Future Energy Sources 1.9.1 Uranium Fueled Nuclear Fission

Fission power production is not the most efficient, because superheating of steam is not implemented in nuclear powerplants, unless technology allowing superheating has been developed in the recent past. Customary reprocessing of fuel results in considerable amounts of waste with long half-lives. However, a reprocessing scheme used by the French reduces the bulk of wastes by a factor of about 50. Sorry, I don't recall the details, but they can be found in last month's edition of either the IEEE Spectrum or Scientific American. Although the stock of Plutonium produced is considered a security risk, terrorists will find a way to secure materials for "dirty bombs" or bona fide fission weapons in any event, unless the utmost in diligence is exercised by the free world.

We cannot afford to be owned by oil-producing societies whose mission is to destroy us. Moreover, global warming from CO2 emissions becomes more of a credible threat as time passes. In this person's view, we must follow the lead of the French and Japanese and generate electricity by nuclear means, and we must do it quickly. While solar power, wind power and other sources can serve electrical needs to some extent, the economy of scale remains in favor of larger centralized generating stations.

Significant progress has been made regarding fission powerplant safety, particularly as illustrated by pebble bed reactor technology.

BernieK

Hi, here some statements without proof to clarify the fundamental facts, necessary for a sound discussion:

1.There is ample uranium existing, the recoverable part expected to grow by a factor of 300 if the price is rising by a factor of 10.

1.1 Uranium reactors need either enriched uranium or some plutonium added to get a chain-reaction or have to use heavy water as a moderater and can use natural uranium.

2.Uranium fission is an ugly dirty process that today requires safe storage for 200.000 years.

2.1 If this time is to be reduced then it is necessary to separate the transuranium elements and burn these in one of the emerging reactor types.

3.Todays uranium reactors are all outdated. not efficient and may be with a minor risc of a big desaster.

4.More modern types are looking for a test (who please has knowledge what type is built in Finland now?), the future types to be discussed at a conference in Turkey, Istanbul this July.

5.Reprocessing of used uranium should be considered as a totally differnt activity that is not necessarily linked to uranium energy generation but necessary to get access to plutonium for nuclear weapon production.

6.Reprocessing of uranium had a bigger risc of "events" than nuclear reactors: Hanford, Windscale, the blow up in Ural,Russia of radioactive waste were not at all small accidents.

7. Both big scale accidents were happening in graphite moderated reactors (Windscale and Tschernobyl).

8. Boiling water reactors are not at all "fail-safe" (three mile island).

9. It is unrealistic to bring nuclear power to nonexistence (some countries rely to more than 50% of electricity generation on them), so it is necessary to make these reactors clean and safe. Or put the reactors in a place where a major accident will not poison vast areas.

10. Any nuclear reactor that is not safeguarded and supervised by international authorities can be a source for plutonium. This plutonium is not "weapon-grade" but a mixture of isotopes. Nonetheless it can be used to build nuclear weapons demonstrated by the US early in the 60ties. One reactor is sufficient to get enough plutonium for 20 to 30 nuclear bombs per year.

12. Future reactors have to have a much higher temperature capability to yield better efficiency.

13. Future reactors have to be inherently safe: no big accident possible intrinsically, that is without any active control.

14. Future reactors have to have the possibility to burn the transuranic elements to bring down the disposal (safe) time from 200.000years to 10.000years -ugly but may be there can be done more.

15. Future reactors have to be built near the sea as today the cooling capacity of our rivers is near exhaustion and nobody wants the rivers to be heated to 30 or 40°C.

16. If the high temperature reactor is revived then there may be the possibility of chemically splitting water into hydrogen and oxygen or more simple the reaction of low grade carbon containing material with superheated steam to generate all types of light hydrocarbons. This reactor development was tested in Germany 40 years ago and was abandoned because some ridiculous engineering flaws broke the graphitic balls that contained the fuel tablets.

17. All this is more or less ready for final development and test but authorities are cultivating the fears of many instead of undertaking an open and sound and realistic discussion about our needs.

18. I think we need this type of energy source as ugly as it can be. We have to make it safe. We will never make it really clean. (Same with fusion).

I wish everybody who feels cold a heating possibility and everybody who feels too warm a cooling possibility.

We will not have the possibility to go back with the evolution to livings with a few furs and a little fire and hunting game with spears and bows.

RHABE

RHABE

Re your point #9.

"It is unrealistic to bring nuclear power to nonexistence (some countries rely to more than 50% of electricity generation on them), so it is necessary to make these reactors clean and safe. Or put the reactors in a place where a major accident will not poison vast areas."

You have not seemingly considered the possibility of eventual replacement of currently existing nuclear fission power plants by some environmentally more aware process.

Nuclear fission power plants are extremely expensive to produce and run, and result in high electricity charges for the end-user.

I do agree however, that they are filthy and dangerous.

One of the best thing about this series of blogs is the presentation of ideas that will help us avoid nuclear fission power production in future.

It appears, however that cold fusion power is being produced without either the expense or the dangerous side effects of fission. More research in this field may yield up a friendly atomic power source.

Mark

This is a response to message 4 from Mark, the Hanyman:

I believe that we all look to cold fusion as the holy grail of energy production, the fountain of youth as it were for future energy sources. However, in the 20 years or so since its first announcement, very little if anything credible has taken place in its most early stages of research.

At Lummus Company 20+ years ago, I worked on a detailed proposal in conjuction with Combustion Engineering and Allis-Chalmers for design and construction of power handling for the Princeton TFTR. At the time, first commercial use of Tokamak based fusion was said to be 50 years away. Well, guess what: Tokamak based, Stellarator based, and inertial confinement based fusion is STILL 50 years away at best. The big deal about the Chinese Tokamak experiment a few months ago was just about plasma heating, something done at Princeton and elsewhere by well-known plasma compression and ohmic heating techniques. The Chinese were not looking for fusion. They were researching plasma heating methods. No duterium or tritium were present in the hydrogen in that experiment.

BernieK

OK, Bernie

But the plasma fusion experiments are not cold fusion, they are hot fusion. In contradiction to your statement that very little if anything credible has taken place in [cold fusion's] most early stages of research, there are cold fusion generators currently operating in people's basements, poviding power to their households.

COLD fusion does not incorporate the plasma arena of science pursuit. The Atomic Fusion (plasma) folks --your former area of research-- are dealing with huge numbers of Kelvin degrees confined in a bottle.

The cold fusion I am speaking of takes place at room temperature and requires no confinement, because of its radioactively minimal net effect. It is merely the fusion of an adsorbed element on the surface of a catalytic rod into the rod itself through the application of a little electrical energy via a coil around the rod. The fusion of the two elements releases energy as it takes place, and this energy is taken off as the new power source. There is quite a bit of current information available via the internet search engines on the process, since both university and armed service research agencies are vigorously pursuing the science. There is even a cold fusion newsletter.

Mark

Hi,

the "cold fusion" you are talking about is not at all fusion but catalytic burning without the need of any ignition of fuels that are sufficiently clean not to poison the platinum catalyst that enables the process.

This is good for small scale pretty clean burning of refined and clean gasoline.

There was some years ago a scientific gossip about thermonuclear cold fusion but this has evaporated to nothing but gossip.

Real fusion reactors will be badly contaminated with radioactivity too.

The tokamak that burnt in England some years ago - true thermonuclear reaction at around 200million degree C - is so badly contaminated since then that it can never more be inspected directly from the inside!

Although a final thermonuclear power plant will be equipped with some additional shielding that prevents the neutrons from converting the tube wherein the plasma is burning into other elements this will relax the problem (a factor of 10.000 to 1.000.000 is estimated depending on purity of the lithium blanket) so after one days burning there will be enough radioactivity to be very dangerous.

With the ample supply of neutrons there can be made all other elements.

So if we have no more uranium available this may be a good alternative. If: the development is not at all at a stage where we can be sure that there will be a success.

