nuclear engineering, and thus one can infer that I am pro-nuclear power. I currently am beginning work on my masters degree in nuclear engineering at the Colorado School of Mines. My undergraduate work is in physics, also at the School of Mines. As far as future plans in the nuclear field, I am in an officer program for Navy nuclear propulsion, meaning that I will operate nuclear reactors on Navy submarines. This is of course assuming that I have what it takes to make it that far...
That is probably more than you guys ever wanted to know about me, so I will get to why you guys are probably reading this. Learning the true risks and benefits of nuclear power is not a task that many in the United States take-up (so props to you guys!). By simply talking with people I have met over the years, it seems that many get their information from the often ill informed mass media, or they make assumptions about nuclear power after learning about only the few incidents and disasters that have occurred due to nuclear power. By this, I mean when I say "nuclear power," the first argument many people seem to have against it are "what if" arguments about another Chernobyl or Three Mile Island incident.
I do not intend to downplay the scope of these disasters or the risks and dangers that can be involved with nuclear power cycle, but I do intend to inform people about the truths behind these risks. For instance what has changed in modern reactors to make such disasters nearly impossible to repeat. This blog is thus setting out with the task of informing about the risks of nuclear power as well as what is being done from an engineering standpoint to reduce the danger.
Nuclear power is one of the most commonly misunderstood issues in the news today and is surrounded by hype and hysteria as to the dangers around it. I only hope to be able to inform a few about the truth and debunk a few of the myths.
