The Grenfell Tower Tragedy

In 1974, a new high-rise public housing apartment building opened in West London.  Called Grenfell Tower, it was 24 stories tall and designed to house as many as 600 people in 120 apartments.  Photographs of it taken before a renovation in 2015 show large windows on one side and smaller ones on the adjacent side. 

In 2014, as reported in this blog, the 63-story Address Hotel in Dubai, United Arab Emirates went up in flames as aluminum-clad foam-plastic panels called architectural cladding or sandwich cladding on its exterior caught fire and quickly spread the conflagration to most of the outside of the building.  Amazingly, no one died in that fire, due to a quick evacuation order by the authorities and the failure of the fire to spread to the interior of the hotel rooms.  But this was only one of numerous exterior-cladding fires that have resulted from the use of flammable architectural materials on buildings that are too tall to be reached conveniently by fire ladders.

In 2015, the Kensington and Chelsea Tenant Management Organization, the bureaucracy in charge of public housing in the Grenfell Tower district, decided to do a renovation, possibly to improve the structure's insulation and lower heating costs.  New windows were installed, thermal insulation was added, and to cover these changes, sandwich cladding panels were installed to cover the four exterior side walls. 

Some, perhaps most, of the cladding was made by the U. S. firm Arconic, which sells various types with different kinds of plastic between the outer aluminum sheets.  A cheaper type uses polyethylene plastic, but is not recommended for structures over 10 meters (33 feet) tall.  A slightly more expensive type is fire-resistant, as was the thermal insulation used underneath the cladding.  But even fire-resistant plastic can burn under some conditions.

When constructed, the building had no sprinkler system, but the apartments were piped for gas cooking and gas lines were present throughout the building.  Each apartment had fire detectors, but a residents' organization called the Grenfell Action Group has voiced complaints to authorities over the past few years about outmoded and non-functional fire extinguishers, flammable clutter in hallways, and other fire-safety issues, with little apparent response.

Residents of the Grenfell Towers, as were most other residents of London, had been instructed in case of fire to remain in place to be rescued by firefighters, rather than attempt an escape on their own.

In retrospect, the Grenfell Towers fire was a disaster waiting to happen:  an aging, open-style building without a sprinkler system but full of gas lines, covered with apparently flammable sandwich cladding outside potentially flammable insulation material, crowded with up to 600 residents who had been told to stay in their apartments in case of a fire.  And in the early morning hours of June 14, 2017, a fire broke out, reportedly in a kitchen on the fourth floor.

No sprinkler system or fire extinguisher succeeded in stopping the blaze before it ignited the exterior cladding, which in a matter of a few minutes spread the flames upward and eventually completely around the structure.  Many survivors got out by disobeying the orders to stay in place.  As of this writing (June 18), the estimated death toll is 58, and is expected to go higher.  If this is confirmed, it will be the largest number of people to die in a single fire in London since the Blitz of World War II.

Fires that kill lots of people at once are not that uncommon, but usually they happen in crowded single-room venues such as nightclubs where fireworks or other sources of ignition catch flammable materials on fire.  The spectacle of an entire high-rise building going up in flames because of flammable exterior cladding is something that is not supposed to happen in modern "fireproof" structures.  But the invention of a cladding material that is light, inexpensive compared to concrete, solid steel, or aluminum, and reasonably durable has led to its use and abuse throughout the world.  And as numerous cladding fires have shown, you can take the most fireproof building in the world and surround it with thin, flammable sheets exposed to a lot of air, and what you get is a giant Roman candle waiting to be set off. 

The Grenfell Towers fire may become a turning point in the politics and regulations of exterior cladding, similar to the infamous Triangle Shirtwaist Factory fire in New York City that killed 146 garment workers in 1911.  Like many of the residents of the public-housing Grenfell Towers, most of those who died in the 1911 fire were poor immigrants, though they died on the job amid flammable clothing materials, not at home surrounded by flammable architectural panels.  The Triangle fire had the good result of inspiring calls for improved fire-safety building codes and regulations, which if implemented can prevent tragedies like this.

British Prime Minister Theresa May, already in a politically weak position, has been jeered and attacked for what many saw as her inadequate response to the tragedy.  She and other politicians could turn this situation to the benefit of their country by leading a thorough investigation into the causes of both the Grenfell Towers fire and other similar fires in which flammable exterior cladding has played a role.  Then, they could take vigorous and definite action with regard to both existing and future architectural cladding that has any significant chance of short-circuiting fire safety by enabling the spread of a fire on an otherwise fireproof structure's exterior. 

It is ironic that after making people suffer for centuries the hazards of living in wooden structures that were chronically prone to burn down, nineteenth-century architects thought they had solved the problem of fire with concrete-and-steel structures, only to torch their triumphs in the last few decades by using what amounts to cheap window-dressing materials that burn like fireworks.  If I were an architect, I would be afraid to show my face in London after the Grenfell Towers tragedy. 

The most basic ethical requirement of a profession is that the professionals look out for the interests of those average citizens affected by their professional activities, citizens who have no way of knowing what hazards they could be subject to and how to avoid them.  I would be surprised if more than a few residents of Grenfell Towers knew anything about sandwich cladding, or the fact that under the right circumstances it would burn.  Well, everyone knows now.  And I can only hope that this knowledge gets applied to similar dangerous situations, and we do whatever it takes to keep another Grenfell Towers fire from happening anywhere, ever again.

Sources:  I referred to news reports about the Grenfell Towers fire carried by the Australian Broadcasting Company on June 17 at http://www.abc.net.au/news/2017-06-17/grenfell-tower-panels-not-suitable-for-tall-buildings/8627790, the Canadian Global News at http://globalnews.ca/news/3536188/grenfell-tower-fire-death-toll/, and the Wikipedia articles "Grenfell Tower fire" and "Triangle Shirtwaist Factory fire."  My blog on the Address Hotel fire in Dubai appeared on Jan. 4, 2016.

Being Green Takes Green: Europe Rethinks Renewable Energy Standards

For the past decade or more, as Al Gore and the majority of climate-change scientists have insisted that the world is speeding headlong toward an environmental catastrophe of epic proportions, European countries have adhered to stringent emission controls in order to lessen their dependence on fossil fuels and replace them with renewable energy sources such as wind and solar power.  And the strictures have been in place long enough to have a significant effect;  Germany, for example, now routinely gets a quarter of its electricity from renewable sources.  But as economist Stephen Moore points out in a recent article in National Review, treading so lightly on one's carbon footprint has a price:  higher energy costs.  A kilowatt-hour in Europe currently costs up to twice as much as it does in the U. S., and European manufacturers who use lots of electricity are starting to take notice.  Companies such as the chemical giant BASF are planning new operations in the U. S. rather than Europe.  As a result, the European Union recently announced that it was dropping its mandatory emissions standards for its member nations, letting them burn more coal and oil, if they can find it.  And one of the places they are most likely to start looking is—you guessed it—the U. S.  New exploration technologies, primarily fracking (hydraulic fracturing), have put the U. S. on track to be a net exporter of energy in the near future, and it looks like Europe will now be a prime customer, their disdain for old-fashioned carbon-based fuels notwithstanding.

