Chernobyl

Typedef

http://www.redding.com/news/apafternoonupdate/past/20030422aptop052.shtml

According to the Russians the concrete sarcophagus that surrounds the reactor that blew up in Chernobyl is degrading at a frightening rate.

The main point is that if the sarcophagus collapses the core will once again be exposed and roughly 10 metric tons of radioactive particles will be released into the atmosphere.
Adding to this is the fact that the molten core of reactor 3 is still spilling radioactive particles into the sarcophagus so radiation levels are actually increasing within the sarcophagus.

http://www.insc.anl.gov/neisb/neisb4/NEISB_3.3.A1.2.html

The magma containing molten fuel is disintegrating in the high radiation fields, providing even more radioactive dust. And the reactor's original concrete and other support structures are losing mechanical strength. The Ukrainians have attempted to deal with this problem through structural reinforcements, not always with success.

Chernobyl poses a threat of pandemic proportions and from where I sit, it seems like one of the most glaring examples of why Nuclear power simply non-viable.
Roughly 30,000 people died as a direct result of the explosion in reactor 3 in 1986 and most of that irradiation was a result of the 180 metric tons of molten Nuclear fuel that was simply exposed to the atmosphere.
Imagine what would happen if the 10 tons of radioactive dust floating around inside the Chernobyl reactor three was to escape, with the potential dust has to be carried in air currents!

The explosion of Unit 4 at the Chernobyl nuclear power plant in 1986 left the reactor destroyed, with some 180 metric tons of irradiated fuel exposed to the atmosphere

The strange thing is that even after the worst (documented) Nuclear disaster in history, the Ukranians continued to run the other three reactors in Chernobyl, despite the fact that there is a six mile exclusion zone around reactor three due to dangerous radiation levels.
For the rabid exponents of the virtues of Atomic energy, it is, I think, difficult to rebuff or justify the need, want or risk entailed in deriving energy from such a dirty source of power, with such catastrophic potential for loss of human life.

Regards
Typedef

Edit : Further information
http://www.insc.anl.gov/neisb/neisb4/NEISB_3.3.A1.1.html

Woden

I think that poll needs to be modified as not all atomic energy is so deadly if nuclear fusion is achieved the by products will not be radioactive and hence not harmful. Putting stuff in context, if nuclear fusion is not developed within the next 80-100 years then i do think that nuclear fission will be the main form of energy production in the world when the fossil fuels go bye-bye. I think properly maintained nuclear fission reactors which are being developed i.e. inherently safe reactors will be the way to go.

An example of this is what is known as the pebble bed reactor which is in germany i think. IIRC it has a negative coefficient of reactivity or something, which means that the reaction cannot run away with itself but just fizzles out. Also online refueling in the form of fuel pellets is possible and the spent fuel pellets are extracted from the bottom. It operates at thermal efficiency of approximately 50% (guess what i was studying today).

Anywho i think these type of reactors could be the future of nuclear power.

Just to put things into perspective if the nuclear fission program was shut down today experts say that apparently it would take 10-15 years to get it back up and running again.

Also a typical pressurised water reactor that is operated produces about 1000MW of electricaly energy a day i think, this is enough to power our national grid and also to produce the same amount of power in an oil power plant operating at a typical efficiency of 40% would required 2000 tonnes of oil to be burned IIRC.

Also as as another comparision a to replace a typical power plant like the one mentioned would require IIRC 50-80 km^2 of wind power or 100-150 km^2 of solar cells or 3000-5000 km^2 of biomass. France has four of these reactors in close proximity over a couple of acres.

Anywho thats my info. i think most of it is more or less correct but the figures might need some checking.

Oh by the way i'm pro well-managed nuclear power.

Trebor

I would agree that nuclear fusion is the future to energy as it is a non or low radioactuve poluting energy supply but it is a few decades away before it is affordable and until then we must invest in renewable sources to offset the continuing depleation of the fossil feuls.

nuclear fission i belive must be stopped as if it is not an option more time and resources will be devoted to making fusion work.
if they have fission why would they spend money researching fusion? unless there are strict penalties for polution then an alternative will never be found as it will not be looked for.

Wolf

Clearly if you look into it at any deapth Cold Fusion is the only viable future of mass energy for the the world. Indeed it is not a question of if we can tap this but when and if you believe in "THEM" it might even be a question of its tapped but been held from us due to oil and coal prices and the effect on the world ecomeny if they were to become redundant tomorrow.

Typedef

Originally posted by Dataisgod
I think that poll needs to be modified as not all atomic energy is so deadly if nuclear fusion is achieved the by products will not be radioactive and hence not harmful.

http://www.lbl.gov/abc/wallchart/chapters/14/2.html

Although these types of reactors would not have the fission product waste disposal problem of fission reactors, fusion reactors generate large number of fast neutrons, leading to large quantities of radioactive byproducts.

Ahem.

I'm no physics student (and there is a science forum for debating science) but, according to the above passage Nuclear Fusion, as opposed to Fission, also produces 'fast neutrons' and consequently 'radioactive byproduct'.

Wolf

Fusion does produce radioactive material but to my understanding its easier to control and the by products arent are radioactive as Fussion and most importantly have no where near the same kind of Half-Life.

edited cus I cant controll my s's

Trebor

saw a documentary about nuclear fusion which said that all byproducts can be dealt with, as oppsed to sitting for thousands of years waiting to decompose.
can't remember how they dealt with them.