RHABE

This is a reply to message 8, from MarkTheHandyman:

Mark: Of course cold fusion and plasma based fusion are not the same. Everyone who knows anything about science knows that.

But: People are generating power from cold fusion generators in their basements? I'd really like to see one credible example of it. Anyone who is successful at doing so in a usable way would be the world's richest person with just a little effort expended on politics associated with protection of proprietary knowledge.

I listened dumbfounded when the first news of Fleishman and Pons supposed success was broadcast 20 years ago. I'm still on the outlook for anything meaningful about cold fusion. Show us one place where it really is happening.

Oh, yes, I've seen the newsletter. I've also seen news coverage of the events in Roswell New Mexico each year. Show us the proof.

BernieK

RHABE: Catalytic Converters/Reactors such as those used in IC engine exhaust lines are not Cold Fusion. Rather, Cold fusion reactors begin with a thoroughly poisoned catalyst that is choked with its adsorptive element, add a little juice through a magnetic coil around that catalyst [rod-shaped], and produce a combination of the catalytic element (for example platinum) and the adsorptive (for example oxygen) plus energy: e.g. pt + O_2(ad) ---emf---> pt + O_2(ad) + ptO₂ + e. According to published reports, microscopic examination of the rod after the process reveals small sites of hyper reaction. Apparently, the process continues until there is not enough uncombined adsorptive or catalyst left available to support the fusion.

Bernie, I'm aware that you do not give credibility to the currently published material on the subject; but just because I'm neither in a position nor of the mind to personally either defend those who are publishing or to come over to your house and build one for you (much as I would like to...the schematic for constructing the thing is found in the literature ) does not mean that either of us can asume that the art does not exist.

Since the literature is full of references from very credible places (e.g. MIT) where you may email for info or actually go and visit to check out the current state of the art of cold fusion; and there may even be somebody near your own location thus involved, I encourage you --if you are really interested-- to personally do some more creative investigation. Until you do, dismissing the idea out of hand is, in my opinion, just a little premature. And after you do, if there's indeed nothing to it, I'd like to be the first to know. Meantime, my own lazy butt is quite content to believe the oh, so promising literature (which, to my knowledge has had nobody yet publishing just to make other than a research buck).

Mark

So, fission creates weapons-grade waste-materials which are hard to get rid of, and fusion is an unsustainable physical process here on earth. What then? Wind? Too occasional to be considered a stable source. Solar? The same, for the same reason. Waterfalls seem like the only stable source, only not to be found all around. so practically, the same.

How about "reducing energy consumption" or "population reduction" as a new "holy grail" for R&D?

Some would say the multitude of regional wars already take care of population control and infrastructure reduction. Is this what we are looking for?

P.S: http://www.physorg.com/news92411487.html (solar to help mitigate global warming).

Nuclear electricity is not expensive unless compared to hydro-electric.

If we want to talk about dirty lets talk about a coal fired plant which in addition to the ash it creates spews tons of CO2, paticulates, various oxides of sulfur and nitrogen, and I am told sometimes a bit of mercury out its stack. Out of site, out of mind. Where as a nuclear plant retains all of its waste. The volume of waste from a nuclear plant is relatively small.

If the waste from a nuclear reactor was reprocessed to remove the U238 only a CANDU reactor would get rid of 90% of the plutonium and 60% of the radioactive actinides generating energy and reducing the amount waste in the process. The U238 would be the same as the depleted uranium used in tank shells and high performance sail boat keels.

The answer to high level wastes that we can't burn in a reactor or an accelerator is deep geological disposal. In Canada the nuclear utilities must contribute an amount from every KWH they generate finance such a facility. The government just needs to get on the stick and do what needs to be done. I have a copy of a 400+ page report commisioned by the government, when I enquired of its status I was told, "A decision is expected."

A previous post said that the vitrified (mixed with molten glass) waste would be red hot for many many years. If that is true then why are the storage pools where spent fuel elements spend their most active time boiling from the red hot fuel elements?

The curious one (and the entire pro-nuke contingent as well. I know you are not going to enjoy the following objection to your favoured form of electricity production):

Curious, you are correct. The old coal-fired boiler production plants (of which, unfortunately several still exist) are dirty too, no doubt about it. Dirt you can actually see, and/or that has adverse environmental effects that you can actually see. Dirt that kills entire lakes and forests and makes people sick. There is developmental technology being examined to produce clean burning coal, but you are correct in your proposition that until those techniques prove themselve, it's a dirty form of electrical production. Ditto for the combustion, degradation, or other utilization of almost every other form of non-renewable resource. We're working on it, but where attention is, thankfully, being paid to cleaning things up, we just haven't solved every issue yet.

That doesn't make a form of electrical power production with non-disposable--in the sense that however it is contained it retains its ability to deal destruction on a whole host of levels-- deadly poisonous waste less dirty because you can't see it or it isn't (currently) killing anything.

Placing nuclear fission waste deep into the earth (or really, any place at all for many other reasons) opens up a series of pollution possibilities that are not as short-term in their remediation as other forms of pollution because the stability of underground storage cannot reasonably be predicted, and because of the rate of radioactive decay and its possible detrimental effects on underground aquifers and their ecologies, as well as on those above-ground systems that depend upon them. It doesn't matter whether you contain spent rods in deuterium, glass, concrete, lead, or anything else. Time and events are too unpredictable to make it a safe proposition. This is where the controversy originates; not with those of us who oppose nuclear fisssion-produced power because the waste is filthy.

Even the very existence of the production of nuclear power, completely aside from its waste production, has been as well; although in isolated incidents, a source of filth.

Certainly, nuclear energy is here now, and a viable source of electricity supply until it can be replaced with environmentally responsible technology.

Which it is not. Consider the evidence.

Atomic facilities represent the continued creation of dangerous end products for which no satisfactory waste disposal method has yet been found. Environmentally irresponsible filth production.

To a lesser extent, but still of some historical importance, the production facilities themselves have been susceptible to seismic disturbance, human or/and Machine error causing coolant leakage, and ultimately to nuclear accident, making their very existence a conscious form of environmentally irresponsible filth production.

Certain types of reactors produce plutonium byproducts that may be used for manufacturing radioactive bomb components. Environmentally irresponsible Filth production.

Lots of power production methods can be called filthy. On a personal scale, I place nuclear fission power right at the top because we know that once initiated, the damage it can do will extend farther into the future and have a greater negative impact on future genertions than all the other forms of electricity production.

You stated "Nuclear electricity is not expensive unless compared to hydro-electric."

I agree. And per MW$ of hydro-electric production, you can probably substitute for "hydro-electric" in that sentence every other known form of electrity production there is.

Although I don't actually know the cost of the new dams or their forecast electricity production, the forecasts of costs for natural gas or other replacement technologies for Nuclear, etc., I can quote others who do. The Ontario Clean Air Alliance offers a conservative rebuttal to a report written by the Ontario Power Authority Dec 9, 2005 (don't know if that's the report you are referring to) which states unequivocally that the report is heavily biased in favour of Nuclear Fission Power production, and offers this observation when making comparisons with natural gas production (probably reflecting its own bias!):

"Applying real numbers to the OPA's hypothetical analysis makes it clear that nuclear power is, by far, one of the highest-cost options for meeting Ontario's incremental electricity needs. It also demonstrates how pouring billions of public dollars into nuclear power is likely to pull significant financial resources away from more viable options, including efficiency and conservation initiatives and renewable power development."

Hydro Dam projects, as damaging as they are (see my previous post on the subject in the 'multi-generation' blogset), are cheaper to build per MW production, as you have pointed out. Just how much cheaper becomes apparent when you consider that the Three Gorges Dam project is estimated to cost US$25bil, and will produce an expected 18.2 gigaWatts of electricity.

In a recent statement, the Royal Academy conservatively assumed [that nuclear power plants would cost] ₤1,150/kW to build.

My solution would be: let's just use the nuclear power plants we have, work like beavers to find good substitutes for them so we are not forced to rely on new ones being built, and when they die, phase them out.

