The Past, Present, and Future of Nuclear Power

I live about 50 miles from the largest nuclear power plant in the country. (I think that's right)

Frankly, I wouldn't want to live any closer to one, but I see nothing else that will provide the transition we seem to need from oil to whatever the next fuel of choice is.

We need to realize that a nuke plant is incredibly complex, but they can be safe.

If it is planned, designed, constructed and run by honest ethical people, I'm all for it.

However, there must also be some level of fear for this level of safety to be implemented. As the technology proliferates and the general population becomes more comfortable, the safety tends to be one of the first things to have corners cut to reduce construction, operations and maintenance costs. As our comfort level in technology grows we tend to stop being as concerned about contractors cutting corners, and business "ethics" are driven by the bottom line. so unless it is likely to cost them more money due to bad press or fines, they will cut corners, and as we relax regulations and stop being as observant they will continue to push the envelop. It is true that Chernobyl did not have nearly the enduring impact on the local ecology and people as first suspected, and american designs tend to have much more redundancy inherent to their design. However, as time passes you could see such things begin to be chipped away as they represent additional costs to bringing a new fiscal resources for a company online and adversely impact maixmization of profits. American designs are so safe because of the great fear, and their lack of understanding of the technology, amongst most Baby Boomers who grew up at the beginning the nuclear age. This fear and lack of knowledge pushes the safety envelop out for this technology, against businesses natural tendency to try and collapse the safety envelop as much as they possibly can without adversely impacting their marketing/sales/lobbying efforts. We must always be aware, as nuclear fuel is inherently more dangerous than the fuel used in most other energy production facilities and must have safety protocols maintained to be utilized. The general public and private businesses are not the US military, so i would not have the same expectations of them as they have different organizational motivators and cost definitely matters much more outside of the military.

Moose;

All of this may be quite true; but the fact remains that the taxpayer has taken on the financial burden of waste storage with the plant operators paying one mil per KWH into the waste fund in order to avoid this cost of doing business. The taxpayer is now paying the operators for the on site storage of the waste.

I think its unfair to burden the taxpayer with this very significant "cost of operations."

Until the industry takes on the financial burden of waste disposal then I will remain unconvinced of the economic viability of the industry.

Without the taxpayer taking on this financial burden the industry could not compete, even against the most expensive alternatives; the life cycle costs are that high.

Gavilan

Nuclear power is certainly one of the energy sources we are going to have to start implementing to grow away from fossil fuel. I'd like to make a couple of points though about nuclear waste.

Nuclear waste can certainly be nasty hazardous stuff. But unlike other nasty byproducts of industrial processes, it is relatively easy to detect and locate where any radioactive waste has gone. Even minute amounts are easy to detect. This cannot be said of the mercury released from burning coal. Also some radioactive waste elements do have very long half lives, but they do all have half lives. The mercury I just mentioned does not have a half life. Mercury will be a hazardous material far longer than the plutonium trapped in the spent fuel rods.

The truly scary part of nuclear waste is that reprocessing spent fuel is basically the same technique required for making weapons grade fuel. So migrating to nuclear power will likely promote nuclear weapon proliferation.

Dear CQ,

I strongly agree and want to contribute some more super positive benefits of the CANDU principle, that is available as ACR1000.

ACR plus reprocessing can bring down necessary waste storage time from 500,000 years to 5,000 years. Acceptance will be much better, no storage of very long lived waste necessary.

Todays worst product of nuclear reactors is waste, waste contains fission products and trans-uranium elements.

Todays reactors cannot burn trans-uranium elements but CANDU and successors can !!!!!!

So with an additional reprocessing the trans-uranium elements can be separated and processed to new fuel rods. This procedure will be expensive as the long-lived waste will be concentrated within these new fuel rods.

So no more expensive waste processing to deposit valuable fuel. nor a conflict like Yucca-Mountain or Gorleben.

This is necessary with any reactor if the waste is to be deposited as concentrated highly radioactive waste. So better make fuel from waste. Cost is similar.

Then CANDU can and is burning Thorium!

Then: CANDU can burn the todays (highly radioactive) waste, eliminating very long storage time and relieving press on existing reactors.

Then: CANDU can burn continuously at refueling. So costly downtime is very low!

Then: CANDU is inherently safe as any failure in fuel rods or heavy water tubing will immediately turn off the reactor.

This is not my wisdom but from the experts of ICENES 2007 conference, where these new concepts were discussed. I am a specialist in precision engineering and have no experience with reactors and nuclear except 6 weeks practical work as a student 40 years ago. But one of my friends organised ICENES and told me about. So if anybody wants more details I can ask him for a copy of the details.

But US, German, French and Russian reactor-builders will stick to their old concepts until these new concepts are coming back from India and China - incredibly cheap and simple. Or the power produced nearby will come if we do not let in the reactors.

So press the politicians to open their mind!

RHABE

Hi redfred,

I think you have the balance about right. Storing nuclear waste is not a trivial problem, but short-term it might be less of a problem than our current system of storing the waste products of fossil fuel plants in our atmosphere, our lungs, and our body fat. Increased use of nuclear power will most likely lead to the spread of nuclear weapons which will pose a serious military threat, but sending tanker loads of cash to people who don't much like us poses it's own security problems: our enemies grow stronger while we go broke.

I don't see nuclear as a great or even good choice - it is just a less awful choice. I don't think it is wise to hype nuclear power as wonderful, nor do I think it should be hyped as an end-of-the-world disaster. I don't think it is wise to hype anything, because it chokes off honest discussions for a generation or so. Too many people are like wind-up toys: once an idea makes it through their skulls it gets stuck in their heads for a lifetime. Conditions and technology can change quickly, but half-baked ideas (both pro and anti nuclear) foisted on our people by skilled marketing experts last much longer.

As for people who want to blame it all on politicians, this just doesn't square with the facts as I remember them. When we first started to build nuclear plants, no one in the insurance industry would sell them public liability insurance. I'm sure the insurance actuaries hired physicists for guidance, and after looking into the matter they decided to take a pass. The market spoke, and the politicians had to step in.

It confuses and saddens me greatly to see some of the arguments made in favour of nuclear power.

Like 5,000 years of highly toxic waste is acceptable (as if making the comparison that it used to be 500,000 years, so - wow what an improvement!). The civilizations of 5,000 years ago left us the potters wheel, great pyramids, bronze age, chariots and indoor plumbing. We will leave a bunch of plastic and nuclear waste among other things that may or may not seriously destabilize the biosphere. But this is OK, because we need cheap power and convenient goods right now!

As for the issue of safety, yes, catastrophic incidents are rare (but in many cases closer than we think - the CANDUs in Ontario were shut down by the regulator because of things like a containment building that hadn't been working, corrosion that led to leaking tritium and heavy metals into the Great Lakes (largest freshwater bodies in the world), however the bigger issue is the ongoing contamination of the biosphere with nuclear waste that is not going away in our life time. From mining to processing to operations and then waste management, nuclear power has left a devastating swath of pollution and health risks.

In addition to the safety and health risks, nuclear is just plain uneconomical. This is from my experience following the issue in Ontario, where CANDU reactors have (for new and refurb jobs) ALWAYS come in far over budget, and the bill ends up getting paid by us, the taxpayers. In the late 90s, our utility which had built and managed the plants wrote off their stranded debts by passing almost $40 B debt repayment obligations onto our electricity bills.

Yes green house gasses and mercury are a problem, but not one that results in mutations of the building blocks of life as radiation does.