Typedef

Hmm.

I don't really think the 'potential' for fusion to work 'maybe' if humans ever make a reactor that outputs significantly more energy then is input is the issue.

What I'm getting at is that Chernobyl has already been a catastrophe in that 30,000 people have died as a direct result and 25% of all babies born in Belarus have thyroid abnormalities (according to the Marian Finucane show 27/04/03), action needs to be taken immediately to stop 10 tons of radioactive dust being violently vented into the atmosphere not to mention a renewale of exposure of the molten fuel to the atmosphere ameliorating the radioactive dust cloud and it's contamination.

More to the point fission reactors are dirty, cause cancer spots even in the so called 'safe' Western style Nuclear energy paradigm and are extremely costly.

Woden

Many fission reactors such as the pressurised water reactor are commerically viable so that isn't necessarily an issue, with regards to chernobyl thats wasn't our fault nor is it our responsiblity but the responsibility of the ukrainian government

anywho there are inherent design flaws in the type of reactor used in chernobyl

"Unfortunately, there are large flaws in the design of an RBMK reactor:

The graphite, while being more efficient for weapons making and a fairly effective moderator, does not take to the extreme temperatures very well. Graphite, which is carbon based, will burn in the core if it is exposed to air. If the graphite burns, the neutrons will hit at a greater velocity, causing more heat to be produced. Great care must be taken to keep air away from the core.

There was no containment vessel at the Chernobyl plant. In all U.S. nuclear power plants, there is a mandatory cement and steel reinforced containment "bubble" covering the core and other components. Chernobyl had a pressure seal designed to keep the pressure in, but nothing in case of an explosion. "

With regards to the fusion i was mistaken and while yes radioactive isotopes are produced due to the fast neutrons released as perhaps mentioned the isotopes have short half lifes and quickly decay to background levels.

mike65

Fision is the only game in town for the forseeable future
but fusion would be the great breakthrough for our long-term wealth. Until we get fusion esp at room temperture then we'll just have to learn how to run our world on fewer watts consumed. A few cheaper technologies need proper attention like all the old favourites (wind, water, solar, thermal etc) while cracking affordable "ambient" superconductivity would also be a boon. I dont have a figure but I belive something like 40% of power produced gets "lost" en route to your house. Think of the ppwer saving there.

Mike.

chernobyl

chernobyl happened for many reasons but mostly from stoopidity. I am absolutely positive that there have been many close calls around the world in these stations but im sure that safety is an absolute at these stations too as they are watched so closely.

Nuclear Fission is the only viable option at the moment but it has not proven economically sound either (at least in sellafields case) but i doubt that all countries using this power source are absorbing these losses.

Fusion is a pipe dream for the moment and i dounbt i will see it in my time.

Alternative power sources such as wind power are not effective for widescale use, you would end up with incredible visual and audio noise pollution to replace one with the other.

I used to worry a little about the "what if's" off Sellafield going to the worst but no i couldnt give a ****, if it does happen ....

Gaffo

with regards to chernobyl thats wasn't our fault nor is it our responsiblity but the responsibility of the ukrainian government

It wasn't our fault no, but we still have a responsibility as humans to help with it. Just cos it isn't on our front door and we don't directly see the effects doesn't mean we can dismiss it like that. What if Great Britain's nuclear plants were quite ineptly run and one exploded. I think the answer would be different then.

Woden

Originally posted by Gaffo
What if Great Britain's nuclear plants were quite ineptly run and one exploded. I think the answer would be different then.

I think some of them are ref. Sellafield and stuff has been done but to no avail but if i don't care about Sellafield i'm hardly gonna care about a plant in eastern europe?

seamus

As far as I can see, Nuclear Fission is only a stopgap solution. Demand for power around the world has grown much faster than conventional (i.e. non-nuclear) power production methods can produce it.

IMO, we need nuclear reactors for the moment, but there should definitely be some sort of UN committee in place which vets the need for each and every new reactor that's built. I.e., is it really needed, or is it some country just using a way to produce relatively cheap energy, without properly researching what alternatives are available?

The world can only sustain a very limited amount of nuclear reactors. Developing countries are going to be especially eager to begin installing reactors (if they haven't already) in the future, and it could do some serious damage.

IMO, the idea of breeder reactors hasn't been given enough research. Breeder reactors generate their own fuel as they work (in fact they generate more fuel than they use), and produce relatively less waste than standard fission reactors. Serious research has been all but abandoned since the first few failed attempts back in the 60's/70's, but if a young man with nothing more than a passion for physics , and a job in McDonalds, can build one in his own back yard, than enough research hasn't been pumped into the idea.

Woden

the problem with breeder reactors is that when people start using them other people think they are breeding plutonium for nuclear weapons, apparently it only takes about 6months to a year to breed enough plutonium for a weapon current breeder reactors (which i presume is what you are getting at) don't produce anywhere near the power of a "normal" fission reactor. Hence the current problem in north korea, they say they have a power shortage which everyone agrees with so they open up a nuclear reactor however its a breeder reactor not a "normal" fission reactor well you can draw your own conclusions

With regards to fission reactors do i don't think breeders are a particular requirement as the problem with nuclear reactors at the moment is not one of fuel availability, the difference is the waste generated is another matter which i don't know anything about.