Posts by Calliban

I have always thought that 3D printing was an overhyped technology. I can see niche applications for it. If there is a need to produce one off components without the expense of creating a custom mould. But the materials choices are clearly quite limited. You cannot easily 3D print with molten steel. And if you tried to, spraying a liquid onto an already solid layer would create weaknesses within the material - grain boundaries that are weakly fused for example. This would happen because one layer of metal had already formed grain boundaries as the layer on top cools and solidifies forming relatively weak bonds with the layer below. It is precisely to avoid problems like this that casting requires very specific cooling rates for any high stress components.

3D printing of concrete sounds like something that would be time consuming. You must wait for one layer to set before you add another, otherwise the structure will slump under its own weight. Given that turbine towers are mass produced anyway, what does this do for anyone that cannot be achieved by pouring concrete into moulds, and allowing them to set in controlled conditions? The same is true for thermoplastic components, as soon as you want more than just a few of something. Injection moulding can do just about anything that 3D printing can. And it is quite old technology now.

The most recent NASA white paper.

https://ntrs.nasa.gov/api/citations/20210026340/downloads/White%20Paper%20regarding%20LCF%20and%20Fusion-fast-fisson.pdf

The lattice confinement fusion is the fast neutron source for fast fission of depleted uranium or thorium. NASAs interest in this is its ability to produce compact nuclear power sources that do not need enriched uranium or plutonium. The reactors are not radioactive on takeoff.

"As Neil deGrasse Tyson put it, "The good thing about Science is that it's true, whether or not you believe in it." Your opinion does not count. What counts is what is reported by the scientists doing these things."

Which scientists exactly? I agree, my opinion doesn't count. I don't have all the answers. Neither do you. The difference between you and I, is that I least have enough introspection to admit that.

Quote from THHuxleynew

You are I think forgetting that in matters of health we do not count all deaths equally. There is a proper argument about whether to lock down or not is best. You have not put the factors here into any balance - so until you attempt this I won't comment much. My (not very strong) view is that the type of disruption seen in Italy - where health services collapse - is overall worse than lockdown, but I agree it is arguable, and probably unknowable given that the future course of epidemics has that nasty exponential characteristic.

Governments have more immediate pressures. politically, arguments about what might be pale to nothing compared with the outcry for action when inaction leads to a health service being overwhelmed. That was, at the time likely given best available evidence, without lockdown,

Long-term harm? Yes - but we allow many things in society that have proven large long-term harm. For example, massive marketing of unhealthy foods, and a food production system that means those needing to eat cheaply must eat poorly. That kills many more people, and has bad effects on children. There are many other examples where we prioritise prevention of directly caused deaths over things that in a whole population are statistically certain to lead to poorer health outcomes.

I am not saying that I like this - I accept it is not easy to change the politics in a democratic country.

THH

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THH, I mostly agree. The situation is complicated. Governments are under pressure to do something that at least looks like it will help. They often act with imperfect information as well. I accept that. It don't expect people to be perfect in their actions or judgement. And I know there are facts that I'm not aware of and don't understand. I just find it absurd that any keyboard warrior on this site can display the hubris to insist they know what is the right decision and what is not. I don't have the answer. At least I have the humility to say so. Some on this site would never have the humility to admit that they don't know.

Quote from THHuxleynew

You might think the antivaxxers would like this as reducing availability of vaccine for use in humans?

I guess that supposes rational thought, rather than what Freud called primary process thinking.

'Anti-Vaxxer' is the name given to anyone that isn't prepared to take on faith the medical propaganda handed down by their 'betters' in the political establishment. Given that this designation is handed out to anyone that refuses to prolate themselves, I think we can assume it is a coverall term for people who, in reality, have a lot of different opinions, outlooks and backgrounds, whose only common uniting factor is that they don't swallow official BS hook line and sinker. In much the same way, if you fail to take on faith the official lines on immigration, you are 'a fascist or racist'. If you don't want drag Queens playing women's football or sharing toilets with your daughters, then you are a 'homophobe'. These labels are intended to slur and intimidate anyone that refuses to bow before officialdom.

I don't known who it is that objects to animal vaccinations or what their reasons are. For all I know, this article is propaganda and what they are talking about never happened. But the arrogance of sluring people and grouping them because they don't tow the party line, is a good example of why many people hate the political left.