If you truly believe that "The government just needs to get on the stick and do what needs to be done" and that 'what needs to be done' is to establish more nuclear fission power plants, we are just destined to disagree on this subject.

Mark

A few points :

1. Mentioned was made of Canadian sub reactors. The Canadian navy once considered a nuclear submarine fleet but instead opted to buy used diesel electric boats from Great Britain.
2. When talking about the expense of an electrical generationg plant, one should not just talk about the capital investment in the plant be it a dam, fossil fueled plant, solar, nuclear or wind. One must talk about the cost of a KWH delivered to the end consumer.
   
3. The cost of electricity from a nuclear power plant is mainly based on the capital cost of building the plant of which a significant portion is related to safety and "defense in depth" accident prevention systems. The cost of fuel is a relatively small portion of the cost of the power delivered to the grid. Fossil fueled plants on the other hand are relatively cheap to build but the ongoing costs of fuel make the major contribution to the cost of the power generated.
4. The Three Mile Island event was as much a success story (I expect to take some heat for this statement) as it was a disaster. It demonstrated that in spite of a melt-down there was no major release of radioactivity to the environment. The containment structure worked!
5. Chernobyl on the other hand was a disaster. The reactor design would never have been approved in most countries. It had no containment building which allowed the overheated graphite moderator to burn when exposed to air after the explosion which I believe was due to high pressure steam. Combine a fatally flawed design with a lack of a safety culture among the staff and you have the makings of a disaster which indeed happened.
6. I can only speak for Canada and the United States. Getting a reactor design licensed by the appropriate government agency is an expensive and time consuming process. The design including not just the actual reactor but safe guards and control systems and the materials that go into them are all considered. The entire design is gone over with a fine toothed comb by experts who are expected to ask the difficult questions.
7. Consider the airplanes crashing into the World Trade Center, what would happen if such an event happened at a North American nuclear site. If the plane hit what is often referred to the BOP (balance of plant which includes the turbines, generators, switch gear, etc. everything outside of the reactor and associated systems) it would be like the plane crashing into a conventional power plant. If it hit the actual reactor containment structure which is about six feet of heavily reinforced concrete, often with a steel interior lining, the plane would be crushed against the building and the wings would probably come of and wrap themselves around the building. The jet fuel would cause a major fire but the likelihood of the plane penetrating the containment building is very low. The folks who flew the planes into the World Trade Center had large targets, the piloting skills required to fly into a relatively low containment structure would probably be lacking in such individuals, they would be as likely to hit the ground in front of the containment structure or over shoot the target, maybe they would just clip it with a wing which would result in the plane spinning out of control the main part of the aircraft would hit something else.
8. I may have already mentioned in this forum or in one of the others that I participate in that the government of the Canadian Province of Ontario has mandated that all fossil fuelled generating stations be closed and they have even given a date by which this is to be accomplished. Ontario already gets about 50% of its power from nuclear stations and there are few if any potential hydro sites left so they are left with one alternative. Conservation, wind, solar, and biomass can not make up the difference.
9. The environmentalists would have us believe that wind and solar are the answer to our prayers but solar doesn't work at night and in some parts of Canada the nights are very long in the winter, where I live in Alberta during the winter I would drive to work in the dark and drive back home in the dark. Solar isn't always there and sometimes the wind doesn't blow. There are also the alleged bird kills caused by wind turbines and wind turbines coming apart flinging their massive blades through buildings and people, something I don't particularly find worrisome.
10. There are also those who worry about the ecological damage caused by major hydro electric projects by flooding large areas as the reservoir is created behind the dam and they claim that without a good winter to provide a deep snow pack which will melt and refill the reservoir every year, the hydro solution might not be viable either. I don't find this particularly troublesome. In some areas provisions must be made for migrating fish populations, particularly where salmon like to go home to breed and die. The young then go to the ocean to fatten up, mature, and then repeat the cycle if they don't end up in a fisherman's net first or get eaten by a bear who find salmon to be particularly delicious and good source of energy to be stored for the winter hibernation.
11. It is not difficult to see that nuclear does provide a solution for high volume base load power generation. Nuclear power plants are the most economical when being run at or near capacity and because the fuel represents a small part of the cost of operating the plant it is important to get the most out of the capital investment.
12. The economics of fossil fuel plants makes it economically possible to run them at reduced capacity without resulting in an increase in the cost of the electricity being produced.
13. A possible thought is that when the full capacity of a nuclear plant is not required on the grid, the excess power could be directed to a large hydrolysis plant to break down water and produce hydrogen and oxygen both items with a market value and the former also being in support of the hydrogen economy that everyone is talking about.
    
14. Nuclear plants are also attractive because they retain all of their waste unlike the fossil fueled plants that send it up the stack and take the out of sight, out of mind approach.
15. The issue of nuclear was disposal, reprocessing, etc is the subject of another forum.
16. Fusion is often described as the eventual source of unlimited clean power. I was just reading an article on the ITER project an in international attempt to solve the problems associated with a sustained fusion reaction. Fusion readtors are big machines with huge super conducting magnets and cryogenic cooling systems as well as water cooling systems and high power microwave generators to help get the plasma hot enough. It will consume large amounts of electricity just to get it hot enough to start working. One of the concerns with the ITER project is that when they have finished proving what ever they can with it, major portions of it will have become radioactive from intense neutron bombardment that will result from the processes going on inside the contained plasma. The decommisioning, destruction/disassembly of the device and returning the site to a green field will be a major task which may take as long as a decade.
    

Well I have babbled on for long enough, I will make no secret of the fact that I am pro nuclear and a fan of the domestically developed CANDU system which is now running in Canada, Romania, Argentina, China, Pakistan, and India. When Pakistan and India developed their weapons programs we withdrew support for them but India like the CANDU design so much that they have constructed several CANDU clones.

For further information on the CANDU system visit the Nuclear FAQ site and visit the Atomic Energy of Canada site, use the "contact us" facility to request a copy of the booklet "ACR-1000 Technical Summary" a well done 40 page booklet describing the next generation of CANDU technology, my enthusiasm for CANDU not withstanding, I think that it is quite well done combining diagrams, tables, text, and comparisons to previous CANDU systems. It is also free and they mail it first class. I would even reccomend that Mark read it if for no other reason than to "know thy enemy".

Curious one:

response. Thanks.

Still anti-nuke, though, for the reasons mentioned. Don't regard it as 'the enemy', of course, only as something we tried and will hopefully get past, again for the reasons mentioned. I'll download and read the suggested piece.

Have you investigated cold fusion? It seems to be closer to a reality than the alternative, and is purportd to create much more energy than it uses to get started.

Mark

In a previous post I left out a word or two. Instead of reading:

A previous post said that the vitrified (mixed with molten glass) waste would be red hot for many many years. If that is true then why are the storage pools where spent fuel elements spend their most active time boiling from the red hot fuel elements?

<>It should have read:

A previous post said that the vitrified (mixed with molten glass) waste would be red hot for many many years. If that is true then why are the storage pools where spent fuel elements spend their most active time not boiling from the allegedly red hot fuel elements?

First off, I'm glad that people are still posting to this, since elaboration is frequently needed, and finding time to do it right isn't easy.

RHABE {#9} made several points in response to my {#3} that I should be getting back to, including:

"The "factsheets" are known more or less since some time but the critics are going on and I would not be sure if no water will enter the deposits and leach the whole stuff in a short time. As the glass blocks are red-hot for many thousands of years these would readily react with water. So if I would decide on that problem I would inquire for a system of medium time depository of used fuel rods without active cooling but would cancel the reprocessing totally (unless the uranium price is 100 times the todays price what will not happen.)"

