Monday, February 11, 2008

Construction Times for Nuclear Power Plants

I had thought we were pretty much done but the kids in the basement came up with another reason why we can't use nuclear energy. Nukes take too long to build! they whined, their lips quivering. It took ten years to build them before. Jim Hansen at NASA says we only have ten years to stop all the greenhouse gases or we're gonna die! We'll build windmills instead.

Now, how could anyone know all that? The estimable Dr. Hansen actually says
"The Energy Department says that we're going to continue to put more and more CO2 in the atmosphere each year--not just additional CO2 but more than we put in the year before. If we do follow that path, even for another ten years, it guarantees that we will have dramatic climate changes that produce what I would call a different planet--one without sea ice in the Arctic; with worldwide, repeated coastal tragedies associated with storms and a continuously rising sea level; and with regional disruptions due to freshwater shortages and shifting climatic zones."

Dr. Hansen goes on to make concrete suggestions, such as a cessation of building new fossil-fired power plants. He offers the possibility that in ten years it might be necessary to bulldoze all the existing ones.

Actually, a better plan would be to replace all the boilers with nuclear reactors. Most of the construction cost and effort is in the generating portion of the plant, anyway, so replacing the boilers will be much cheaper and faster than building new nuclear plants from scratch.

His other recommendations, such as financial incentives and improving the efficiency of buildings and vehicles, agree with the views of just about everyone who's looked at the issue.

But besides oversimplifying Dr. Hansen's remark, the kids are presuming to know more than they do.

We don't know how long it will take to build nuclear plants. In Japan they can build them in less than five years. If other countries got serious and cranked up their capacities for building them they could do it even faster.

The new designs are simpler than the earlier designs. The designers have incorporated features into them that make them inherently safer so that the risk of accident is lower even while the safety systems are less complex. Furthermore, manufacturing and construction technology has advanced in the last few decades. Just as office buildings can be put up faster and cheaper, so can power-plant structures. Computers and laser-guided machine tools have revolutionized the manufacture of heavy machinery. New testing techniques ensure quality control both cheaper and more thorough.

Besides, wind farms take more construction effort than nukes. Consider that a 1000 MW nuke will average over 850,000 KW. A very big (rotor-tip height ~ 450 feet!) wind turbine rated at 1.5 MW will average less than 500 KW. So 1 nuke equals more than 1700 big turbines.

As luck would have it, the British House of Lords studied the question and compiled some comparative data (and you wondered what the lords did!). A good measure of the construction effort is the energy inputs required for manufacturing and construction. What they show is that a 1000 MW nuke takes 6280 terrajoules per average GW, while a 25 MW wind farm takes 20,575, more than three times as much.

This is not an energy comparison, because that's much more complicated. We're only using these numbers to represent the manufacturing and construction effort.

What it shows is that the kids got it wrong. Again. Even if wind could provide full-time power, it still couldn't outpace nuclear in converting away from fossil fuels.

Sunday, February 10, 2008

The Linear-No-Threshold Hypothesis

In a recent article we discussed the BEIR VII report's conclusion with respect to the linear-no-threshold (LNT) hypothesis concerning low-level radiation's possible health effects. It's worthwhile to compare it with other reports' findings, all from professional organizations in the US.

First, here's the pertinent statement in BEIR VII
"At doses of 100 mSv or less, statistical limitations make it difficult to evaluate cancer risk in humans. A comprehensive review of available biological and biophysical data led the committee to conclude that the risk would continue in a linear fashion at lower doses without a threshold and that the smallest dose has the potential to cause a small increase in risk to humans." [A typical person in the US receives 3 milliSieverts per year.]

That's a tepid justification for retaining LNT, but compare that with the statement from the National Institutes of Health:

"It is very difficult to detect biologic effects in animals or people who are exposed to small doses of radiation. Based on studies in animals and in people exposed to large doses of radiation such as the atomic bomb survivors, scientists have made conservative estimates of what might be the largest doses that would be reasonably safe for a person over a lifetime. But these calculations are estimates only, based on mathematical models. Low-level exposures received by the general public have shown no link to cancer induction. Even so, the U.S. Government uses these estimates to set the limits on all potential exposures to radiation for workers in jobs that expose them to ionizing radiation. International experts and various scientific committees have, over the years, examined the massive body of knowledge about radiation effects in developing and refining radiation protection standards."