Quote from JedRothwell

You don't have to. Every public health agency, every major hospital, and every doctor on God's Green Earth has carried out investigations of the mRNA vaccines. Billions of vaccines have been given, and more patient data has been collected on the vaccination outcomes than all other medical data in history, combined. This data has been analyzed with big data computers and supercomputers with far more processing power than anything that existed ten years ago. The vaccine RNA has been modeled and tested in far greater detail, with better technology than existed ten years ago. In short, no technology has ever been developed, deployed or monitored with as much knowledge and as much surveillance and data collection as this. We have millions of times more data on the performance of these vaccines than we had for things like the polio or smallpox vaccines. We can analyze its performance down to the level of individual molecules. We have the complete human genome, which is a depth of knowledge people could not have dreamed of decades ago. This is the epitome 21st century technology. It would have been science fiction in 1990, and it would have been unimaginable in 1960. Based on all of this, we know for sure that the mRNA vaccines are the safest, most effective and best medical intervention in human history. Also, by far the fastest ever developed, and the most carefully tested and monitored.

You might doubt that, but just about every expert on earth disagrees with you. I am sure they are right and you are wrong, just as I am sure that people like Fleischmann and Bockris understood electrochemistry and calorimetry better the editors at the Scientific American and the anonymous idiots at Wikipedia.

I don't think that's remotely true. And I don't think you are the position to know half the things you claim to be true. Practically every post you make is about pushing some personal emotion based bias or another. You don't seem to have the self confidence to even question your own biases. You form half baked opinions and then produce these arrogant brain farts asserting that everyone else is stupid because you say so and therefore it must be so.

You really think that 'Every public health agency, every major hospital and every doctor on God's green Earth' have the time, expertise and resources to carry out epidemiological studies on the effects of mRNA vaccines? How much time and money do you think these people have? I think you have a very skewed impression of the way the medical establishment works. Many of these people will be on the front line and most will have an opinion of their own, but they have to defer to higher authority when it comes to the science. They will have access to exactly the same medical studies that you do. And they are basically winging their way through life like the rest of us.

As for what their opinions happen to be, I don't think you are in a position to be able to speak for all of them, or even tell me what percentage think one way or another. My GP told me quite bluntly at the height of this so called corona virus crisis, that mortality rates in our town were about the same as they had been for years. He was critical of the lock downs, because he believed that the isolation and forced changes would create an unprecedented mental health crisis. He was certainly right about that. I strongly suspect that lock downs had negative public health benefits overall. Many people put on weight, many developed mental health problems and the disruption to social life was extreme.

Yet anyone questioning the lock downs at the time was considered to be an anarchist, a fascist, a scaremongering terrorist, etc. Many were actually arrested. Pretty much the same thing happens to anyone questioning the efficacy of vaccines now. If they work in the medical establishment, they are unlikely to keep their jobs. In some places, they may actually get arrested. In such an environment, it is bold indeed to claim without a shred of evidence that 'all medical personnel, everywhere', think these things are perfectly safe. The fact is that there are risks involved in practically every form of medicine. If that doesn't apply to mRNA vaccines, then they are unique in the history of medical science.

Jed Rothwell, all power plants of all kinds experience component failures that cause them to trip offload. The fact that we see 4-5 trips every month in a US fleet of 100 PWRs and BWRs, does not seem to be strong evidence of poor reliability in light water reactors. Many of these faults will be corrected within hours. Some SCRAMS are actually planned events. And the important thing is they are not correlated. One trip does not lead to another, because they are caused by independent failures. This is a very different issue to the seasonal and daily intermittency associated with renewable energy sources. The problem here is regional fluctuations in the availability of the energy source. It effects all generators of that type simultaneously.

Incidentally, you are aware of the large batteries that are installed between large windfarms and solar power plants and their grid connections? Many non-engineers think these are there for 'storage', I.e. to buffer intermittent energy generation. Their true function is a bit more complex. Wind turbines in a farm are not independently connected to the grid. Power electronics is used to synchronise individual turbines onto a common wave form that aligns with the grid sine wave. A single malfunctioning turbine can distort that waveform and result in frequency shifts that cause cascade failures leading to the entire farm dropping off grid. Individual turbines can trip off the busbar to prevent this from happening. The bigger the individual turbines, the larger the wave form distortion that a single point failure can cause and the greater the probability of tripping the whole farm off grid. The batteries are there to prevent frequency surges that would crash the entire grid and allow sufficient time for back up plants to activate. Those back up plants are usually gas turbines.

