Hi there! I
have been reading about nuclear energy for some time now. And wanted to
share what I had read and digested so far. So here comes this long long
post. Hope you enjoy it.
Ever wondered what will be the energy source of the future, to sustain humanity? Of course, the very same energy that powers millions of stars in our universe - Nuclear fusion!
Where do we stand today? Humanity has tamed nuclear fission since long i.e. splitting of atoms to release vast amounts of energy. And what do we get in this process? We get
• Loads of energy i.e. converted into electricity
• Loads of radioactive waste material. Different kinds of radioactive waste have different half-life i.e. time taken to decay. This could be a short span to millions of years. Nuclear fission gives us a considerable amount of radioactive waste that takes millions of years to decay! You may be asking now - where on earth, do we hide this waste? Well, this sure is a big headache. Check the following links out - https://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_repository or https://en.wikipedia.org/wiki/Waste_Isolation_Pilot_Plant.
Enter Nuclear Fusion i.e. fusing/joining two or more atoms. Is this better than fission? Of course yes! Read on
• Well to start with, Nuclear fusion releases around 3 to 4 times more energy than nuclear fission. And by the way, nuclear fusion is mother nature's preferred way of powering the universe. Nuclear fission does not normally occur in nature. No wonder fission gives us unwanted waste. We source fission with uranium or plutonium. On the other hand, Hydrogen is the most simple, basic and abundant source needed for a fusion reaction (fusion can use other light and heavy chemical elements too)
• Fusion results in very little radioactive waste (relative to nuclear fission). Moreover, this radioactive waste usually has a half-life of a few decades only
• How about safety? You have heard or read about the nuclear fission disasters at Chernobyl, or the latest one being Fukushima (triggered by a tsunami). The waste material coming from a fission plant generates huge amounts of heat and that is why such plants need some cooling mechanism. Now, if the cooling mechanism does not work for some reason, the radioactive material generates enough heat to melt the nuclear reactor (known as a meltdown). And this may lead to some serious hazards. Fusion, on the other hand does not have any such problem. It can be stopped spontaneously (read on for a simple explanation later).
So you ask further, why don't we have commercial nuclear fusion power plants? Oh, the answer here is simple. This is because scientists have not managed to tame nuclear fusion reaction to create unlimited energy :) There have been successful experiments but that is it. Scientists have successfully sustained nuclear fusion reactions for a few minutes only! A nuclear fusion reaction needs very high temperatures (tens of billions of degrees). This is like recreating the core of the Sun, on our planet. The good news is that scientists know how to achieve these unimaginable temperatures - by confining the fusion source (usually in the 'plasma' state, which is a fourth state of matter. I know, I know, we all grew up with 3 matter states - solid, liquid and gas. This fourth state is a topic for discussion on some other day). The confinement squeezes the plasma to such an extent that we achieve temperatures far greater (nearly 10 times hotter) than the Sun's core temperature . And voila, there comes our fusion reaction!
Tokamak - The most successful plasma confinement magnetic device used for experimental fusion.
Sustaining such high fusion temperatures require a lot of energy and there are technical challenges too. Imagine trying to squeeze a balloon uniformly with your bare hands. The balloon will bulge out from places with least pressure. Now you can probably appreciate the problem at hand - trying to confine a plasma uniformly. This was one of the challenges that had dogged the great scientists till this very age. This confinement is now achieved using magnetic fields with great precision. The Russians gave us a device named 'tokamak' that uses magnetic fields for confinement - refer to https://en.wikipedia.org/wiki/Tokamak for more reading on this. If the magnetic field is decreased in strength, the plasma is no longer confined and tends to expand. And expansion leads to cooling down. Hence, the fusion reaction stops immediately because of the cooling effect. So it seems to be theoretically much safer than fission plants.
Still with me? Let me summarize - humanity is still experimenting with fusion energy for commercialization (which is at-least half a century away). Fusion requires very high temperatures, which we can now produce on our planet earth. The next step is to nail down the technicalities of building a commercial nuclear fusion reactor.
The future is being molded as you read this post ITER - International Thermonuclear Experimental Reactor (https://www.iter.org/mag) - this is a global multi-cultural mega scientific project that aims to build the world's biggest tokamak (in Southern France), to produce fusion energy. And in the process, scientists will learn more about how to solve the engineering, manufacturing and industrial challenges. The aim is
"to deliver ten times the power it (i.e. ITER tokamak) consumes. From 50 MW of input power, the ITER machine is designed to produce 500 MW of fusion power—the first of all fusion experiments to produce net energy.
Ever wondered what will be the energy source of the future, to sustain humanity? Of course, the very same energy that powers millions of stars in our universe - Nuclear fusion!
