For the next installment of my analysis of the future of nuclear power in America, we're going to take a quick look at some of the questions regarding it's safety, and it's vulnerability in the event of a terrorist attack.
Perhaps the biggest concern that the public has about nuclear power is the threat of a catastrophic disaster, like a meltdown or a core breach. A meltdown is the technical term for when the reactions inside of a nuclear reactor go out of control. As some of you may know, a nuclear reactor uses fissile (radioactive) material to generate heat in a slow, controlled way. Just like an atomic bomb releases a great deal of heat, radiation, and energy in an instantaneous blast, a nuclear reactor is designed to release the equivalent amount of energy over the course of years, even decades, using the same physical process: fission. Fission is the splitting of a large atom into smaller components - a heavy metal like Uranium or Plutonium is generally the fuel source for a fission reactor. These metals are made of atoms that, compared to other elements on the Periodic Table, are extremely heavy and large. This makes them easy to split. Splitting these atoms generates a great deal of energy, which is turned into heat, which is then used to boil water to drive a steam-turbine. This turbine is connected to a generator, which cranks out the volts that light up our world.
Nuclear reactors are designed with failure possibilities in mind. There are many complex safeguards in place to deal with almost any event. For example, if the core temperature rises to dangerous levels in a classic "meltdown" scenario, the computer is designed to automatically insert rods of control material into the reaction chamber. These rods are made of material that absorbs radiation and prevents it from spreading. The details aren't critical*, but the basic result is this: the nuclear fuel rods exchange radioactive particles, causing atoms to split at a controlled rate. The control rods keep the reaction from getting too hot or too intense. If the reaction does get too intense, the control rods are inserted by machines in groups to lessen the transfer of radiation and nuclear energy in the core of the reactor. This slows the reaction down to safer levels.
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| The control rods are spaced around the radioactive fuel rods - as they are inserted into the reactor, more and more neutrons are absorbed by the material, preventing a chain reaction. |
There are other safeguards as well, including a last-ditch measure that in practice is basically foolproof. This is called the SCRAM, and the acronym has a funny origin. At the University of Chicago in 1942, during tests of the first ever nuclear reactor (sometimes called the Chicago Pile), a procedure called SCRAM was invented. The acronym stood for Safety Control Rod Axe Man, and it refers to the act of cutting a rope from which a high-absorption control rod is suspended. Cutting the rope causes the rod to drop into the reactor, and the reason the scientists set it up this way is so they could shut down the reactor even if the power failed. Of course nowadays this system is laughably obsolete, but the term SCRAM remains in use to denote a full emergency shutdown of the power plant. Modern reactors are designed in even more ingenious ways - some use battery powered pumps to inject liquid into the reactor core. This liquid has the same radiation absorbing properties of the control rods (insiders call them neutron poisons, because they poison the chain reaction by starving it of neutrons), and when it is squirted into the core, immediately bring the chain reaction to a halt. Other systems use pressurized gas, like inert nitrogen or argon, to drive pistons that insert the control rods as a backup.
These systems can be designed to be as foolproof as any technology built by man can possibly be. The US Navy, which has been operating nuclear powered warships since the submarine USS. Nautilus was launched in 1954, has spent billions of dollars over the past half-century designing and testing reactor control equipment that is built to withstand the rigors of combat on the high seas - or in the case of Nautilus, under the high seas. Naval reactors are hardened against shock damage, and are built with layered redundancy that has influenced reactor design on the civilian market. For all this time, the Nuclear Navy has operated without a single radiation accident, or a single nuclear reactor meltdown. The small reactor inside of a modern nuclear submarine, like the USS. Seawolf, is capable of putting out enough power to light up a city the size of Albany, NY. At the same time, that same reactor is designed to survive enemy torpedoes, depth charges, and all sorts of other nasty weaponry in times of war. The safeguards introduced into the Nuclear Navy by Admiral Hyman Rickover (yes, that is his real name) have made our naval reactors as foolproof as technology can allow - there is no reason why similar measures (or even directly copied designs) could not be introduced into the civilian power market.