The instability problems associated with trying to keep hundreds of individual wind turbines synchronised to a single grid connection, is one the things prompting a rethink in how these units are designed. In many ways it makes more sense fitting individual turbines with hydraulic pumps and connecting the hydraulic main to a single generator on the ground. A certain amount of storage is then provided by a flywheel on the central generating shaft.

"Coal is also unsuitable for dispatchable energy. Again, because the plant itself is so expensive, it has to be used for baseline generation. Also, you cannot have coal mines, miners, and railroad trains full of coal sitting on the sidelines, delivering fuel only when it is needed at irregular intervals."

Capital cost is not the primary reason why coal plants are unsuitable as back up power plants, though poor utilisation will damage their economics. Also, months worth of fuel is routinely stored in coal heaps ready to load into mills. Coal deliveries respond to long-term demand trends. Boilers, steam drums, pipework and turbines are thermally thick steel components. They require lengthy thermal soak time before a unit can be brought on load. That consumes fuel and boilers often have to be started using oil and gas. Even so, repeated thermal cycling between hot and cold conditions gradually knackers them. It pushes maintenance costs through the roof. It is a problem for any thermal power plant being used as back up, though gas turbines suffer the least.

Nuclear power plants can shed load without tripping. It takes many hours to bring the plant back online from a cold start, but they can in principle operate at half load. The bigger problem is that reducing load means reducing reactivity with control rods. That distorts the flux profile of the core leading to uneven burn up in the fuel. You end up having the to refuel at about the same interval regardless of power history.

Quote from JedRothwell

Months ago, I read that CDC experts and pharma company experts ran simulations and decided not to reformulate the vaccines. They concluded that continuing with the same formula would prevent more sickness worldwide than reformulating. The pharma companies have developed newer formulas. They have tweaked the RNA. I think they said that to begin manufacturing the improved vaccines, they would have to interrupt production, close down the factories for a while, and then restart and test the output vaccines carefully for some weeks. It was better to produce millions of doses and distribute them worldwide quickly, even though they are not as effective at preventing disease. They still effectively prevent hospitalization and death.

That was the situation last year. Maybe it has changed now?

The situation resembles some weapons production during WWII. The UK and the US developed jet aircraft during the war, but they did not start production because they already had propellor fighter aircraft production lines putting out tremendous numbers of airplanes. To make jet aircraft, they would have to interrupt production at some factory. By the time the restarted, the war would probably be over. It was better to have thousands of obsolescent propellor fighter airplanes than a few hundred jet aircraft. The Germans went ahead and manufactured Messerschmitt Me 262 jet fighter aircraft. These were effective, but they could not make many of them. The UK and the UK developed jet aircraft prototypes but they did not manufacture them until after the war. (Except that a small number of British Gloster Meteor jet aircraft were used in combat.)

The point is that it costs an enormous amount of money to develop a new medication. Corporate bodies are primarily interested in shareholder value. They will not commit resources to a product that is unlikely to achieve sufficient distribution to generate good financial returns, especially for a disease with high mutation rate, with newer COVID strains being less lethal. Big decisions always have to be about achieving a balance of risks and costs, and those risks are financial as well as personal.

Quote from JedRothwell

All vaccines do that. There is no reason to think that an mRNA vaccine will cause more tissue damage than any other. On the contrary, billions of doses of mRNA vaccines have been given, and they have produced less damage, fewer side effects, and fewer deaths than any other type of vaccine in history. They are far safer. Your "information" to the contrary is a mixture of bullshit, ignorance, anti-vaxxer Death Cult Lunacy, and propaganda from Russia intended to stir up trouble and kill people.

Thats rather a strong statement, given that I haven't presented any hard data or drawn any specific conclusions. I am not prepared to draw any hard conclusions, precisely because I have not carried out a balanced and thorough investigation. I have seen isolated reports that seem to provide conflicting information. But I know enough at a qualitative level to at least list the concerns, even if I am not prepared to reach firm conclusions. And I can see what is going on politically.

Most big decisions in life come down to choosing a solution that achieves the best balance between various benefits and risks and costs. To get the best solution, you need to approach the problem by honestly weighing all factors. That is the mature way of approaching decisions, not simply looking to validate a preformed conclusion that was based on some deep seated emotional bias. Your post here, like too many others you have made on this board, tell me that is exactly what you do. You are not interested in honest research, you just want to push personal biases. It is exactly because of this sort of behaviour that society ends up being driven in disastrous directions, whether it be in health policy, energy policy, immigration policy, foreign policy, whatever. Idealists always end up ruining the world.