The cost over runs are probably those associated with Darlington. The government cause construction to start and stop several times, stretching out the construction process by several years and running up the interest costs. They have a law in Ontario that power plants can't be paid for out of cash flow but they must be paid for from the electricity generated by the finished plant so there is a large interest component that could be much smaller if they could pay at least part of it from their current cash flow.

The CANDU's built in China and Romania have been at worst on schedule and on budget, a couple of them were ahead of schedule and under budget.

yes political meddling in Darlington resulted in cost over runs. Initial budget was $3.9 B and final cost was $14.4 B so maybe a quarter of the debt is attributable to that - the facilities were (as I understand) all financed through debt anyhow, so the overruns added to but are not the sole cost of the debt. There was a recent announcement that the refurb of Darlington could cost $10 B, which may really mean $20 B plus if the previous refurbs are any indication of a trend.

All of the refurbishments of CANDUs within the last few years are well over budget. Again, in part to mis-management, but there are also structural issues around the design concept (large centralized plants and associated distribution systems).

Also, the tech only exists thanks to massive government subsidies into the development of the CANDU reactors and probably others.

One question I always have is where does the fuel for nuclear power come from? Is it more toxic if very small quantities pollute the environment than the basic materials already in the environment that it is derived from?

Admittedly, I can see polluting a few limited pristine areas where radioactive ores do not exist. But it seems like all we are really doing is concentrating a component of the dirt from somewhere like Canada or Colorado, and using it in a localized facility somewhere else. Where it is possible through small releases that we increase the radioactive constituents in the environment and thereby the risk locally. But by removing the ore from some other area, we have reduced the risk in the ore producing area locally. Overall it could be a push if we are discussing water or soil pollutions (air would be different because for the most part the ores are not typically available in any significant quantities over long periods of time in the air (except as infrequent dust). Unlike plastics and other materials that have been substanitally chemically altered, nuclear source materials are just ore that are concentrated, "refined", to provide an increase in the localized source energy. So as long as you remain separated from the concentrated ore in mass, you should not be in much higher risk than anyone digging around in the dirt. In this cases, dilution really is a solution, since it comes from the earth in a diluted by the mass volume of earth it occupies.

I have read in one source that the tailing ponds (exposed to the air, water and wind - so just because it's in the middle of nowhere in Canada does not mean it does not blow into the atmosphere and into populated areas) can leave behind 85% of the radioactivity (15% is captured as raw material for fuel).

The raw ore is then taken (mostly) to Port Hope on Lake Ontario and the town has essentially been turned into a toxic waste site. It's all over the harbour (and subsequently moving into the Great Lakes currents) and through the town in improper storage facilities (the liberties allowed for short term storage ensure contamination and apparently have no time line associated with how long is short term).

As for "infrequent dust" it does not take many particles of alpha radiation to kill you. And there is plenty of potential for the dust to kick up off the giant tailing ponds and slag heaps. The global standards for acceptable levels are oddly based on levels of contamination in the biospohere after decades of above ground nuclear testing within the last 60 - 70 years. As if this is a period long enough to understand the long term impact on humans and other life.

The nuclear materials buried hundreds and thousands of meters below grade in rock formations is not 'diluted' nor is it released by 'digging around in the dirt'. There are few places where this radiation exists in any level of concentration and it is encapsulated in the earth.

So since the removal of radioactive ore from the area reduces the total radioactive load, the waste derived from use of radioactive materials would (since the activity is reduced through usage) be best suited to be disposed of in the former locations of the strip mines. That would then have a net positive impact when compared to a the do nothing alternative in relation to ther radioactive load on the local environment. Basically you would be placing a less radioactive waste back in the pit to replace the more highly radioactive ores, and then could place the surface soils that were removed back over as a cover. As far as management and handling of the ores, well that is an issue that might have to be dealt with as the dust could in large quantities represent a huge risk for inhalation, but dust is easily managed (of course this assumes the dust from imported ores is more radioactive or would increase exposure relative to the dust found in the local environment, which may be itself derived from the natural radioactive ores).

Radioactive materials are part of the natural components of the soils of the Earth. One of the reasons that smoke from tobacco is so carcinogenic is that the tobacco plant concentrates naturally occurring polonium.

It bothers me when people think that radiation only comes from man made sources. Have you not heard of Carbon dating? Did you think that the C ¹⁴ elves magically appear upon death of all living things and inject a batch of neutrons to convert a calibrated percentage of C ¹² to C ¹⁴ so that people in the future can date the age of the dead? Natural radioactivity occurs all the time. The average background radiation dose for an adult per year is 360 mrem (aka 3.6 mSv). Please try to keep this in mind when you hear about detectable radiation levels and the lethality of a few alpha particles. Now, it does not take many milli-curies of an ingested alpha emitter to produce an expected lethality of 4500 mSv. But that's an enormous number of alpha particles absorbed.

We do learn from past mistakes and there are currently projects underway to clean up the problems in Northern Saskatchewan and Port Hope.

Hi RCE,

as the Uranium ore is a mix of Uranium and its decay elements - and some of these much worse than Uranium it is very difficult to set a safe limit.

Most dangerous are the alpha-emitters. Not at all dangerous if at more than millimeter distance but killing cells if ingested or (worse) inhaled.

These ores are oxides, sulfides and phosphates, partially soluble in our body fluid and excreted with urine. So kidneys and ureters and bladder may suffer worst.

I recently made a protest to local water suppliers that wanted to establish 10µg of uranium in 1 cubic meter as a safe level. This level will result in above 4000 Becquerel of alpha-radiation in the kidneys - not too much of all damaged cells will die, but much too much if some are surviving and damaged in a manner that the growth limiting mechanisms no longer work: cancer.

If you remain separated from the concentrated ore you are very likely in the region where the Uranium is deposited that was soluble by weathering of original granite rocks. (Most within 50Km distance).

So dilution is not a solution but absorption by clay and deposition.

RHABE

Alpha emitters can be a dangerous radiation source only if the source enters the body. Different radiation sources have different penetration depths. So an alpha particle will not penetrate the dead cell layer of skin because it will lose all of it's kinetic energy by then. However, if the source can reside inside the body, then all of the alpha emissions will deposit their energy into the surrounding 45 μm of tissue. (I would expect that this would then produce an encapsulation of dead tissue around the source that would now act as a shield to the healthy tissue. But I am not a physician, or health physicist; nor can I find a link to support or refute my opinion so let's not take a tangent on my speculation.) This complete absorption of alpha particles in a very localized area is why physicians do not use alpha sources for medical treatments. (If you can get that precisely close to tumorous tissue, just mechanically remove it with surgery.) Now if the alpha source element is chemically bound to a molecule that can permeate and disperse though out a body then and only then can an Alpha source be a direct radiation hazard to a person. Now, depending on what the Alpha source transmutes to with each scintillation this might become a truly dangerous beta emitter or gamma emitter, but I'm limiting this part of my reply to what the Alpha particle itself will do.

Now, the Beta particle emission is more difficult to quantify what damage will occur and to how much tissue for unlike Alpha particles, Beta particles have many different energy levels depending on what nuclear decay occurred. In the penetration depth link the two energies of 2.3 Mev and 1.1 Mev have a water penetration depth of 11mm and 4.6mm. In both cases this will affect a much larger volume of tissue. This means that a Beta source internal to the body is much more damaging, for it does not have to disperse in the body to be damaging to significant amount of tissue.

