the "artifical sun" made by china

Vlad Plasmius said:

Um, have any of you actually look at the first post. It was never said that China created a fusion reaction, only passed an engine test. In fact, EAST is only an experimental platform not intended to produce plasma like that needed to acquire energy.

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No reason to get snippy with me. I never one mentioned it being a fusion reaction generator. In fact, if you read my post I actualy place it in as a 'Run Of The Mill' Thermonuke Generator. Although I realize there is no such thing as a 'Run of the mill' Thermonuclear power device, it isint the fusion reaction system everyone is spazzing out about. I apologize if this was not directed towards me, and in that instance retract said argument.

And Dsuky, that is fairly obvious from the readings. But it does bring one thing to mind. How does one shut down and remove such a test reactor safely once the experements are complete? Do they just bury it like they used to do for the old Nuclear reactors in the U.S and Russia or do they do some other method?

Kampfwagen said:

And Dsuky, that is fairly obvious from the readings. But it does bring one thing to mind. How does one shut down and remove such a test reactor safely once the experements are complete? Do they just bury it like they used to do for the old Nuclear reactors in the U.S and Russia or do they do some other method?

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Why would they bury it if it is a fusion reactor? There shouldn't be radiaocative waste or contamination since water is the main byproduct, right? It's not the same as fission reactors that after 50 yrs. use are radioactive for thousands of years thereafter. I can see it just being dismantled and either have the materials scrapped, recycled, or reassembled in a museum.

Dear Sirs,

As I mentioned before in my first post, the chief reactions are the D-D (deuterium - deuterium) and the D-T (deuterium-tritium) rxns. The end product of all these reactions is Helium-4 (or rather it's nucleus, which is also known as an alpha particle). Helium is a noble gas and is chemically inert. It is also non radioactive and has a stable nucleus. Thus we should not fear it as a source of radiation.

However, remember how I mentioned that most of the energy of the thermonuclear reaction is in the incident neutron (about 85 percent in fact)? Well the only way to recover the neutrons' energy (and therefore most of the power produced by the thermonuclear reactor) is by collision (in a fission, i.e. conventional, nuclear reactor one would call it moderation) with a nuclei; preferably a light nuclei. Collisions in which the neutron scatters without interacting are called elastic collisions, all others fall under the category of inelastic collisions.

Modern themonuclear reactor designs surround the core with a so-called blanket, which serves a number of purposes, namely to capture the energy of the neutron by a large number of collisions, and also to breed tritium fuel. Light nuclei are selected because they are the most effective in slowing down the neutron (moderation). Graphite is one of these typical materials. To breed tritium fuel the blanket also must have the element lithium in it.

The problem is that in many of these inelastic collisions (which involve neutron capture) an intermediate nucleus is formed, which is often radioactive. So to answer the question posited, thermonuclear reactors do produce radioactive by-products. Simply put, they and their materials will become a source of radiation.

I hope this helps.

Best Regards,

Dusky Lim

Yes but the by products, can be treated. The same amount of waste as a normal fission reactor will be produced. However it will be safe in a few hundred years, unlike the thousands due to fission. Also the is a kind of of cross over reactor that you surround a fusion reactor with waste from fission reactors and the waste from fission reactors can be broken down (I read 96% of radiation lost in approx 30 years) and it will produce a lot of heat of a waste product, hence energy. Again it’s experimental.
The reactor ITER is making will be mostly steal (the blanket), but in future new materials will become available and they will be less radio active at the end of the plants life.

Thread name change?

Kind of off topic, but is it possible to change the title of the thread? It's kinda misleading.

walter said:

Why would they bury it if it is a fusion reactor? There shouldn't be radiaocative waste or contamination since water is the main byproduct, right? It's not the same as fission reactors that after 50 yrs. use are radioactive for thousands of years thereafter. I can see it just being dismantled and either have the materials scrapped, recycled, or reassembled in a museum.

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*sigh* I was talking about the modern methods of dismantling a thermonuclear reactor under the assumption that the generator in question was a 'standard' thermonuclear reactor. Lest I misunderstand something in the translation (which is about 50-70% likely) that this is a Thermonuclear Reactor being used as a testing platform for the possibility of Fusion reactor and testing it's fesability. I realize that Fusion reaction produces water as a byproduct, but of course it makes sense that this water is inheritly radioactive, for however long a time that may be.

So my question still stands, un-ansewered. What exactly is the plan once the testing stops? It seems a little bit impractical to just leave this thing there for thirty-odd years untill it's safe to use it as a drinking fountan, dosent it?

And yeah, it is a little bit misleading and would likely aleviate some of the confusion if we changed it.

if china had managed to make a nuclear fusion reactor as u have manage to interpret, then it would to be kept underground as the helium produced will be radioactive, due to at the end it is still a nuclear reaction and will be induced radioactive.

Also, China has not told the world a lot of things, (remember the anti malarial drug back in the 60's), so they could have been secretly developing this technology without the West knowing.

If it was just an engine test or a platform of some sort then it just shows that China is catching up on technology.

托卡马克= tokamak

therefore it is a nuclear fusion reactor

a question

fuel breeding aside, can water/steam or another inert gas be used? I recall that these are used in PWR/PHWR as the neutron moderator. The only instance, as far as I have seen, where graphit is used, is in the RBMK series (aka Chernobyl).

this is a fusion reaction, it fuses things together. if heavy water was used, it would just vapourise into D and O, which will cause the Ds to fuse and form He which provides a lot less energy.

I fink the reactors of Chernobyl were fission reactors (my nuclear knowledge only specialises in fusion, JET and ITER). The PHWR uses the heavy water as a moderator which reduces the need for enrichment.

PHWR can use U-238 as fuel after a enriched mixture starts the reaction.

However, my question was regarding the prospect of using steam/water or an inert gas to act as the neutron absorber.