Gentlemen, mRNA vaccines are specifically designed to trigger an immune response that develops antibodies. That immune response is essentially an inflammatory response that will cause tissue damage. It is an inevitable side effect of how these things work and shouldn't surprise anyone. Some people will die as a direct result of taking the vaccine. It is inevitable.

Taking a vaccine is about trying to reduce total risk. You are reducing the risk of dying from a disease, but accept a certain risk of being damaged by the vaccine. What matters is that you reduce aggregate risk. Even though the vaccine has risks of its own, it is still worth taking if it reduces risk overall. In much the same way, seat belts reduce your risks of dying in a crash, but may impede your escape.

The reasons the coronavirus vaccines are controversial:

(1) Risk from COVID and risk from the vaccines will always be different for different people. For some people, the vaccine will carry a greater risk than the disease itself. To coerce people into taking it is immoral;

(2) The vaccine was developed in a hurry and there isn't good understanding of its long term health impacts. What if we discover in five years time that it has caused cardiovascular damage?

(3) The politics behind the whole corona virus issue is completely toxic. There is now a political divide between those of the right that are naturally sceptical of coerced medicine and those of the left, who tend to favour centralised control over personal freedom and want to force the vaccine on the people out of spite for daring to question their authority. Neither side is objective or rational.

(4) Yyou have corporate interests that have invested a fortune in developing the vaccine and want the biggest return possible. They will use financial leverage on politicians to sell as much vaccine as they can. They will suppress any reports of health consequences. They will attempt to demonise any opposing voice. They will use their influence to coerce compulsory vaccination, against the wishes and best interests of many people.

For relatively small turbines, stone and quartz have effectively infinite durability. We have stone structures that have stood for a thousand years in Europe. Due to its large footprint, it would work best if the tower had another functional use as a building, rather like the old wind mills of Europe.

This website sings the praises of concrete as a wind turbine tower material.

USING CONCRETE FOR WIND TURBINES - RJPotteigerConstructionServicesInc

www.rjpotteigerinc.com

I accept most of their conclusion, but I think they overstate the matter. Using steel has not limited tower height to 80m. We already have steel towers about triple that. But concrete is a much cheaper and energy efficient material, within its limitations. High strength concretes are now routinely used with compressive strength of 100MPa. That is is 40% of the yield strength of low alloy structural carbon steel. For a material that has about 2% of the energy cost of steel on a volume basis. This is why concrete is such a ubiquitous material in the built world.

Hybrid approaches probably offer the best options. Hexagonal cross section towers could have steel prestressed cables running through ducts in the concrete. This allows the tower to resist flexural loads using easily replaceable steel components. This avoids having to use fat Cross section towers that would otherwise be needed to absorb all forces compressively. Concrete has close to zero tensile strength. Loading concrete with embedded steel reinforcement is a good way of limiting its life to no more than a few decades. Prestressing cables are components that can be replaced when they reach the end of their fatigue life.

Here is an example of a wind turbine tower that has actually remained standing for 200 years.

Bidston Windmill - Wikipedia

en.m.wikipedia.org

It is a compressive structure. The bending moments induced by the wind are balanced by compression and gravity induced static friction. These towers were often made from stone or brick masonry. They do not suffer fatigue issues, because they do not rely on tensile stresses to counteract bending forces. They do not corrode, because masonry is already an oxide. If we could build onshore wind turbines like this, then the towers could indeed be made to last for generations. Maybe we should?

There are other option using steel towers that would increase lifespan. They could increase the sectional thickness of tensile steel members in steel towers, thereby reducing tensile stresses. Towers could be reinforced by prestressed tensile cables that are periodically replaced. Engineering design is always a trade off that attempts to achieve the best balance between competing cost pressures.

Quote from JedRothwell

I do not know that, but the experts at the DoE and all of the companies that construct towers say that is the case. They probably know more about this than you do.

Show me a reference. What you are saying would be a significant departure from past experience of flexural steel structures in a marine environment. A wind turbine tower is subject to severe and frequent bending stresses from gusts. It is especially vulnerable to corrosion fatigue.

"That is true, but the steel is recycled indefinitely. So, once you mine enough to make all wind turbine towers, you do not need to mine more."

