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There is no question that nuclear plants can be cost effective, as even though the process of acquiring/enriching fuels is expensive, only a fraction of the amount of fuel is required compared to use of fossil fuels. Additionally, while nuclear plants cost millions upon millions of dollars to build, a comparable fossil fuel burning plant costs almost as much.

Finally, a 40 year window of nuclear plant operation is also comparable to what you get from a fossil fuel using plant. After 40 years the efficiency at which these plants operate starts to become a cost impediment, meaning they have to be renovated or replaced.

 

In comparison to coal plants, you are right. The investment costs are roughly equal. But modern gas plants are much cheaper.
The time for big plants is over. The future lies in smaller, more flexible plants.

The problem is not the costly building process only, but all of my points above together. The britisch government tried to privatise the british nuclear plants two times. Both times it didn't work, because no investor wanted to bury his money. Nuclear energy is only cost effective when it is subsidied.

You got something wrong there. Reactor casings have a lifetime of about 40 to 60 years.

But there are a lot of sensitive systems in a nuclear plant which have a lifetime of only 25 years. 30 at a maximum. Heat sinks for instance. These things are that expensive that it is cheaper to shut the plant down than to exchange them. That's what I meant with maintenance nightmare. And you have to take the special security requirements in count.

If there are plants where the expensive sytems are exchanged, then the next question that you should ask is: Where did they get the money?

 

Where do you put all the nuclear waste?

 

It's been a long time since I worked in the industry and I haven't kept up, but here goes. Unfortunately, I have little reason to expect that this assessment has changed much since the early 90's, except to get even closer to the "full up" mark.

A long-term solution to the issue of nuclear waste storage has yet to be arranged, for reasons that are far more political than scientific. Currently at US plants, the spent fuel bundles are kept first in large storage pools in the reactor building, and then transported into dry cask storage elsewhere on the site. IIRC France does reprocess their fuel to extract the useful uranium for re-use in new bundles; I don't know how they store the waste from that industry.

@Fabius Maximus: 1) Reactor vessels have a DESIGN lifetime of 40 years. Tests have been/are being run that show the many, many conservatisms built into those design calculations can be racheted down to keep the reactor in useful ife even longer. 2) Yes, disposal of the old, contaminated components is factored into the cost-benefit analysis of secondary-side equipment upgrades, and keeping the existing plant running is STILL coming out ahead of building a new plant. 3) In the US, the nuclear power industry already is privatized, so your argument that privatization doesn't work is actually what doesn't work.

 

Well, it's good to hear from somebody who know what she's talking about

Anyhow, if I remember correctly, there is not really that much nuclear waste to take care of. The whole ammount for US is about 50,000 tons, which seems a lot, but if you put it together

(from the Yucca mountain site). It's kind of hard to think that one cannot find a space of the order of a football field somewhere to store this waste (of course, you'd need more than that, because in reality you don't pack it together, but anyhow).

Moreover, if you reprocess the waste, you can pick out the more active components (those with a short life time, and therefore the most dangerous), and use them as fuels again. I think US does not want to advocate reprocessing, though, due to issues related to nuclear arms control (I think a result of reprocessing is plutonium, which can be used for bombs).

Finally, I remember reading that burning coal releases more radioactivity in the air than a nuclear plant, for the same energy output.

 

Rally, subsidies for nuclear power in the US are still an issue. Limited insurances and state investions for R&D are widespread, and Pres. Bush has announced about 550 Mio. dollars for new plants. According to this site, the amount of subsidies spent for nuclear energy in the US amount to ca. 145 billion dollars in the last 50 years.
Privatization does not prevent getting money from the state.

As for the lifetime: As I said, the vessels (casing may be the wrong term) have long lifetimes. Other systems do not.

 

I still don't think that we'll ever have energy as cheap and easy as petrol has been. I still think that some reduction in energy use will be forced upon the world sometime this century, to complement the increased use of alternative sources.

I still come back to the fundamental physical principles that you can't create energy out of nowhere. With petrol, we have been releasing the potential energy that has been stored over billions of years.

 

What are you thinking of, FM, as far as the design lifetimes of equipment? You realize, of course, that the secondary side if a nuclear plant is identical to that of a fossil plant (except perhaps in scale), so you can't be talking about that since those lifetimes and associated maintenance costs are a wash (seeing as how the secondary side of a PWR is completely isolated from the nuclear contamination of the primary side - but you must have known that already, too).

Paying for research into new technologies and safety improvements is also a wash, IMO, since it's done for every area of the sciences (OK, every area other than stem cell research). If you can show me that an inordinate amount of money is being spent on nuclear research, and that money - other than the Price-Anderson liability cap, which is merely promised but has yet to be spent for any utility other than GPU Nuclear - has actually been spent to subsidize the ongoing daily operations of private nuclear plnats, then your objection will hold water.

 

Classic stuff, Taluntain. Can you spell "Lip Service"?

 

On the topic of subsidies: you realize that any energy industry (oil, gas, coal) gets government money (either directly, or as tax breaks). IIRC, the amount that the oil companies got in tax breaks for the past year was of the order of several billions. It's not only the nuclear power industry who benefits from government handouts.

Related to this: blaming the oil companies for the high gas prices is disingenuos at best; that's a direct consequence of Bush's foreign adventures (you canot really call them policies). However, it's still true that they made money hand over fist over the past years; so the tax breaks they got probably are not really needed.

 

I am not sure what you are talking about. Do you care to elaborate?

I am not that familiar with the US structure of nuclear energy policy and politics, but 145 billion dollars just for research and design seem to be a whole lot of money.
It is still a lot if you count in the incomplete insurancy covering. And for the search of a final storing place.

