Ronin of the Spirit

Because reality is beautiful.

Nuclear Power

I’m reading about nuclear power. A fellow blogger wrote a post on the general coolness of pebble bed reactors, and I’ve been trying to “get” the whole nuclear power thing. It’s strange to find what’s out there. I had no idea there were so many types of reactors, or fuel methods, or methods of operation.

And I hate to admit this…they scare me a little.

I pride myself on being able to divorce my emotions from a topic of consideration, but emotions exist for a reason. We tend to think humans are unique in having emotions (we’re not) or that emotions are useless (they’re not). Emotions help us make decisions in the absence of meaningful data. Survivors of traumatic brain injuries who have received injury to the emotive part of the brain find it very difficult to do simple things. They excel at things such as playing chess, but may struggle for hours to do something as simple as step into a room. Without an “Emotioner” they can’t determine the value of the data they receive, so the angle in which they cross a threshold is of equal importance to them as things like oxygen and not starving to death.

So, I am nervous about nuclear power not because I can’t get any data; far from, I am awash in data. The problem is deciding the relative value of each datum.

Some of the most common “facts” about nuclear power are, in fact, bologna. For instance:

Chernobyl was not a nuclear explosion. It was plain, old-fashioned boiler explosion in a pressure vessel which had nuclear materials in it. The same thing would happen if you took World War I locomotive, and put uranium in it, for the same cause and reason: heat something which is cooled by boiling water, let the water run out, and it blows up.

Chernobyl did not release more 30 times fallout of Hiroshima. It didn’t release any “times” more of anything. The differences between the two are large enough you can’t really pin it down with a mathematically precise comparison. You might be able to say “…the calculated mass of fallout from Hiroshima following a nuclear explosion was roughly a 1/30 the calculated mass of the total sum of all the radioactive materials that were vaporized without a nuclear explosion in the steam explosion and following fire at Chernobyl.” But even that is pretty misleading. A lot of the mass of Chernobyl had a half life measured in seconds. That is to say, in less than a minute, it was totally harmless.

Three mile island was a total non issue. Due to stupidity and laziness on the part of both plant designers and plant operators, the first three fail safes didn’t work. The forth kicked in fine, and there was still 5 and 6 to go. Was “radioactive material” released into the environment? Yes. About 6 bananas worth. Every person reading this who isn’t a nuclear scientist just went HUH??? Bananas are full of potassium. Totally naturally, some potassium is radioactive. The amount of radioactivity released was about the same as the total radioactivity of 6 everyday bananas, per capita.

The standard anti-terrorism yardstick is now “747 resistance.” No one will put it in those words, but in all seriousness, it is everybody’s terrorism related question. So yes, reactors are 747 resistant. The part of the reactor made to withstand high-pressure and high temperature from the inside will do about as well from the outside.

The kind of reactors which are the best at making a lot of electricity are totally incapable of making materials for nuclear weapons. This is not because of regulation, this is because of the inescapable laws of physics. You have a better chance of making nuclear materials in your backyard with home made equipment. Read the Radioactive Boyscout if you don’t believe me.

But then there is the other side…

However, the above much touted fact sort of obscures this one: the reactors which are pretty good at making power are also pretty good at making new fissionable materials. Many of these fissionable materials are only useful for electrical production, but some are the type needed for nuclear weapons, and sometimes (depending on the reactor type) these materials are presented in a relatively convenient way. (Note that this is how India got the material to build their bomb. They got this from a totally normal US/Canadian experimental reactor, which makes about 10 Kilograms of Plutonium a year.) England had a reactor commonly called a Magnox reactor. France, and North Korea use an identical design. It makes a lot of electric power and a lot of weapon grade material. The Magnox reactors is what the UK used to build their entire nuclear arsenal.