You and I both know that recycling is imperfect at best. Only a fraction of steel can be recovered and recycled. For offshore wind, it will be much more difficult, dangerous and expensive to retrieve turbines at end of life. And there is no removing the reinforced concrete monopile from the sea bed. Assuming you recycle steel, you don't get the same alloy properties from recycled steel. Which is why for a lot of applications, virgin steel is preferred. Turbine blades are not recyclable. They are either burned or chopped up and sent to landfill. The concrete is not recyclable. Only a portion of steel reinforcing in conccrete is recyclable. Copper is heavily recycled. I am unsure about rare earth's in these applications.

"It is not contaminated with radioactivity the way steel, concrete and other materials in a nuclear power plant are."

Only a tiny proportion of steel and concrete in a nuclear power plant is radioactive or contaminated. Essentially, it is the interior of the primary circuit and about a hundred cubic metres of shielding concrete around the core. The primary circuit is extremely compact. You would know that if you actually researched the matter. Part of me suspects you actually did know that.

"As you see, that information comes from the American Nuclear Society (ans.org). That is the world's preeminent source of information on nuclear power, and it is very strongly in favor of nuclear energy. So, they probably know more about nuclear reactors than you do. You have never heard of this, but they have.

Anyone who has seen a nuclear power plant will have seen it has empty land around it, so I am surprised you did not know this."

I am a safety engineer, with degrees in mechanical engineering, nuclear engineering, fire engineering and systems engineering. I have had plenty of exposure to both nuclear and renewable electricity technologies over my career. I have also built my own home wind power system to power my workshop, a solar heating system for household hot water and I am designing a atmospheric steam engine for combined heat and power. I am no stranger to nuclear sites and I have worked on many of them. They are typically surrounded by farmland, not abandoned wasteland. It is desirable to avoid building houses too close to the perimeter fence, because it complicates emergency planning. But that doesn't mean the land around the plant is useless, anymore than the land occupied by wind turbines is useless for other things. The situation is really no different to a wind farm. You wouldn't want to live too close to one of these because of the danger of blades being shed and the disruption resulting from the constant noise.

I grow increasingly suspicious of your posts. You appear to cherry pick information to support technologies that you advocate, apparently for aesthetic and emotional reasons that have nothing to do with how well these systems work in the real world. And you embrace unsupported assumptions when it favours what you are advocating. That sort of idealism is toxic. It ends up obscuring the truth in order to push preordained solutions. It is exactly this way of thinking that has led us into the energy crisis we are in. If this board is worth anything, it is to get to the truth of things rather than obscure it with sophistry, to defend pet ideas and technologies.

I have never heard of this 1-mile exclusion zone you are talking about. It isn't like nuclear power plants have got a mile of land around them that no one can use for anything else. Most of the licenced sites I have been to have farmland around the site boundary. Some, like naval bases, have houses literally feet from the site boundary. If possible, it is advantageous to put them in rural areas away from urban centres. It makes accident planning easier. But it isn't always the case. The sites themselves are not built to minimise the use of space. That's not because it isn't possible. It isn't a priority. For wind and solar power, those space requirements and the huge materials budgets are inevitable because they are inherent to how these things work.

There is no way wind farms take up 64 times less space as a nuclear power plants per unit capacity. How on Earth did you arrive at that estimate? The maximum achievable power density of a wind farm is 2-3W/m2. That limit is imposed by wind shadowing. A wind farm with turbines at the maximum possible density will need about 500km2 to produce 1000MW of average power. These are facts. They aren't negotiable. They aren't things that you can argue your way out of! Neither are the the steel and concrete requirements of powerplants. Some things just are what they are.

Quote from JedRothwell

They take far less materials. You can put them on your roof. Putting the equivalent weight of 10 kW worth of nuclear plant on your roof would crush the house flat. Think of the containment structure and the cooling towers! The only power source that takes more material than a nuclear plant is a hydroelectric dam.

Hydroelectric dams last much longer than nuclear plants. At least 100 years. So, the mass of material per year may be lower. The turbines generators in the dam are replaced periodically, but they can be melted down and recycled. That is also true of wind turbine generators. Most of the material is in the tower, which should last 100 years, a lot longer than any nuclear plant. So material consumption measured per year, or per watt-hour of electricity over the life of the system is much lower than a nuke. A wind turbine generator can be completely recycled. The blades cannot be recycled at present, but that may change. I doubt that any part of a nuclear reactor is recycled. It is radioactive. Recycling solar cells is improving. In other words, over the long term (hundreds of years), with recycling, the total mass of materials needed to generate electricity with wind or solar is much lower than fission reactors.

