Are nukes safe?

With the threat of nuclear "meltdown" adding to the troubles in Japan, and even more so adding to the worries of the US, I've been thinking about nuclear power. Darwin Catholic has a lot of good links and information on his site today. The question that people seem to be debating (and have been for a long time) is should we use nuclear power in light of its safety record.

I found a document (Comparative Assessment of Natural gas Risks) online about the safety of various means of energy production. The aim of the paper is to demonstrate the safety of natural gas vs. other power sources, so we should keep that in mind. However, it does present a rather complete analysis of data across a wide range of power sources. Here is a summary of some of the raw data, from 1969 through 2000. The data includes "severe" accidents that resulted in one or more of the following:

1) at least five fatalities or
2) at least ten injured or
3) at least 200 evacuees or
4) extensive ban on consumption of food or
5) releases of hydrocarbons exceeding 10’000 t or
6) enforced clean-up of land and water over an area of at least 25 km2 or
7) economic loss of at least five million USD(2000).

Whenever any one of the above criteria is satisfied, the accident is considered to be severe. Here are the numbers presented.

Technology	Accidents	Fatalities	Notes
Coal	1130	20,510	(a)
Oil	455	21,424
Natural Gas	159	2,273
LPG	124	4,436
Hydro	11	29,938	(b)
Nuclear	1	31	(c)

(a) Including China
(b) Banqiao and Shimantan dam failures together caused 26,000 fatalities
(c) Latent fatalities are treated separately.

By these criteria, nuclear is extremely safe. However, as noted the table does not include latent fatalities. Here's what they have to say about latent fatalities:

The presence of nuclear in these tables is primarily due to the Chernobyl accident, with a contribution from the Three Mile Island (TMI) accident to the economic losses and evacuation. Estimates of latent fatalities and latent cancers are only available for the nuclear chain for which they are of particular relevance. Delayed fatalities are likely to have occurred for the other chains with no records available; their significance per accident should, however, be incomparably smaller in comparison with the Chernobyl accident.

Later in the paper nuclear latent fatalities are given as 33,000. No figures for latent fatalities from other sources are given. This presents a dilemma. One can't compare the technologies' relative safety without all the data. Not including latent fatalities, nuclear is clearly the safest energy source there is. Including latent fatalities for only nuclear energy make nuclear look bad, but we don't know what the numbers would be for other technologies. For instance, how many people die of latent effects of chemical exposure in an oil accident?

Adding to the uncertainty is the assumption that these technologies do not result in deaths when they are working properly. For instance, should we include black lung deaths to be latent deaths from coal generation, even though they aren't associated with an accident?

In the case of nuclear, there are additional issues. The number of latent fatalities is itself a hotly disputed subject. Claims for deaths from Chernobyl range from 4,000 to 500,000. According to the IAEA's (International Atomic Energy Agency) publication "Ten Years After Chernobyl":

Compared with other nuclear events: The Chernobyl explosion put 400 times more radioactive material into the Earth's atmosphere than the atomic bomb dropped on Hiroshima; atomic weapons tests conducted in the 1950s and 1960s all together are estimated to have put some 100 to 1,000 times more radioactive material into the atmosphere than the Chernobyl accident.

They also note that the design flaws of the Chernobyl reactor have been fixed in other reactors.

The most serious deficiencies in other operating RBMK reactors are being addressed through safety upgrades. Between 1987 and 1991, a first stage of upgrading was performed on all RBMK units to eliminate the design deficiencies which contributed to the Chernobyl accident, to improve shutdown mechanisms and heighten general safety awareness among staff. There are plans for further safety improvements.

So, should Chernobyl be counted? Nuclear reactors aren't designed and built that way anymore, and the ones that were built that way have been improved, so the failure that occurred there shouldn't in theory be possible anywhere else. On the other hand, it can be argued that all technologies improve over time and if we exclude that event we should exclude events from all technologies that were not up to the latest safety standards. That would leave us with virtually no data to work with, and that would be skewed by the current state of the art in that field.

So I worked the numbers both ways - with and without nuclear latent deaths, and using the estimates in the original article of 33,000 latent deaths from Chernobyl. Understand that the truth lies somewhere between the two sets of figures.

Lastly, there is disparity in the number of deaths because some technologies are more prevalent than others. The following table shows fatalities per GWeyr (fatalities per Gigawatt of electricity years). This is IMHO a more meaningful number than just fatality numbers, because it takes into account the fact that more electricity is generated by coal and oil than hydroelectric and nuclear.

	Fatalities per GWeyr
Technology	Immediate	Latent
Coal	1.762	--
Oil	1.032	--
Natural Gas	0.196	--
LPG	16.853	--
Hydro	10.288	--
Nuclear	0.048	48 (6.4-800)

For nuclear, 48 fatalities per GWeyr is the figure used in the document. Using the 4,000-500,000 numbers results in the range shown (6.4 to 800 fatalities/GWeyr).

