Energy Density Comparison
One of the primary advantages that nuclear energy sources have over chemical energy competitors is energy density. Using our current, rather primitive technology that essentially obtains nuclear energy from the 0.7% fraction of uranium that is easily fissioned with a single, low energy neutron, uranium contains about 16,000 times as much energy per unit weight as coal. As we improve our technology, and the need for improved utilization increases, we will begin using high energy neutrons with repeated interactions to break the far more common U-238 into smaller pieces plus energy and we will take advantage of the excellent properties of Th-232 to fission after being hit with two low energy neutrons.
When those known techniques reach the commercial stage, the ratio of energy content per unit mass between nuclear fuels and chemical fuels will be closer to 2,000,000 to 1 and even that measure understates the advantage that nuclear reactions have over chemical reactions.
The understatement there is caused by the fact that combustion fuels are not self contained; they will only release their energy when combined with oxygen. If you count the mass of all required reactants, which is often not done since our common atmosphere contains sufficient quantities of oxygen to support combustion, the ratio of energy density between nuclear reactions and chemical reactions is closer to 10,000,000 to one. The implications of very dense fuels for machinery and support equipment design can be incredible if the engineers and accountants can learn how to take full advantage of the physics.
All those numbers can be complicated to explain to people. My artistic friends at PopAtomic.org have produced a poster that helps visually explain the first set of numbers. Comments are always welcome; I will admit to pride of authorship, but also a desire to learn and improve. Based on what I know about PopAtomic, they feel the same way.
Nuclear energy produces both operational and decommissioning wastes, which are contained and managed. Although experience with both storage and transport over half a century clearly shows that there is no technical problem in managing any civil nuclear wastes without environmental impact, the question has become political, focusing on final disposal. In fact, nuclear power is the only energy-producing industry which takes full responsibility for all its wastes, and costs this into the product – a key factor in sustainability. Ethical, environmental and health issues related to nuclear wastes are topical, and their prominence has tended to obscure the fact that such wastes are a declining hazard, while other industrial wastes retain their toxicity indefinitely.
Do you ever wish they’d let us have smokestacks and ash ponds? (just kidding! Really!)
That was me, above, Meredith Angwin. I’m out of town using a computer without cookies. Never knock cookies….
Rod,
This is probably not the way one would like to make the argument, but people are pretty clear about the distinction between a chemical explosion and an atomic explosion. The origin of the difference is of course the same. Of course that just reinforces the misconception that nuclear plants can explode like an atomic bomb. Too bad, otherwise this gets the idea across very efficiently.
We went through a series of edits with this ad and finally came up with this number as the most simple brake down of energy density without going into the science of chemical vs. fission reactions (I might have to rework it with John’s numbers below!). Hopefully people’s understanding of the greater release of energy in an atomic weapon vs. traditional explosions will actually reinforce our point that nuclear reactions simply output more energy, and that energy can be created in a controlled environment and used to create electricity rather than bombs.
I must admit this has been a sticky comparison, especially with the nature of the ad not allowing much further scientific explanation. Lets just hope the image and message are strong enough to peak people’s interest and get them started on their own research!
More great graphics from PopAtomic!
Another way to look at energy density is on a volume basis. A cubic meter of coal will provide the electric power for an average American home for about two months. A cubic meter of uranium or thorium fuel in a breeder reactor such as an IFR or LFTR will power a one GW reactor for 19 years. That
Like the Chinese
Is this an argument against democracy?
(Ie, the Chinese can machinegun Greenpeace protesters, and we can’t…)
Rod,
As I recall you provided a comparison of a gallon of nuclear fuel vs. a gallon of gasoline. Please help me remember correctly. I am thinking you said a gallon of gas in a car that gets 20 mpg will take the car 20 miles while a gallon of nuclear fuel in the same car would take that car 750 million miles. Please respond.
Thanks for the Atomic Blog.
Keith – you remember correctly. The article was titled “The 750 Million Mile per Gallon Carbureator”. It is still available at https://atomicinsights.com/FTROU/3-06-01.html
How about an Ad showing the solid waste from a coal plant for a year vs. the storage container for a years worth of fuel rods?
EXCELLENT. “The 750 Million Mile per Gallon Carbureator” is a GREAT link and info. I believe we must continue to spread the gospel of nuclear power using this approach.
It isn’t just a question that nuclear power is overwhelmingly more energy-flux-dense than prior forms
of power, but that of the quality of nuclear as a power source. Nuclear represents a new universal principle–the fissioning of the atom–which has a transformative capability for the entire physical economy, leading us into the isotope economy of the future. Nuclear can do what no “alternative” source can. For more on this concept,
see “The Astounding High Cost of `Free’ Energy,”
http://www.21stcenturysciencetech.com/Articles%202008/Energy_cost.pdf
@Marje — That is one of the most informative articles on energy that I have read. The comparison of horsepower and electricity really makes a statement, particularly as it relates to competing economies. What is appalling is the energy ignorance of too many of our elected officials and the influence they exert on the people they are supposed to represent. Harmful policy is borne of this ignorance.
@DocForesight – I think you are being too kind by using the word “ignorance”. That word describes a situation where there is a lack of knowledge. In the case of at least some of the decision makers, they had all the knowledge they needed; they CHOSE to keep focusing on less energy dense, but far more lucrative forms of energy. Those lucrative forms not only have a more established model for putting enormous sums of money into the pockets of selected or lucky people, but they also are much more useful from a geopolitical power point of view.
Do you realize just how empty a threat it would be if you told a country with a lot of nuclear power stations – “you better behave or we will not sell you any replacement fuel when you really need it – in 18-60 months.”
@Rod — LOL, that’s right, “I am going to count to 537 billion and if you haven’t sat back your seat, well, I’m going to count all over again. See how you like that!” Energy, productivity, self-reliance, independence, freedom — it would appear to be a 4 dimensional chess match on who controls and exerts power and influence over the people.
And yes, I am too charitable. Maybe I should have used “willful ignorance” to identify the culpability inherent in the decisions made and policies passed. A person could become depressed if you spent too much time lamenting the situation.
@Doc – “A person could become depressed if you spent too much time lamenting the situation.”
Too right. If you have been a long time Atomic Insights reader, you might have visited the original site at https://atomicinsights.com.
I am not sure how many people have noticed, but there are long periods of time with no productivity or publication. That was when I spent a lot of time lamenting and not enough time doing something about it. Counseling helped, but so did having lots of friends and supporters who helped me to get moving again.
It is kind of fun to take on big tasks with a loosely organized team of supporters. Perhaps it is because I am a bit of a Cervantes fan from my days as an English literature major.
@Rod — Cervantes, yes! To dream the impossible dream … You know, it’s too easy to spend hours on YouTube watching excellent performances by talented artists. Some surprises, too. Derek Paravicini is one.
In the “lament” realm, I found myself a bit depressed recently but didn’t like how I felt. So I stopped. Problem didn’t go away but my reaction to it changed. Am thinking more clearly now.
Thanks again for hosting a great, informative blog and sharing your dreams.