Gamma particles are the most difficult to predict what damage they will cause for they are high energy photons that have no net charge. Also a wide array of different energy levels for the Gamma particles can occur. So the penetration depth greatly increases to include in many instances distances farther than the dimensions of the human body. (A clarification is due here. The penetration depth dimension is not the depth that a specific particle will travel before stopping. Penetration depth is the depth where a certain percentage of particles (I think 99.9%) will have come to a stop some where along the way.) Since some gamma particle species will likely leave a body long before colliding with tissue found in the body, the realm of nuclear tagging can exist. This is one of the reasons that nuclear stress testing can happen.

What is often overlooked in these discussions are the fact that with every Alpha and Beta scintillation, an atom of the source transmutes into a different element. The chemical implications of alpha and beta emitter transmuting to a different element and thus a different molecule.

Hi Redfred,

"Alpha emitters can be a dangerous radiation source only if the source enters the body"

yes I agree, but these particles will enter the body! This is dust, anything below 10µm mean diameter is dangerous. Some bigger particles will be stopped in the nose the throat and the bronchus and cause cancer there. Most airborne dust is much below this diameter and will settle only by electrical forces.

15 µm Silicon-Carbide has a settling velocity of a few centimeter per second, so any turbulence will rapidly re-disperse it.

I did not know about this big penetration depth of alpha particles in living tissue. This is equivalent to 100 to 200 cell mean diameters! And any of these cells will be severely damaged or killed. So the likelihood of damage is much bigger than with beta or gamma radiation.

As the mass of an alpha-particle is 8000 times the mass of an electron or positron, so the chance to hit a critical part of the cell is much bigger.

So in usual safety sheets there is a factor of 10 less allowed alpha particles compared to beta. Gamma is different as penetration depth is a complicated function of energy.

The biggest problem is the long lead time that a tumor needs to develop to a critical size. Around 30 to 40 doubling times are needed to grow from a single cell to a 100g tumor. (If doubling time is constant- not likely, and if the tumor starts with a single cell - doubted today.) But regardless the doubts - any animal experiments are not valid to predict allowable human exposition.

Only with Uranium ore (from the miners), with Plutonium (from 3 accidents 1945 to 1966) there are some data.

Also with Uranium in drinking water and with Radon in living spaces.

Uranium in drinking water: US army had a quarter where the drinking water of a natural source had an elevated Uranium content of (my memory) 170µg/liter. Today allowed is 10 to 20 µg/liter - much too much I think.

Experience with Radon is from Swiss houses for private living. They had a statistic that most lung cancer in some places came from natural Radon sipping from below into more or less encapsulated houses. So some years ago the government supplied dosimeters to be placed on the floor for some months and then to decide if more insulation or ventilation is needed. Result was that nearly 50% of houses needed better air! Think about if you live within 40Km of mountains (any size) or clay- or shale -sediments near old mountains.

A more or less safe level may be extracted from the Potassium in our body - nearly 40 % is beta-radioactive with a long half-life of above 1 Gyears.

Worry a bit and be happy!

RHABE

Now seems like the time to give people something eles to think about regarding radiation and the dangers of it. One guiding principle is "The Danger is in The Dose". There are two theories regarding the dangers presented by small doses of radiation. There is no question that massive doses of radiation can be fatal and the dieing process is not a gentle one.

The oldest theory was there is no such thing as a safe, low dose of radiation. It is called "Linear, no Threshold (LNT)".

There are radiation biologists who now believe that there is a phenomena called Hormesis. Hormesis is a DNA repair mechanism that is capable of repairing radiation induced damage to DNA and if repair is not possible, it can cause the cell to die rather than mutate into a malignant cell. This repair process has been observed in animal cells.

I just thought that I would stir up the pot a bit.

I was afraid that the point of my posting would get warped. Yes, particulate coating (dust) onto the organ with the both the largest surface area and the shallowest depth (walls of lung alveoli) with an Alpha source will maximize the damage that an Alpha source can produce. But to achieve this maximum lethality one must meet the narrow two criteria of particle size and airborne dispersal you indirectly cite, to target the most sensitive organ to this radiation source. Beta sources do not need this kind of targeting to do their damage. A Beta source inside the body will do its worst anywhere in the body. Beta sources, in my opinion, are much more dangerous than Alpha sources.

But as I mentioned earlier, I despise disputing rumours. I do not know where you get your dust dimensions. The Center for Disease Control (CDC) states that airborne particulate matter less than 5 μm is the considered threshold for particulates to be retained in the lungs. The CDC considers less than this size dust a hazardous size for any substance due to silicosis disease. Yes, an Alpha emitter will compound this hazard and therefore less dust will likely be needed for early lethality. But nowhere has concentrations densities of the dust cloud or the number of Alpha emitters been mentioned. So I again say that Beta sources are more dangerous, since anything this small lodged in the lungs will cause damage.

I also do not understand your source for "100 to 200 cell mean diameters!" The penetration depth of an Alpha particle is 45 μm as I cited earlier. The magazine Experimental Physiology places the average diameter of an erythrocyte (red blood cell) at 8.8 μm, not 220 to 450 nm. Now an alveoli has a nominal diameter of 200 to 300 μm and the capillaries in these alveoli have only a little more than one erythrocyte for an inner diameter and very thin walls. So with these cited dimensions the alveoli of the lungs are still the one organ site that an Alpha source will do considerable damage. But I think you exaggerated a little too much.

_{This is supposed to be a blog that people with good mathematic skills reside.}

Hi,

my statement about number of cells that are hit by an alpha particle was wrong, correct is 10 to 20 cells that are hit.

The erythrocyte is a pancake like structure that is deforming to a bell-shape to pass the small capillaries of only 4 µm inner diameter. Only by this deformation the high exchange rate of oxygen and CO2 can be maintained.

Beta sources are estimated to be a factor of 10 less dangerous than alpha sources. (Official data - I don't know if trustworthy. Derived from experiments with short lived lab animals, so no extrapolation to longterm problems allowed? )

You mention silicosis: this is only with quartz of sharp surface structure, freshly produced dust by grinding or drilling. Else any dust storm in the deserts would kill the inhabitants. Most quartz particles in the deserts have rounded surface structures.

The situation is different with clay particles but these definitely do not cause silicosis.

Same with any (?) other natural mineral. Exception: the fibrous asbestos crystals. And artificial: aluminum dust.

Back to Uranium: if from natural ores this is not an oxide but more soluble sulfides or phosphates. If inhaled then dissolved in the body fluid and excreted via the kidneys.

So Uranium gets concentrated in the kidneys. I tried to get some data in a recent discussion about Uranium in drinking water but no success.

"But nowhere has concentrations densities of the dust cloud or the number of Alpha emitters been mentioned."

You can calculate yourself: take the origin of the dust and its typical content of Uranium and its decay products.

Get a radiography on old fashioned photo paper or film to detect if it is distributed evenly or point-wise after being weathered to dust.

From the content in the dust with the half-life of the different species you may calculate all the radiation exposure.

But then: nothing will result.

The alpha is more dangerous as it hits more massively the cells structures. If the cell nucleus is hit, most cells will die. Most of these by controlled self-destruction: apoptosis. Some by complete sudden death. But those that survive and the apoptosis mechanism damaged will become a problem if at the same time the tissue-growth-limiter function is destroyed.

Look at the Nuclepore filters with mica as the filter membranes, the pores are from alpha particles, later enlarged by chemical etching. Along the path of the particles the crystal-lattice is completely destroyed.