The reality of nuclear material recycling is this: we can recycle huge quantities of nuclear material. Nuclear physics allows us the near magical ability to transmute waste into fuel and use it again. So called “breeder reactors” are real and usable. In fact, they are used all the time. See above. The insurmountable fact, mentioned above, is the recycling process produces weapons grade materials. Now these weapons grade materials can be used in the right kind of reactor to make electricity, and more waste which can go back to the breeder reactor and continue the process. It’s fascinating, its exciting, and hopefully we can do it some day. But don’t be misled, it does mean weapons grade material.

Reactors ARE NOT “coal plants with nuke plants instead of coal burners.” Yes, the generator side of a nuclear power plant is identical to coal plants. Even the “feed water” pumps, without which, both coal plants and nuke plants will have catastrophic steam explosion are identical. But the differences come up immediately. When coal plants explode, radio active materials are not released into the air. Many reactors operate in non-intuitive ways. The Chernobyl reactor is a good example. If you cooled it off very quickly, it flushed out all the radioactive materials which had damped the reaction, and the reactor suddenly became more reactive. The Chernobyl reactor didn’t explode until they tried to keep it from exploding, after hours spent trying to make it explode. Seriously. Nuke plants are different.

Now this is the non-nuclear part and where my emotions come into play. People are stupid. I believe there is about 1 out of 10,000 people in the world who can truly create. That leaves 9,999 who are all destroyers. And at least 1 out of 10,000 of those disassemblers is a Newton or Einstein in their particular line of work.

When you read about nuclear reactors you will run into the words “Intrinsically Safe.” And that’s stupid. Three Mile Island was considered to be intrinsically safe…until it wasn’t. There is no such thing as “Intrinsically Safe.” My brother worked in a window factory. He ran a machine that had 6 “deadman” controls on it. (A deadman is a switch that shuts off if the person holding it is injured or killed.) This particular machine had a deadman for each foot, each hand, and each knee. You activated the moving part of it with you right knee, after holding down every other switch. In the 50’s this same machine had one foot switch. You loaded the material in and hit the switch. The reason the 90’s version had 6 switches was because consistently, over the years, people somehow kept getting one body part or another somehow injured.

Nuclear power will never be “intrinsically safe”. The cross roads of radioactive isotopes, high pressure/high temperature gases, huge machinery, and human frailty will aways be a dangerous intersection. Nuclear power is risky and anyone who says otherwise is a fool. The question is, “How does the risk of nuclear power stack up against other risks in this crazy life?” Quite well, actually. Thousands of people die every year in coal mining accidents. Around 40,000 die a year from car accidents alone. Life is a constant game of risk management. The winners get to add to the gene pool; the losers do not.

In the end, I guess my observation is this:

You can’t diffuse a bomb after it goes off. Magical thinking tells us that if we wish enough against something it will go away. Nuclear energy will never go away. Ever. If some killer virus killed all the human beings, in x number of years, a new species say, Proboscidea Sapiens (sentient elephants) will develop. They will have their Hiroshima. Even without us, nuclear power will be discovered. We need to accept the fact we have the power to kill ourselves, and choose not to. Prohibiting nuclear weapons while encouraging nuclear energy is not possible. Not because the reactors have to make the material. They don’t. It’s impossible because that’s the way man is.

Abstinence kills. Countries which teach “abstinence only” sex ed to their teens have the highest teen pregnancy. Regions which require total abstinence from hand guns have higher gun crime than nearby regions which are do not have total abstinence from hand guns. Total abstinence from alcohol (a.k.a. The Prohibition) reduced total alchohol consumption by only 60% (remember this was a total ban) and created organized crime. Countries such as Denmark and the Netherlands which have the least restrictions on pornography have some of the lowest crime rates against women.