Engineers made it possible for Germany to achieve the impressive feat of running a quarter of a modern economy on renewable energy alone.  Engineers also have made it possible for the U. S. to increase its oil and gas production in recent years beyond the wildest dreams of everyone but a few farsighted oil-exploration entrepreneurs.  In the absence of government controls or restrictions, customers for energy will buy the cheapest convenient fuel available.  Everyone agrees that except for a few isolated localities, there are no strictly economic reasons to build lots of renewable-energy sources into a large-scale power grid.  A fossil-fuel power plant is much cheaper to build, its output is more reliable, and the continuing cost of the fuel is often more than offset by the construction, maintenance, and other costs associated with the relative unreliability of wind and solar energy. 

But such a strictly economic analysis ignores a cultural and political factor:  the perceived virtue of using renewable energy as opposed to the use of fossil fuels.  In the moral universe in which many government and science leaders live, burning fossil fuels is as close as you can get to a mortal sin against future generations, and against those living now who may be harmed by the consequences of anthropogenic global warming.  The desire to avoid this sin is so great that, at least in Europe, it led to the European Union's mandatory emissions standards which effectively imposed renewable-energy quotas on its member nations.  But even the bureaucrats of the EU can recognize impending economic disaster when they see it, and as the costs of living with a renewable-energy grid began to pile up, they and their constituents saw the consequences of idealism in their power bills.  And it got to be too much.

This is not the place to debate the truth, falsity, or somewhere-in-betweenness of the connection between carbon dioxide emissions and global warming.  What is of more immediate concern is the public's perception of the issue, and how that perception (or rather, spectrum of perceptions) influences governmental policies and laws.  For whatever reason, the EU, with its relatively opaque governing structure and increasingly centralized power over its member nations, responded promptly and vigorously to the perceived threat of global warming with practical measures that had significant negative economic effects.  The fact that the same leaders are now backing off on these measures in the face of rising energy costs says volumes about their real priorities, which turn out to be similar to those of politicians in other parts of the globe.  The slogan "The economy, stupid" was part of Bill Clinton's successful 1992 presidential campaign that brought down George H. W. Bush's presidency, and while Brussels bureaucrats do not face the same sorts of political pressures that U. S. presidential contenders do, they appear to have more sense than they sometimes get credit for. 

In a free society, individual members can try to live off the grid entirely, or buy three Hummers and take cross-continental trips in them, or anything in between.  But things like national power grids are, by necessity, creatures of politics, policies, and law.  And any society which wants to pay the price for eschewing fossil fuels may do so. 

The problems come when an elite leadership that is persuaded of the evils of fossil fuels tries to implement its expensive energy tastes, however virtuous, on the backs of a populace that has to pay for it.  That experiment has been tried in Europe, and we are witnessing its failure, to a great extent, although Europe will probably continue to rely on renewables to a greater degree than the U. S. does for some time to come. 

It may come as a surprise to some of my readers that in good old "ahl-bidness" Texas, where much of the technology of hydraulic fracturing was developed, and where petroleum is regarded roughly in the same light as mother's milk, we lead the nation in wind-power generation.  In fact, on a particularly windy day in 2013, for a short time Texas surpassed Germany in renewables use,  because for a short time more than a fourth of the total electricity being consumed was supplied by wind power.  As in other parts of the world, the growth of renewables didn't happen without a substantial government incentive, namely a guaranteed purchase price for wind-generated electricity that encouraged the construction of huge wind farms in West Texas.  But this shift to wind was achieved without the penalty-laden restrictions on the construction of conventional fossil-fuel plants that the EU emissions standards imposed.

Decades, if not centuries, will elapse before the whole story of fossil fuels, global warming, and all that can be written.  In the meantime, billions of people on this planet want and need, the advantages that cheap, reliable electric power can provide.  Other things being equal, most of them would probably want to save the planet rather than cook it for breakfast, but things are not equal—not economically, not politically, and not culturally.  And in this inequality lies the complexity of the ethics of energy policy today.

Sources:  Stephen Moore's article "Europe's Green Collapse" appeared in the Feb. 24, 2014 issue of National Review.  The record 28% of electric power generated by wind in Texas occurred at 7:08 PM, Feb. 9, 2013, and was reported in the Abilene Reporter News at http://www.reporternews.com/news/2013/mar/01/texas-wind-energy-sets-record-grid-expansion-in/.  The report that Texas leads the nation in installed wind-power generation capacity is taken from the website of the American Council on Renewable Energy at http://www.acore.org/files/pdfs/states/Texas.pdf.

Tianjin Tragedy: A Painful Lesson

Last Wednesday, Aug. 12, people living near the coast of Bohai Bay, in the southeast part of the port city of Tianjin, were awaked by the sound of sirens and the flickering of a fire.  A chemical warehouse on the bay was ablaze, and several residents got out their smartphones and videoed the impressive conflagration as it illuminated nearby apartment and office buildings.  At 11:30 PM, eyewitnesses saw a blinding flash as a huge detonation went off, followed a few seconds later by an even bigger one that registered 2.3 on the Richter scale of seismographs many miles away.  Acres of new cars awaiting shipments were incinerated, huge shipping containers were tossed around like matchsticks, and

as of this writing (Sunday Aug. 16), the confirmed death toll from the explosions has reached 112, with 90 more reported missing.  Hundreds have been injured, many seriously, and evacuations and property damage have rendered several thousand residents temporarily homeless.  Sodium cyanide, a highly toxic chemical, has been detected in the port's sewer system and the sewage outflow leading to Bohai Bay has been cut off. 

At this point, there are more questions than answers, as reporters who attended a news conference called after the tragedy learned before officials abruptly ended the conference.  Why was such a dangerous collection of chemicals stored within 2,000 feet of a residential area?  What was in the warehouse that exploded?  And last but not least, how can such a tragedy be prevented from happening again?

A chemical fire is one of the firefighter's worst nightmares, even when the nature of the chemicals is known.  The warehouse that exploded was owned by the Rui Hai International Logistics Company, which was unable to provide officials with a complete inventory of what was in the building when it caught fire.  Records indicated that the firm had a license to store calcium carbide, which produces highly flammable acetylene gas when it gets wet.  And sodium cyanide is not something you want to spread around either—an amount the size of a single small pill can kill you.  If there is enough left of the warehouse and its records to investigate, we will probably find out that there was a lot of something—ammonium nitrate, perhaps—stored in one big pile that went off all at once.  Sadly, many of the fatalities were in the ranks of the first responders who approached the warehouse with fire hoses after the first alarm was turned in.  Some of their bodies may never be recovered.

