What's the difference between a light water and a heavy water nuclear reactor?

Haynes

What are the differences other than the process to get the fuels? Are there differences in energy efficiency? Which one is cheaper/easyer to operate? Why?



Jefferson

Designers choose to use heavy-water in order to minimize the need for enriched uranium. If you use regular water as moderator and/or coolant, the water absorbs a significant amount of the neutrons needed to keep the reaction going. That means you need a big reactor, one with a lot of regular uranium, and lots of moderator and careful attention to saving every possible neutron. If you want to make a small reactor, or one that will run a long time, then you can't use regular uranium-- you have enrich the uranium, which is extremely expensive and requires huge investment in plants and energy. Plus the enriched uranium is excellent bomb-making material so you have to worry about that. An alternative is to design the reactor to use heavy water, deuterium, as a moderator and coolant. deuterium has all the good properties of water, including high heat conductivity, high heat capacitor, relatively non-corrosive, and low neutron absorption. If you use heavy water then you can get by using all natural uranium, which is very cheap. The Canadians designed a few reactors, the "CANDU" series, which work this way. The downside is you need a small boatload of heavy water, which is not cheap either, but a whole lot cheaper than enriched uranium. Heavy-water reactors have not really caught on very much, probably due to various factors, like competition and lack of heavy-water supplies.



Olustee

nope, its just that light water is hydrogen dioxide, u better know as H2O. heavy water is deuterium dioxide or D2O... its used as moderator.. for slowing down neutrons produced in a nuclear chain reaction for a controlled reaction... D2O is more efficient and hence used. not H2O...



Garland

"Light water" is the water to which you are accustomed. It consists of 2 hydrogen atoms and one oxygen atom. The hydrogen atoms both have one proton and zero neutrons. The oxygen atom has 8 protons and 8 neutrons. Among the entire molecule, there are 10 electrons, well-shared to form covalent bonds."Heavy water" still has the same types of atoms and each atom still has the same count of protons (otherwise they wouldn't be hydrogen and oxygen), and among the whole molecule there are still 10 electrons...BUT, the hydrogen atoms each have extra neutrons. The isotope of Hydrogen with a neutron is called deuterium. The Hydrogen isotope with two neutrons is called tritium. Deuterium and Tritium are both much more radioactive than ordinary hydrogen, Tritium more than deuterium. The sun uses Tritium as a source of nuclear fuel. H3O is NOT heavy water. I had an instructor incorrectly try to teach this to the class. H3O+ is the hydronium cation to which ordinary water dissociates normally (the corresponding anion is OH-). Ordinary water, even the purest water a chemist can make, constantly dissociates in to H3O+ and OH - ions. This is what enables water to act as a solvent for ionic chemistry reactions and acid-base phenomena. It is the isotope of hydrogen which classifies water as "heavy" or "light"...not the ion.-----------------In the contexts of nuclear reactors:A light water reactor uses the rocket water grate on nerves which you are habitual as a coolant of the atomic reaction core. No nuclear material is probable to encounter the light water. Other materials such as graphite are hand-me-down as moderators apprised of the nuclear rebound to absorb turn aside neutrons. Deuterium exists as the hydrogen broach the heavy water atomic reactor coolant loops. The cooling water is intended to be the moderator advised about the nuclear reaction, gripping the stray neutrons. Upon absorbing stray neutrons, Very light water becomes heavy water.---------------You keister answer your own additional questions...I unqualifiedly don't skilled in those answers.



Moberly

Heavy water is H3O... Duterium Oxide. It has an extra Hydrogen atom in the molecule. Simple.



Beaverton

Hydrogen comes in three forms. The regular version has one proton and no neutrons. Deuterium has 1 neutron; tritium has 2. They're two and three times as heavy as regular hydrogen. Tritium is rare, but you can get water which has a significant proportion of deuterium in it. It's about 10% heavier than regular water. More importantly, those neutrons keep the water from absorbing extra neutrons from a nuclear reaction. Water is used as a moderator in nuclear power plants. When an atom decays, it releases neutrons, and if those neutrons hit another atom, it can cause further decays. That's the chain reaction. But the neutrons must be slowed down (moderated) to be useful; otherwise, they just zip off without encountering other atoms. If you use light water in the reactor, it absorbs some of the neutrons it's supposed to be slowing down. That means you have to use fissile material which produces more neutrons. That's expensive enriched uranium. Enriched uranium is also dangerous, because it can be used to make bombs. If you use heavy water instead, you can get away with less-enriched uranium. The operating costs are roughly the same; there are so many factors going into the cost of operating a atomic adeptness factori that the choice cognizant of reactor has more grate on nerves do alongside other factors than the price in the know about the inputs or the cartouche. You listen a lot about heavy water reactors broach the news because it's the array in on thing we fundament safely account to Iran added to North Korea to produce atomic power without having the facilities to refine uranium referring to bombs.



Bucksport

You need a larger scale to weigh the..."heavy" water some of which is in the..."light water"! Hummmm!