I say again TOTAL ABSTINENCE KILLS. Total abstinence NEVER, EVER, comes from a rational mind. Total abstinence is an intrinsically unreasonable standpoint which says, “Even a little bit of ‘whatever’ is infinitively worse than anything that might be inflicted upon us to ‘protect’ or ‘free’ us from it.” People have drives. If abstinence doesn’t keep people from smoking, drinking, using drugs, masturbating, hitting women, killing people, or getting pregnant, I doubt, very seriously, it will prevent the drive to dominate a neighboring country and take their stuff by any means necessary.

We don’t need a ban on reactors that can make weapons grade nuclear materials. We need education starting at a grade school level on how energy works, nuclear and otherwise. Raise a generation of rationalists and nuke plants will be built and staffed by good people. Keep doing what we are doing and nuke plants, and anything else we need, will be prevented by legions of superstitions, fearful, illogical people who think they can make a problem go away by not liking it hard enough.

May 11, 2008 Posted by | Ecology, Government, Politics, skepticism, Uncategorized | , , , , , , , , , , , , , , , , , , | Leave a comment

Sterling Engine Analysis

In 1816, the Reverend Robert Stirling invented a engine. From time to time an astute reader will hear about this engine as the solution to the world’s problems in general, and as the perfect candidate for automotive hybrids specifically. Pure bunk and here’s why.

First, you have to know a little about hot gas. (Gas like air or CO2, not like gasoline.) When gas is heated, it wants to get bigger (ie. increase in volume). When it has its heat removed (cooled), it wants to decrease in volume. If it is in a sealed container, it can’t increase its volume, so it presses against the walls of the container all the harder when heated (pressure). That’s why aerosol cans say to not expose to temperatures of more than 120 degrees. They are full of gas at a certain pressure and if they get too hot, the pressure gets too high and they pop. (Also, if you have a weak container, like an empty closed pop bottle and stick it in the freezer, it will collapse. The removal of the gas’s heat causes a reduction in volume, which reduces the pressure, meaning the air pressure on the outside is higher, and it squishes in.) There are mathematical formulas that describe these relationships of pressure, volume and temperature called gas laws.

Nice suit!

A man named Carnot (above) put all of the gas laws together and drew some rational conclusions. He performed a thought experiment about the perfect heat engine. (An engine being a device for turning heat energy into mechanical energy.) The perfect heat engine would be made out of a magic material which would let heat in but not out at one point, and out but not in at another. It would have no friction, and would never leak. That way, any energy flow could be controlled and monitored.

(1.) Heat would be added perfectly instep with the expansion of the gas, so that no energy was wasted. (Heat is added but the temperature doesn’t increase, because it’s expanding instep.) It expands while taking heat, pushing the piston down.

(2.)The heat in the gas is then “used up” as the gas continues to expand without new heat. It expands while cooling, still pushing the piston down.

(3.)The heat is then removed from the gas, causing the gas to shrink (reduce in volume), pulling the piston in.

(4.) Now the piston is pushed in (further reduced in volume), raising the temperature of the gas back to the temperature it was before the heat was added in step 1.

For various reasons deduced from the gas laws, Carnot’s engine is the most efficient on earth. Since we know what perfect is, we know the best way to design any engine on earth.

Though every part of Carnot’s cycle is right, none of them are true, and therein lies the problem. There is no material which can conduct heat only in one direction, give us choice of direction, and switch direction at whim. There is no gas which behaves exactly as the gas laws say they should, though hydrogen approaches it. There is no material that is totally frictionless and perfectly sealing at the same time. Carnot’s engines says the key to efficiency is the difference between the temperature of the heat input in step (1) and the heat removed in step (2).

Material science is the kicker. The engine’s material must be a good conductor of heat or the heat in it will build up until it melts. But it must not be too good a conductor of heat or it will take heat out of the engine which the engine is supposed to be making power out of. It must allow a tight seal for the piston but without to much friction.

Long story short, the engine must be all at once: a good conductor, insulator, bearing surface, and pressure vessel. Due to the properties of combustion, it must do all of this while white hot and resistant to corrosion.

