Nuclear Energy?

Question

I have 3 questions of nuclear power.

1). Why is there an explosion if nuclear fission is not controlled

2). How do we make nuclear fission, if we can't let the neutrons collide with the Uranium 235 atom just after we find uranium atoms? My encyclopedia says to increase the nuclear fuel, so what is the nuclear fuel?

3). Why does nuclear fusion create lots of energy, light and heat?

Answer 1

1. Fission is the splitting of very heavy atoms with the use of neutrons.

With fissile material (U-233, U-235 and Pu-239, 240) if there is a sufficient mass (critical mass) when the first couple atoms split and release their 2-3 neutrons, the chain can go wildly out of control: 2 neutrons first generation: 4 neutrons second generation: 8 : 16: 32:....until all atoms are fissioning pretty much at once. This is called a "chain reaction." This can be enhanced, helped, by showering the material with more neutrons, more starting points. This leads to what we call super-criticality (a bomb).

2. We make fissions happen but in a controlled manner. We need to slow the neutrons down to increase the probability that they will cause fission. We generally use water to do that. We also do not run with large amounts of U-235. Instead, we only have 5% of the uranium able to fission that way. Some of the 95% (U-238) will split with fast neutrons, too.

The nuclear fuel is about 5% U-235 and 95% U-238. It is a metal powder that is compressed into pellets with a little glue added. The pellets (about 250 per rod) and then put into a zirconium metal tube - called a fuel rod. The rods are then put together in kind of an egg-crate looking setup where they are bound together. That is a fuel assembly. Each assembly costs about $750,000. We replace an assembly after it has been run in the reactor about 5 years.

3. Nuclear fusion is energy of combining (not splitting like fission). Some very light atoms release energy when pushed together. Hydrogen is one of them, helium another. Our sun burns mostly hydrogen and helium, forming new elements and releasing energy.

Answer 2

This is NOT a "Wikipedia" answer, OK?

1) NUCLEAR REACTORS DO NOT EXPLODE. What happened at Chernobyl-4 was an uncontrolled fission. What happened really was this: The control rods (made of graphite - such material can slow down neutrons very fast) were all out of their place (going against international regulations about safety). So the core (the vessel containing the fuel rods) went to a temp of 2800ºC (melting point of nuclear fuel). The moderator (another sustance which stops neutrons - in the RBMK case, water) started to evaporate, filling the entire building with vapor. What goes on when you over-inflate a ballon? That's right: it blows up. So the rooftop blew up. Then the air from the outside came in, but there was carbon (remember the control rods?). So the final answer is: there was no nuclear explosion, it was a just a graphite combustion. If it were a thermonuclear explosion, we were not probably here (the radiation released is similar to 100 Hiroshima bombs).

Now, back to the bussines of your question. a) Nuclear reactors don't explode because the U-235 concentration is barely 4%, while in bombs is 99%. b) The fissile materila for bombs is Pu-239, not U-235. c) If there is a bomb, IT IS SUPPOSED TO FISSION WITH NO CONTROL. So what a bomb does is make a piece of fissile material strike another in such a way both pieces can geometrically fit. Try to take out a cone-like piece from an orange, and you'll understand me. nuclear reactors are made of pellets 1cm high (and a pencil has more diameter). So there is no way that pellets can trike each other the way bombs do. So don't worry. Now, a chain reaction is something to care about. I can tell you hundreds of examples, but you gotta see it on your own: fill your room floor with mouse traps, one against another, and then throw a ping pong ball. It's really amazing. Can you imagine millions of billiard balls striking each other at the same time? Can you believe the quantity of energy released?

2) This is all based on probability distributions like normal or X^2. It depends entirely on the neutron velocity. Fission is entirely random, you never know when or where a neutron is gonna strike, and even if it strikes, it's gonna make the NUCLEUS (you are talking about atoms - electrons don't count in this) split or just release a gamma ray.

3) Hey, have you ever tried to make two pieces of bread fill the same space at the same time? Nah, just kidding. To make fusion, we need two very small nuclei (two hidrogen nuclei will be alright). Now we have two protons, and we'll try to make them bond. When we "bond" them, we are trying to overcome the law of same sign: you know, same sign they repel. The result is a lot of energy, because what we just formed is helium. Helium has less energy than the two protons (the hydrogen nuclei) each one.

Answer 3

It takes a particular style of Nuclear Reactor to offer weapons. that's stated as a Breeder Reactor and it extremely is shape is easily detected. A reactor for study or electricity is an totally diverse style of reactor. it extremely is the flexibility of the destiny as there is not any longer adequate aspects to construct the variety of wind turbines mandatory for a fashionable living standards, and photograph voltaic voltaic cells value greater power to offer than the cells can supply returned. The spent gasoline rods (truly pellets stacked on splendid of the different) could be wiped clean of lead and different contaminates and reused many 1000's of time. that's peoples worry of old technologies that brought about state rules prohibiting the transport of spent gasoline rods to South Carolina the place they are able to be wiped clean and reused. extraordinarily much each and every great city in Europe has a nuclear reactor offering power and that they have got not had injuries. The technologies is obtainable, we merely could desire to apply it.