Years ago, in the late 1980s, I visited Tianjin during a trip related to my research activities.  My first impression of the city came as we emerged from an underground railway station into a square which was dominated by a strange assortment of suspended wires that I recognized immediately as a shortwave transmitting antenna.  This was back when shortwave radio was one of the main ways that people in totalitarian countries could get news that wasn't controlled by the government.  Accordingly, the government erected local shortwave jamming stations that tried to cover up Voice of America broadcasts with racket that sounded like a battle between two buzz saws.  Control of outside information is a lot harder nowadays because of the Internet, and the government of China has quit trying to suppress undesirable information completely, as the aborted news conference proves.  But just knowing how awful an accident is doesn't guarantee that something will be done about it.  Can we expect this horrific disaster to lead to any improvements in safety?  That depends.

One thing that is clear beyond a doubt:  people all over China and the rest of the world know how bad this explosion was.  And at a minimum, the residents of Tianjin are going to demand changes in the way the port operates and keeps track of hazardous materials.  Sometimes local politics in China is a lot more quasi-democratic than you would expect from a nominally totalitarian government system, in that incompetent heads roll and genuine reforms can take place if public pressure is great enough. 

The larger question is whether the Tianjin explosion will create a drive toward safer operation of industrial facilities in general across China.  The pollution problems in Chinese cities are notorious, with one expert estimating that 16 of the 20 most polluted cities in the world are in China.  Lacking a formal means of influencing their government through meaningful elections, the Chinese people have taken to mounting lots of protests, and one Chinese Communist Party official estimated that in 2012 alone, about 50,000 environmental protests took place.  This is evidence of a great deal of frustration on the part of the country's citizens, who have enjoyed tremendous economic growth in the past few decades, but have paid the price by living in overcrowded, polluted, and increasingly dangerous cities.

There isn't much that is nice about a totalitarian government, but you can say this—once the people in power make up their minds to do something, they can go ahead and do it without a lot of compromises and political bargaining.  If Beijing wants to enact much stricter regulations about the types of chemicals stored in port warehouses such as Rui Hai's, they can do so tomorrow.  But regulations alone aren't enough.

Tragedies similar to the Tianjin explosions here in the U. S., such as the fertilizer-plant explosion in West, Texas in April of 2013, have emphasized how important it is for accurate inventory information to be available at all times to first responders, who in turn need to be educated about the various dangers and appropriate techniques that should be applied in case of a chemical fire.  Ideally, the Rui Hai warehouse would have been constructed and equipped with sprinkler and alarm systems so that it wouldn't have caught fire in the first place, or at least the fire could have been extinguished before it got out of control.  But despite the best precautions, chemical fires sometimes get out of hand.  In that case, fire departments need to know when to try to fight a fire, what to fight it with, and when to look at the online inventory and decide, "Let's issue an evacuation order and clear out ourselves too—this is too dangerous."  But there has to be an accurate online inventory and first responders who are trained to know what to do and when to do it.

These things are not rocket science, but they represent a change in the way people do things.  Let's hope that not only in Tianjin, but all across China, the sad lessons of last week's explosions lead to safer ports and better information exchange in the future. 

Sources:  I referred to news reports on the disaster carried by CNN at http://www.cnn.com/2015/08/15/asia/china-tianjin-explosions/, the New York Times at http://www.nytimes.com/2015/08/15/world/asia/rising-anger-but-few-answers-after-explosions-in-tianjin.html, NBC News at http://www.nbcnews.com/news/world/tianjin-china-explosion-area-evacuated-over-sodium-cyanide-fears-n410371, and the Wikipedia articles on "Tianjin explosions" and "Environmental issues in China."

Mines of Tears: Uranium Mining and the Navajos

Suppose you are a member of the Navajo Nation living on a reservation near Shiprock, New Mexico in 1960.  You hear of a great opportunity to earn money and help the United States besides.  Uranium has been discovered in many locations in and around the reservation, and a private company has opened a uranium mine in Shiprock.  The work is hard and dirty, but the pay is better than anything else you can find without leaving your land and your people.  You apply for the job and you’re hired.

Something like this was the story for one hundred and fifty Navajos who worked at the Shiprock uranium mine at various times from the 1950s through 1970, when it closed.  A decade later, a public-health researcher managed to track down records of these 150 miners.  By that time, as little as ten years after some of them finally left their jobs when the mine shut down, 133 of these men had died of lung cancer or various forms of lung fibrosis.  That’s 88 percent mortality—a pretty big chance to take for earning a decent wage for a few years.  And it’s even worse when you realize that most of these men had no idea of the chance they were taking by working in a uranium mine.  The 150 Navajos studied are just a sample of the thousands of native Americans affected by uranium mining and its aftereffects.

Mining is dangerous, uranium can be dangerous, and uranium mining can be one of the most risky occupations of all in terms of long-term health hazards unless extraordinary precautions are taken to protect the miners from radon and its products.  Radon, a heavy, odorless, highly radioactive gas, is produced by the decay of U-238, the major constituent of uranium.  Breathing radon and its decay products is one of the best ways to get lung cancer, which is why basements with even very slight detectible levels of radon are a health hazard.  Extensive ventilation of uranium mines and continuous monitoring of radon levels can reduce the risks of uranium mining to reasonable levels, but in many of the mines in and near Navajo land in the American West during the “uranium-boom” period of 1948 to 1970, these safety precautions were neglected in a rush to exploit domestic sources of uranium for both peaceful nuclear reactors and nuclear armaments.  And worse, the miners—many of them Navajos who spoke little or no English—were not informed that they were working in conditions that would very likely shorten their lifetimes.  The Navajo language did not even have a word for “radiation.” 

Even after most of the mines closed following a global decline in uranium prices, the hazards continued.  In 1978, the same year that the Three Mile Island nuclear plant suffered a contained meltdown, a containment dam broke that was holding back 93 million gallons of radioactive and poisonous tailing solution.  This hot muck ran into the Puerco River and contaminated miles of the river and acres of aquifer recharge zones.  Judging by the total amount of radioactivity released, this was arguably the worst accident involving radioactive materials in U. S. history, far exceeding the radiation that Three Mile Island put into the biosphere.  But no official disaster declaration was made, few news outlets mentioned the Puerco River disaster, and only in the last few years has some effort been expended on investigating the full extent of the damage and cleaning up the contaminated areas. 