RHABE

RHABE,

I've enjoyed many of our discussions and wished to continue to debate with you in the future, but you seem to be consciously ignoring what I thought were clear points of my arguments. I am not a physician or a health physicist, so I support my unqualified opinions with cited references to what is not my opinion. (I happen to work daily with health physicists which is why I get a little passionate about this topic.) I considered expanding this discussion to include the discovered mechanisms of radiation poisonings. But realized that this would also likely prove to be an exercise in futility.

To prove my point that this will be pointless, allow me to cite your only quote that happens to be of me and your reply.

"But nowhere has concentrations densities of the dust cloud or the number of Alpha emitters been mentioned."

You can calculate yourself: take the origin of the dust and its typical content of Uranium and its decay products.

How can I calculate what has not been cited?

REDFRED....

I have heard it said that analogies are dangerous. So lets take a walk on the wild side.

In the center of a tropical rain forest, a gun is placed that launches projectiles (with sufficient speed that the projectiles do not stop at least until a living object has been hit) repeatedly, each time in a new randomly selected direction. Would a localized area be cleared of most life more quickly if the projectiles were 2000 lb solid steel balls, or 1/4 lb solid steel balls? Assume the rate of fire and energy per round are similar (yet at least enough to launch the larger projectile with sufficient speed that it does not stop until striking some living object).

If the firing of projectiles did not cease, would 1/4 lb or 2000 lb projectiles have living objects in closer proximity to the gun, assuming similar rates of fire, energy per round and growth rates of living objects?

Alpha particles are ~8000 times more massive than are Beta particles. Typically a internal dose of alpha radiation of a certain mrem is considered to be roughly 20 times more dangerous than an internal dose of beta radiation of the same mrem. This is accounted for in the quality factor.

The tobacco in cigarettes gives us a lot of data on insoluble alpha emitters in the lungs. Tobacco happens to have a very high affinity for Radon gas. Affixed radon goes through a decay chain of some seven elements (through lead twice, I remember) before ending up as Polonium; a relatively insoluble alpha emitter.

There are numerous studies that support the idea that idea that while it takes relatively a relatively small internal dose of alphas to induce problems, the internal dose of beta emitters is much higher. http://www.jstor.org/pss/3580106 here is one.

Here is a fun fact. You ingested a source of betas strong enough to show up on internal dosemetry measurements.....last time you ate a banana. Naturally occurring K41 is easily seen when doing internal dosemetry readings. The K41 betas are not very high energy (though enough to be picked up outside the body), and of course being betas don't result in extremely localized damage like alphas.

On another note: the discussion about the risks and benefits of nuclear power are never as simple as either the proponents or opponents claim....

Yes, coal plants are responsible for massive volumes of radioactive chemicals and other harmful chemicals (like mercury) being introduced into the atmosphere. It is not unreasonable to state that far more contamination is released into the environment from a typical coal fired plant in a year than over an extended lifetime of a typical nuclear power plant.... but it misses the quality factor of the contamination.

It is not unreasonable to point at the very few nuclear accidents and perhaps claim that the most damage done by the accident at Three Mile Island was by the mishandling of PR. It should have been defined as a triumph and not a disaster.

It would be foolish however not to consider that sediment samples from the bed of any river in the world show markedly higher concentrations of long lived high energy radioactive isotopes of fission products Cesium and Rubidium after the Cherynobl incident than prior. It is very difficult to predict the effects this will have.

I share your passion for useful discussion as well as what I suspect is your disdain for fanciful speculation.....so much that I continue to comment on CR4 as a guest after being banned for pointing out fallacies in logic, inaccuracies and misleading statements of those who would rather believe they are perfect than embark on improvement.

Benbenbanned.

Hi Village Technologies,

you are right about mining and dust distribution. This is a very serious problem.

Any miner is allowed an input of only 1mg/year. (to the lungs mostly, most damage done there)

Many mining activities are now leaching from geologically old river beds - so "no" problem there.

Open mining should be done only with water spray to wash down the dust. If the dust is absorbed by clay and or phosphate it is stable and not readily redistributed. This is shown by the many sedimentary uranium concentrations that are derived from weathered granite. Granite is containing Uranium typically 30 to 300g/m³. If you extract this you need a transportation permit.

So any attempts to grind or saw granite (and some shales too) shall be done with water cooling!

You are right too that the remains of early nuclear activities are horrible. Hopefully we know more today and act accordingly.

Early activities were driven by nuclear weapons (including reprocessing). Now the situation changed.

RHABE

Why not pebble bed reactors?Inherently safe, no rivers of cooling water required, no expensive heat exchangers.Can be built with pre manufactured components and assembled on site quickly and very cheaply compared to conventional nuclear plants.The pebbles are recycled when depleted, and present no high level exposure.

The uranium is embedded in graphite spheres, coated with ceramic, which limits the concentration of energy to a safe level.

Google it:

Pebble bed modular reactor.

We should be building these now!

These guys are doing it.

Hi,

there was an early version of a similar reactor in Germany that failed because of serious design flaws.

(Rumors are that these design flaws were introduced by the established reactor builders.)

This was called the THTR300 (Thermal High Temperature Reactor 300MW)

Uranium dioxide was used as fuel (particles 0.1 or 0.2mm diameter), encapsulated in pyrolytic carbon to ensure tightness against leaking waste. These pressed into tablets (near 2 x 3 cm), these screwed into graphite balls 7cm diameter.

The graphite balls were piled and will be critical if density is sufficient. So control rods (diameter 20cm) to stabilise were introduced from above! This was the major design fault as to push the big rods into the pile of spheres caused a lot of spheres to be damaged. Why not from below? Simple solution hat should work.

Helium gas was pumped through the pile and heated to 2000°C, heat exchanged to copper-walled heat exchangers.

The biggest task was the Helium turbine to drive the Helium loop. No ball bearings allowed and spiral-groove bearings (non-contacting dynamic bearings) at that time in early stages of development. (The liquid oxygen pumps of the Space-Shuttle had similar problems).

This reactor type was thought to produce steam for chemical processes.

Never discussed again after shutdown.

Remaining question: why is your proposed pebble bed reactor inherently safe?

RHABE

The South African government has recently announced that it is withdrawing financial support for the PBMR while continuing to spend Billions for the World FIFA tournament. The PBMR could have been a great blessing to a country with energy shortages and a potential export item.

For the sake of the country I hope that the private investors will be able to keep the project going.

Very sad, it is all a matter of getting ones priorities right and what could possibly be more important than football to keep the masses quiet for a few more months while Rome is burning.

As for the private investors - I thought they had all left!

I guess we are preaching to the choir regarding pebble bed reactors. Today is 3-15-11, shortly after the Japanese earthquake and tsunami.

EVERYONE is decrying nuclear power. Politicians in their uneducated blowhard way are calling for a moratorium on new reactors here, shutting down some, yet not a WORD about the pebble bed alternative. Most of the hot air generators probably would not know a pebble bed reactor from an elephant. Maybe we can harness THEIR hot air as an energy source. Its not worth much, however.

BernieK

It is my experience that all sources of energy have inherent DANGER e.g. Natural Gas Explosions,electrocution, Coal Dust in mines,carbon emission,and the list goes on.

The Question boils down to 'Can the risks be managed?' and if so 'Do the rewards outweigh the risks?' (In the case of Chernobyl, the answer was a resounding NO)

Where are we today? According to LYNLYNCH and Dr. Moose The course is clear.

Not that I necessarily agree or disagree!

Keep in mind that Chernobyl was a very primitive and poorly constructed reactor, with almost no safety features, and what few they had had been bypassed repeatedly. And yet, the damage from that "accident" was nothing like what the alarmists had predicted.