All this takes away a lot of responsibility and investment need from energy supply companies.

I know. This is a phenomenon you can find around the globe. And it is quite strange. Established industry sectors should be able to compete on the market without direct or indirect subsidies. At least, that's what the liberal economic school of thought says.

So, stop paying the freaking power suppliers for using out of date technologies and start paying for new and not yet fully developed technologies like the renewables. That's where spending money makes sense, until they are able to compete.

And even then: Don't spend more money on developing technologies than it makes sense. I don't know if you know about the FutureGen plants. I read about them a few years ago. The technology is coal-based, and quite advanced so, complete with CO2-segregation.

The joke about it were the cost division for the development. The US federal government took over 80%, the companies the rest. That's ridiculous. It means essentially that the companies were not convinend that this kind of technology had a future.

 

[NucE 101]

Most electricity-generation facilities use steam to turn a trubine which in tunr moves a magnet through a coil, producing electricity that goes out over the wires. What makes a power plant nuclear is that it uses fissionable material as fuel for generating the heat that produces the steam, as opposed to the combustion of fossil fuel. The "primary" side of any plant is the steam-generation side, while the "secondary" side is the equipment that makes use of that steam.

Most US (and French, at least in my day) nuclear reactors are PWRs, or pressurized water reactors. This is a closed system where a heat exchanger is used to produce clean steam that powers the turbine; it's called "pressurized" because the water inside the reactor vessel is kept from boiling by pressures around 2200 psi. The steam that gets to the turbine has never been in contact with the nuclear fuel and therefore is clean.

Alternatively, a BWR or boiling water reactor generates its steam right inside the core. While this means that the turbine blades do come in contact with "dirty" steam and eventually must be considered as nuclear waste. It's low-level stuff, but it's a large volume of it.

There are other types of reactors, such as the heavy-water reactors used in Canada, but I'm much less familiar with that technology and hesitate to propound, lest I lead anyone astray.

[/NucE 101]

Should anyone be interested, I'll go into the difference between radioactive material and contamination tomorrow. That's the largest concern when it comes to disposing you nuclear waste. Right now, bed calls.

 

Rally, I took the heat sinks, not the heat exchanger, as an example for a expensive system that drives maintenance costs high. I gather that nuclear plants need a special kind of heat sink, because they get hotter than the average coal plant.

And I did not mean the pollution, but the cost to exchange these things.

 

@FM: That supposition is incorrect.

 

@ Rally - Here's one thing that I never had explained to me adequately, and you may be able to help. How much nuclear fuel is used in a typical nuclear reactor, and who long does that material last before it needs to be replaced?

 

Although this is off topic:

FM,

The federal government in the US took the majority of the development cost of nuclear power for a few very sound reasons:

1. The top scientist in nuclear fission were on the US government payroll.
2. Nuclear power was considered classified (i.e., a government protected secret). The government was not going to allow just any company to get involved.
3. The biggest push for nuclear power was coming from the US military. The vast majority of earlier funding was Army and Navy -- the Army opted out after SL-1. But the Navy had more nuclear reactors than anyone else in the world for many years (and those reactors are still considered classified).
4. With such a high risk to public safety, it became appearant the individual companies could not possibly foot the bill for both research and safety development. The safety factors in the development of nuclear power were unprecedented in US (or world) history.

Aldeth, the amount used depends on the reactor. The Navy reactors use 'highly enriched' uranium -- allowing for the reactors to weigh less (they consequently use much less uranium by weight). The Navy reactors typically last 15-20 years on one set of fuel cells, but they have a lot of down time (the ship is not underway all the time). Commercial reactors are much, much larger and operate at full power almost all the time. They typically have a three to five year refueling cycle and each refueling can take a few hundred thousand pounds of uranium. The uranium used by commercial plants may or may not be enriched (but never 'highly enriched'), this means the fuel is only 0.7% to 3% uranium 235.

 

T2's got it pretty well right, altho' when I left the industry refueling cycles were commonly two years. It wouldn't surprise me to learn that they've been stretched out that far. As far as "severl hundred thousand pounds"... *shrug* I'm used to thinking of things in different terms, and I don't have time to calculate the equivalence right now, so I'll take his word for it.

You need to know that designing a reactor core is a very, very tricky thing. The reaction is nothing like coal, where the fuel is consumed in the process, but a situation where the fuel is changed. Some of those changes help the fission reaction to keep going, and some try to stop it. The designers have models that show what's going on in every centimeter of every fuel rod in the core, at any point in the cycle.

When it's time to refuel, you don't take out the old core and put in a fresh one. The uranium in some bundles has been sufficiently depleted that they can no longer contribute usefully, and they'll be replaced. Other bundles will be moved to new locations within the core to optimize the power distribution over the fuel cycle.

 

Bruno: I suppose it makes sense. But only so far as other countries spend equally high sums of money on nuclear energy, but not only for R&D.

In Germany, before the decision to cease using nuclear plants, the tax payer paid for security (the insurance threshold lies at 250 Mio. Euro per plant, which is a joke), the search for an final storing site, and lost about 30 billion euros through indirect subsidies until 2000, because of the reserves system. The energy suppliers have to accumulate a certian amount of money for expected waste removal. This money was a tax free capital investment. The resulting interest was used by the companies to cement their market position. Even in other branches of industry.

And this for a maximum of 19 nuclear plants.


@Rally: If my assumption is wrong, than why are so many nuclear plants switched off after about 25 or 30 years? There has to be a reason.

Maybe you know the costs of the main contents of a cooling system?