This story is not one of unmitigated gloom.  Because many of the mines and Navajo miners were in Utah, in 1989 congressmen of that state sponsored a Federal bill to provide monetary compensation for uranium-mine workers whose health was affected by their employment in mines and related processing industries.  This measure was signed into law by President George H. W. Bush in 1990, and by 2009 over 20,000 workers had received a total of over $1.4 billion in reparations.

But no amount of money will bring back the lives of those who died early deaths because they only wanted to earn a decent living doing something they thought was helping the nation that had treated them so shamefully in the past.  This situation echoes the dismal conditions imposed by early Spanish explorers on the native Americans who were forced to work in gold mines under circumstances that amounted to slavery.  A person of a different color who speaks a different language than you do is easy to regard as a different species, unworthy of the consideration and justice that you give to your own kind.  Some of the earliest protests against Spanish exploitation of the natives were lodged by Catholic missionaries who saw the maltreatment of mine workers as a blasphemy against the God whom they served. 

Perhaps not coincidentally, I first learned of the Navajo experience with uranium mining from a brochure I happened across which was published by the Maryknoll Missioners, a group of lay persons, religious sisters, and priests who devote their lives to serving the underprivileged of the world.  One of the sisters was featured in an article about her activities in trying to establish the extent of radioactive pollution from uranium mining in areas where Navajos live today. 

No doubt, there were engineers involved in the design and operation of the U. S. uranium mines, and it would be easy to blame them in retrospect for the harms done.  In their defense, it must be said that the hazards of uranium mining were poorly understood as late as the 1950s, because until the advent of nuclear weapons and reactors, uranium was only one of a number of specialty metals, and experience with mining it was limited to a few European mines and scattered studies of uranium miners.  The first substantial U. S. Public Health Study of the subject was done with a sample of Navajo uranium miners, and by the time the results confirmed that such mining without proper ventilation was very dangerous, most of the damage had been done, because the lung cancer and other problems that radon causes take twenty years or more to develop.  Nevertheless, enough information was available as early as the 1950s to indicate that the mining of uranium was especially hazardous, and little or nothing was done technically to account for this fact.  At a minimum, the financial reparations paid to the Navajos and their families are a partial acknowledgment that they were deeply wronged, and teach us that long-term health effects are worth considering in any kind of employment.

Sources:  Besides the Maryknoll brochure from which I first learned of this issue, I referred to a Science Education Resource Center website maintained by Carleton College at http://serc.carleton.edu/research_education/nativelands/navajo/humanhealth.html and the Wikipedia article “Uranium mining and the Navajo people.”

America's Chernobyl Waiting to Happen

"Dallas, Texas, Mar. 30, 2005 (AP) --- An apparent nuclear explosion in Amarillo, Texas has cut off all communications with the West Texas city and regions in a fifteen-mile radius around the blast. Eyewitness accounts by airline pilots in the vicinity report an 'incredible flash' followed by a mushroom cloud reaching at least 35,000 feet. Speculation on the source of the explosion has centered on Amarillo's Pantex plant, the nation's only facility for construction and disassembly of nuclear weapons."

In case you think you missed something a year ago last March, the news item above is fiction. But according to some sources, it is plausible. It could have happened. And there is reason to believe that unless some serious housecleaning takes place in Amarillo, the chances that something like this might happen in the future are higher than any of us would like.

The end of the Cold War brought hopes that instead of piling up megaton after megaton
of mutually assured destructive power in the shape of thermonuclear weapons, the U. S. and the Soviet Union (or what was left of it) would begin to disassemble their nuclear stockpiles to make the world a safer place. Over the past fifteen years, international agreements have been reached to do exactly that. From a peak of over 30,000 nuclear warheads in 1965, the U. S. stockpile has declined to just a little over 10,000 as of 2002. And here is where the engineering issues come in, because for every downtick of that number, somebody somewhere has to disassemble a nuclear warhead.

A nuclear bomb or missile is not something that you just throw on the surplus market to dispose of. First it has to be rendered incapable of exploding. Then the plutonium and other dangerous explosive materials have to be removed in a way that is both safe to the technicians doing the work, and also to the surrounding countryside and population. As you might imagine, these operations are difficult, dangerous, and require secret specialized knowledge. For more than thirty years, the only facility in the U. S. where nuclear weapons were made or disassembled has been the Pantex plant outside Amarillo, Texas. It is currently operated by a consortium of private contractors including BWXT, Honeywell, and Bechtel, and works exclusively for the federal government, specifically the Department of Energy. If you want a nuclear weapon taken apart, you go to Pantex, period. And therein lies a potential problem.

Where I teach engineering, the job of nuclear weapon disassembler is not one that comes up a lot when students tell me what they'd like to be when they graduate. I imagine that it is hard to recruit and retain people who are both willing and qualified to do such work. But at the same time, it is not the kind of growth industry that attracts a lot of investment. So it is plausible to me that as the demand for disassembly increases, the corporate bosses in charge of the operation might tend to skimp on things like deferred maintenance, safety training and execution, and hiring of additional staff. That is the picture which emerges from an anonymous letter made public recently by the Project on Government Oversight, a government watchdog group.

Anonymous letters can contain exaggerations, but what is not in dispute is the fact that on three occasions beginning Mar. 30, 2005, someone at Pantex tried to disassemble a nuclear weapon in a way that set off all kinds of alarms in the minds of experts who know the details. I'm speculating at this point, but as I read between the lines and use my knowledge of 1965-era technology, something like this may have happened.

A nuclear weapon built in 1965 probably contained no computers, relatively few transistors, and a good many vacuum tubes. Any safety interlocks to prevent accidental detonation were probably mechanical as well as electronic, and consisted of switches, relays, and possibly some rudimentary transistor circuits. But somewhere physically inside the long cylindrical structure lies a terminal which, if contacted by a grounded piece of metal, will probably set the whole thing off and vaporize Amarillo and the surrounding area.

A piece of equipment that has been sitting around since 1965 in a cold, drafty missile silo is probably a little corroded here and there. Screws and plugs that used to come apart easily are now stubborn or even frozen in place. The technician in charge of beginning disassembly of this baby probably tried all the standard approaches to unscrewing a vital part in order to disable it, without success. At that point, desperation overcame judgment. The official news release from the National Nuclear Safety Agency puts it in bureaucratese thus: "This includes the failures to adhere to limits in the force applied to the weapon assembly and a Technical Safety Requirement violation associated with the use of a tool that was explicitly forbidden from use as stated in a Justification for Continued Operation." Maybe he whammed at it with a big hammer. Maybe he tried drilling out a stuck bolt with an electric drill. We may never know. But what we do know is, the reasons for all these Technical Safety Requirements is that if you violate them, you edge closer to setting off an explosion of some kind.