Greetings Dr. Moose!

I agree and can attest to some of your statements having worked at Three Mile Island.

Flying a 747 into the reactor building would have little effect,every weld was x- rayed

etc. We seemed to be 'ready' for Nuke Power in the 70's, but it was shelved.Why?

Political reasons? Safety reasons? Unreasonable reasons?

I thought that this discussion was about the future of nuclear power, rather than the likelihood of radiation poisoning. To listen to some of the comments, it's quite remarkable that massive swaths of the biosphere haven't been exterminated already, humans included. I am not a health physicist, I have no sources to cite, but I take note that no such massive die-offs have come to my attention, and I do not have my head buried in the sand.

As I have already said. Nuclear power has an impressive safety record, and nuclear power facilities are so well built that it would take a nuclear strike to take one out. Their waste products are a fraction of those produced by conventional generating stations, and fairly easily dealt with.

The simple fact remains that without electrical power, this civilization of ours would grind to a halt, and I'm not talking about Monday Night Football. I am talking about our industrial plant, food production, hospitals, etc. Without electricity, billions would perish, and very quickly. So the important question is what the HELL are we going to do about it?

Some have poo-pooed nuclear power. What's your alternative? As has been pointed out over and over again, wind and surface-based solar are only effective as long as the sun shines and the wind blows, which they don't always do. Space-based solar is a ways off. Tidal, geothermal, fusion? Equally far removed. Am I missing anything?

The bottom line here is that we have only two viable near-term choices, fossil fuel plants, and nuclear plants. Which would you rather live next door to? I know which I would choose.

One can not separate nuclear power from nuclear poisoning. Just as one can not separate fossil fuel combustion from atmospheric pollution. All forms of power do have consequences and they need to be taken into account when discussing the efficacy of a technology or it's future use.

Massive die-offs and catastrophic incidents at plants are not the issue. I would suggest, if you are so inclined, to read "No Immediate Danger" by Dr Rosalie Bartell, to better understand the long term implications of increasing exposure to nuclear waste / pollution.

In summary, the result of increased acceptance of nuclear pollution with no real regard to long term issues, has been an increase in cancer and decrease in fertility. THis is evidenced by the so called cancer clusters around nukes.

I have lived within a few KM of both nukes and fossil fuel burners and the choice you've posed is an interesting one, and I choose combustion if the emissions control strategy is modern and in line with international best practices. The fact is that anywhere with a winter is likely already beside many fossil fuel burners, and if you have roads where you live, combustion is close by.

Of course we depend on electricity. We wouldn't be having this conversation if that was not the case. But just because we depend on it does not mean we need to keep over building the supply. (BY the way you missed the best option - hydro or wind assisted hydro, and tidal is not really that far off.)

The case for energy efficiency is massive - we are terrible wasters of electricity in Canada and the USA. So start there - reduction of power use through intelligent design (first) and habitual changes.

Nuclear power is the choice of central planners and big government. And bankers (lenders) and insurance companies (who are protected with limited liability in Canada and USA as I understand). They have historically (in Ontario and perhaps elsewhere) dramatically over estimated consumption level projections. This is in large part to justify huge projects at public expense, on loans with interest payable by the taxpayer. The private sector does not build nukes (they will build the technology, but not the plants) as far as I know anywhere in the world.

Nuclear power reduces choice and disempowers people who want to get out of the grip of utility companies, and skews the field of competition away from smaller, distributed generation which is inherently more economical and facilitates a free market.

You miss an important point. The world's industrial plant is the greatest consumer of electrical power. Do you propose that we demand that every manufacturer immediately update his plant to minimize power usage? It seems more likely that the owners will tell you to bugger off and go out of business.

I admit that I rather like the idea of small-scale power generation. I think it would be an excellent thing if everyone had a roof-full of solar cells, a wind-charger, and a basement full of batteries. But again, these things are expensive, and they do not address the needs of the industrial plant.

I am fully cognizant of all of the real and imaginary/alarmist concerns regarding radiation, both short and long term. The simple fact is that we have been living with long-term radiation exposure for-ever. We are constantly bombarded by cosmic, gamma and ultra-violet radiation from the sky and airborne particulates, and have been since the dawn of time.

BTW, I looked up Dr. Bartell. It appears that she is a nun and something of a crackpot. High priestess of the alarmist fringe.

Oh, another question. Please cite your sources regarding these "cancer clusters" around nuclear generating stations. Frankly, what I know of nuclear power stations is that their workers receive lower daily radiation doses than the fellow holding the traffic sign on a road construction site.

As you point out, hydro-electric generation is a nice option, with the added side benefit of flood control. And I rather like the idea of small scale generating stations utilizing current rather than damns. I designed exactly such a small plant for a friend in Alaska a number of years ago (not certain if it was ever built). But the problem is that for really large scale power generation, you have to build big dams. This also tends to flood out a lot of land. I wonder how many suitable rivers are still available?

As for wind, the mills are going up all over the world, and I don't think it's a bad thing. But again, what do you do when the wind isn't blowing? Tide? Where are the plants? I know of a few being built, but only a few. I do know there are issues of siting, to properly channel the tidal flows. From what I've been able to learn, such sites are in limited supply.

Bottom line. Daily demand in the United States alone is on the near order of 19 terawatt hours per day. Tell me how you propose to meet that kind of demand without conventional and nuclear power stations. All the solar and wind and tidal plants in the world today don't produce more than a fraction of that, and are not 24/7 reliable.

DRMoose you are clearly an intelligent person, but unfortunately you are using the style of argument often used by proponents of a technology. Obscure the facts, hide behind inconclusive evidence and to call people names... It does not help the debate.

FYI, I am in the business of energy efficiency and renewable energy systems. We have clients (and I am not at liberty to divulge them at this time due to mutual NDAs) who are massive corporations (fortune 500) who have engaged us to help them reduce power use. As energy pricing begins to come into line of recouping actual costs through time of day useage and increased rates across the board, teh case for energy efficiency is a case for good business.

C level executives or Members of the Boards of these companies can no longer justify profit being wasted from operations, and the intelligent companies are getting their houses in order now. It is saving them significant $$

http://www.mckinseyquarterly.com/economic_studies/productivity_performance/how_the_world_should_invest_in_energy_efficiency_2165 or also see the work being put out by the Harvard Business Review since the 1970s... The business case for efficiency is here now, and it only gets better as fuel prices go up.

As for living with radiation, sure it's been around forever. But not in the way we've exposed ourselves for the last 70-80 years. I attended a panel talk where a physician indicated that humans now have greater levels of radioactive materials in the bones and teeth when compared to bones from 100 years + ago. A nuclear plant and a nuclear bomb is no where near what the industry is trying to say is 'background' levels. They are way up thanks to the industry.

You looked up Dr Bertell (I misspelled her name previously) but none of my other facts or assertions? Interesting. Read the book - it is science based and cites all sorts of references. Are you implying because someone is a nun or person of faith that they are unqualified to study, be granted phds and do research? She does not reference her faith nor God anywhere in her book, so her religion and life path are irrelevant to the debate, as is calling her names.

http://www.guardian.co.uk/politics/2002/jul/14/greenpolitics.science for cancer clusters, or look for it online, as you did for Dr Bertell. TO be sure, there are assertions that they mean nothing (like from the IAEA - a body dedicated to nuclear promotion - http://www.iaea.org/NewsCenter/PressReleases/2009/prn200910.html ), but I tend to agree with the precautionary principle and reasonable assertions based on facts. The nuke industry along with many others, cite doubt and conflicting evidence generated by people they pay (tobacco industry all over again).

