Fission FAQ v 1.5

[J_S_Bokchoy]

So choosing a midpoint of 200 kwhr per SWU times 209000 @ 7 cents/kwhr would cost about 8 million for a third of a year's fuel. If the choice is between making fuel out of natural U or re-enrichment of stored tails, let the breakeven price equal B and solve for B as follows: $24 million = 10 (natural to fuel ratio) X 30 (tons a year) X 2000 lbs per ton X B, so B= $40 a pound. That's where it's at now, so I guess they might as well just leave their ore in the ground for 8 years until the million or so tons of tails worldwide get used up! At least it seems like that could inhibit the price from going much higher. But then if the value chosen for kwhr per SWU is 300, then B goes to $60. What other constraints could hold prices down, besides another TMI?

[J_S_Bokchoy]

AND please disregard preceeding inquiry, I forgot to include power expense on the right hand side. After that my hypothetical breakeven point was only $20 so the question must be pointless if the price is double that already. Maybe hedge fund speculation, panic inventory building or even the limited enrichment capacity now in operation washes out mere cost accounting.

[Tanada]

AND please disregard preceeding inquiry, I forgot to include power expense on the right hand side. After that my hypothetical breakeven point was only $20 so the question must be pointless if the price is double that already. Maybe hedge fund speculation, panic inventory building or even the limited enrichment capacity now in operation washes out mere cost accounting.

You are forgetting a couple key ingredients in the whole deal, so to speak. One factor is time and inertia, most Uranium is bought on long term contracts with the mines, not on the spot market because none of the power companies is going to risk sitting around with an expensive to build power plant and no fuel on hand. As those long term contracts expire new contracts are written based on more current market conditions, this raises the contract price more slowly than the spot market price, but the rise is less subject to short term uncertainty. As the long term price goes up the producers are incentivized to invest in greater production which will most likely exceed short term demand and drive the price back down.

For going on 15 years now the price of Uranium has been very depressed because back in the 1970's a lot of power companies signed very long term contracts or stockpiled large quantities of natural Uranium and stored it when prices were lower. Then on top of those factors the demand side was less than projected because TMI sensationalism badly hurt the nuclear industry in the USA and new plant construction ground to a halt. This left a few large companies with stockpiles for plants that were no longer being built and many companies with stockpiles for several plants but only one plant completed. If you buy a contract to fuel a set of 3 plants for 10 years and then end up with only 1 plant you have a potential 30 year fuel stock for that plant. Then add in the fact that the USA and USSR/Russia arms reduction treaties added even more Uranium to the market, so much that the price crashed and the treaty had to be renegotiated to reassure producers that well under half of any years supply would be reclaimed weapon material. On top of all that France aggressivley pursued reprocessing and MOX use that even further reduces demand for fresh Uranium.

Of course once the price crashed a new balance on the enrichment side was reached, especially in the USA where everything was still done with cold war designed gasseous diffusion plants and SWU is expensive. To save money cheap natural Uranium was only depleted to .3% instead of .15%, which leaves a bit more depleted Uranium but saves big bucks on enrichment costs, it cost about twice as much to deplete the tails to .15%. Halving the tails assay changes about 4% of the total feed from Tails into Fuel, how much does the feed have to cost and how cheap does your SWU have to be to make doing that a good idea economically? It is my understanding that in France they even reduced tails depletion to .35% or for a time .4%, but I don't have any documentation to confirm or deny that this happenned.

[cube]

a layman's question on fast breeders.

Everywhere where I read about those breeders there are arguments being made that the reactors are unprofitable, unreliable and things.

I think (anybody who disagrees feel free to step in) MOST breeder reactors were not built with the primary intention of supplying energy.

Since breeders can "produce" Plutonium it has definite military applications. Modern nuclear bombs are fusion and not fission bombs. Therefore they do not recieve their power from plutonium per say. Instead the PU is used to create a fission reaction which produces massive amounts of heat. The heat "triggers" the fusion reaction. Basically every fusion bomb is actually 2 bombs in one. A fission reaction is necessary to create a fusion reaction.

Because of its significant military applications I would assume all breeder reactors must be government owned. That would explain their unprofitable history.

[Tanada]

a layman's question on fast breeders.

Everywhere where I read about those breeders there are arguments being made that the reactors are unprofitable, unreliable and things.