The energy cost is about the same for all three. It is measured in energy payback time. That is, how long does it take for the nuke, wind turbine, or solar cell to produce as much energy as it took to manufacture it? It ranges from 3 to 6 months for all three. Some solar installations take a lot longer -- up to 2 years. I expect they are put in places where other power sources are not available, such as remote locations.

Solar, wind, or burning your furniture is 16 times cheaper than the nuclear plant being constructed in Georgia, but that is because of engineering mistakes and mistakes in construction, not because of the materials. The materials, and the complexity and danger of the equipment alone would make nukes about 10 times more expensive than wind or solar per watt of capacity, taking into account capacity factors (EIA). More than that over the life of the plant because uranium fuel costs money, and decommissioning costs tons of money, whereas solar does not require any fuel and it is cheap to decommission, and will eventually be cheap to recycle.

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Hydroelectric dams are indeed long lived pieces of equipment. Compared to other renewable energy sources, they have much higher power density, especially the moving parts and are controllable. This is why they were the first large scale electricity generating plants to be built. Ideally, we would like to have more of them. But large rivers are a limited resource. I do not have any detailed figures on hydroelectric materials consumption per TWh.

The situation could hardly be more different for other more intermittent renewable. Wind power declined in Europe as soon as the steam engine became available. However, steam, coal and diesel power, are precisely what enabled large hydroelectric dams to be built. Power density is everything. It is why we are bothering to pursue LENR when there is already abundant sunlight available. The promise of nuclear power, with all it's power density, without hard radiation.

Solar cells are not at present recyclable. The steel, aluminium and glass may be. The copper and silver no doubt will be to a degree at least. Only a tiny fraction of a nuclear power plant steel and concrete is radioactive. The primary circuit, the shielding concrete around the core and some surface contamination in the fuel ponds. The remainder is recyclable.

Jed Rothwell, you are trying to wordsmith your way around the laws of physics. All discussions with renewable energy enthusiasts seem to end this way. They always tie themselves in knots trying to argue the unarguable. This is why we are in the energy mess that we are in. People end up advocating courses of action based on ideology rather than arithmetic.

Rooftop solar is the most expensive commercially available electricity source. Yes, with a lot of human labour, you can do away with the steel support frame needed to hold it at a 30 degree angle against the weather. But you must also contend with the fact that the majority of roof tops are not going to be optimally orientated or at the optimum angle.

Jed Rothwell wrote: "The 1154-MW nuclear power plant can typically occupy about 50 acres of land, often wth a buffer space of land area of at least 1 square mile."

By that estimate, a nuclear power plant has 1000x the area power density of a solar power plant and 2000x the area power density of a wind farm. Making NPPs more compact hasn't been a priority, because the cost of 50 acres of land is trivial compared to the economic value of the electricity. A good example of a volume optimised nuclear power plant is a submarine. The area covered by a solar PV plant isn't land that you can live on or use for anything else. You could farm the land covered by wind farms. I doubt many people would want to live there.

Jed Rothwell wrote: "The graphic also wrong because it says wind turbines only last 20 years. The blades in some units last 20 years. The generators last 30 to 40 years, and the towers probably 100 years. The tower is by far the largest and most expensive component"

You don't know that. Wind turbine towers are flexural steel structures that have a fatigue life. Oil rigs are marine steel structures. Fatigue and corrosion limit their life to about 20 years. You will find most container ships get about the same. Wind turbine towers take higher flexural loads than either of these and they are usually in coastal or offshore environments.

Jed Rothwell wrote: "Needless to say, the Fukushima accident contaminated very large areas of land. Coal fired plants create gigantic piles of coal ash, which causes accidents and environmental destruction. Nothing like that would ever happen from wind or solar power."

Actually, it does happen every time you build a wind farm or solar power plant. The materials used to build these things doesn't just appear out of nowhere. They have to be mined out of the ground. Most of the world's solar panels are made in Xinjiang, the Uigyer region of China. They are made here because the Chinese can use forced labour to mine otherwise stranded coal reserves. This is what is needed to produce such bulky equipment so cheaply. The copper tailings, rare earth mining waste and coal ash, release as much radioactivity into the environment as a major nuclear accident.

Post

RE: Conventional Nuclear (AKA Nuclear Fission) a thread for discussion of the pros / cons.