Once again, on the issue of exposure, I see you trying to shift the argument away from the point being made and proven - radiation gets into the biosphere at many points during the nuke cycle, and just because inside the plant is somewhat safer (some times - http://www.torontosun.com/news/canada/2010/02/18/12930436.html ). My brother has worked as an electrician in a few nuke plant refurbs and he says that accidents on exposure happen fairly frequently...

Huge centralized hydro plants are not ideal, but there is still a lot of capacity in Northern Manitoba and Quebec. Micro hydro is a far better option and can go on many small streams and rivers.

I have read that tidal sites are abundant and the problem is transmission, which is possible to deal with.

I admit I don't have all the answers (just as industry never has but we figure it out when we can acknowledge there is a problem), but there's a fairly straight forward way to reduce energy demand by 30-50% plus in the cases I have worked on, and yes there is a cost, but in the big picture (again if big brother is not making the choice and footing the bill, knowing our grandkids are going to pay the costs) . I also know enough to see how nukes are not economical nor 'better for the environment" than fossil fuels or other potential generating options.

Sir,

I did not realize I was calling anybody names. Regarding Dr. Bertell, I was merely citing what I had read. As for her being a nun, so what? I happen to be a man of faith myself, and have stated my faith within this forum on more than one occasion. Yet many here and elsewhere seem to believe that I am also a man of reason, and a clear, deep, rational and respected thinker. And just for the record, I am also one who thinks it necessary to think in terms of generations and centuries.

Now, I absolutely agree with you that it is important to improve our efficiency. For myself, I have switched completely to laptop computers which use less than a tenth of the electricity of my old workstations. I also use CFLs and LEDs exclusively for lighting in my home, though I do admit some reservations concerning CFLs.

On a larger scale, I do believe that improvements in efficiency, such as replacing all outdoor lighting with LEDs, would be a very good thing. I have been the chief engineer of a small number of manufacturing plants in my career, and one of the larger uses of electricity was lighting. Furthermore, developing large-scale electrical storage is a very good idea, which would go a very long way towards reducing our need for peak generating capacity. And of course there are other ways to improve our efficiency as well.

Regarding cancer, I watched both of my parents die from it. In particular, I held my mothers hand for six weeks at the end of her life. My family had no history of cancer before them. I dare say I have some small, personal knowledge of the subject.

In the near term, a great many generating plants are nearing the ends of their lifetimes, and I absolutely agree that replacing them with more efficient and lower polluting plants is necessary. The fact remains that while alternative, green power generation stations can help take up the slack, without large-scale storage, these can in no wise replace conventional and nuclear power stations. Though as I've said repeatedly, small-scale solar/wind/hydro/etc, are a wonderful option for residential users.

The problem remains however that fossil fuels do pollute. No matter what we do with them, they release carbon, sulfur and nitrogen compounds into the air when burned. And, eventually, they will run out, or at least become so hard to get to as to be no longer worth drilling and digging for. Fissionables seem likely to be available for somewhat longer, and improving technologies seem likely to reduce the dangers of radioactive releases.

In the long term, I believe that space-based solar is our best option, and again I have declaimed in some detail on the subject. Fusion will, once all the bugs are worked out, be a very nice system also, where self-contained power generation is necessary, such as ships and (dare I say it?) spacecraft. But again, that is looking a rather long ways down the pike.

Moose - you were the one raising the fact that she was a nun and using disparaging language about her. Anyone can read just about anything about anyone on the internet, but when nasty names and general attacks are repeated, the tone of the debate is taken down many notches.

As I mentioned, you should read her book. Her argument is about the long term impact, and as mentioned, thoroughly cites credible sources.

I have also experienced a couple of cancer deaths in our otherwise healthy family. These people lived near the Pickering Nuke, but I do not blame it specifically.

Yes fossil fuels do pollute. So does uranium, and the construction of the nuke plants and the processes to operate use a lot of fossil fuels. Yes fossil fuels will run out, and so will all other non-renewable resources, including uranium.

I think we both agree there is no magic bullet to meet the energy needs of the future, but we disagree on the type of pollution and waste we think is acceptable to leave for future generations. Energy has never been priced to reflect true costs, and has always been a sector where government involvement has been huge. I would like to see that change, and certainly that can not happen if nuclear plants continue to be built, because no one in business is ready to pay for them...

Intersting, though having worked for some large food and energy companies and agencies, e.g. DOD, Chevron, BP, Shell, and Frito-Lay on some energy conservation system upgrade studies, I never had to sign a non-disclosure. What are the companies you are working for so concerned about, that these other large companies were not?

Also, it appears you have a very simplistic understanding of radiation exposure. Having worked as a hazardous waste environmental engineer responsible for site remediations, I can tell you exposures to radiation are much more complicated that you seem to understand. Background radiation alone can be substantially higher than most laymen understand, sun light alone presents a great deal of radiation exposure. There is the issue, and importance on effects, of exposure pathways based on the different types of radiation you can be exposed to. Then there is the acute and chronic dose to consider. However, generally the chemical source of the radiation is irrelevent except where the chemical source will become residual within the bones and other organs, but the type of radiation exposure is what is important. The way you present your discussion seems a bit rudimentary and has some appearance of a bias leaning towards promotion underlying the statements, possibly to promote a business interest. Keep in mind radiation is always in the biosphere everywhere we go, even without nuclear facilities. Nearly every atom on the periodic table has some sort of radiation emitting isotope that occurs naturally in the air we breathe (carbon, hydrogen, oxygen all have such isotopes), the water we drink, and in the soil (we actually use the decay rates of the various common radioactive isotopes to date things). The real issue is about radiation greater than background getting into human habitats, thus increasing our exposure risk significantly against the natural background. Just having soils derived from granitic parent materials increases your exposure risk by orders of magnitude.

I have not worked for those other companies so I don't know.

These guys have us working with their engineers, and I suspect they are going to capitalize on the IP created by patenting some of what we are helping them figure out. Once the project has been deemed a success they have said we can take some credit and talk about it.

As for my bias, yes it is there, and yes my points underscore that bias. That's what happens in a debate or discussion.

The common argument of "radiation is everywhere" is fine, but it does not justify adding more through nuclear power. There's carbon in the air naturally too, and particulate matter and other stuff that we don't want to add more of...

As for promoting a business interest, I am a designer working on high performance buildings and renewable energy systems in large part because of my history growing up on the edge of the burbs near a nuclear plant run by engineers who make biased statements and obscure the facts to promote their business interest.

My interest in reducing deadly pollution is not only a business interest, but a personal one too.

I do not know the case in the US, but in Canada, the historical and ongoing subsidies (direct and indirect preferential tax treatments, along with permission to use the air and water as a waste sink) to fossil fuels and nuclear far outstrip the incentives now offered for renewables. I would prefer to see all the subsidies end, in favour of a level playing field.

I am an advocate for true cost accounting, and in the absence of it, I use figures which are justifiable and reasonable, and will turn some clients away, or guide them towards technology which may not be so sexy, but will work for them.

As for saying designer, it is easier than saying architect (my training and licensing), self trained and now partly licensed engineer of building services (plumbing electrical and mechanical), industrial designer (product and plant operations jobs done in this regard) and musician designing pieces and performances (more of a hobby, but sometimes paid gig).