I think (anybody who disagrees feel free to step in) MOST breeder reactors were not built with the primary intention of supplying energy.

Since breeders can "produce" Plutonium it has definite military applications. Modern nuclear bombs are fusion and not fission bombs. Therefore they do not recieve their power from plutonium per say. Instead the PU is used to create a fission reaction which produces massive amounts of heat. The heat "triggers" the fusion reaction. Basically every fusion bomb is actually 2 bombs in one. A fission reaction is necessary to create a fusion reaction.

Because of its significant military applications I would assume all breeder reactors must be government owned. That would explain their unprofitable history.

I guess it is better to be half right than all wrong

The problem starts with the premesis, a breeder reactor has one primary design goal, which is to produce more fuel than it consumes. They were not designed primarily ofr energy production, but rather for fissile fuel production. So long as Uranium remains cheap and abundant they are rather like the F-T Coal-to-liquid process, yes they work and yes they produce a usable fuel, but the natural abundant fuel is cheaper and easier to handle so why go to the extra expense and difficulty?

Commercial breeder reactors are all designed to produce elecricity to help offset the expense of running them, do a web search on Fermi I at Lagoona Point in Monroe, MI. It was the first commercial breeder and provided a lot of lessons to the electric utilities on just what was needed to make a commercial breeder work. It was not an economic success, but it was a technical success, the reactor produced more fuel than it consumed along with some electric power which was sold over the grid. In order to be a commercial success a breeder has to either be so efficient that it overcomes the cost difference in fuel manufacturing and reprocessing. In the past with aqueous 'chop-leach' reprocessing that was a very high hurdle, the new pyrometalurgical process however is vastly cheaper and produces a lot less secondary waste and may provide an economic incentive to build commercial breeders.

Weapons material reactors are hugely different from commercial breeders, they require frequent or constant refueling to keep the bred material from degrading in quality, and frequent reprocessing to recover the bred material. For the military with their bottomless budgets for nuclear weapons this was not a handicap, but for the electric utilities it is the road to financial ruin.

[DoctorDoom]

A few informative links regarding nuclear power:

http://www.uic.com.au

Tons of information, including facts debunking the outrageous claims of low EROEI and negligible GHG benefits, graphs showing how the most radioactive materials decay very rapidly (in decades), while the waste that remains "for 1000s of years" is not nearly as radioactive and indeed can be rendered into a form less radioactive than the original ore.

http://www.pbs.org/wgbh/pages/frontline/shows/reaction

Most interesting was the description of the French experience. I especially liked the part about how the waste of producing 20 years of electricity for a family of 4 is a glass cylinder the size of a cigarette lighter. The FAQs are also interesting. Confirms that we really need to breed plutonium for the nuclear option to make sense long-term. Also debunks the assertion that plutonium is the most toxic substance on earth.

[DoctorDoom]

UIC - that's like asking GM if an SUV is the right vehicle for you
Gentle hint - it's aka propaganda.

The PBS one has more interesting links. Thanks.

I'll take facts from any source. I'll take 'em from UIC or Greenpeace in equal measure. Everyone has biases.

UIC's site has a lot of factual information. Obviously any source may present only facts supporting it's position while omitting ones that do not, but, well, facts are facts. You just have to separate them from opinions. I always consider the source when reading anything. The only page I've found on UIC (so far) that is questionable is the one dealing with fuel availability. There is a mix of facts (like proven resources of 3.1 million tonnes, the value of reprocessing, expanding fuel by 60x with breeders) and unsupported assertions (reserves could be doubled if exploration was resumed, we could get Uranium from seawater at $1000/kg). Even there, at least they don't pretend there isn't a possible fuel issue. I contrast this with most anti-nuclear writings that contain lots of rhetoric and little useful information.

[Joe0Bloggs]

So, breeders convert more fertile material into fuel than the fuel it consumes, but the reprocessing is expensive. Why is it that the fuel has to be taken out for reprocessing at all? Why can't the newly produced fuel be used directly?

Is it possible to design a reactor where fuel rods only have to be put in and taken out once--where the reactor continuously produces fuel from the fertile material and uses it up, until all the fertile material has been converted and all the fuel used up--and the spent fuel rod would be worthless and can be taken directly to disposal without reprocessing?