And with the statement from the Health Physics Society"

"There is substantial and convincing scientific evidence for health risks following high-dose exposures. However, below 5–10 rem (which includes occupational and environmental exposures), risks of health effects are either too small to be observed or are nonexistent."

"In view of the above, the Society has concluded that estimates of risk should be limited to individuals receiving a dose of 5 rem in one year or a lifetime dose of 10 rem in addition to natural background." [5 rems would be 50 milliSieverts.]

Professor Bernard Cohen goes on to estimate what would be the health effects of low-level exposures and compares them with other health risks, using the LNT model even though he shows in his analyses that it overstates the adverse effects and probably understates the beneficial (hormesis) effects of low-level radiation.

As an exercise we'll do something simple here. The BEIR report says ten million mSv would cause 1140 deaths. And it says that, on average, 304 million Americans receive 3 mSv per year, so the total would be 912 million mSv. So all of the radiation-induced deaths add up to 104,000 per year. Of that number, according to the report, 0.2% are due to nuclear energy, the rest mainly being due to natural radiation. If the LNT hypothesis is right, 208 deaths per year can be attributed to nuclear energy.

In comparison, every study done shows that tens of thousands of Americans die every year from the pollution generated by coal-fired power plants. The most comprehensive study done so far puts the range between 33,000 and 121,000 per year, just counting adults over 25. In 2006, according to DOE, coal generated 1930 billion KWH of electricity and nuclear generated 787 billion KWH, so if nuclear replaced coal an additional 510 deaths would take place, but at least 50,000 lives would be saved.

And all of the radiation-related deaths depend on a hypothesis that hasn't been proved and which specialized professionals don't believe.

Here's the kicker: Coal plants emit more than ten times as much radioactivity as nuclear power plants. If the LNT hypothesis were true, 5000 of the coal-related deaths would be avoided by converting to nuclear energy just because of reducing radioactive emissions.

If some form of renewable energy could provide full-time power, this might be a harder decision to make. As we saw in an earlier article, though, there aren't any that could.

So those are the two options. We can let over 50,000 Americans die every year from coal or we can switch to nuclear energy and start cleaning up the environment while minimizing the threat of global warming. What to do, what to do.

Saturday, February 9, 2008

The Latest on Biofuels

This week's Science Magazine (or Science Lite as it's sometimes called) includes a story that's got a lot of press coverage (way to go, guys!) but really just fills out the picture slightly.

The authors make the point that if you increase plant cultivation for biofuels, you either have to displace existing crops or clear additional land. But if you displace existing crops then the demand for food leads to the clearing of additional land, anyway. And it's the clearing of additional land that causes the problem. This seems obvious if the clearing is done in forests, as it usually is. A mature forest contains decades' worth of accumulated carbon so if the forest is burned then most of that carbon goes into the atmosphere as CO2. It's not as obvious but, according to the authors, plowing up grassland to grow biomass also releases more CO2 than it saves.[LA Times]

It's been known for a long time that ethanol is a loser.[source] It takes as much fuel to produce it as the process yields. So, in the US at least, it's always been a boondoggle aimed at making farmers rich. Still, some researcher think switchgrass can offer a better payoff ratio.

There's been some hope that oil-bearing crops could produce biodiesel, but so far the results aren't much more promising.[source]

So that seems like a daunting challenge by itself. But then we look at the land requirements and the prospects are even more dismaying. As we showed in another article, there isn't enough arable land available to grow the amount of biomass that would be required.

Maybe all this attention will do some good. Most people whose knowledge of enviromental subjects comes mainly from popular media have the idea that biofuels are a practical solution. A closer look shows that, by themselves, biofuels can at best be only an expensive non-solution, an illusory exercise that benefits a few people financially but only aggravates the problem.

As we face this bleak outlook, there's only one thing going for us. Hydrogen can increase biofuel yields by a factor of three. Then, biofuels can function mostly as a medium for hydrogen. They provide an imperfect means for onboard storage of hydrogen fuel for motor vehicles.

The most efficient way to convert water to hydrogen is with high-temperature processes, at temperatures nuclear reactors can provide. The nominal efficiency is over 45%.[source] But the heat left over from the conversion can be used to generate electricity, so the hydrogen production is effectively 100% efficient.

