Sang'oro Hydroelectric Power Station

Transcription

Have you ever been in an argument about Nuclear Power? We have, and we found it frustrating and confusing So let's try and a grip with this topic It all started in the 1940s. After the shock and horror of the war in the use of the atomic bomb, Nuclear Energy promised to be a peaceful spin-off of the new technology, helping the world get back on its feet. Everyone's imagination was running wild. Would electricity become free? Could nuclear power help settle the antarctic? Would there be Nuclear powered cars, planes, or houses? It seemed that this was just a few years of hard work away. One thing was certain, the future was atomic! Just a few years later, there was a sort of atomic-ish hangover. As it turned out, Nuclear Power was very complicated, and very expensive. Turning physics into engineering was easy on paper, but hard in real life. Also, private companies thought that Nuclear power was much too risky as an investment. Most of them would much rather stick with gas, coal, and oil. But there were many people who didn't just want to abandon the promise of the atomic age: An exciting new technology, The prospect of enormously cheap electricity, The prospect of being independent of oil and gas imports, And in some cases, A secret desire to posses atomic weapons, provided a strong motivation to keep going. Nuclear power's finest hour finally came in the early 1970s, when war in the middle east caused oil prices to skyrocket worldwide. Now, commercial interest, and investment, picked up at a dazzling pace. More than half of all the nuclear reactors in the world were built between 1970 and 1985. But which type of reactor to build given how many different types there were to choose from? A surprising underdog candidate won the day. The light water reactor. It wasn't very innovative and it wasn't too popular with scientists, but it had some decisive advantages: It was there, it worked, and it wasn't terribly expensive So what does a light water reactor do? Well, the basic principle is shockingly simple. It heats up water using an artificial chain reaction. Nuclear fission releases several million times more energy than any other chemical reaction could. Really heavy elements on the brink of stability like Uranium 235, get bombarded with Neutrons. The Neutron is absorbed, but the resulting is unstable. Most of the time, it immediately splits into fast-moving, lighter elements, some, additional free Neutrons, and energy in the form of radiation. The radiation heats the surrounding water, while the Neutron repeats the process with other atoms, releasing more Neutrons and radiation in a closely controlled chain reaction. Very different form the fast, destructive, runaway reaction in an atomic bomb. In our light water reactor, a moderator is needed to control the Neutron's energy. Simple, ordinary water does the job, which is very practical, since water is used to drive the turbines anyway. The light water reactor became prevalent because it's simple and cheap. However, it's neither the safest, most efficient, no technically elegant nuclear reactor. The renewed nuclear reactor hype lasted barely a decade though. In 1979, the three mile island nuclear plant in Pennsylvania, barely escaped the catastrophe, when it's core melted. In 1986, the Chernobyl catastrophe directly threatened central Europe with the radioactive cloud. And in 2011 the drown out Fukushima disaster sparks new discussions and concerns While in the 1980s two hundred and eighteen new nuclear power reactors went live, their number and nucleus global share of electricity production has stagnated since the end of the 80s So what's the situation today? Today, nuclear energy meets around 10% of the world's energy demand. That are about 439 nuclear reactors in 31 countries. About 70 new reactors are under construction in 2015, most of them in countries, which are growing quickly. Or at all, 160 new reactors are planned world-wide. Most nuclear reactors were build more than 25 years ago with pretty old technology. More than 80% are various types of light water reactor. Today, many countries are faced with a choice: The expensive replacement of the aged reactors possibly with more efficient, but less tested models, or move away from nuclear power towards newer or older technology with different cost and environmental impacts. So, should we use nuclear energy? The pro and contra arguments will be presented here next week. Subscribe and then you won't miss it! Our channel has a new sponsor, audible.com If you use the URL audible.com/nutshell, you can get a free audiobook and support our channel. Producing our videos takes a lot of time and we fill a lot of it by listing audiobooks. For really entertaining book, we recommend "Into thin air" by Jon Krakauer. He's a great writer and the story is really absorbing and true. Go to audible.com/nutshell to get the book for free. thanks a lot to audible.com for supporting our channel and to you for watching