In the case of the Otto engine (the kind most likely in your car), you can add to all of those challenges this: the heat is not made outside the engine, but in it, and the gas not heated by an outside source, but within the cylinder itself by flame. Furthermore, there are the complexities of piping the gas in and out.

At this point one might cry, “Wait a moment! Do you mean to tell me that the efficiency of an engine is based of the difference between the temperatures at the beginning and end of the cycle? My exhaust manifold GLOWS red! I must be throwing away a huge amount of energy!” Yup.

And that’s a very good thing. The reason you can afford a car is because the Otto cycle, with all its oddities of valves and spark plugs and not reusing the working gas, dumps excess heat out the exhaust stream. If it didn’t, the engine block would need to be made of the same alloys that jet engines are made of, instead of cast aluminum or cast iron.

So, here’s the danger of a little information. (And full circle back to the Stirling engine.) The Stirling engine does not burn inside the engine, it burns outside of it. Its gas is sealed away inside. Of all the engines in the world, Sterling comes the closest to Carnot’s imaginary engine in its cycle. Only in its cycle. Remember that Carnot’s engine is imaginary and made of unobtanium? Carnot’s cycle only has meaning as a thought experiment because you can’t make an engine out of magic alloys which do not exist.

People read that the Stirling engine is theoretically the most efficient heat engine and assume they don’t have one under their hood because it was simply never maximized. Actually it is not that it has not been maximized but that it CANNOT be maximized. Though combustion creates temperatures of thousands of degrees, the Otto engine need not operate at that temperature. If a Stirling was going to operate at that temperature the heat would have to move through the engine and then into the gas. So the engine block, under full power generating stress, must be hotter than the low stress exhaust pipes of an Otto cycle.

Though invented in 1816 to save people from the danger of boiler explosions, the Stirling was never widely used. Steam engines are also external combustion engines, but they have the boiling of water to serve as a temperature regulator. Stirlings do not have this, and a frequent and persistent complaint is burnt out parts.

Another HUGE misunderstanding about Stirling engines is their ability to use very low temperature differentials; that is to say, freakishly small differences between input temperature and output temperature. It’s true. In a 72 degree room, a small Stirling can run off the heat of your palm. These tiny engines create just enough power to overcome their own friction. What would happen if you scaled it up? You would have an enormous engine with equally enormous bearings. Again, the engine would create just enough power to overcome its own friction.

But just for the sake of argument, let’s say you had a truly enormous engine, one the size of a house. The hot part is in the sunshine, and the cool part is in the shade. The low temperature difference would be overcome by the truly enormous amount of energy available, right?

A qualified no. The smaller the temperature difference, the greater amount of gas the engine has to pump around to get the same amount of power. There’s no free lunch. For the same amount of power, high temp = small working mass, low temp = large working gas. The losses to pumping all that gas through the small passages necessary for heat reclaiming mount up very quickly. For this reason, efficiencies are very low. While low efficiencies with free power (like solar) are OK, it’s a niche application.

Another route to efficiency is high pressure. Reverend Robert made his Stirlings low pressure and large (For instance, about a cubic foot of displacement per horsepower, or 172,800% larger than an Otto cycle of the same HP.). The modern trend is to make them high pressure and small. But then they must be filled with inert gas and sealed just so, because if air and lube oil are pressurized and heated the Stirling engine becomes a bomb. This is also why Rev. Stirling could make his engines with a foundryman and bricklayer and modern engines are “lab queens” in college physics departments.

Finally, another story that pops up now and then is Ford’s Stirling research in the 1970’s. Yes, they made a Stirling engine. No, they didn’t produce it. They didn’t produce it for the exact same reason Chrysler didn’t produce its turbines nor GM its Wankle. Material science could not mass produce certain key components at low enough cost to get enough people buying. This, in turn, means mass production could not be used, further raising the price and decreasing the market in a vicious catch-22.