If we're lucky, a better way of storing hydrogen will be invented so biofuels won't be required. Either way, hydrogen is going to be the fuel of the future. The best way to produce hydrogen is with nuclear energy.[source]

Friday, February 8, 2008

Bernard L. Cohen

This is the easiest to write of the articles on this blog. The only important part is a link to Prof. Bernard L. Cohen's website, THE NUCLEAR ENERGY OPTION. Here you'll find the most authoritative treatment anywhere of all aspects of nuclear energy as it relates to the public, and it's written clearly enough that any reasonably well-educated person can understand it perfectly.

This article could end right here, but maybe it's worthwhile to offer one example of his explanations. Since safety is the one place where most people's knowledge of nuclear energy is dodgy, what follows makes a good sample.


With the benefit of this perspective, we now turn to the risks of nuclear energy, and evaluate them as if a large fraction of the electricity now used in the United States were generated from nuclear power. The calculations are explained in the Chapter 8 Appendix, but here we will only quote the results.

According to the Reactor Safety Study by the U.S. Nuclear Regulatory Commission (NRC) discussed in Chapter 6, the risk of reactor accidents would reduce our life expectancy by 0.012 days, or 18 minutes, whereas the antinuclear power organization Union of Concerned Scientists (UCS) estimate is 1.5 days. Since our LLE from being killed in accidents is now 400 days, this risk would be increased by 0.003% according to NRC, or by 0.3% according to UCS. This makes nuclear accidents tens of thousands of times less dangerous than moving from the Northeast to the West (where accident rates are much higher), an action taken in the last few decades by millions of Americans with no consideration given to the added risk. Yet nuclear accidents are what a great many people are worrying about.

The only other comparably large health hazard due to radiation from the nuclear industry is from radioactivity releases into the environment during routine operation (see Chapter 12). Typical estimates are that, with a full nuclear power program, this might eventually result in average annual exposures of 0.2 mrem (it is now less than one-tenth that large), which would reduce our life expectancy by another 37 minutes (see Chapter 8 Appendix). This brings the total from nuclear power to about 1 hour (with this 37 minutes added, the UCS estimate is still about 1.5 days).

If we compare these risks with some of those listed in Table 1, we see that having a full nuclear power program in this country would present the same added health risk (UCS estimates in brackets) as a regular smoker indulging in one extra cigarette every 15 years [every 3 months], or as an overweight person increasing her weight by 0.012 [0.8] ounces, or as in raising the U.S. highway speed limit from 55 miles per hour to 55.006 [55.4] miles per hour, and it is 2,000 [30] times less of a danger than switching from midsize to small cars. Note that these figures are not controversial, because I have given not only the estimates of Establishment scientists but also those of the leading nuclear power opposition group in this country, UCS.

I have been presenting these risk comparisons at every opportunity for several years, but I get the impression that they are interpreted as the opinion of a nuclear advocate. Media reports have said "Dr. Cohen claims . . ." But there is no personal opinion involved here. Deriving these comparisons is simple and straightforward mathematics which no one can question. I have published them in scientific journals, and no scientist has objected to them. I have quoted them in debates with three different UCS leaders and they have never denied them. If anyone has any reason to believe that these comparisons are not valid, they have been awfully quiet about it.

Thursday, February 7, 2008


Maybe the National Academy of Sciences has a perverse sense of humor. Otherwise, I can't explain its 2005 report, Biologic Effects of Ionizing Radiation (BEIR VII: HEALTH RISKS FROM EXPOSURE TO

In the very first paragraph of the summary brief, is this sentence:

"A comprehensive review of available biological and biophysical data supports a “linear-no-threshold” (LNT) risk model—--that the risk of cancer proceeds in a linear fashion at lower doses without a threshold and that the smallest dose has the potential to cause a small increase in risk to humans."

This is a statement that could warm the heart of the most discouraged anti-nuke. NIRS jumped into this like a kid into a pond. Let's compare how NIRS represents the report with what the report says when you get past the first paragraph.

NIRS: "There is no safe level or threshold of ionizing radiation exposure."

BEIR: "At doses of 100 mSv or less, statistical limitations make it difficult to evaluate cancer risk in humans. A comprehensive review of available biological and biophysical data led the committee to conclude that the risk would continue in a linear fashion at lower doses without a threshold and that the smallest dose has the potential to cause a small increase in risk to humans." [A typical person in the US receives 3 milliSieverts per year.]

