Should we be wary of nuclear power?

[blackhole123]

A friend I was debating claims that nuclear power is THE answer, and that other countries (not US), use a lot more than us.

 

He then claimed that Canada stores ALL it's nuclear waste in one place the size of a football field. I find this VERY hard to believe. Is he wrong about this?

 

Why are most people opposed to nuclear power (including my science professors), is it the waste or the risk of a meltdown?

[insane_alien]

well, the amount of waste IS very small. but it would probably need to be a larger storage facility than a football field. but it is likely that they transport the waste to a single place.

 

the biggest reason to be wary is the waste. meltdowns are nigh on impossible these days and only 2(out of 8) released a significant amount of radiation. one was the windscale fire(biggest consequence of the radiation was a lot of milk was thrown out) and the other was chernobyl.

 

in the first it was caused by inexperience(the US wouldn't share info on the manhattan project despite britain playing a major role in it).

 

and in the second it was caused by a combination of sheer dumbassery and poor reactor design, the safety mechanisms(which stpped the meltdown several times before some smart ass decided to order disabled so he could perform tests that were causing them to trip) were disable and the reactor house had insufficient containment.

 

if a modern reactor underwent meltdown(despite the multi-redundant safety mechanisms to stop such an occurence) the worst that happens is that it is no longer possible to use that reactor and you have a very expensive clean up on your hands.

 

but, most people are afraid of nuclear power because they immediately think NUKES! CHERNOBYL! RADIATION! MUTANT FISH OFF THE SIMPSONS!

 

a little bit of education would go a long way here.

 

but it is true that fission is a messy solution, but on the other hand it is looking like it will be a necessary solution with oil and gas getting more sparse, greenhouse gasses and insufficient progress in renewable source.

 

ideally we'd want to get some fusion up and running since it eliminates a lot of the problems with fisson and fuel is more abundant

[ydoaPs]

if a modern reactor underwent meltdown(despite the multi-redundant safety mechanisms to stop such an occurence) the worst that happens is that it is no longer possible to use that reactor and you have a very expensive clean up on your hands.

If a modern reactor had a meltdown, it would shut itself off(they tend to have negative temperature co-efficient of reactivity for inherent stability). The real danger in the meltdown would be twofold:

1)release of fuel and fission products into the moderator/coolant(which really just means a REALLY BIG cleanup and more waste[even though fuel and fission products are hardly radioactive since they have half-lives of billions of years])

2)Steam explosion.

 

Now, 2 combined with one would be pretty bad(that's what happened at Chernobyl. They had a positive void co-efficient, so when the reactor got hotter, it's power went up making it hotter, etc. The relief valves, IA's mention of "dumbassery" were made inoperable for testing that shouldn't have been done on the operating reactor, didn't lift. That means steam pressure kept rising until the pressure vessel failed and launched the closure head through the ceiling of the building. There WAS a meltdown, so the steam took fuel and fission products with it. That's why there's low level radiation due to contamination in the area.

 

Now, modern reactors use a pressurized water design(at least all of the ones I've worked on). This lets us design the geometry of the core such that we have a negative reactivity addition due to temperature(when temperature goes up, power goes down and vice versa). And there are several redundant safety features with minimal requirements for operation. There are also VERY strict operational procedures(even if you've done something hundreds of times, you have to read out the steps out of the book while you're doing it). It's virtually impossible to have a meltdown.

[zombie]

If a modern reactor had a meltdown, it would shut itself off(they tend to have negative temperature co-efficient of reactivity for inherent stability). The real danger in the meltdown would be twofold:

1)release of fuel and fission products into the moderator/coolant(which really just means a REALLY BIG cleanup and more waste[even though fuel and fission products are hardly radioactive since they have half-lives of billions of years])

2)Steam explosion.

 

Now, 2 combined with one would be pretty bad(that's what happened at Chernobyl. They had a positive void co-efficient, so when the reactor got hotter, it's power went up making it hotter, etc. The relief valves, IA's mention of "dumbassery" were made inoperable for testing that shouldn't have been done on the operating reactor, didn't lift. That means steam pressure kept rising until the pressure vessel failed and launched the closure head through the ceiling of the building. There WAS a meltdown, so the steam took fuel and fission products with it. That's why there's low level radiation due to contamination in the area.

 

Now, modern reactors use a pressurized water design(at least all of the ones I've worked on). This lets us design the geometry of the core such that we have a negative reactivity addition due to temperature(when temperature goes up, power goes down and vice versa). And there are several redundant safety features with minimal requirements for operation. There are also VERY strict operational procedures(even if you've done something hundreds of times, you have to read out the steps out of the book while you're doing it). It's virtually impossible to have a meltdown.

 

I thought the idiot hippies that opposed nuclear power got a law passed that prevents the creation of new nuclear power plants, and the updating of old ones? Pretty sure I saw a documentary on it.

[Moontanman]

Trying to stop nuclear energy by touting problems with the reactors now online is a whole lot like trying to stop air travel based on the study of 1920's aircraft. Modern reactor designs are as far removed from what should be running as modern jet liners are from bi planes. Having said that I have to say "yes we should be wary of nuclear power" misused it can indeed be dangerous but we tend to over look coal fired power plants that release huge amounts of non radioactive heavy metals they also release huge amounts of radioactive material, One coal fired power plant releases far more radio isotopes than a comparable Nuclear power plant.

 

http://en.wikipedia.org/wiki/Fossil_fuel_power_plant

 

As most ores in the Earth's crust, coal also contains low levels of uranium, thorium, and other naturally-occurring radioactive isotopes whose release into the environment leads to radioactive contamination. While these substances are present as very small trace impurities, enough coal is burned that significant amounts of these substances are released. A 1,000 MW coal-burning power plant could release as much as 5.2 tons/year of uranium (containing 74 pounds (34 kg) of uranium-235) and 12.8 tons/year of thorium. The radioactive emission from this coal power plant is 100 times greater than a comparable nuclear power plant with the same electrical output; including processing output, the coal power plant's radiation output is over 3 times greater.[17]

 

http://www.scientificamerican.com/article.cfm?id=coal-ash-is-more-radioactive-than-nuclear-waste

 

Over the past few decades, however, a series of studies has called these stereotypes into question. Among the surprising conclusions: the waste produced by coal plants is actually more radioactive than that generated by their nuclear counterparts. In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.

Edited September 19, 2009 by Moontanman

[Humphrey Paulu]

How are nuclear power plants and nuclear bombs related?

[Moontanman]

How are nuclear power plants and nuclear bombs related?

 

They both use energy released from the nucleus of the atom. Often they they use the same radioactive elements to make power. Nuclear power plants can use thorium and other isotopes of elements that nuclear weapons cannot but they essentially make power the same way, from the splitting of atoms.