The Yucca Mountain criteria, if I'm reading them right, seems to be, for spent fuel to be about 12 kw for a 21 PWR assembly disposal cask. I believe that High Level Waste (HLW) canisters are loaded to a limit of about 1 kw per 24 inch OD, 15 ft high loading canisters. Perhaps 5 of these canisters will be loading into a disposal cask. From start to actual repository closure may be almost 100 years. I assume there will be active ventilation before closure. I recall there was some debate about cold vs. hot repository design, with that referring to whether any groundwater in contact might boil in the early years. These temperatures are relatively trivial compared to reactor coolant or vitrification temperatures. I don't think this scenario of hot waste readily reacting with planned or unplanned water exposure has any credibility. It seems certain that leachability with temperature considerations has been evaluated.

RHABE, if you see this let me know, otherwise I'll repeat it when I get to the rest of your points.

Hi N&P and others,

if the containers (for the Yucca mountain depository) are this big (only 1 KW for nearly 10m² outer surface area?) this can be considered low thermal load.

Do you have a temperature for the outside?

How is the cooling done? If passive either from the start on or after some time it may be safe.

The situation is very different for the German plans of high activity waste to be melted in a glass block. These will have 8 to 10inch diameter and nearly 20inch length and are heated by the decaying elements to around 550°C depending on the natural cooling by the surrounding salt.

I know about other plans in Europe not to store the waste in salt deposits but in clay with very low permeability for water. As being deformed without big forces these clay deposits are estimated to remain tight and sealed also after movements by earthquakes.

For both plans I never heard about the concept of energy dissipation. If the thickness of an encapsulating material is thick the temperature will rise a lot until an equilibrum between energy production and cooling capacity is reached.

So judging the risks I would not like to leave very ugly material for the next 200.000 years. This cannot be reversed by very secure storing sites. But we can reburn a part of this waste and the most ugly part as soon as we have some new reactor types running.

That's why I am pleading for momentary storage. This lastung for 100 to 1000 years and then reprocessed and most of the stuff reburnt.

RHABE

A slight correction, the actual limit per HLW canister is 1.5 kw.

http://www.nwtrb.gov/meetings/cwd625.doc provides some basic Yucca Mountain Repository Configuration and temperature data. The document is about 6 years old, but I think this is still the basic configuration. Long term temperature look reasonable and lower than what you described for German plans.

One thing is that the the time-to-closure might conform to your final thought. Until closure, Yucca would effectively be an underground storage. And reprocessing and burning is being looked at under the Global Nuclear Energy Partnership (GNEP) and related programs.

I'm not a big fan of toxicity comparisons without release and transport mechanism considerations. With these factors, geologic repositories, with a modicum of realism in otherwise conservative evaluations, do work. Nevertheless, the GNEP evaluations are directed to closed fuel cycles with spent fuel processed in proliferation resistant configurations under international controls. The basic benefits are:

1. Long-lived isotope destruction, including fissile material, simplifying repository modeling and the theoretical long term risks.
2. Long term extension of nuclear fuel material supplies.
3. Elimination, for a long time, the need for follow-on repositories.

http://www.nea.fr/html/ndd/reports/2002/nea3109-ads.pdf gets into considerable detail on concepts for closed fuel cycles and actinide and long-lived fission product destruction.

I'm happy to see that you don'n forgot the great Phyisisist[in physic's Science] R.Feynman author of 'Feynman's Lectures of Modern Physics' !

Nic

I must complement N&P, The_curious_one and MarkTheHandyman on the quality and depth of the posts in this thread. The have all been excellent and have both raised and answered may critical points. Discussions like this are what I had hoped this blog would generate so you have made me a very happy little vegemite.

There was however one question hat The_curious_one posed that hasn't bee answered yet.

"A previous post said that the vitrified (mixed with molten glass) waste would be red hot for many many years. If that is true then why are the storage pools where spent fuel elements spend their most active time not boiling from the allegedly red hot fuel elements?"

It's a good question and the answer is that the storage facilities have thumping great cooling plants that keep the fluid that they are stored in cool. With the lack of any long term storage facility many of the short tem storage facilities are dangerously overloaded. Overloading has two potentially disastrous side effects.

1. The overcrowding means that the used fuel elements are stored closet together than originally intended and this increases the rate of fission and hence a greater heat output.
2. Having more used elements, radiating more heat than initially planed for is a double whammy. It puts considerably more strain on the cooling plants of these short term storage facilities that are now looking like long term facilities.

There have been several near disasters caused by cooling system failures at short term storage facilities. You need to keep in mind that these facilities were never meant to store the spent fuel rods for the lengthy periods they are now being forced to.

The result is we have systems that are being used way longer and at much greater loads than they were designed and that is a recipe for disaster.

Here are some links that I found on the storage of nuclear waste:

• Nuclear Waste Storage
• Nuclear Waste Problems of Japan

Masu,

To clarify a few things on the issues you've raised:

Item 1: Fissioning in spent fuel racks, which are subcritical, is not a significant heat source. Those sources are spontaneous fissions of a few isotopes and a little subcritical multiplication. Decay heat is, far and away, the dominant heat source. High density racks are used to increase storage in a given storage area. The rack criticality safety criteria is the same, so multiplication would be the same. Higher burnup fuel trends increase the spontaneous fission rate, but don't change the basic conclusion regarding fission heat importance.

Item 2: The effects of higher density racks in a given pool are to allow storage of more old fuel, thus increasing capacity. Heat removal is principally a function of just recently discharged fuel. For instance some plants do a full core offload to their spent fuel pool. If this is accomplished at say 3 days after shutdown the decay heat from that fuel will be ~0.4% of full power. Lets also say the plant is on a two year fuel cycle and discharges 38% of its fuel at each refuel. The total heat from the previous 20 year of fuel would be about 1/20th of the above. The heat transfer from spent fuel in a pool is such that even with loss of forced cooling, a boiling pool, and newly out of the reactor fuel, the fuel is not threatened, high density rack or not.

The principal issue these days relate to terrorism that might be postulated to remove the water, either by breaching the structural boundary and/or indefinitely removing cooling and defeating water makeup efforts, and whether something, such as checkerboarding, should be used to aide heat transfer to prevent cladding fire. I won't be getting into the credibility of this scenario or mitigation needs. Sorry.

In response to your intro. Absolutely, but I did have to look up vegemite. Thank you Wikipedia.

I wrote a Dido on in this blog. Can we build a 1000 year generator? Instead of using fusion the reactor would use decay. The reactor would take waste nuclear materials and not only store them, but re-use them. To make this generator work for 1000 years there would be little or no moving parts. Processes must be naturally occurring cycles. All wear parts must be quad redundant. I looked at the OTEC (Ocean Thermal Energy Cycle) generators of the 1980's as a model. Water and the water cycle has some advantages. Using 2 egg shaped holding tanks. Between 10 degrees and 20 degrees F is needed for procress. One holding the waste materials the other used as a heat sinc. Instead of turbines I would arrange the waste in five spirals arms around an open water level equalization tubes, so cold water would heat up and spiral out to the edges. This heating pattern would also cause a spiralling of the air column above. At the top would be 4 transfer tubes transfer tubes would be be lined with gold coated graphite nano tubes. Velocity in transfer tubes would hit a max of 200 mph. Using a Newtonian discovery. When ever a fluid goes over a surface an electric current is produced. Vortexing in the transfer tubes would increase output by increasing surface exposure. After about a 200 to 400 foot rise in height the water vapor would condense out and fall back down into the heat sinc tank. 4 transfer tubes set just above water level would let the cold air go back into waste holding tank to be heated up again. Cold water would sink down and get transfered to waste holding tank through 4 small tubes at the base of each holding tank. Later blogs to this posting. Gave me am answer of using Helium in stead of water or salt water as the medium of transfer. It was brought up because I brought up a concern about deuterium or the increase of heavy water to the performance of the generator over time my quick calcs showed a balancing of affects in the down draft pressure increases, but I wasn't sure. A helium system would be a smaller scale generator and easier to get through government revues. One of the ways to make sure that the toxic wastes are stored safely is to make the safe storage useful and profitable. What are your thoughts about this?

Dear Rory,

For some unexplained reason I must admit: this is not half-bad.