[Tanada]

So, breeders convert more fertile material into fuel than the fuel it consumes, but the reprocessing is expensive. Why is it that the fuel has to be taken out for reprocessing at all?

Mainly two reasons. Firstly at the enrichment concentrations allowed for civilian fuel the rods accumulate enough fission fragment waste over time that the breeding ratio falls below 1:1 and technically at that point they are high burn up converters, not breeders. Secondly if you use the fuel systems as currently used they can only maintain their physical integrity for a few years, as the Uranium/Plutonium/Actinides fission the fragments continue to build up. These chemicals are less dense than the heavy metals they derive from and hence require more space for the same weight of material. Once you have reached a certain pressure the fuel rods start to streatch, warp, or even crack open from internal pressure and gasseous or volitile fission fragments then escape into the primary coolant.

Why can't the newly produced fuel be used directly?

Well actually quite a bit of it is used directly, however when the fission fragments accumulate they are like ashes on a fire, they tend to smother out the reaction by absorbing neutrons.

Is it possible to design a reactor where fuel rods only have to be put in and taken out once--where the reactor continuously produces fuel from the fertile material and uses it up, until all the fertile material has been converted and all the fuel used up--and the spent fuel rod would be worthless and can be taken directly to disposal without reprocessing?

The short answer is no, provisionally. Instead of using solid fuel rods you can use molten salt as a fuel carrier and constantly seperate out the fission fragments while the reactor keeps running 24/7 except for maintenence periods. A Molton Salt reactor consumes actinide metals and produces heat and fission fragments and is so efficient in its neutron economy it can operate as a breeder with Thorium/Uranium/Plutonium/Actinide in a constantly adjusted ballance. If reactivity starts to fall the operators can just add fuel directly to the fuel flow channels brininging the reactivity back up. If you want more details simply google MSBR and MOSEL (Molten Salt Breeder Reactor and Molten Salt Epithermal Reactor).

[Tanada]

Magical Thinking About Nuclear Waste

By ROBERT ALVAREZ

As a senior energy adviser in the Clinton administration, I recall attending a briefing by the National Academy of Sciences in 1996 on the feasibility of recycling nuclear fuel. I'd been intrigued by the idea because of its promise to reduce the amount of waste that had to be buried, where it could conceivably seep into drinking water at some point in its multimillion-year-long half-lives.

But then came the Academy's unequivocal conclusion: the idea was supremely impractical. It would cost up to $500 billion in 1996 dollars and take 150 years to accomplish the transmutation of dangerous long-lived radioactive toxins.

...

We are better off by investing in renewable energy and conservation, rather than pouring billions of dollars into the same old limitless energy schemes of our nuclear laboratories.

What does a pollitically motivated anti nuclear rant have to do with reallity? Very little, it gives no facts that can be checked, no figures that can be tested. Just generalities and speculation.

I have respect for http://www.wise-uranium.org/ and related websites because they give you their assumptions and let you test them. I don't agree with some of their conclusions, but I beleive they are sincere.

The pollitical hack you cited above, not so much.

[EnergyUnlimited]

Physical laws do not bend to pollitics, that is what PO is all about. If you don't understand that I feel very sorry for you.

Sure they do.

Say there is a "physical law" that says if you do the calculations right there is enough energy in the uranium of the earths crust and oceans to supply 9billion people with double the energy the USA consumes today for the next 20,000 years.

BUT if the politics don't allow the construction of nuclear facilities then that "physical rule or law" will never be realized.

It will remain hypothetical, which is exactly what much of the discussion on nuclear energy is about. How it can hypothetically solve our energy conundrum.

At some point, when energetic disaster became obvious all NIMBY considerations will go to bin basket and hundreds of nuke plants will be build in haste and according to shabby standards.

Physical laws are likely to put limits on that in another fashion.
Rates of production of fuel, enrichment of it and rates of dealing with waste or rates of production of some critical materials for reactor construction, production of critical spares etc will not allow to run more then so or so reactors concurrently worldwide.
And the maximum number of concurrently operating reactors may be dissapointingly low at "saturation point".

Or say that a country like ummm... France decides to heavily subsidize their nuclear electrical generation capacity (political)...