Partly licensed Engineer? not sure what that means. As far as I am aware, with regard Civil Engineering License, one day I was not a professional Engineer, the next day I was. I never received a part of a license in the interim. Isn't Canada really strict on the use of the term Engineer. I heard they went after microsoft on the usage of that term in there MSCE programs.

RCE,

Thank you for your opinion,which is in actuality, my purpose in this 'Thread'

A Contributor's Qualifications are immaterial to The Subject Matter. whether He Be "Lic ensed" or not, is inconsequential! I want to know what The CR4's think! (Since this forum represents a Viable Think Tank, in my humble opinion)

Do Problems in Japan mandate Nuclear Power Moratoriums, or is this Political Bluster?

Via Con Dios

K

Still not sure about the statement indicating partial licensure as a engineer. Immaterial or not, the statement of qualification was already made by the contributor. I am just asking for clarification on how that happens?

Ah yes the cancer cluster argument. Every time this argument comes up there's almost always one significant piece of information missing from the cited article. (Which I did forget to thank you for citing. Thank You. ) Most of the times this is omitted from pure ignorance or confusion about its meaning. Your article does not explain why this localized group of individuals that have cancer could not just be a random coincidence. To do this one must make a collection of reasonable assumptions and do a theoretical statistical analysis of the random rate that people contract this disease and will it be likely that they happen to have some geographic common location just by luck. This is a very confusing calculation that relies on the initial assumptions being true.

Now to get back to an earlier post I made, detecting the presence of radioactive materials is much more sensitive today than in the past. The bones in my body were formed during the years that we were foolishly doing atmospheric testing. Because of this, when I get a whole body radiation scan the detectors must be set a little higher due to the Strontium 90 present in the air in those days. (Oh Strontium 90 has a 28 year half life, decays solely by Beta emission to Yttrium 90 which quickly decays again by Beta emission to a very stable Zirconium 90.) Now if a frisk for radioactive material in the environment these people reside shows no errant sources, I would believe that this is either a random coincidence or that a cosmic ray produced a local shower for short lived isotopes in that area. As unlikely as it might appear for either of those scenarios, each are more likely than the possibility that the people living near the power plant got a power plant originating dose from a leak that left no trace.

Radiation leaks / routine emissions from nuclear power plants do not "leave no trace" .

Saying that is ABSOLUTE NONSENSE, and only someone very ignorant, or someone very interested in promoting nuclear power would say it.

http://energy.probeinternational.org/nuclear-power/nuclear-safety/candu-reactors-buyer-beware

http://www.ccnr.org/tritium_2.html

I do my own lobbying. The energy industry pays a lot of people to do it for them - are you one?

If you're going to try to refute my comments by quoting them, at least get the quote correct.

It's obvious that you refuse to listen and acknowledge somebody who has a different point than yourself. Ignorance can be cured. Stupidity is forever. Refusal to consider another perspective shows a completely irrational mind.

My point is the very antithesis of the nonsense you've morphed in your bigoted mind. Radiation measurement technology is so sensitive today that real radiation leaks can always be detected. If a sweep of a suspected radiation contamination area with the most sensitive equipment available today shows no radiation sources, then there is no radiation source there.

I try to convey my ideas in a polite, concise fashion. Occasionally my words do muddle the meaning I intend to impart. In those times, I try to rephrase my ideas to get my idea across.

You certainly are free to believe any substantiated or unsubstantiated belief that you wish. But if you insist on ignoring what I have to say, keep it to yourself. In simpler words, shut up.

You implied in your comments that no radiation leaks from the power plants, and that is not true. A leak is not just something that is a mistake. Radiation is emitted from the plants as a matter of operation. I pointed to this evidence and you call it into question...

After rereading my comment I still do not see the implication. I did not state nor imply that any nuclear facility, be it a power plant or a dental office, does not produce ionizing radiation. In all cases, statistics and quantum mechanics dictates that some percentage of radiation must leave each facility. But when that percentage is so small that measurement cannot isolate this man made source from the higher level naturally occurring background radiation, then it cannot be the dominant source of radiation. In other words if one succeeds in reducing the man made source to zero, then no net dosage improvement will occur.

Now in your cited case, you are correct that tritium is a difficult isotope to measure due to its low energy Beta particle production. Tritium contamination is also very dangerous since as the possible hydrogen component of water it will readily permeate throughout the body. But this too can be measured.

This may be more of a question than an input but I believe is still largely relevant to Nuclear power as used in the United States. The demand for power varies with the time of day (graphs can be found on the Department of Energy's website). There is a low demand at night when people are asleep, a spike when everyone wakes up, a spike when everyone gets home from work and turns on all the lights and appliances in their house, and other highs and lows in the demand depending on the temperature. Currently, Nuclear power is used as the "base load" for our power generation. It produces the same amount of power 24/7. The coal plants raise and lower their power production based on demand, with natural gas turbines firing up to assist during peak hours. Hydro-electric plants (although on a MUCH smaller scale) even pump water BACK up into the reservoir at night (when power is cheap) to be used/sold when power is expensive during the hours of peak demand. So my point/question is can nuclear plants really replace all the coal plants? and the natural gas turbines? And are nuclear plants able to efficiently vary their power output hour by hour?

A very good question sir (ma'am?). The simple truth is that while demand curves can be and are plotted, demand can spike at any time. Therefore, public utilities have to have sufficient capacity online to meet demand. Failing that, we have blackouts.

The simple problem is that there is no viable form of large-scale power storage. Given super batteries or ultra-capacitors, we could store all of the power that isn't used at any given moment and use that to meet peak demand. This would rather dramatically reduce our need for total generating capacity.

As to "throttling" of nuclear power plants, I cannot tell you with any certainty. But I do know that military reactors can go from full power to zero to full again in a matter of seconds. Look up a maneuver called the "Crash Back" to see what I mean. So I see no reason why civilian reactors cannot be throttled to at least some degree.

Nuclear power production does get throttled. Some designs are easier to partially throttle than others but all can be shut down completely. Part of the difficulty of all "alternative energy" sources is responding to demand load changes and growth. But these are engineering design tasks to be considered in all cases. None of these concerns should be considered a reason to exclude any of these sources as impractical.

Oops, I forgot to cite anything to support my argument. Here's the Wikipedia article on control rods.

Thanks for that link. Having worked on both PWR and BWR reactors, I can say with impunity that both are less harmful to the environment than coal or oil plants. Gas turbines break down too frequently, and I gave up working in the power industry because coal plants were too filthy for anyone to work there. Painting crews were composed of convicted felons. Not so in nuclear.

Regards, Carl

Dr Moose made the statement that -"The simple problem is that there is no viable form of large-scale power storage."

This is true only when Hydro-storage is excluded. An old technology, fully understood, that can be scaled to meet almost any variable demand.

Gavilan

A neat idea, but the problem with hydro-storage is that it is not quickly responsive, as would be a battery or capacitor. With this technology, you pump water to a higher level and extract the potential gravitational energy the same way you would with any hydro-electric plant. Would it not be somewhat inefficient as well, losing something to thermo-dynamics each time water is pumped to a high storage and then used to spin turbines? I suppose it might be made to work for pattern loads, such as the dinner hour, but for spikes? I don't see how this is a solution.

The quick response to surges on the grid consists of the total rotational inertia of all contributors to the grid (gensets, turbines of whatever type). They all slow down a bit, throwing that increment of energy onto the grid, and then (hopefully) recover by being fed a bit more fuel, steam, water, or whatever. That's for short-term transients.