It's imaginative, it makes some strange, intuitive, half-baked, positive sense.

Being very doubtful by nature, you took me by surprise here.

Rory:

"Instead of turbines I would arrange the waste in five spirals arms around an open water level equalization tubes, so cold water would heat up and spiral out to the edges."

Are you saying that the heating water is in contact with the heated air through a heat exchanger composed of a tank of some sort heated by the spiral arms? Couldn't you eliminate the water tank and just use the air flow for more efficiency?

"Cold water would sink down and get transfered to waste holding tank through 4 small tubes at the base of each holding tank."

If you are using water that is expected to condense to a holding tank, do the transfer tubes have a one-way valve of some description at their upper ends to prevent condensate returning back through them to slow the air rise or interfere with the electricity production surfaces? Or are you expecting the flow's velocity to maitain a dry environment?

Mark

One of the better suggestions was getting rid of water and going with helium. Helium does have advantages to the water. But water has more thermo-density than helium so less waste material is needed for each generator so the generator is smaller. The shape of the waste storage container is also changed from egg shaped to teardrop rain drop shaped. Also the thermo-sinc is changed to condensing coils. In ascents you have a heat pump or entropy engine.

Advantages of Helium is

1 Helium doesn't corrupt, become radioactive, in a presents of a radiator. Minimal danger from a leak.

2 Boiling point is minus 452 degrees F. Allows heat sinc process to continue in definitely in deep space a possible 2000 year useful life of generator on earth.

3 Smaller in size easier to locate in more places. Originally I saw as possible locations for these generators were in limestone caves and limestone mines or non coal mines in general. As undergrounds which could be used as bio-storage and research facilities. Safe places with a long term power source and stable controllable environment. The smaller size would allow a greater diversification a long those lines.

Downside:

Current NASA generators use expensive alloys. From my days building turbines (18 years old) last time I looked the alloys used the scrap sells for the price of platinum. So each generator is expensive. One of the things stopping nuclear power is the high up front cost. Banks, investors and electric coops are quite honestly scared away. Originally, I had started this blog to seek lower cost solutions. I see an explosion of new materials to either act is to reinforce more standard materials ie: nano graphite tubes coated with gold nitrate. Or NCEM (Near Center of the Earth materials) which are coming of age with processes which emulate the manufacturing of glass (sheets are floated on top of molten metal) and uses steam driven shock wave compressors to combine ceramics with metals instead of explosives to make materials which has high heat resistance with malleability. Such manufacturing techniques would decrease the cost of these materials. Nuclear generators are not being considered viable because of up front costs and storage costs. Only by solving those costs does nuclear energy become viable.

...Minimal danger from a leak...

May not impose danger when it leaks, but is does leak like hell.

It wouldn't even form molecules, and rather stay atomic.

When reviewing the suggestion to use Helium. I looked at the Helium molecule as a noble gas. The small nuclei is a relatively small target. Alpha particle corruption is neglectable. Beta particle is higher, but beta particle is defeated at skin level. A piece of paper defeats it's progress. The gal who made the suggestion to use Helium is sound advice. I need to find the links she gave me and re-post them here. Gas is low density add moving, add small target. Sorry must disagree.

...Sorry must disagree...

I'm not arguing your suggestion, it is a noble gas, with all benefits attached.

I'm only mentioning, that a special care, needs to be taken into account, concerning it's porosity, it's high ability to escape vessels.

It is reluctant to form molecules, and tries to remain as unattached atoms due to it's balanced electron shell. It's essentially an atomic gas, not a molecular gas. It also demonstrate weird behaviour in low temperatures, where it's porosity gets higher and higher.

This is good because it makes it a small target, as you just mentioned, it is also good because it makes it essentially inert (chemically inactive), but it's bad in the sense that it tends to escape more easily than a molecular gas.

So, special attention is needed to tackle it's tendency to escape. That's all. No harm done.

She pointed to 2 types of current decay generators the Racine generator and the Sterling generator. Which are approved for space use if I read right. There where no mention of Helium loss rates, The Sterling looks to be a boxer design. Mine being larger than theirs one would have to look at loss rates when building one to last 1000 years. I don't believe the next noble gas in line neon 10 weight would be as good though. If I remember Neon does isotope. As I remember the isotope does act a lot like sodium too. Quite chemically re-active. I was 24 when I looked at isotopes now I'm 50. Helium is still a better choice in this case. May have think of keeping spare Helium if I go down this road. Carbon dioxide does have some promise though, even though it too will isotope. Isotopes are still predicable. Though viscosity would increase over time, Also the switching from gas to solid. I do believe. What gas would you suggest?

Thank You.

...no mention of Helium loss...

Then they probably got a tight container. "Tight" in the sense of a tight lattice geometry, or an efficient coating.

How do they keep helium any way?

Helium sounds ideal at face value. Especially if you say it's already used for such. Stirling should ideally be a low-pressure heat-transfer device. Get the thermal characteristics of helium, and see how much it expands.

It's heat capacity is said to be:

(25 °C) 20.786 J·mol⁻¹·K⁻¹

It's Thermal conductivity is said to be:

(300 K) 151.3 m W·m⁻¹·K⁻¹

I get that helium triple-point is really weird: Expands to a point, then starts to contract suddenly.

Here's Wiki: "...Like other cryogenic liquids, helium I boils when heat is added to it. It also contracts when its temperature is lowered until it reaches the lambda point, when it stops boiling and suddenly expands. The rate of expansion decreases below the lambda point until about 1 K is reached; at which point expansion completely stops and helium I starts to contract again..".

It's lambda point is where it suddenly agrees to become a molecule...

It's a weird substance, man.

Here's a gadget for it.

Cold water is denser than warm water no need. Use of what moves the gulf stream. Only need shut offs for repairs and inspections.

Mark you are right a one-way-valve is needed at the base water equalization tubes. I realised my error ripping a part a bathroom, Honey do.., Heavy water transformation can not be discounted. if reversal would occur a possible Dead Sea Generator effect could occur in the condensing tank with cold water acting like a cap would allow the hot heavy water to super heat. If no mixing occurred - a steam blow back event might occur. Good question!

Redirect super heated water jet, to drive the mixing? Is this to far-fetched? A spin-off feedback governour...

Redirect super heated water jet, to drive the mixing? Is this to far-fetched? A spin-off feedback governour...

Back when I was maybe 16 my dad took me to a seminar on Solar Energy in Chicago. This where I learned of the experiments in the Dead Sea. The guys would wait until noon. Throw a thin layer of cold 40F distilled water over an area of the Dead Sea. By 2:00 they had steam coming out of tubes. Effect is temporary though, because of mixing. But my time in aircraft has taught me that anything that has a provability greater than zero will in time happen. Time line is 1000 years no matter how improbable an event is you must make a contingent for it. So one way values would need to be added. Can't take for granted that hot heavy water wouldn't sink in water transfer tubes get trapped in and go to steam there. Thanks for the support, but point taken.

Sorry, I am in the middle Funeral arrangements, should be able to comment next week. Have notes on questions, but little time.

Thank You

Rory Houlihan

Are you saying that the heating water is in contact with the heated air through a heat exchanger composed of a tank of some sort heated by the spiral arms? Couldn't you eliminate the water tank and just use the air flow for more efficiency?

Part of my background is in aircraft. If you ever fly over a spring fed lake be careful not too be to low there is always a down draft over those springs. A micro event that will put you in the drink. When you fly you become aware of the micro events. Water is a great heat exchanger all by itself. I'm counting on it. As far as the five arms. Have you ever had the answer in front you and not seen it? Well I like to have space photos as my screen saver. I had a photo of one of our local neighbors and one we'll run into sooner or later. Well looking at it one day I realize I was looking at convection currents billions of years old. Looking at it with new eyes I flipped through other photos. Long short of it I saw a natural machine driven by forces we see every day in our weather and I plan to use it to advantage if I use this water based design.

Hi, RoryHoulihan!