It is really useless to claim that subsidies are making nukes not attractive.
Once electricity price go up (inevitable), you will no longer need those.

[EnergyUnlimited]

It is really useless to claim that subsidies are making nukes not attractive.
Once electricity price go up (inevitable), you will no longer need those.

Except it looks like Solar will have it all over nuclear price wise.

Solar does not work overnight and wind blow at random.
I agree, that you may get solar or wind cheaper than nuclear, but such energy will not always be available.
Nuclear is about the only serious energy source other than FF and hydro, capable to provide baseload supply.

NB. I have great doubts about storing solar heat in form of molten salts, nitrates alike. We could easily run into white elephant project here...lakes of molten nitrates...
No serious installation using it is working now.

And what, if cloudy day follows frosty night?
What about polar regions, or even non-tropical/subtropical regions?

[EnergyUnlimited]

Nuclear Future?

Dream on nuke advocates...

He told his audience that fuel is four to five times the ‘hyped’ cost of nuclear power – between 20 and 25 percent instead of the mere five percent.


Dr. Kim shot down the premature conclusion that utilities would rather pay the high prices instead of going through a costly decommissioning process. He said, “There is no compulsion to immediately decommission – stations can be held in standby or cold shutdown.”

Finally, he took up the matter of ‘utilities not caring about fuel costs.’ He pointed out, “Take $900 million from your company’s annual net profits. See how happy your management is.”

Read this and weep nuke saviours

If there is any long term future of nuclear, it will either be based on thorium cycle or FBR.

Thorium cycle is better bet, as it was demonstrated to work in civilian set up and certain type of reactor already in use can work with it. On the other hand civilian FBR are failures up to date.
There is also 200 times more thorium around, than U235.

[DaveMart]

Is it possible to design a reactor where fuel rods only have to be put in and taken out once--where the reactor continuously produces fuel from the fertile material and uses it up, until all the fertile material has been converted and all the fuel used up--and the spent fuel rod would be worthless and can be taken directly to disposal without reprocessing?

They don't use up all of the potential energy in the fuel, but pebble bed reactors do operate continuously as the pebbles cycle down to the bottom, and are just topped up. They are also modular which should reduce construction costs and interest.
http://en.wikipedia.org/wiki/Pebble_bed_reactor

CANDU reactors do not need to stop for refuelling either.

[Dezakin]

This doesn't make geopolitical sense. The old Soviet Union would never evacuate a city of 50,000 people for a mere 5,000 deaths. That's not the way the regime operated. CBS News recently reported on a contaminated Russian nuclear weapons testing zone where the average life expectancy has dropped to about 50 years. Great numbers of the Russian population in the area of "Nuclear Lake" have birth defects. The U.S.S.R. ordered no evacuation. Chernobyl must have been a far worse disaster.

Chernobyl was as bad of a nuclear disaster as you can imagine. You had one of the largest reactors in the world vaporize of tonnes of nuclear fuel with no containment in a region with an iodine deficient population with no stay indoors order. But then you're linking it to some obscure nuclear test site without citations suggesting that this place was so bad that the average life expectancy dropped by decades, and that nuclear testing was directly responsible. Citations would be nice.

I find these U.N. death estimates to be not credible. Perhaps the USSR/Russia, as a member of the UN Security Council, has requested that UN agencies hush up about Chernobyl as a political bargaining chip.

Right, international conspiracy is far more plausible...

There's a current danger that the new-growth forests in the vicinity of Chernobyl will catch fire someday, releasing huge amounts of long-lived radioactive isotopes into the air again. Plenty of fuel has been building up on the forest floor. I predict that in 50 years the Chernobyl area will still be hazardous to human life.

You think thats bad, try living next to a coal plant where they dump tonnes of uranium and thorium into the air every year as a matter of course. Or even worse, that tobacco farmers are allowed to use phosphate based fertilizers that have high uranium concentrations on them; The several hundred kg of strontium and cesium in the soil around the ruins of Pripyat are far less of a concern than some of the dangers we're faced with every day. Ask one of the survivors of Bhopal.