The pumped hydro storage won't respond so quickly, but it can help to equalize longer-term swings of load, such as day/night.

My point precisely.

I think we're on the same wavelength here. My post should have been to the general thread, rather than to yours. It is a bit surprising not to have heard of this consideration already. I'm not that much of an expert, but even so have encountered the concept before. (Walking through something like Grand Coulee Dam brings it home nicely-- LARGE rotating elements.... And then just think of adding it all up.)

<...the problem with hydro-storage is that it is not quickly responsive...>

These people are claiming zero to full output in 14 sec.

Okay, so we have a viable power storage system. Though it seems to me that it's one very expensive battery. I can't help but believe that these things have to have been fantastically costly to build.

So, suppose we build these things to store excess power and balance the load during high demand periods? Great idea, assuming that the cost of building them doesn't drive up the cost of of electricity more than building new generating stations. I'd love to see a cost-benefit analysis.

But still, when demand spikes, 16 seconds is a long time to wait for these things to come up to speed.

Cost-benefit is one analysis method.

Capital cost per kWh stored is another analysis method, which might be used to compare a scheme like Dinorwig with a similarly-rated battery- and HT conversion-based installation.

The Dinorwig scheme was operated in parallel with the recently-decommissioned and nearby Trawsfynydd nuclear power station. While the grid has cheap power in reserve, it pumps water up to the upper lake. When a surge of power was needed (10pm UK telly time, for example, is a surge time - everyone puts the kettle on for a brew-up) 14 sec was a good deal, and that's when Dinorwig proves its value.

I'm glad to see that somebody succeeded in this approach of power storage. Mid 70% efficiencies seems like some very good storage capabilities. Back in the 60's Con Edison tried to do this in the Storm King area of upstate New York.

Aha, the beginnings of the environmental wacko movement. No wonder the Brits had to build theirs underground.

The link you provided to Dinorwig scheme answered my question above about the ability of nuclear power plants to "throttle" their power output.

"The original purpose of the scheme was to deal with the difficulty that National Grid would have had if the large numbers of nuclear power stations then planned had been built. These are technically and economically inflexible, ideally needing to run at full output all of the time, and effectively a home was needed for some of the night-time power when the demand for power dropped off."

So, at least for some of the older nuclear stations (most here in the US are OLD), it would appear from this article that they have very little throttling capability. Perhaps someone more familiar with the NEW designs could comment on their throttling capability?

As I mentioned earlier, I do not know about civilian reactors used in generating stations. But I do know that military reactors used in warships can be throttled, and quite rapidly. There is a maneuver called the "Crash Back", in which the ship goes from All Ahead Flank to All Stop to All Back Emergency in a matter of seconds, which takes the reactor from full power to zero and back to full again.

Thinking about it, it is logical to assume that a reactor can be throttled. It has control rods which are used to dampen the fission reaction and even bring it to a complete stop. It seems to me that varying the position of the control rods could allow any level of fission from barely ticking over to just short of melt-down.

Anybody know anything more about this?

Hi DrMoose,

civilian reactors can be shut down within less than a second: SCRAM signal will let fall down boron containing control rods so within fall-down time shut off the chain reaction.

After-heat (fast decay radioactives) will stay very high (at or near prior level) for around 2 minutes.

Restart to power will take much longer as first of first the reasons for a fast shut down have to be established, reported to the authorities, require discussion maybe including the public, so restart is earliest days later, often months or years later.

The Kruemmel nuclear power plant of Vattenfall (I grew up very near there, so I have a special interest) had a transformer blow up of unknown origin. Totally non-radioactive. There was a first such accident in 2007 and after 2 years of repair after only 2 weeks a second transformer overheated and ignited the overheated cooling-oil.

This fire gave rise to a fast shut down as the second available (not damaged) transformer was shut down by some safety protocol, then the main cooling pumps had no more energy and the required energy was drawn from the electric public power grid. This required 1.5 seconds switching time, so by this time without cooling power the fast shutdown of the reactor was triggered.

As a side effect the operating personnel was endangered by smoke from the fire as the clean air input was near the burning transformer. One of the men had to use the available respiratory masks.

At the same time there was an indication of a defective fuel element that was proven to be the consequence of a 1 x 2 mm foreign particle in the metallic shield. Further investigation going on.

There was also a loss of data as the main power failed and the data-storage switched over with changing priority rules. This is changed today but the data loss is permanent.

The transformer station will be renewed totally including the separate building - estimated mid 2010. The officials hope of restart some day this year. The anti-nuclear movement hopes for a permanent shut-down.

Any water reactor can be throttled down to only Watts of power, maybe milliwatts. Only (?) the old-fashioned graphite moderated (Chernobyl, Sellafield) have a low-power stability problem.

RHABE

Pumped storage has been used in a number of places in South Africa since the late 1970's and more are planned.

South Africa has 3 running, one under construction due in 2012 and I think another one proposed. (Drakensberg, Palmiet, Steenbras and Ingula (2012)

China has 40 odd running with another 20 odd proposed. There is a list here for worldwide pumped storage - no idea of the accuracy, but interesting.

The extra power could be used to generate H₂ and O₂ by electrolysis. Both products with a commercial value. While reactors can be throttled to some extent a full shutdown brings the risk of Xenon poisoning. If a reactor is shut down for more than a few minutes an isotope of Xenon accumulates which absorbs neutrons and it can take a couple of days for the Xenon to decay to the extent that the reactor can be restarted.

When I found out the American Taxpayer is now the de-facto owner of the current (and future) waste produced by our commercial reactors it occurred to me that perhaps the economics of the technology was not quite as it appeared; at least to the tax payer. Granted, its a great deal for the plant operators; but perhaps not so great a deal for the folks who inherit the by-product.

I have come to conclude that I don't like nuclear power because the tax payer gets stuck with the waste. The recent sweet heart deal with the UAE is a continuation of what has been happening for decades. A single company (there is only one fuel producer in the US) benefits from what amounts to very significant subsidies in order to sell their product.

I have listened to the pundits of this industry from near its beginnings; when the electricity produced from nuclear power plants was going to be both environmentally benign and "too cheap to meter." I am now waiting to here how the "new" closed fuel cycle will generate a processed waste product that can be used as garden compost.

Unlike other alternative technologies; once the decision is made to proceed; the tax payer is on the hook for hundreds if not thousands of years. I believe it is quite possible that without the hidden financial support from the tax payer; this industry would have gone belly up a long time ago.

The industry "fund" that was to finance the waste storage was based on a 300 year responsibility life span at centralized sites with much of the calculated value of that fund based on ski pie speculation of the value of government securities. The deeper one looks, the wider the financial abyss opens. Given the definitions given in the amended "Nuclear Waste Policy Act" it appears even the high level infrastructure of the plants themselves will be come the tax payers responsibility after the useful lifespan of the plant.

The facts are what they are - the tax payers effectively own the waste and are paying for the on site storage. It appears we will get stuck with the plant sites themselves. We are also paying for the incoming foreign waste from the sweetheart deals we signed in the 70's, 80's and 90's and are rapidly becoming the nuclear waste dumping ground for the world.

Profit has a way of skewing the metrics of risk benefit analysis and denigrating business ethics. When I see an honest attempt by the industry to educate instead of simply propagate; then perhaps I will have a little more faith in the integrity, and therefore processes, of the industry.

In every other energy alternative, waste handling is a cost of doing business. Why should nuclear energy be any different?

The technology may be safe; but the tax payers are getting screwed.

Let capitalism work; based on a level economic playing field.

Gavilan