Well, Good luck in your design. It'll be interesting to watch your progress. Let us know, from time to time, how it's coming along.

Mark

OK. You seem to know your way around heavy nuclei. Keep going. Is this forum limited to uranium fission? What about thorium? What about using natural uranium for fission (vs. enriched uranium) in so-called heterogeneous reactors? In a natural uranium reactor, there are four different neutron capture processes which compete for neutrons. A lot of data on heterogeneous reactors was developed by Dr. Wigner's group, at the Metallurigical Lab, in Chicago (see J. Applied Phys; 17, 857 (1946), by E. P. Wigner). Surely in the past 60 years, there have been advances in controlling the velocity of neutrons and applied nuclear cross-section, focusing neutron flux, etc. Wigner, again, did some work on the theoretical treatment of resonance absorption, where the effective absorption cross section can be treated as two distinct areas: volume absorption (proportional to the number of uranium nuclei per cc), and surface absorption, which is proportional to the surface to mass ratio for the uranium. In an entirely different direction, I would love to know the amount of "depleted uranium" that exists around the world in weapons rounds, both in storage and dispersed into the environment. One can guess at the amount of plutonium that exists from the available numbers of nuclear weapons publicized. Perhaps in another hundred years, a successor to the United Nations will be able to collect all the nuclear weapons and "burn" that nuclear fuel, which should last for quite a while! Will there be a separate forum on "fission" as a source for power, and for fusion also? I look forward to them! Again, as an aside, I took my U Mass classes thru the Seabrook Nulear Power plant during its construction, until they buttoned up the containment building and installed the reactor and began fueling. An interesting narrative could be about the huge sea- water cooling tunnels, carved thru bedrock, to provide cooling for the heat transfer from the operating reactor.

1.1 Uranium reactors need either enriched uranium or some plutonium added to get a chain-reaction or have to use heavy water, or graphite (Heaven forbid) as a moderater and can use natural uranium.

3.Todays uranium reactors are all outdated. not efficient and may be with a minor risc of a big desaster.

Where are the references for this blanket statement?

5.Reprocessing of used uranium should be considered as a totally differnt activity that is not necessarily linked to uranium energy generation but necessary to get access to plutonium for nuclear weapon production.

The weapons grade vs reactor grade plutonium subject has been discussed in other posts. the long periods that the fuel remains in a power reactor results in plutonium isotopes that have only been used in a bomb that was already 80% weapons grade plutonium. A bomb made entirely of reactor grade wold be difficult if not risky to manuafacture because of the possibility of a premature detonation.

6.Reprocessing of uranium had a bigger risc of "events" than nuclear reactors: Hanford, Windscale, the blow up in Ural,Russia of radioactive waste were not at all small accidents.

There is no doubt that Hanford is an ecological disaster that was built in time of war where urgency combined with a lack of understanding resulted an indescribable mess.

7. Both big scale accidents were happening in graphite moderated reactors (Windscale and Tschernobyl).

Chernobyl was a combination of bad design, no containment vessel and a poor safety culture.

8. Boiling water reactors are not at all "fail-safe" (three mile island).

TMI was in one form a success story, the containment vessel held in the vast majority of the radiation.

10. Any nuclear reactor that is not safeguarded and supervised by international authorities can be a source for plutonium. This plutonium is not "weapon-grade" but a mixture of isotopes. Nonetheless it can be used to build nuclear weapons demonstrated by the US early in the 60ties. One reactor is sufficient to get enough plutonium for 20 to 30 nuclear bombs per year.

This has already been addressed

13. Future reactors have to be inherently safe: no big accident possible intrinsically, that is without any active control.

14. Future reactors have to have the possibility to burn the transuranic elements to bring down the disposal (safe) time from 200.000years to 10.000years -ugly but may be there can be done more.

The answer is CANDU, loss of coolant means loss of moderator, means reaction stops.

18. I think we need this type of energy source as ugly as it can be. We have to make it safe. We will never make it really clean. (Same with fusion).

It will always be cleaner than fossil fuels.

Masu, you've been doing a great educational and provocative service in bringing these energy issues to this forum over the last months.

Is the use of U235 fueled fission the answer to our energy needs? No, but it is one of them. In the US, the 104 nuclear power plants, because they are not coal fired, each year avoid emissions of CO2 in an amount exceeding that produced annually by all US automobiles. Large developed countries like the US, Canada, and Australia have per capita CO2 emissions in the 18 to 20 metric tonnes/year range. Smaller fully developed European countries have per capita emissions around 10 tonnes/year, because of transportation efficiencies, oil and natural gas use, and some nuclear use. France, with a large fraction of electricity produced by nuclear is at 6.7 tonnes/year.

Waste...is highly radioactive and contains transuranic elements like plutonium that are highly toxic. Clearly highly radioactive, sometimes to the point of being self-protective. Highly toxic and highly controlled. Toxic industrial chemicals, toxic radioactivity, toxic household products, all merit respect and prudent management. Transuranics, whether in intact spent fuel or in a fuel reprocessing facility, are readily controlled and not dispersed.

Contrast that with mercury emissions from coal fired plants. The mercury is all dispersed, either in air or in ash. Mercury doesn't have a half life. It will always be with us in some form. The best that you can hope for is that it is diluted or removed from the biosphere by some natural process.

...reprocessing can also create the material required to manufacture nuclear weapons. While providing a poor material and undesirable route for nuclear weapons production, clearly reprocessing should be designed to be highly diversion resistant and subject to international controls and maybe even international management.

The waste from these reactore remains hazardous for something like half a million years and to date, there is no way to guarantee its security on this sort of geologic time scale. http://www.ocrwm.doe.gov/factsheets/doeymp0010.shtml would be a starting point. Clearly, some of the delay in developing geologic repositories has been and continues to be political. Decisions delayed are always easier on that front, but after 20 years, one begins to question whether "due process" can become "undue process". At some point I'd hope we take Ben Franklin's advise that "well done" is better than "well said".

Reprocessing of spent fuel for energy source recovery is attractive, if it's cost-effective. This could also support processes such as actinide and fission product burning that can reduce geologic repository demands in space and time. These functions aren't vital but bear consideration.

On, and the biblical hyperbole adds little to the discussion.

The near term bottom line is that we need energy, used wisely. Conservation provides a lot of low-hanging fruit, but all of my light bulbs are compact flourescents, and appliance relatively new and energy efficient. The next projects may be more capital intensive with long paybacks.

Any energy source that can compete should be considered, be it fossil, nuclear, or the renewables that you've been outlining. Costs of emission effects should be factored into the equation. On the nuclear side this is done by waste funds, decommissioning funds, self-insurance, and minimal emissions, radioactive or otherwise.

Regarding RHABE's comments a few quibbles:

3. Todays uranium reactors are essentially all light water reactors (LWR), a technology that is well understood and developed, and refined. Generation IV reactors have a number of features that will be attractive, some of which are mentioned in RHABE's follow-on points. While I'm intrigued by them as well, considerable development efforts remain to be done, and many advantages remain theoretical.

LWRs may be less efficient (~33%) than fossil (38%+) in converting heat to electricity, but nuclear fuel costs in the US are less than $0.01/kwh so added efficiency, when accompanied by added capital costs, may not necessarily pay.

Related to efficiency, I understand that Australia has under early consideration the use of nuclear energy as a tool for CO2 emission reduction but that considerable concern has been expressed on the above efficiency as it would impact water use for waste heat dissipation. My thoughts are that, where fresh water is precious, ocean salt water sources should be used for heat dissipation so that fresh water supplies are unaffected. That's easier with nuclear, that can be put near a coast, whereas, coal fired plants are best sited near mine-mouths. Coastal coal plant entail major fuel transportation expenses.

4. The new plant being built in Finland is a European Pressurized Water Reactor.

5. As stated above, reprocessing is only desirable if plutonium recycle is for power or actinide and fission product burning to reduce repository requirements, with safeguards. If you want plutonium for weapons, build a reactor for that purpose like the North Koreans, without safeguards. Even then, getting it to work right appears tricky.