Not every explosion that could happen at Pantex would be The Big One with the mushroom cloud and a megaton of energy. The way nuclear weapons work is by using cleverly designed pieces of conventional high explosive to create configurations that favor the initiation of the nuclear chain reactions that produce the big boom. A lot of things have to go right (or wrong, depending on your point of view) in order for a full-scale nuclear explosion to happen. Kim Jong Il of North Korea found this out not too long ago when his nuclear test fizzled rather than boomed. But even if nothing nuclear happens when the conventional explosives go off, you've got a fine mess on your hands: probably a few people killed, expensive secret equipment destroyed, and worst from an environmental viewpoint, plutonium or other hazardous nuclear material spread all over the place, including the atmosphere.

This general sort of thing was what happened at Chernobyl, Ukraine in 1986, when some technicians experimenting late at night with a badly designed nuclear power plant managed to blow it up. The bald-faced coverup that the USSR tried to mount in the disaster's aftermath may have contributed to its ultimate downfall. So even if the worst-case scenario of a nuclear explosion doesn't ever happen at Pantex, a "small" explosion of conventional weapons could cause a release of nuclear material that could harm thousands or millions of people downwind. Where I happen to live, incidentally.

I hope the concerns pointed out by the Pantex employees who apparently wrote the anonymous letter are exaggerated. I hope that the statement from Pantex's official website that "[t]here is no credible scenario at Pantex in which an accident can result in a nuclear detonation" is true. But incredible things do happen from time to time. Let's just hope they don't happen at Pantex any time soon.

Sources: The Project on Government Oversight webpage citing the Pantex employees' anonymous letter is at http://www.pogo.org/p/homeland/hl-061201-bodman.html. The official Pantex website statement about a nuclear explosion not being a credible scenario is at http://www.pantex.com/currentnews/factSheets.html. Statistics on the U. S. nuclear weapons stockpile are from Wikipedia's article on "United States and weapons of mass destruction."

"Alas, Babylon" Revisited

A family is torn apart by war.  The wife, son, and daughter take refuge with a brother-in-law in rural Florida.  The twelve-year-old daughter happens to be looking out a window when a thermonuclear bomb goes off only a few miles away.  As the flash fades, the daughter finds that she is literally blinded, and cries out for her mother.

Grim stuff.  Just as the image of the exploding hydrogen bomb was etched on the daughter’s retinas, the image of the flash that blinded her is etched on my memory. On April 3, 1960, I was watching the TV show Playhouse 90’s retelling of Pat Frank’s apocalyptic science-fiction novel Alas, Babylon.  Rather than just showing a white screen for a few seconds, the producers of this black-and-white drama represented the nuclear flash by switching the entire scene to look like a photographic negative in which black looked white and white looked black.  At the tender age of six, I had never seen such a creepy thing before, and it terrified me.  I had nightmares about atomic attacks off and on for years afterwards.

Alas, Babylon was the most well-known early literary version of a genre with which we have since become perhaps too familiar:  the post-nuclear-holocaust survival story.  Published in 1959 and still in print today, it follows the fates of two brothers, Randolph and Mark Bragg, as full-scale nuclear war comes to the U. S. when the Soviet Union retaliates for an accidental bombing of a Syrian seaport.  Mark, an Air Force colonel, receives early warning that war is coming and sends his wife and children from where he is stationed at a nuclear-missile site in Omaha, Nebraska, to stay with brother Randolph in Fort Repose, a fictional small town in central Florida.  Once hostilities begin, Mark, along with several dozen million other Americans in most large U. S. cities, is vaporized, and Randolph gradually assumes leadership of a small self-sustaining community that forms around an artesian well on his property.  There is the requisite love story, a violent battle with roving highwaymen, and after a year of total isolation from the outside world, the tale ends with a helicopter visit from what is left of the U. S. government.

Pat Frank was a military publicist before he moved to Florida and began writing novels. Alas, Babylon is his most well-known work, and probably one of the most realistic novelistic treatments of how things might actually go after a total nuclear war.  But even in 1959, it embodied some wishful thinking.  Given its almost flat topography, Florida probably has few if any self-pumping artesian wells.  In a real nuclear-war disaster, water would be even scarcer than the novel implies.  If I were to try to rewrite the book today, I would set it on a ranch in far West Texas, which is one of the least likely locations for an enemy with any prudence to toss a nuclear weapon.  And I would use windmill-driven water wells and perhaps a wind generator in the plot to give our survivors some chance at staying in the twentieth century.  It would be no stretch at all to assume they would have plenty of guns and ammunition, because these things are nearly universal in that part of the country.

While it is true that nobody much worries about nuclear war these days, the simple mechanical facts that both we and Russia have enough weapons to do tremendous damage to each other have remained unchanged since 1959, though lots of other things have changed since then.  And you could make the case that today, with Iran striving to make nuclear weapons and Israel moving its itchy finger toward its nuclear trigger in response, that the world (if not the U. S. and Russia) may be approaching a nuclear crisis as serious as the Cuban missile crisis of 1962, in which the USSR tried to put nuclear weapons in Cuba and the U. S. blockaded their efforts.

Because nuclear war has fallen off the bottom of the lists of what most people worry about, our preparedness for such a disaster, which was never very good even at the height of the Cold War, is abysmal today.  The only way I can think of in which we are perhaps better off than Pat Frank’s fictional survivors of 1959 is in communications, and this advantage may be largely illusory.  One reason the Internet was designed with distributed resources that are robust against the failure of several nodes is that the military provided the original funding and wanted a system that could survive a nuclear war.  It is by no means clear that this robustness has been preserved to the present day, and I don’t know how many major cities you would have to vaporize before the U. S. Internet failed.  But it might not be that many.  Once the Internet and telecomm systems fail, all you have left is satellites (if the ground stations haven’t been vaporized) or ham radio.

In every other way, I think we are less prepared than in 1959—more vulnerable in terms of power networks, emergency food and water supplies, and an intangible but vital characteristic I would call community spirit:  a recognition that a lot of individual rights and freedoms would have to go out the window for even a small community to survive.  I’m sure there would be exceptions, but I’m afraid lots of people in this country would face such a national emergency with mindless, selfish panic that would both harm themselves and others, and reduce their chances of survival to zero.

I am not an off-the-grid survivalist living as though nuclear war was coming tomorrow.  But I do think it is wise every now and then to at least give a thought to what we might be called upon to do if the worst happened, and even one terrorist nuclear weapon detonated on U. S. soil.  All the same, let’s hope we never find out for real how we would react in such an emergency.

Sources:  Pat Frank’s novel Alas, Babylon was published in 1959 by J. B. Lippincott, and can be found today in paperback editions.  I consulted Wikipedia articles on Pat Frank and Playhouse 90 for this blog.

High-Speed Rail Crash in China: Too Fast Too Soon?