They are putting in a Hectare of solar on the farm next to my lab. There's virtually no concrete. Gravel access roads (very few). All the solar panels are mounted on square steel tube frames which are bolted to pads on top of large rebar corkscrews augured into the ground. There are 4 guys on site, they reckon 3 weeks to finish their part plus another 6 weeks wait for a grid connection. It's all designed to be 'plug and play' they say.

Alan Smith

Apr 25th 2022

The link below provides a brief description of the Waldpolenz solar park. It is a fairly typical utility scale PV project in Germany.

Waldpolenz Solar Park - Wikipedia

en.m.wikipedia.org

It's capacity is 52MWe and it produces some 52GWh(e) each year, on average. That is a capacity factor of 11.4%. It covers an area of 220Ha, which is 2,200,000m2. That makes its average area power density 6.84W/m2. Of course, sometimes it will produce more than that. In the winter, a lot less and at night, none at all. But let's work with the average.

To produce an average of 1000MWe of power, about the same as one Westinghouse AP-1000 reactor and about enough for a city of 1 million people, a scaled up solar farm with the same specifications as Waldpolenz, would need to cover 146km2 of land. That's as big as some major cities in Europe. Copenhagen for example has an urban area of 180km2 and is home to some 800,000 people! This tells us that a solar farm big enough to power a city, needs to be about the same size as the whole city.

Previously I referenced the volume of a VVER-1000 nuclear steam supply system. It would comfortably fit into a single 3 storey building. The containment dome, steam turbines, cooling towers, etc, are a lot larger. But still, we are looking at a shopping centre sized power plant, not a city sized power plant. The enormous size of solar power plants is why they take so much energy and materials to build. This is a direct consequence of low power density. For a wind farm, the material volumes are less dramatic, though still an order of magnitude greater than a light water reactor of equivalent annual electricity production. Still, the maximum power density of wind farms in Northern Europe is about 2-3W/m2, depending upon local capacity factor. To power entire countries, RE systems need to be country sized. And they need country sized quantities of concrete and refined metals and all of the fossil fuel powered mining and ore reduction and manufacturing and transport needed to make them and transport them to where they need to be. This is the inescapable drawback of low power density. It is why calling these things 'Green' is really a bad joke.

The worst of it is that these country sized pieces of infrastructure will not even replace FF power stations. These stations still need to be built, maintained and manned and run. And they have to sit there doing nothing, waiting for mother nature to switch off the sun or wind. The most the RE plant can do is reduce the fuel bill in these fossil power plants. And the materials cost associated with that limited achievement is vast. It is why there are serious concerns that PV may not break even in energy payback terms in Northern European countries.

Daniel, he probably just misread the post. Easy enough to do.

The reason the PWR figures are so low compared to competing energy sources is the high power density of nuclear systems. Below is a link detailing the primary circuit component volumes for a VVER-1000 power plant.

Volume of Coolant in Reactor Coolant System

The volume of Coolant in Reactor Coolant System. In typical modern pressurized water reactors (PWRs), the Reactor Coolant System (RCS) consists of several…

www.nuclear-power.com

For a power plant producing 3GW of heat and 1GW of electric power, primary circuit volume is 285m3. That is incredibly compact for a machine that can power a city of a million people. Were it not for the mass of steel and concrete in the containment dome, a PWR would be the most compact power plant in existence.

Quote from Wyttenbach

Your post is just junk. The amount of concrete needed is at least 100x larger...

May be they refer to an open air reactor with no shield no cooling tower etc...

Here are some steel and concrete input estimates from Berkeley, University of California.

http://fhr.nuc.berkeley.edu/wp-content/uploads/2014/10/05-001-A_Material_input.pdf

For a vintage PWR, they estimate 40 tonnes concrete per average MW for the whole powerplant. Over a 50 year life, that is 40 tonnes for 438,300MWh, or 91 tonnes of concrete per TWh. I think the US DOE estimate may actually be conservative.

At least one of the innovations that has developed from LENR (Lattice Confinement Fusion) has the potential to reduce further the embodied materials and energy required to establish a nuclear power programme. If it can be scaled in the way NASA and US Navy foresee, future nuclear reactors will not need uranium enrichment. DU or Natural U can be used as fuel in light water reactors. This can happen because LCF functions as a neutron multiplier in a nuclear reactor. One of the first things than LENR is going to provide humanity is better and cheaper fission reactors.