This is quite a different statement. The report admits the data don't support the view that the risk continues all the way down to zero exposure, but concludes that it does anyway. This is the conundrum radiation safety analysts have struggled with for as long as there have been radiation safety analysts. The only way to be sure is to assume the worst case, so that's what we'll keep on doing.

The BEIR report gives anti-nukes what they want most, a solid-gold slogan, and then says something different in the explanation.

NIRS: "Radiation causes other health effects such as heart disease and stroke, and further study is needed to predict the doses that result in these non-cancer health effects."

BEIR: "Radiation exposure has been demonstrated to increase the risk of diseases other than cancer, particularly cardiovascular disease, in persons exposed to high therapeutic doses and also in A-bomb survivors exposed to more modest doses. However, there is no direct evidence of increased risk of non-cancer diseases at low doses, and data are inadequate to quantify this risk if it exists. Radiation exposure has also been shown to increase risks of some benign tumors, but data are inadequate to quantify this risk."

In this case NIRS turns the BEIR report upside down, attaching a conclusion for high-level radiation to low-level.

NIRS: "It is possible that children born to parents that have been exposed to radiation could be affected by those exposures."

BEIR: "Studies of 30,000 children of exposed A-bomb survivors show a lack of significant adverse genetic effects."

What does NIRS mean by "possible?" Is it possible in the sense that our atoms could all rearrange themselves and each of us could turn into linoleum flooring? The evidence says it hasn't happened, but it's still possible? That certainly isn't what BEIR says.

What is especially significant is what the anti-nukes don't say about the BEIR report. The report shows that of all the radiation a typical person receives, less than 0.2% comes from all of the nuclear fuel cycle. In comparison he gets sixteen times as much radiation from consumer products.

The report already has told us nothing can be concluded about doses under 100 mSv and at the end of it we learn what is needed:

Continued research is needed to further increase our understanding of the health risks of low levels of ionizing radiation. BEIR VII identifies the following top research needs:
• Determination of the level of various molecular markers of DNA damage as a function of low dose
ionizing radiation.
• Determination of DNA repair fidelity, especially double and multiple strand breaks at low doses, and whether repair capacity is independent of dose.
• Evaluation of the relevance of adaptation, low-dose hypersensitivity, bystander effect, hormesis, and genomic instability for radiation carcinogenesis.
• Identification of molecular mechanisms for postulated hormetic effects at low doses.
• Reduction of current uncertainties on the specific role of radiation in how tumors form.
• Studies on the genetic factors that influence radiation response and cancer risk.
• Studies on the heritable genetic effects of radiation.
• Continued medical radiation and occupational radiation studies.
• Continued follow-up health studies of the Japanese atomic-bomb survivors, 45% of whom were still alive in 2000.
• Epidemiologic studies to supplement studies of atomic-bomb survivors, for example studies of nuclear industry workers and persons exposed in countries of the former Soviet Union.

Setting out its own limitations makes the report more valuable. And it emphasizes the folly of drawing strong conclusions as NIRS has done.

The final irony is that anti-nukes have succeeded only in forcing the world to use more coal. And coal-fired power plants emit more than ten times as much radioactivity as nuclear power plants.

Wednesday, February 6, 2008

Nuclear Fuel Reprocessing

People who've paid any attention to the subject often have some misunderstandings about the relationship between spent fuel and the possibility of weapons proliferation. The source of the misunderstanding is that special production reactors were used in the weapons program and the material produced in them was used in making some kinds of atomic explosives. So we need to cover the difference between the weapons fuel cycle and the energy fuel cycle.

Wikipedia has some good information on reprocessing. For information on the difference between uranium and plutonium bombs, the US DOE has a good page on their history.

The first difference is the length of time the material is in the reactor. As the reaction goes on, some of the U238 turns into Pu239, going through some intermediate steps. If the material stays in much longer, some of the Pu239 turns into Pu240.

Pu240 makes the material unsuitable for weapons because it fissions spontaneously. When the bomb mechanism combines the fissile material into a critical mass, the fission of Pu240 causes it to pre-detonate, causing the material to separate, and the bomb only burbs instead of exploding.

So, in production reactors, the fuel has to be extracted in some short time, months instead of years, and sent to the separation facility. In power reactors, the fuel stays in for years and accumulates a high proportion of Pu240. To make the spent fuel into bomb material requires isotope separation on top of chemical separation. If a country has the resources to separate the plutonium isotopes, it would be better off separating uranium isotopes, because that would save it the trouble of operating a production reactor.