6. Reprocessing needs to be done carefully, and without the KGB making the productivity, safety and radiation protection decisions.

7. One of the reasons to be careful about the "grass being greener" under yet to be developed concepts.

8. A real quibble here, TMI was a pressurized water reactor.

9. Agree, to a degree.

10. Agree.

12. That would be preferable. Same with 13.

Hi N&P

thank you for the sound and well thought comment. Some remarks:

"Transuranics, whether in intact spent fuel or in a fuel reprocessing facility, are readily controlled and not dispersed."

Unfortunately this is sometimes not readily controlled.

There was an uncontrolled bringing out of plutonium from a German research institute, there was a recent finding of enriched (reactor grade) uranium in a private household in Germany, and if you measure the concentration in the north sea near Sellafield or LeHague you will find some.

" ...reprocessing can also create the material required to manufacture nuclear weapons. While providing a poor material and undesirable route for nuclear weapons production"

This can be done much better - as was discussed once more in the newspapers about the Iranian attempts - by using the fuel only for 1 to 6 months.

What N.Korea did is not known so forget it for the moment.

The "factsheets" are known more or less since some time but the critics are going on and I would not be sure if no water will enter the deposits and leach the whole stuff in a short time. As the glass blocks are red-hot for many thousands of years these would readily react with water. So if I would decide on that problem I would inquire for a system of medium time depository of used fuel rods without active cooling but would cancel the reprocessing totally (unless the uranium price is 100 times the todays price what will not happen.)

Concerning the toxicity of coal plants emission we can get out the mercury without big cost. And we should do this and ban the mercury in the protection of wheat seed aginst fungus and rodents.

But mercury is not nearly as poisonous as plutonium.

Mercury is allowed near 1microgram per kilogram of food (which may be too high).

Metallic mercury and the sulfide (cinnabar) is not poisonous but the soluble salts and most poisonous the organic mercury is badly poisonous. (We will learn about most other metals to be the same but knowledge takes some time to diffuse.)

Uranium is much worse: 1milligram is allowed per year for workers in uranium mines. (Uranium is not pure in the mines so toxicity is worse than with pure material.)

Plutonium is still much worse: 100million times the toxicity than uranium.

It is said that this is chemical toxicity but nobody with critical thinking will believe this.

(Have a look at polonium, why is it even more toxic?)

So avoiding the reprocessing would be a sound decision.

RHABE

All the critic's are right about steam driven reactors, but non steam driven reactors such as the Canadian sub reactors or the Racine re-actors or the Otec entropy reactors have the promise of both storage of and safe use of. They rather than using fission use just plain decay as source for heat. They have the promise of being 1000 year reactors. The question is can we build them cheap and well enough to compete with coal? Look at an earlier discussion. Can we build a 1000 year re-actor?

Why do people insist on talking about Canadian sub reactors? There have been several references to them in this thread. Canada considered a nuclear submarine fleet but they ended up buying used diesel electric boats from Great Britain.

I once read a reference to using a SLOWPOKE research reactor in a small submarine but that never came to fruition.

Right on, Curious!

Plus, many people don't realize that Canada is not a member of the nuclear weapons group of nations. The national policy is, and has always been no nukes in the armed services. Even our reactors are designed to eliminate the possibility of easy weapons-grade byproducts.

Maybe that ban includes nuclear powered submarines. Certainly, we have the ability to build them here if we ever wanted to. I seem to recall that Babcock Wilcox had a model nuclear-fired steam system they may have built for some shipping clients once upon a time.

Mark

The beauty of the cosmos building blocks are not ony in that which is weighted, but by that is logical as well.

Is it true one state the size of Pennsylvania could produce all Americas energy by growing algae for biofuels application?

I am personally more worried about our water reserves and the proper conservation and utilizations of such.

We can talk about the dangers of nuclear fission and it's so-called waste until we are blue in the face. But the real answer is to recycle the used fuel.

The operating plants in the US create 2200 tons of this used fuel annually and are running out of storage space for it. By 2015 42 of the active reactors will run out of storage space.

The Yucca Mountain storage repository is only rated to store 77,000 ton of waste and it is not slated to start operation until 2020!

There are going to be new plants built, in 2005 Nuclear plants produced 4,000 billion kilowatt-hours and this will increase to 5,800 billion kilowatt-hours by 2030.

The projected "waste" will reach 94,600 tons by 2050, but this the only way to increase the needed electrical power with out increasing the greenhouse gases.

I have worked in many nuclear plants and I always feel safe. I have also worked in many chemical, refinery, steel mills, glass plants, ships, submarines to name a few places I have to compare the nuclear plants to.

Nuclear fusion - cold or hot - have yet to be proved as a viable option, and may never produce usable sustainable power.

The only option is oil or coal powered plants. The scrubbers to reduce the toxic acidic gas exhausts now cost far more that the actual plant it self.

Wind power is self limiting, wave power has its own limits, geo heat may prove to be a high producer of clean power, but it too has its dangers and limits.

So nuclear fission with controlled used fuel recycling is for now the further of power production.

Would or do any of the proponents Uranium based power production, live next door or directly down wind, from one of these marvels of safety?

Now of course there will be a reply about how dangerous & toxic other forms of power production are!

Making decisions that can't be taken back for 100'000+years is not something that should be undertaken by a small group, that hopes the problems can be resolved after the fact.

Think about the implications of what you are proposing!

When the current waste is recycled, then would be the time to think about making a new mess.

When the current waste is recycled, then would be the time to think about making a new mess.

All the critic's are right about steam driven reactors, but non steam driven reactors such as the Canadian sub reactors, (Canada built just one research nuclear sub to be operated under the Arctic sheet ice,(Water based system) or the Racine or Sterling re-actors (ie NASA)(Helium based) or OTEC (Ocean Thermal Energy Cycle) reactors (Water based)(The one I threw out as a crude example higher up in the discussion. Please feel free to add your thoughts on this) have the promise of both storage of and safe use of. They rather than using fission use just plain decay as source for heat. They have the promise of being 1000+ year reactors. The question is can we build them cheap and well enough to compete with coal? Look at an earlier discussion. Can we build a 1000 year re-actor?

I have I lived a couple of miles from both a Coal in Kentucky and a Nuclear in Milwaukee and My sinuses were a lot better in Milwaukee. We dust all the time and I am about 20 miles down wind. The plant is now using the decaf coal. Pre-scrubbed. I see both sides of the discussion. As far as Coal vs Nuke. There is long term wastes are on both sides. Quick lime is produced in scrubbing coal this waste expands 10 times its original size when exposed to water ie. steam. CL is one of the most caustic substances out there. You fall in it all some-one has to do is stir a little and they won't even find your bones. About a year and a half ago a giant slag pile and slag holding pond failed in Eastern Kentucky wiped out a town. One of the worse ecologic disasters in ten years. Did it make the news? No. Sorry a little known news agency called NPR (National Public Radio did! When they ask for support - donate if you want to know what is going on.) Did the EPA issue large fines and make Massey clean-up the mess? No, "the Report was lost" by the higher-ups in the EPA. Translation Massey gave a large donation to key GOP members. Massey owns Kentucky politicians (both Parties). No secrete there. Understand this... Money may make the world go 'round, but it takes energy to print those bills. As long as Massey produces cheap coal for our Electric Coops it is the darling of the electric industry. Period!