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| Funny name for a serious business. |
Safeguards like these mean that modern reactors are almost impossible to meltdown in a catastrophic accident. Even the control system failure at Three Mile Island back in March of 1979 was only a partial meltdown, and it was the result of a series of errors that are unlikely to occur in sequence ever again. Let's say you happen to slip and fall down the stairs. That's a pretty common occurrence in the world - probably happens a dozen times a minute. Now let's say you slip and fall down the stairs while delicately carrying an armful of barbed wire. That is obviously going to be a much less common occurrence, right? Well, the chain of events in the Three Mile Island accident would be like falling down the stairs with an armload of barbed wire, while naked, and also while suffering from hemophilia. Again, that's pretty damn unlikely. And now imagine that you not only survive the fall without a scratch, but get right back up and keep walking with barely a bruise. Yeah - that's cuz nobody died at Three Mile Island, and the average dose of radiation received in the surrounding community was equivalent to getting a chest x-ray at the doctor's office.
And yes, Chernobyl was a different story. But that's a Russian reactor, with Russian safeguards, operated by Soviet authorities, with nuclear engineers who probably earned more selling patent Glowing Vodka on the black market than they did while sitting in the control room of the power plant. And that disaster was similarly hyped. I'll discuss that in another post later on.
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| Typical Soviet-era safety protocols in action. |
Finally, we have the potential of a terrorist attack on a reactor complex. While this would undoubtedly be a disaster, what exactly would it accomplish? Even a powerful car or truck bomb would probably not breach the thick concrete walls that house the reactor, and even if they did, the reactor itself is a large steel cask inside of those walls, with the radioactive material and it's control equipment located within. Assuming the car bomber got through the guarded gates of the nuclear complex, it is highly unlikely that they would be able to do serious or threatening damage to the reactor core. These facilities are built to withstand explosions - some were built to withstand atomic bombardment during the Cold War - and it would take an extremely powerful bomb to cause any sort of damage. But even then, it's probable that the safety systems, independent of the atomic core, would be able to prevent a meltdown. In some cases, these systems are designed so that in the event of a disabling explosion, the neutron poison only needs gravity to bring it into the reactor core, stanching the neutron exchange and cutting off the chain reaction. Even flying an airplane into the reactor dome would probably not cause any kind of serious meltdown - though exposing radioactive material to the surrounding air could cause contamination on a local level if the emergency response is not rapid enough.
Or maybe not, as the following video shows . . .
As you can see, the plane is going 500 miles per hour and still fails to penetrate the thick concrete blast barrier. That's pretty impressive - and remember, beyond that concrete would be a high-yield steel containment vessel housing the actual nasty radioactive bits of the reactor.
In any case, it's absurd to stop building nuclear power plants because of what might happen in the event of a random terror attack. It's much better to continue thinking up creative ways to protect them in the event of such an attack. Heightened security, including military forces on alert in times of dangerous signals from the international terrorist community about impending attacks, is probably all that would be realistically needed, but the government and private industry have explored other options as well. Anti-aircraft missiles, or even laser systems, could prove to be the new-wave in nuclear security, and some firms are already marketing electronic weapons to power plant operators. None of this is even strictly necessary - if it seemed that a hijacked or erratic airliner was making a beeline towards a nuclear facility, there are protocols in place that involve the FAA alerting the facility in question, giving them enough time to safeguard the reactor, either by shutting it down entirely or programming it to skip the secondary and tertiary safeguards and go straight to total SCRAM in the case of a malfunction or actual attack.
In summation, the risk of a nuclear accident or meltdown, by either a system failure, power failure, or determined terrorist attack, are almost all anticipated in the construction and engineering of modern reactor plants. If the military can build reactors that operate under the threat of war, there is no realistic reason why the civilian market cannot be supplied with the same technology and apply it to providing power to consumers nationwide. Only fears stoked by environmental activists, liberals who watched The China Syndrome and had nightmares, and even oil companies afraid of market competition, are what prevents us from becoming a truly atomic-powered nation
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