The second difference is the chemical process. For the weapons program, the whole point of processing was to separate out the plutonium. For commercial power, that's not necessary. It's cheaper and easier to keep the plutonium mixed with the leftover uranium.

Most (I think all) of the countries presently reprocessing spent fuel use the acid process, called PUREX, or something similar. In the US, a new facility is being developed at Savannah River, South Carolina, for an entirely different process based on molten salt instead of acid. This other process uses less energy and emits no significant amounts of greenhouse gases. In theory, it's less vulnerable to proliferation due to diversion of spent fuel; as we just saw, though, proliferation with spent fuel from commercial power plants isn't really a concern.

Tuesday, February 5, 2008

Droughts and Nuclear Power Plants

Anti-nukes and pro-nukes are stuck in the same muddle. For decades, anti-nukes have been tossing up reasons not to use nuclear energy and pro-nukes have been batting them down. Both sides have run out of things to talk about.

So, Associated Press ran a story that warned nuclear plants could face power decreases or even shutdowns because droughts have lowered some stream flows. That indeed is a concern, and it applies every bit as much to fossil-fired plants. It's just curious that AP chose to mention only nuclear power plants.

Not having much to talk about, anti-nukes crowed that "Water is the nuclear industry’s Achilles’ heel. You need a lot of water to operate nuclear plants. This is becoming a crisis."

This is silly, of course, because there are alternate ways to cool power plants. In most cases, the problem is that stream flows are so low that adding waste heat would raise the stream temperature unacceptably. The solution is to add cooling towers. What's the penalty for doing that? The US Department of Energy did a study of all the thermal (fossil and nuclear) plants in the US. They found that if 100% of the power plants in the US (except in the Southwest) that rely on stream water were retrofitted with wet cooling towers, the energy penalty could be as high as 3%, but only during the hottest 88 hours of the year.

In an extreme situation, stream flows could be so low that wet cooling towers couldn't be used because of the water consumption. In that case, dry cooling towers can be used. Then, the penalty could be as high as 10%, again during the hottest 88 hours of the year. The authors didn't attempt to evaluate conditions for plants that were designed for dry cooling, but acknowledged that the penalty would be lower. Probably, the penalty would be about the same as for the ten percent of plants best suited for retrofit, which is about 1%.

As we look into the future, we can see that as long as new plants are designed to accommodate cooling towers, the penalties will be minimal.

In the meantime, as small as these penalties are, even they can be avoided most of the time. When stream flows are adequate the cooling towers can be bypassed. And when they are operated, it'll be unusual that the plants have to rely entirely on them; the cooling load can be shared between the cooling tower and the stream, or between a wet cooling tower and a dry one.

But the best solution will be to use the waste heat productively, as industrial heat or for heating homes and businesses. The waste heat can even be used for air-conditioning, by use of absorption chillers.

So drought and low stream flows won't be a hindrance to nuclear energy in the future. That means nuclear power plants will be able to provide backup to wind and solar energy.

Monday, February 4, 2008

The Academic Approach to Anti-Nuclearism

For a long time there's been a belief among anti-nukes that you can prove anything if you write enough. You just have to beat science with statistical analysis and smother it with paper.

This came up again on another blog, which uses a lot of scientific language but is dedicated to the proposition that the laws of nature can be over-ridden if they're inconvenient.

In this case, the writer of the article is determined to show that part-time energy sources can provide full-time power, if you just do enough mathematical manipulations.

First he cites "Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms" by Cristina L. Archer and Mark Z. Jacobson, which argues that if enough wind turbines are interconnected they can provide base-load power. According to the authors, the part of the average output that can be considered 87.5% reliable is between 33% and 47%, depending on how many wind turbines are interconnected. However, the area they studied, centered on the Texas and Oklahoma panhandles, has the most reliable winds in the US and their results don't translate to the country as a whole. Even so, they show that wind farms would have to be oversized by a factor of at least 2. They elect to call it base load, but that's not appropriate. It only can be base load if there is also some form of load-following power.

That's a problem. Without fossil fuel and nuclear energy, load following is limited to whatever hydro and pumped storage can be made available, and at most that can only be a few percent.