Now on the Nuke side got to be fair. Plutonium is 100% carcinogenic (an atom of it in you will cause cancer.) Uranium is also the same way. So there is no acceptable level. Period! Fortunately mining of it in the US is automated. One guy sits in a AC trailer and works three mining machines. Thanks to wireless technology. Now there is still a need to do maintenance on those machines and during maintenance there is some danger to exposure, but has been reduced to almost zero with clean suits and washing procedures. Processing exposures again is significantly reduced by automation. Coal mining is far more dangerous and enivromentally damaging to the enviroment. IE last years deaths in Kentucky and Virginia mines. This is by the nature of the mine there will always be trapped methane gas in a coal mine along with CO2 and other 'tanes. The wastes of nuclear fission stay hot sub fission for about 10 to 100 years after that period temperature drops by half every hundred years give or take, that is why I posed the question. Can we build a Thousand year generator? My biggest critics came from guys that the wastes products wouldn't stay hot long enough for a sealed system to still be operating for 1000 years. Something that actually took me by surprise at the time. I kept on pointing out I wasn't making steam, but only causing a 10 to 20 degree increase over ambient temperature.

There are folks who see the need to develop decay generators that recycle wastes with closed systems. That this use of nuclear energy is far better way to use these materials. That this type of generator doesn't increase the toxicity of the nuclear material. Are necessary for any expansion of nuclear energy. Currently the debate on decay generators is should we use a Water based system or a Helium based system. What are your thought to this?

Hi RoryHoulihan,

"that is why I posed the question. Can we build a Thousand year generator?"

The problem with using the waste to generate power is the instability of the energy being released for the waste. The fissile rate decays exponentially with time and since the energy output is governed by the this rate the amount of energy being released also drops at an exponential rate. When the fuel is in the core and close enough to become sub critical they use moderators to stabilize the fissile rate and regulate the energy output. Once the fuel decays to the point that they get close to needing all the moderator to be removed the core is no longer viable and requires replacement.

The big problem with trying to use this waste is the inconsistency in the rate of decay and hence energy output. To operate some sort of generating system you need to have a relatively constant output of energy and this is where the problem lies.

When you initially suggested the development of a machine like this I was skeptical and it would be a very difficult and expensive system to develop. None the less I now think that it is something that is worth looking into especially if it were to work in conjunction with monitoring and storing the waste.

Something that I find greatly worrying is the fact that the nuclear waste we are currently generating requires constant attention and monitoring. To date there is no way that it can be passively stored and left to decay without some sort of intervention on the part of humans. This waste is going to remain dangerous to the environment and require monitoring for at least 100.000 years and probably considerably longer. Now that's roughly 20 times longer than anything we can call a civilization has currently existed.

I find it extremely arrogant for us to think that we have the slightest chance of actually being able to do this. Think about it, we can't even get society to remain stable for 100 years let alone 100,000 years.

The question is not what happens if we stop looking after this waste but what happens when we stop looking after this waste.

Until we develop a guaranteed method of passively disposing of the waste from these reactors it is extremely arrogant and negligent of us to carry on creating more of it.

Heat (rate atom vibrates) lags decay (rate atom gives off neutron) not by much, but over time is significant. Now back to original thought - egg shape needed (terrestrial water system not space) - reason needs to be deeper in the middle shallow to the sides. Why hotter wastes (less stable) in the middle more stable wastes (less hot) to the sides, five arms max (just works out that way), Arms are coma shaped like a cold front. I came up with this looking at my screen saver. Picture of the Andromeda Galaxy. You get use to something and you stop looking at it, thing. I switched it to the crab nebula, while doing that I was presented with about twenty to thirty pictures to choose from. Suddenly I realise I was looking at convection currents when I looked at a Galaxy. If you look at Galaxy in the middle of it's quasar phase and you really see the convection processes working. Pin Wheel Galaxies are that way, because of the convection currents created during the accretion disk stage of their life, but there is also a back flow. Pin wheel Galaxies conserve their energy and mass. Energy flows in the direction of least resistance, it wants to follow a path. Even if one part (young hot wastes) have an uneven output the vortex current produces an average heat output. The vortex current in the water moderates the waters mean surface temperature. The water's vortex current also will cause the air above to eventually vortex to. Increasing the surface contact of the air in the transfer tubs. I had a friend who leaned that the water way. He flew over a spring fed lake. Where the spring was there was a strong down draft. He dropped about a hundred feet and two feet off the water before he leveled off. You have dependable cycles going. You'll get good output. I am nodding off so I hope this makes sense.

I'm certain that when you wake up, you'll read it again and make any changes you need to make better sense of it.

Mark

Man, I was hypnotised, reading this post. You have a magician in you, or something.

I felt like a Little child being told of far-away places, over the grand sea.

It felt like the science class of first grade, when the future was bright and the horizon was vast and inviting.

Poetry in motion.

A fivestar rating, to express my appreciation.

No big science or Places Far Far Away - simple model can be tested with a 20 lb tank of propane and a scale model. Remember some convection currents are dust devils and water spouts. On Earth things like to spin why not work with it - not against it. I learned to take right turns to get to work if I wanted to get to work on time.

had a chance to talk to a guy on batteries. Saw as possible solution. One of the ways to make a battery element is lay out chemicals on/in a foil or film and whine up the film. Technique adds surface area and gives a more reliable output. Why can we adopt thiis same technique to nueclear fuels and their waistes? Sometimes it is best to forget the sledge hammer and use a finishing hammer instead. Even with the current reactors this technique would aid in fuel rod efficiency and on the backside would help out with instability.

Now You're talkin

Turn a liability into an asset.

@ least suck enough power off the decaying waste to power the neighborhood.

All good points about coal

http://kpfa.org/

Even less coporate funding than public radio, lots of info on enviromental justice.

Increasing eficency is going to be key to slowing growth of energy consumption.

How many fluorescent light bulbs the ones that replace incandescent do you have? Do you dry your clothes on a clothes line or in a dryer. Do you turn off your computer and router when you're not using it? TV too? Have you moved from the suburbs to the city and sold your car? All things that will significantly reduce our carbon foot print. I remember seeing energy saving bulbs come into our Lowe's and bought a bunch when they were clearancing them out. Not enough sales! We are into convenience not into savings. We are dealing with 2 Barbie doll generations and the generation that created them. I love to talk about saving energy, but as I find that convenience gets in the way. I remember my first introduction into Mining and Metallurgy. It was @ UW Madison, I was a junior in high school and I was listed as a candidate (1 of 3) for the program by one of my professors. Funny the speech was on the limits of our energy supply, (oil and coal) energy and the need to conserve. The reason I was picked wasn't my GPA, good not great, but because I had created several Solar Collectors. Started a solar company. I made plastic solar collectors that fit into your window and turned your window into an active solar collector. Had three designs and they all worked great. Great idea, but the design (the most efficient) my backers chose women didn't like, because it darkened the place too much. My first run into the comfort and convenience wall of consumers. In general we are creatures of comfort and convenience. Go with it-win, go against it-loose. I am a hopeful pragmatist. I see all things as both bad and good and you try to make the best of things. Conservation won't happen until it costs too much. Better to take advantage of an untapped resource now while things are relatively stable than wait for all hell to break loose and wish you had, because the guy that made the speech was right. It'll last forever - not!

Hi RoryHoulihan, in answer to your questios,

"How many fluorescent light bulbs the ones that replace incandescent do you have? "

All of the incandescent lights in our house except the ones that are on dimmers, have been replaced with fluorescent bulbs.

"Do you dry your clothes on a clothes line or in a dryer?"

Clothes lines primarily, the only time a dryer is used is when there has been a protracted period of wet weather. Considering we are in the midst of the worst drought in 1,000 years the clothes dry is fairly redundant at the moment.

"Do you turn off your computer and router when you're not using it? "

No but while it is not in use it is normally doing something constructive like a backup, virus scan, disk defragmentation etc. I use a laptop as well that has a total power consumption of around 70 W

"TV too? "

No again but the TV is a LCD unit that draws little power when turned on compared to the older cathode ray versions.

"Have you moved from the suburbs to the city and sold your car?"

We live approximately 15 Km from the city center and the only way to get there is by public transport as there is absolutely no parking available. The only hassle with this however is the price of property close to the CBD in Sydney is astronomical. The majority of people have not chance of affording to live this close so have no option but to live in the outer suburbs.

http://www.icenes2007.org/

Anybody interested in nuclear technology of fission reactors should have a look here.

RHABE