Where do we stand today? Humanity has tamed nuclear fission since long i.e. splitting of atoms to release vast amounts of energy. And what do we get in this process? We get
• Loads of energy i.e. converted into electricity
• Loads of radioactive waste material. Different kinds of radioactive waste have different half-life i.e. time taken to decay. This could be a short span to millions of years. Nuclear fission gives us a considerable amount of radioactive waste that takes millions of years to decay! You may be asking now - where on earth, do we hide this waste? Well, this sure is a big headache. Check the following links out - https://en.wikipedia.org/wiki/Yucca_Mountain_nuclear_waste_repository or https://en.wikipedia.org/wiki/Waste_Isolation_Pilot_Plant.
Enter Nuclear Fusion i.e. fusing/joining two or more atoms. Is this better than fission? Of course yes! Read on
• Well to start with, Nuclear fusion releases around 3 to 4 times more energy than nuclear fission. And by the way, nuclear fusion is mother nature's preferred way of powering the universe. Nuclear fission does not normally occur in nature. No wonder fission gives us unwanted waste. We source fission with uranium or plutonium. On the other hand, Hydrogen is the most simple, basic and abundant source needed for a fusion reaction (fusion can use other light and heavy chemical elements too)
• Fusion results in very little radioactive waste (relative to nuclear fission). Moreover, this radioactive waste usually has a half-life of a few decades only
• How about safety? You have heard or read about the nuclear fission disasters at Chernobyl, or the latest one being Fukushima (triggered by a tsunami). The waste material coming from a fission plant generates huge amounts of heat and that is why such plants need some cooling mechanism. Now, if the cooling mechanism does not work for some reason, the radioactive material generates enough heat to melt the nuclear reactor (known as a meltdown). And this may lead to some serious hazards. Fusion, on the other hand does not have any such problem. It can be stopped spontaneously (read on for a simple explanation later).
So you ask further, why don't we have commercial nuclear fusion power plants? Oh, the answer here is simple. This is because scientists have not managed to tame nuclear fusion reaction to create unlimited energy :) There have been successful experiments but that is it. Scientists have successfully sustained nuclear fusion reactions for a few minutes only! A nuclear fusion reaction needs very high temperatures (tens of billions of degrees). This is like recreating the core of the Sun, on our planet. The good news is that scientists know how to achieve these unimaginable temperatures - by confining the fusion source (usually in the 'plasma' state, which is a fourth state of matter. I know, I know, we all grew up with 3 matter states - solid, liquid and gas. This fourth state is a topic for discussion on some other day). The confinement squeezes the plasma to such an extent that we achieve temperatures far greater (nearly 10 times hotter) than the Sun's core temperature . And voila, there comes our fusion reaction!
Tokamak - The most successful plasma confinement magnetic device used for experimental fusion.
Sustaining such high fusion temperatures require a lot of energy and there are technical challenges too. Imagine trying to squeeze a balloon uniformly with your bare hands. The balloon will bulge out from places with least pressure. Now you can probably appreciate the problem at hand - trying to confine a plasma uniformly. This was one of the challenges that had dogged the great scientists till this very age. This confinement is now achieved using magnetic fields with great precision. The Russians gave us a device named 'tokamak' that uses magnetic fields for confinement - refer to https://en.wikipedia.org/wiki/Tokamak for more reading on this. If the magnetic field is decreased in strength, the plasma is no longer confined and tends to expand. And expansion leads to cooling down. Hence, the fusion reaction stops immediately because of the cooling effect. So it seems to be theoretically much safer than fission plants.
Still with me? Let me summarize - humanity is still experimenting with fusion energy for commercialization (which is at-least half a century away). Fusion requires very high temperatures, which we can now produce on our planet earth. The next step is to nail down the technicalities of building a commercial nuclear fusion reactor.
The future is being molded as you read this post ITER - International Thermonuclear Experimental Reactor (https://www.iter.org/mag) - this is a global multi-cultural mega scientific project that aims to build the world's biggest tokamak (in Southern France), to produce fusion energy. And in the process, scientists will learn more about how to solve the engineering, manufacturing and industrial challenges. The aim is
"to deliver ten times the power it (i.e. ITER tokamak) consumes. From 50 MW of input power, the ITER machine is designed to produce 500 MW of fusion power—the first of all fusion experiments to produce net energy.
During its operational lifetime, ITER will test key technologies
necessary for the next step: the demonstration fusion power plant that
will prove that it is possible to capture fusion energy for commercial
use."
Source: <https://www.iter.org/proj/itermission>
For those who are thrilled, I highly recommend visiting the ITER website. It has magazines, technical know-how and all. This will keep you busy for a long time to come. Oh by the way, this project is being executed by 7 members - European Union, China, Korea, US, Japan, Russia and India.
For those who are thrilled, I highly recommend visiting the ITER website. It has magazines, technical know-how and all. This will keep you busy for a long time to come. Oh by the way, this project is being executed by 7 members - European Union, China, Korea, US, Japan, Russia and India.
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