The article writer also cites "Improving the Technical, Environmental and Social Performance of Wind Energy Systems Using Biomass-Based Energy Storage" by Paul Denholm, which recognizes that problem and suggests using biofuels for backup. But there are a couple of problems here. One is that nowhere does he consider the fuel required to grow the biomass and convert it into biofuel. Currently, it takes up to a gallon of fuel to produce a gallon of fuel, and certainly a big part of a gallon. It seems unlikely that it will ever take no fuel to produce a gallon of fuel. In the absence of better information, his study has to be considered extremely optimistic.

His optimistic estimate is that it would take 6.9 hectares or .0266 sq mi to produce biofuels that would generate 1000 MWH per year. The US uses 4 billion MWH/year, so the area required would be 106,400 square miles, out of 650,000 square miles of arable land. Suppose wind energy allows us to reduce that in half, which would require a half-million 1.5 MW wind turbines (rotor height = 450 feet!); we still need 53,000 square miles. Since we're using almost all the arable land for food and fiber, it's not clear where the 53,000 square miles will come from. Also, to farm land of this magnitude means using less-productive land. He assumes 11.3 tonnes/hectare yields, which would require prime Iowa land, so the land areas would be much greater and very likely would require irrigation, for which water will not be available. That's enough trouble already, but consider that the need for motor fuels will vastly outweigh the need for bio-electricity, because there is another, better, way to generate electricity but no alternative way to produce non-fossil motor fuels.

So we're still where we've always been. Wind energy doesn't work without a backup, and biofuels won't provide the backup.

As we explained in an earlier article, nuclear energy allows solar and wind to play their maximum part in providing electricity. Further, it allows them to contribute efficiently to the production of hydrogen, by taking some load off the nuclear plants. This is the kind of solution that will minimize global warming. Trying to paper over the limitations of renewable sources with scientific-looking obfuscations, if it's successful, can only keep the world on its present reckless path to self-destruction.

But anti-nukes don't get this. They believe you can change reality by manipulating data. You want windmills to turn when there's no wind? No problem. Just crank out fifteen pages of equations, tables, diagrams, and charts and they'll turn themselves!

Sunday, February 3, 2008

Simpler Living

Simpler Living is the mouse under the feet of battling elephants.

One elephant wants to build nuclear power plants. The other wants to shut down all the nuclear power plants, force everyone to ride bicycles, and run the world with windmills and solar panels.

Lost in the noise and dust is a program that has accomplished wonderful changes by lowering the strain on the world's natural resources and saving huge amounts of energy and allowing people to live fuller, richer lives.

For years, Simpler Living has been saving people from the rat race: too many people work long hours to earn money to spend in the futile hope it will make them happy. It's usually not hard to convince people that a simpler life will do them a lot more good. Simpler Living shows them how to achieve it.

It sounds much like the first three parts of Buddhism: Life is full of suffering; Suffering comes from attachment (in this case, to spending); Freedom comes from giving up attachments. Buddhism then teaches that you have to live like a monk to give up attachments. Simpler Living teaches that you just have to make thoughtful choices.

As in Buddhism, there's a whole discipline involved here. Having spent your adult life spending as though you were cleaning out your pockets, you probably won't change just by announcing to yourself that from now on your spending will be thoughtful.

To do it right, you have to follow the program. It's a little troublesome, but very enlightening. The standard text for this subject is Your Money or Your Life by Joe Dominguez and Vicki Robin. Amazon has it; in line with your new philosophy, see if your public library has it before you buy it.

I'll outline the process here so you'll understand what's involved. Please don't shortcut the process.

First, you keep track of everything you spend. Actually, you might do this for a long time. JD Rockefeller did it his whole life and claimed it was the reason he became rich.

Next, you analyze where your money went.

Then, you redesign your life, imagining how you want it to be.

After that, you base all your money decisions, even small ones, on how they fit your target.

It doesn't mean that you don't spend money, only that you do it consciously. For most people, their spending shrinks and their carbon footprints shrink along with it.

This is the attitude environmentalists have been advocating for as long as there's been an environmental movement. If the executives who run the organizations will catch onto this, we'll make some real progress. It will reduce environmental damage, including global warming, more than all the pamphlets Greenpeace hands out could ever do.