Personally, I would not move to Middletown, PA near TMI unless I knew that I was going to die soon anyways. The area is not what I would consider safe or inhabitable. Non-governmental, independent reports (Mother Jones, Leonard Sternglass) have tagged the city, especially certain blocks in the city, as cancer heaven. Proving any particular thyroid cancer death, like proving that smoking Marlboros caused a particular lung cancer, is impossible. One independent set of statistical estimates put the number of extra cancer deaths from TMI at 50,000. I assume that the nuclear industry will not want to accept this figure.

Well, no. Usually those reports are misapplications of statistics. You can do the same thing by making theoretical links between consumption of herring and high incidence of gay offspring. People are subjected to much higher radiation levels by taking an airplane flight, living next to coal plants, or consuming large numbers of bananas than living near TMI. Hell living anywhere with large granite buildings puts you at higher background radation levels due to excess uranium concentration in granite. Theres a serious crisis of perspective here.

While you're at it you might want to do isotopic separation of all the potasium in your bones to reduce your radiation exposure.

I also notice that TMI's nuclear fuel officially melted out the side of its concrete reactor containment vessel, then down. We should not be afraid to apply the word "meltdown" if that's what actually happened.

Everyone refers to the three mile island accident as a meltdown, because thats what it was; However the fuel didn't melt out the side of the containment vessel.

Readers should be aware of vast discrepancies in ideas between the industry's paid ad agency, its loyal supporters, and its critics. Each side is steering viewers to strongly divergent ways of viewing the nuclear safety problem, to frame the debate in a favorable light.

As opposed to nuclear critics who dont understand the technology and then just make stuff up?

Nuclear power does have real dangers; These dangers aren't unique to nuclear power, they exist in any large scale engineering technology, and we regularly face dangers that are far more severe daily than the risks of nuclear power accidents occuring, even if they were common. No one even thinks about the polonium-210 stuck to tobacco leaves enough to regulate fertilizer use in the industry.

Here's my proposal for disposing of radioactive hazards: We bury them under the corpses of everyone killed by the hazards of the other industries that we deem acceptable risks.

[deMolay]

Any comments on the Canadian Slow Poke Reactor. http://www.cna.ca/curriculum/cna_can_nu ... d=Slowpoke

[Tanada]

Any comments on the Canadian Slow Poke Reactor. http://www.cna.ca/curriculum/cna_can_nu ... d=Slowpoke

I read up on the Slowpoke 3 design back 15 or 20 years ago and thought it was great, the idea of having district heating without any GHG emissions really appeals to me a lot. Though initially designed to run on highly enriched U-235 (20%) the system could also operate on comparable levels of Np-237 or mixed Plutonium recovered from exposed MOX fuel assemblies that are deemed too poor in quality for use in LWR fuel recycle. Because the neutron spectrum is fast it does not need to be high percentage Pu-239/241, the Pu-238/240/242/243 all act as fuel in the fast spectrum a Slowpoke produces.

Basically research reactor style designs are fast burner reactors, if it is fissionable with fast neutrons these gems can use it for fuel. As designed none of them that I am aware of can be refueled, they are small and compact and when they are used up you haul them to a reprocessing plant and just replace them as a unit.

[deMolay]

At one time they were talking of using them in isolated northern communities in Canada's far north as an alternative to fossil fuel. It seemed to just die down tho, no recent discussion on this in Canada that I have seen. I think they just rebuilt them in situ as best I recall.

[Graeme]

New Computer Model Shows Nuclear Fission

Scientists at the US Department of Energy's (DOE) Argonne National Laboratory (ANL) announce the development of a new computer algorithm that allows for them to visualize the reactions that go on inside a nuclear reactor in finer detail than ever before. The neutron transport code UNIC, which is still under development at ANL, will provide researchers in the end with the most detailed view of a reactor's core possible, without them actually jumping inside a reactor.

Engineers and nuclear physicists could use the UNIC algorithm to create safer, more environmentally friendly nuclear reactors, which could benefit a large number of countries in the world. As carbon dioxide becomes an increasing threat, oil and natural gas will be shunned from the market more and more, and renewable energies will take their place. Nuclear fission is one of the safest bets, but new nuclear reactors have not been built in a while. A video of a more detailed simulation of the Zero Power Reactor experiment is available online here.

softpedia

[lper100km]

…the model algorithm showed that the initial reaction would be very slow, but after reaching a critical point, would suddenly accelerate. Dr. (blacked out) said that the curve plotting this reaction reminded him of a hockey stick …..