Only four years ago, the first “bullet train” line in mainland China opened to great fanfare. Like tall buildings and modern airports, a high-speed rail line is considered to be a sign that a nation has joined the industrialized world, and Chinese citizens were justly proud of their new high-speed rail lines, which have mushroomed since then. But last July 23, the Chinese high-speed rail industry received a shock that has reverberated to the highest levels of government.

Details are still hard to come by, apparently, and I am working from secondary sources in English. But the basic story appears to be this: On a rail line leading to the coastal city of Wenzhou, a high-speed train was traveling through a thunderstorm. Suddenly, lightning struck. Exactly what it struck is not clear. Some reports say the train itself was hit, disabling it and bringing it to a halt. Other reports say the signaling system was disabled. In any event, lightning crippled either the power or signaling systems or perhaps both, leaving the train stranded on a viaduct some 60 feet above the ground.

Then a second train approached and slammed into the stranded one. Several cars fell to the ground or were derailed, hundreds were injured, and forty people died of their injuries.

The accident was tragic enough, but public reaction intensified when, after a week or so of competitive and often scathing news coverage accusing the government of incompetence and corruption, the government’s censors clamped down on further negative reporting. This sent many citizens to so-called “micro-blogging” sites similar to Twitter, where people can post up to 140 Chinese characters. And they did, criticizing government censorship of investigations into the crash and questions about whether China has rushed into high-speed rail too fast.

Even in the West where media coverage is over-generous, it would take months for an official board to thoroughly investigate a complex accident such as the Wenzhou disaster. So we should not be surprised that a definitive answer to the question of what caused the accident has not yet emerged. China’s premier Wen Jiabao, who has been visibly concerned about the accident starting the day after it occurred, said on Aug. 10 that China was suspending approvals of new high-speed rail projects and taking steps to ensure the safety of existing systems, including lowering maximum speeds temporarily.

All the same, it creates an atmosphere of distrust to issue orders from censorship agencies to quit covering certain topics. Old habits die hard, and the bad old days when electronic media were limited to a single government-run TV station and a few radio channels, plus the party papers, apparently allowed censors to get used to the idea that they could steer public opinion like a farmer steers an ox. But with the proliferation of modern computer-based media, it’s getting harder and harder to steer opinion this way. Even in China, where the government has made strenuous efforts (often abetted by American high-tech companies) to restrain the free flow of information on the Internet, the censorship regime is showing signs of coming unglued. And the rail accident has only put more strain on it.

Still, the government is the only entity which has the resources and access to technical information to investigate the accident in a competent way. I do not know how such investigations are organized in China, but one hopes there is a measure of independence for the technical experts charged with getting the facts straight. In the U. S., the National Transportation Safety Board has a mostly unimpeachable record of independence from political pressure. In all the many accidents I have looked into that were investigated by the NTSB, I do not recall any incidents in which the board’s integrity was ever questioned because of political motives. This doesn’t mean it has never happened or never will. But the fact that most transportation systems in the U. S. are privately owned (AMTRAK being a glaring exception) means there is little political motive to prettify accident reports.

In China, on the other hand, the government has its economic hands in most major undertakings, including high-speed rail. Add that to the heightened sensitivity to criticism that characterizes new kids on the block, and you have plenty of motivation for the Chinese government to whitewash accident reports. Perhaps the lightning strike was a one-in-a-million occurrence that is unlikely to happen again. With six thousand miles of high-speed rail in operation, much of it built in the last four years, the fact that China has not had another major rail accident of this magnitude says something positive about the system. Lightning can do some pretty unpredictable things, and it may turn out that this accident was way down the list of likely problems that the engineers had to consider.

Publicly owned rail systems seem especially prone to engineering ethics controversies. One of the canonical engineering-ethics cases of all time occurred in the 1970s during the testing of a new Bay Area Rapid Transit train system. Some bad technical flaws were covered up and the engineers involved went public, leading to considerable controversy and a classic engineering-ethics story.

Nevertheless, my sympathies are with those who lost loved ones in the Chinese accident. And I hope that the whole controversy surrounding coverage of the accident will lead to greater openness on the part of the government of China, as well as improved safety for millions of Chinese who ride the rails.

Sources: I consulted several news reports on the accident, including coverage by the BBC (http://www.bbc.co.uk/news/world-asia-pacific-14262276), Bloomberg and Business Week (http://www.businessweek.com/news/2011-07-28/china-high-speed-rail-crash-likely-caused-by-signal-flaw.html), and Reuters (http://www.reuters.com/article/2011/08/10/us-china-train-idUSTRE77946C20110810 and http://www.reuters.com/article/2011/08/01/us-china-train-censorship-idUSTRE7700ET20110801). A summary of the BART train incident can be found in Stephen H. Unger’s Controlling Technology: Ethics and the Responsible Engineer (1982).

From NASA to USSG: Fixing the U. S. Space Programs

As readers of this blog may have realized by now, some problems in engineering ethics lie mainly not in the bad decisions of individuals, but in wrongly conceived or executed institutional organizations and policies. A lot of well-intentioned people working in a poorly structured outfit can nevertheless do real damage. The engineering ethics poster-child example of this is NASA, which holds the dubious distinction of being responsible for one of the leading engineering ethics case studies, the 1986 Challenger disaster. While human lives are invaluable, much harm also results from waste, inefficiency, and mismanagement, and NASA has had its share of that too. But I am not here merely to register another carp about NASA, but to draw your attention to a well-considered and politically astute alternative to the present mish-mosh that is U. S. space policy: the creation of a United States Space Guard (USSG).

Writing in the Winter 2011 issue of The New Atlantis, space consultant James C. Bennett describes an idea that originated with U. S. Air Force Lt. Col. Cynthia A. S. McKinley in 2000. She looked at how a basic structure that might once have been appropriate for a small federal agency, which the National Aeronautics and Space Agency once was in the early 1960s, was inflated all out of proportion during the Great Space Race that got the U. S. to the moon first in 1969. But to use a human-body analogy, what remained after that unique experience bears some resemblance to what might happen if a 110-pound professional jockey decided to become a temporary Sumo wrestler, and bloated up to 600 pounds for one wrestling match. Even if he won, he’d have a lot of trouble getting his old jockeying job back afterwards, and NASA has been the 600-pound Sumo wrestler in the nation’s space efforts ever since.

The domination by NASA of virtually all important aspects of U. S. space activities, whether military, civilian, governmental, commercial, regulatory, or scientific, has distorted and rendered inefficient or neglected a lot of things that might have fared better, and might in the future fare better, if we reorganized our whole approach, which is what the Space Guard proposal does. I don’t have room to describe all the ingenious details that Bennett has added to McKinley’s basic idea, but I will concentrate on the fundamental analogy between a familiar and well-functioning organization, namely the U. S. Coast Guard, and the proposed U. S. Space Guard.