Saturday, February 2, 2008

Carbon Offsets

Do carbon offsets work? They can work, but won't necessarily. There are companies ready to take your money and grant expiation in return. No doubt some of them are honest, but it's up to you to check them out. There aren't any agencies that regulate them.

Another issue is, what kind of carbon-offset schemes work? Some offer tree planting, maybe in some exotic place. But planting trees won't work, because trees all die eventually and give back all the carbon they've absorbed. It only could work if land was set aside permanently for new forests and if somehow it could be guaranteed that the land would never be cleared. There's no way such a guarantee could be made. At the rate the world population is growing, all the arable land will be needed for growing biofuel, not to mention food. In fact, global warming is likely to reduce land productivity.

But a different scheme could work. Non-fossil energy costs more than fossil energy. That's why we use so much fossil fuel, especially coal. So you could pay your local utility to buy your share of electricity from non-fossil sources, with you paying the difference in cost voluntarily. If this plan were structured properly, nuclear would be one of the non-fossil sources. It never is, though. All or nearly all the energy will come from wind turbines.

If you do that much, why couldn't you pay extra to make up for other CO2 emissions?

Here's some CO2 emission rates you can get from the US EPA's website.

For each KWH of electricity, you generate 1.37 lbs of CO2.
For each gallon of gasoline, you generate 20.4 lbs of CO2.
For each gallon of diesel fuel or heating fuel, you generate 22.3 lbs of CO2.
For each 1000 cubic feet of natural gas, you generate 120.6 lbs of CO2.

The EPA doesn't give this figure, but for commercial air travel, figure 50 passenger miles per gallon, or 1000 / 50 * 20.4 = 408 lbs of CO2 per 1000 passenger miles.

Now you can calculate your footprint in pounds of CO2 per year. If your utility has a green-energy program, ask what the premium per KWH is for green energy. At my utility, the rate is 1.25 cents, so the cost of becoming carbon neutral is 1.25/1.37 = 0.91 cents/pound.


Electricity 5000 KWH 6850 lbs
Gasoline 1000 gallons 20,400 lbs
TOTAL 27,250 lbs

Cost of offset = 27,250 * 0.91/100 = $248/year, or $21/month.

So if our example consumer donated $21/month to the green energy program, he'd be carbon neutral, just like former US VP Gore. If your utility doesn't offer such a program, find one of those companies you have confidence in and donate it there. Just don't pay to plant trees.

Now that you're guilt free, let's discuss this sensibly. The only reason carbon offsets work is that we generate electricity in the most stupid way possible. As we move toward non-fossil energy sources, this system will break down. If all the electricity came from nuclear power plants and windfarms, there'd be no way to offset motor and aviation fuels. That means the world has to shift toward hydrogen, battery-powered cars, and electrified rail transit.

Friday, February 1, 2008

Gwyneth Cravens

Gwyneth Cravens was like a lot of people. She knew something about nuclear energy and she was against it.

But she happened to make the acquaintance of D. Richard Anderson, who was thoroughly plugged into nuclear technology. It turned out that he was something of a major force in nuclear safety and he was able to open doors for her. Fortunately, Ms. Cravens is an intelligent, curious person who took advantage of an opportunity to track down all the facts. To make it better, she also is a skilled writer, able to present information accurately and clearly. Thanks to her gifts we are able to go on her Nuclear America Tour.

She and we see it all. Research laboratories, power plants, mines, waste isolation sites, everything that has to do with nuclear energy. But there's even more: she's able to talk with experts, people who've worked in these places for years.

And she lays it all out: facts and figures. The good and the bad. And she compares the alternatives. It's about as complete a reference as you're likely to find.

She describes herself going into it this way: "I lacked a clear sense of what radiation actually was, didn't know much about its sources, didn't distinguish between low-dose radiation and high-dose radiation, and was foggy about the difference between exposure and dose and about radioactive decay. I had no idea how a nuclear plant worked."

Near the end, she quotes a remark made by Anderson:

"One day God could say to us: I gave you the brainiest men and women in human history to come up with an understanding of the atom and its nucleus. I gave you enough uranium and thorium to last you for thousands of years. I gave you an understanding of how when uranium decays it releases energy. You didn't need to invent anything else. You had everything you needed to provide energy for yourselves and your descendants without harming the environment. What else did you want?"

Cravens, Gwyneth. Power to Save the World: The Truth About Nuclear Energy. New York: Alfred A. Knopf, 2007