Don’t get me wrong. I think Stirlings are cool. I think they have applications to green science. But we will never see one in a car produced by market forces. Further, if you want to invest in expensive technologies, fuel cells have higher real world efficiencies than Stirling’s theoretical ones.

April 9, 2008 Posted by | Ecology, Engines, skepticism, Small Car, Uncategorized | , , , , , , , , , , , , , , , , , , , , , , , , , | 4 Comments

One hundred four slaves and counting

giant freakin’ hamster wheel

Ok, so I was paying my electric bill today. Now, you might expect that this is where I complain about how the evil electric company is charging me usurious rates and how unfair it is. I don’t do that, because I am not a freaking commie. I don’t think the answer to any “unfairness” is my life is more involvement from my nurturing federal government.

However, Marxism made some valid points about capitalist excess. Despite what certain economist tell us, consumption is not intrinsically ethical, and more importantly, consuming for the sake of consuming is not virtuous, but evil. I believe in the free market, reigned in by responsibility of each individual participating. Plants, animals, and resources disappear to make room for my fat butt; I’d better consume thoughtfully.

So, anyway, I noticed my electric bill is 20KWH a day. So quick math yields that that is 26 HP hours. One human power is about 1/4 of horsepower if they don’t mind sweating a bit. So, I use 104 man hours a day. To support my lifestyle takes 104 slaves a day.

Now, I am pretty viciously pragmatic pro-capitalist. I believe in what many consider a truly out there level of laissez-faire Objectivism. If slavery takes place between consenting adults and is not removed from market forces (i.e. you can’t stop your slaves from learning to read, for instance), I really don’t give a rat’s tail if there is slavery out there. It’s going to be there anyway. Escorts may be private contractors, but typical street corner whores are not. They are slaves who belong to their pimp. Some people will always be willing to enter slavery and others always willing to be master over others. Making these things illegal does not prevent them; it only makes it harder to offer the victims even a modicum of legal protection. Far better for it to be legal and legislated. So, the 104 slaves isn’t what bothers me.

What bothers me is that I am not getting my 104 slaves worth. I pay for these 104 man hours of energy. Well, if I had 3 slaves, I wouldn’t even need electricity. I wouldn’t need a fridge for instance, as I’d have no reason to store food. My slave could get a day’s worth of food every morning because he has nothing better to do than cook and cooking related tasks all day anyway. I could cook everything with a wood stove and have slave wander around town all day picking up discarded wood to burn all day. I have access to the power of a 104 slaves, and yet, I still have to go to the downstairs bathroom to get toilet paper when I run out. Totally unacceptable.

Now, my point here is not that slavery is good. Despite what I said about thinking that slavery should be legal and regulated, I wouldn’t keep slaves. (Smoking is legal and regulated, I don’t do that either.) I hate slavery, I think it destroys the slave from the inside out and the master from the outside in. My point is that I am not getting nearly enough help around the house for the amount of power I am purchasing.

Case in point my fridge. My fridge uses around 7.2 Kwh a day, or 9.65 HP hours (calculator here), which is 38.62 man hours. So to keep my milk cold, and my leftovers chilled, 39 people would have to be slaving away for for an hour each. That’s retarded. This is one of the reasons I want a Sunfrost. It uses 3.35 man hours a day. My foot print on the earth is 104 slaves a day. I could cut that by 40% just by getting a better fridge.

My personal consumptive goal is for my house to use no more than 72 man hours a day. (That 1 man hour per person.) Which is 18 hp, which 13 KW hours a day. I could happily go under that, but thats my goal. Which, of course, I can’t meet in this apartment.

Anyway, I hope this has been instructive for everyone. The slave math is really easy: Kilowatt hours X 1.34 = HP. HP X 4 = Man power. Pull out last month’s electric bill and see how many slaves are running in the giant hamster wheel to keep your lights on.

March 31, 2008 Posted by | Ecology, Government, Politics | , , , , , , , , , , , , , , , | Leave a comment