Though usually engaged in peaceful work such as search and rescue operations, navigational facilitation for commercial sea traffic, and other fairly routine tasks, the Coast Guard is a cadre of officers in uniform committed to service, at the cost of their lives if necessary. As Bennett points out, the informal motto of the Coast Guard in lifesaving efforts is “You have to go out, you don’t have to come back.” Making personnel of a new U. S. Space Guard similarly sworn to duty, with the recognition of a uniform, military rank and command structure, and so on, would at last acknowledge the fact that space travel and space-related work is hazardous and astronauts, at least, put their lives on the line. We expect that of policemen, firemen, and soldiers, but to expect it of civil servants (technically, that’s what astronauts are) is not fitting, to say the least.

The establishment of a U. S. Space Guard would allow the collection of a number of important but unglamorous space-related tasks under one roof where a common body of experts could coordinate activities which now are spread far and wide. For example, responsibility for communications satellites is presently spread among agencies such as the Federal Communications Commission, the Federal Aviation Administration, the Department of Commerce, and NASA (if any of their launch vehicles are used). The FAA is also presently involved in regulating some “black” (secret) U. S. Air Force military space work, which does not fit the agency well. Transferring these sorts of tasks to the new USSG would make more sense.

Besides remedying such existing confusions and inefficiencies, and freeing up NASA to do what it was founded to do in the 1950s—namely far-out exploratory and scientific research—the USSG could spawn helpful and fruitful new efforts. We could start a Space Academy, along the lines of the other service academies such as Annapolis and West Point. We could maintain a Space Reserve of former USSG service people who could be recalled to active duty should the need arise. And best of all from my point of view, the USSG would be a fresh start organizationally, instead of yet another patch or fix to the dysfunctional organization that is NASA today.

This is not to say that NASA has no good features. Obviously it does. Its unmanned science programs are still among the best in the world, doing wonders with inadequate funding. But so much of what NASA does depends not on national needs and plans, but on whose congressional district and which company does it, that only a well-planned and politically wise transition from the status quo to a new order in which the USSG plays the main role will improve things. At least, this idea is the best one I’ve seen addressing the question of what the U. S. should do about space. I just hope that for once, reason and common sense will prevail over the less salutary aspects of politics, and we’ll do the right thing about it.

Sources: James C. Bennett’s article “Proposing a ‘Coast Guard’ For Space” appears in the Winter 2011 edition of The New Atlantis, pp. 50-68.

Some Answers About the Panhandle Cornfield Meet of 2016

A “cornfield meet” in railroad parlance is a head-on collision between two locomotive engines.  Needless to say, such occurrences are avoided if at all possible.  But on the morning of June 28, 2016, two freight trains collided head-on in the Texas Panhandle, killing three people and causing an estimated $16 million in damage.  At the time I blogged about it, the only information available was news reports.  A few weeks later, the National Transportation Safety Board (NTSB) issued a preliminary report on the accident.  While the NTSB has not made public any additional data on the accident since then, the preliminary report makes clear that human error was likely at fault.

           

The BNSF line through the town of Panhandle is a single-track line, and two-way traffic is managed with a series of sidings.  The dispatchers, probably in the Fort Worth regional train control center, planned to switch the westbound train to a siding near the town, where it would remain while the eastbound train passed by on the main line.  If the eastbound train arrived in the area of the siding too soon, before the westbound train had time to move completely from the main line to the siding, two signals were set along the main line west of the eastern switch, where the westbound train was going to leave the main line for the siding.  The first signal the eastbound train encountered was solid yellow, which means for the engineer seeing the signal to slow the train to a maximum of 40 MPH and be prepared to stop at the next signal.  The second signal was set to red, which forbids the engineer from moving any part of the train past the red signal. 

So the plan was for the eastbound train to slow down at the yellow signal and stop at the red signal, while the westbound train arrived at the eastern switch and eventually cleared the main line by running onto the siding.

What happened instead was this.  Before the dispatchers had a chance to change the eastern switch from the main line to the siding, the eastbound train passed the yellow signal on the main line going at 62 MPH and the red signal at 65 MPH, heading through the switch on the main line straight for the westbound train.  When the engineer on the westbound train saw what was happening, he managed to jump from the cab.  But his conductor died in the resulting crash, as well as the engineer and conductor on the eastbound train.  The NTSB report somewhat ruefully notes that positive train control (PTC) was scheduled to be installed on this section of track later in 2016, although planned PTC installations have suffered repeated delays in the past.

PTC is a semi-automated system that promises to reduce the chances for human error in train operations.  A PTC system would have figured out that the two trains were heading toward a collision and would have at least slowed them down, if not preventing the accident entirely.  As it stands, the physical evidence points responsibility for the accident toward the crew of the eastbound train, as they failed to respond to the clearly visible yellow and red signals in time. 

We may never know what distracted them, but people make mistakes from time to time.  And some mistakes exact a fearful penalty. 

While even one death due to preventable causes is a tragedy, some context to this accident is provided by a slim volume I have on my shelves:  Confessions of a Railroad Signalman, by James O. Fagan, copyright 1908.  It was written at a time when railroad-related fatalities (passengers and railroad employees combined) were running at about 5,000 a year, a much higher rate per train-mile than today.  Fagan’s concern was that railroad employees of his day had to deal with on-the-job pressures that encouraged them to take risks and shortcuts that flouted the rules, and that the management system was ill-equipped to discipline misbehaving employees. 

While much has changed in railroading since 1908, any system that relies on a human being’s alertness can still fail if the person’s attention flags.  And that seems to be what happened outside Panhandle, Texas on that summer morning in 2016. 

If and when PTC is installed on most stretches of U. S. railways, the hope is that fatal and costly accidents will decline to even lower levels than what we see today.  The limiting factor after that will be mechanical malfunctions, perhaps, or dispatching errors at a high enough level to overrule the PTC system.  In any case, we can expect rail travel and shipping to be even safer than it is now, which compared to 1908 is pretty safe already.

Machines and systems are deceptively solid-looking.  It doesn’t seem possible that thousands of tons of steel rolling stock and rails can change very fast.  But the way it’s used can change, and PTC promises to do that.  Eventually, I suppose that the nation’s entire rail system will be run by computers and will resemble nothing so much as a giant version of a tabletop model train, running smoothly and without collisions or hazards.  Of course, automobile drivers will still manage to stop on grade crossings and people will walk on train trestles, so those types of accidents can’t be prevented even by PTC.  To eliminate those types of accidents, we’d have to tear up the whole system and rebuild it the way the English built their rail systems from the start:  fenced-off railroad property, virtually no grade crossings (tunnels and bridges instead), and other means to keep people and trains permanently separated. 