So nuclear is the safest or the most dangerous power source, or something in between. If we consider all historical data, nuclear energy appears to be far less safe than other methods of electricity production (assuming latent deaths from other technologies are not significant). However, if we consider the Chernobyl accident an anomaly and consider only modern, properly designed reactors, nuclear becomes the safest method of electricity production by far. It all depends on one's assumptions. So, I'd have to say that the results are inconclusive. There are arguments to be made on either side.

What did surprise me in researching this was how dangerous hydroelectric power is. To be fair, 90% of those fatalities were due to two disasters in China, and if those are considered anomalies then the safety of hydro would be in line with oil. I didn't consider this data to be anomalous because it was not due to a flaw in the design, but a natural disaster, just as the current nuclear accident in Japan is due to a natural disaster. One can argue that a bad design, once fixed, is eliminated from future consideration, but a natural disaster such as a flood or earthquake is not controllable by humans.

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Light bulbs are cool

Here's a cool video on a seemingly simple thing - the filament of an incandescent light bulb.

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Big Brother's Driving You

I read this article "How electric cars could pull the plug on U.S. highway funding" and it got me thinking. The gist of the article is as follows. Currently US transportation projects (like highway maintenance and improvements) are mostly paid for by state and federal taxes on gasoline. Revenue from those taxes has been falling in recent years, to the point where there is no longer enough income to pay for the projects. The government has had to subsidize these projects with general tax revenue (which as we know is nearly limitless). But why can we no longer afford to maintain the roads we've built?

The problem, according to the article, is that people are driving less, and cars are more efficient. However, if you look at the graph at right you will see the real problem. Between 1998 and 2000 spending went from $20B to $30B and is now almost $40B.

Either way it is clear that the projected spending is not sustainable with the projected income. This is exacerbated by government subsidies of electric cars, which result in reducing income further.

Most people, when they realized they were spending their income to reduce their income, would stop doing it. But our government marches to the beat of a different drummer. It is more important to follow the political agenda than to make sense. The solution is to raise more tax revenue.

But how? We need to take back those subsidies from the electric/hybrid car folks. One good way to do that is to tax people by the distance they drive, rather than by the amount of gas they buy. Given we need the revenue, I actually think that's a good idea. It's fair in that the people who use the resource (roads) are the ones who will pay to maintain/improve them. True some people drive highway more than local roads, but except for outliers this is a good system.

But of course, there's a catch or I wouldn't be writing this. How would you measure how far people drive? If it were me, when the cars went in for their annual state inspection I would record the mileage and use that as a basis for taxing. Obviously cars that are junked or sold would have to have their mileage recorded or the owner would pay a penalty, perhaps equivalent to the expected mileage on the vehicle.

However, the proposed solution will use GPS tracking to monitor your car's mileage. According to the article, this is the system being implemented in the Netherlands and Poland. Aside from the fact that every car would now require a GPS, and that the system will require billions in computer technology, the government would then have the technical capability to monitor the movement of every citizen. You can probably guess how I feel about that.

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Junk? Science?

I recently stumbled upon a "60 Minutes" (for those abroad "60 Minutes" is an hour long weekly news show) video segment from April 22, 2009 (my anniversary! Yay!) about Cold Fusion. "Isn't that just junk science?" you might ask. Well, check out the video and come on back for the rest of this post.

I remember the day 20 years ago sitting in my Bell Labs' office, pondering with my office mate whether or not the discovery would be confirmed. "I'd bet against it" he stated, matter of fact-ly. That way if it's fake at least I win the bet, and if I lose the bet at least we'll have cheap energy. I wasn't such a pragmatist. I really wanted it to work. My friend and I actually spec'd out palladium, so if the experiment were confirmed we could grab some before the price went through the roof and start experimenting with our own cells.

Alas, it was not to be. When the news came that results could not be duplicated, I was crushed. But some people didn't give up hope, and it seems for 20 years they've been trying to duplicate the experiments of Pons and Fleischman, with varying decrees of success. Now, according to 60 minutes, there are a number of experimenters who have results that are indisputable. Of course, most scientists still dispute it, and I would hardly consider 60 Minutes to be my weather vane for science. Still, I hope the effect turns out to be something real, although I'm not pricing palladium this time.

If there's any moral to this story it's this. We are taught in science class, and indeed even in history class that scientific discoveries are absolute and empirical, and that they are based purely on observation, hypothesis, prediction and test, using reason and logic only. The truth of science is it is filled with as much faith, doubt, and uncertainty as the religion some scientists spurn.

So, don't hold your breath, but you might want to look into deuterium futures. What do you think?

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