But I suspect we as a society are not that exercised to eliminate the last possible railroad fatality from the country.  So instead, we will enjoy whatever benefits PTC brings along and hope that we personally can stay out of the way of the trains. 

And modern-day cornfield meets will at last join their ancestors as a historic footnote, a quaint disaster that simply can’t happen anymore.  Like soldiers dying on the last day of a war, the crew members who died in the 2016 accident may be among the last to depart in that singularly violent way.  But for those of us who remain, and whose continued survival depends on our being alert, whether behind the throttle of a locomotive or the wheel of a car, this story is a good reminder to keep awake and pay attention.

Sources:  The NTSB report on the June 28, 2016 Panhandle, Texas accident can be found in the agency’s listing of railroad incident reports at https://www.ntsb.gov/investigations/AccidentReports/Reports/DCA16FR008-PreliminaryReport.pdf.  For those with a certain type of morbid curiosity, there is a collection of silent movies of three or four intentionally-staged cornfield meets between steam locomotives that can be viewed on YouTube at https://www.youtube.com/watch?v=CMpdpgZxt78.  Confessions of a Railroad Signalman was published by Houghton-Mifflin. 

Carbon Sequestration: Worth the Trouble?

In August of 1986, over 1700 villagers living as far away as 25 km from Cameroon's Lake Nyos died when a mysterious, invisible suffocating cloud enveloped them. They were victims of one of the two known limnic eruptions in recorded history. For years, the waters of Lake Nyos had absorbed carbon dioxide from underground sources, probably volcanic in origin. Because of temperature differences in the lake, the gas-saturated water remained at the bottom until something, possibly as insignificant as high winds, triggered a lake turnover. Once the eruption began, the lake began to boil like a soft-drink bottle you leave out in the sun and open by mistake. A giant cloud of carbon dioxide spilled out of the lake and smothered people and animals for miles around.

This is the same compound that, if numerous carbon sequestration projects now underway are successful, will be buried under tremendous pressure in dozens or hundreds of locations all over the world. The question is: will it stay there?

Ever since humans discovered fire, we have been adding to the amount of carbon dioxide in the atmosphere. Until the 1800s, the quantity of carbon dioxide humans put into the air was negligible compared to that contributed by natural causes such as forest fires and volcanic activity. The concern with rising levels of atmospheric carbon dioxide, of course, is that it tends to raise the Earth's temperature, other things being equal (which they never are). There is a general scientific consensus that (a) human activity has caused much if not most of the rise in carbon dioxide levels in the past two hundred years and (b) this will cause some increase in the Earth's average temperature, though how much and for how long is a matter of debate. Some theories even posit that a short temperature rise will trigger an instability that will wind us up in another Ice Age a few decades afterwards. Whatever actually happens, the political fact these days is that reducing one's carbon footprint has become a virtue, while emitting carbon, even for a good cause such as bringing the blessings of electric power to poor people, is a sin.

The business world has seen the politicians writing "cap-and-trade" on the wall, and so there is big private money to be made in developing systems that will capture the carbon dioxide generated when fossil fuels (most notably coal) are burned in power plants. A French firm called Alstom is currently building several pilot plants around the country, including one attached to a coal-fired power plant in New Haven, West Virginia.

The technology itself is rather clever. After cooling and washing the flue gas with cold water, they bubble it through a solution of ammonium bicarbonate (contains hydrogen) and ammonium carbonate (no hydrogen). Nearly all the carbon dioxide combines with the ammonium radicals. They pump the fizz-rich liquid under pressure to a heater where the carbon dioxide boils off and is compressed to send it underground. And there, in my opinion, the real trouble begins.

Never mind that the whole pile of machinery is doing something that engineers of an earlier era would have considered ludicrous: capturing the main gaseous combustion product and shooting it underground. The operation adds nothing to the efficiency of the plant, takes a fair amount of energy itself, and creates a long-term hazard compared to which nuclear waste is relatively harmless.

Look at it this way: would you rather live five miles from some well-shielded solid radioactive stuff whose emissions can't even be detected outside the plant boundaries, and which will just sit there and gradually cool off for the next few hundred years; or, would you like to live an equal distance from the wellhead of a giant underground reservoir which, if released, will suddenly spew out and make Lake Nyos look like a minor traffic accident? For my money, I'll take the nuclear stuff any day.

Presumably, geologists have been careful to select locations where the underground carbon dioxide is relatively safe and isolated. Okay, but our experience with large underground gas reservoirs of artificial origin is limited, to say the least. While natural gas has been stored underground for many years (often in depleted gas fields, not coincidentally), the two cases are significantly different. For one thing, natural gas storage is limited to transient market-related storage needs, and so the pressures and volumes required are relatively modest. By contrast, carbon sequestration will be "permanent"—the whole point is to send it down there and make it stay there indefinitely. If it escapes to the atmosphere we are back at Square One after spending billions of dollars for nothing, plus quite likely having numbers of dead citizens on our hands. The pressures and volumes eventually needed for carbon sequestration, if carried out on a large scale, will dwarf the current natural-gas underground storage facilities. While I am unaware of any major accidents that have happened with underground natural gas storage, there may have been some. Of course, carbon dioxide doesn't burn and natural gas does, but suffocation from a non-flammable gas makes you just as dead as if you had burned to death.

What makes a whole lot more sense from a technical point of view is to replace coal-fired power plants with nuclear plants as fast as we can. Nuclear energy generates zero carbon emissions, the nuclear waste problem is manageable even without the ill-fated Yucca Mountain disposal facility that the Obama Administration recently axed, and there are no particular concerns about running out of nuclear fuel any time soon. If we get low we can switch to the kind of reactor that makes more than it consumes.

That is the technical reality. But the political reality right now, which engineers as well as everyone else has to deal with, is that nuclear power is under the same emotion-laden mushroom cloud that has characterized it ever since nuclear weapons ended World War II, and has never freed itself from the almost superstitious fear that the word "nuclear" inspires in many people. Some of that fear has now been transferred to plain old carbon dioxide, a gas which each living human being emits every time we take a breath. When you end up being afraid of yourself, there's no place to hide.

It is still early in the carbon sequestration business, and there is time for the political winds to change before we all get burdened by carbon cap-and-trade taxes to pay for giant sequestration plants that send carbon dioxide into the ground, only to have some of it pop up one day in an unexpected place. Let's hope that cooler heads prevail and we reach a consensus that does sensible things about carbon emissions without burying a lot of unwelcome surprises for our descendants.

Sources: A good article originating at the Washington Post, describing the technology and politics of the carbon sequestration process pioneered by Alstom can be found at http://www.pittsburghlive.com/x/pittsburghtrib/business/s_638488.html. A description of the geology surrounding the Lake Nyos disaster can be found at http://www.cevl.msu.edu/~long/nyos.htm.