11/05/2007 01:09 pm ET Updated May 25, 2011

The Truth About Nuclear Energy

Last week at an Arizona nuclear plant, guards, who are required to search every vehicle that enters the grounds, detained an employee at a checkpoint 1.5 miles from the plant when a five-inch long improvised pipe bomb was found in his truck. The news media kept referring to the pipe bomb as a scary threat and speculating on various deadly but impossible scenarios. But did this incident reveal how vulnerable our nuclear plants are? And if a pipe bomb were detonated at the plant, would a dangerous release of radioactive pollution occur? And what source of electricity generation poses the greatest risk to public health?

As an opponent of nuclear plants who believed them to pose a great risk, I went on a nuclear tour of America with a scientist, Dr. D. Richard ("Rip") Anderson. Among other things, he's an expert in risk assessment, environmental health, and nuclear safety. Having led several big programs at Sandia National Laboratories, he has a high-level security clearance. Even with his credentials we couldn't just drop in at a nuclear power plant. To arrange visits took months. We had to provide all our data to a liaison and to wait for approval. We were given a date and time to appear at the gate. We had to have a guide who worked for the company with us at all times. On the road to the plant, our escort pointed out security cameras. We were already being watched. We had to pass various checkpoints guarded by burly men with AK-47s. They wore bullet-proof vests hung with electronic communications equipment. Even though we rode in a company car, the squad checked its underside and trunk, and had us get out and walk about half a block away from it so that some other, unexplained search could occur. Meanwhile, inside a guard booth our IDs were being checked by an official who made phone calls. After what seemed a rather long time, we were permitted to continue. We passed a plant fire department and a clinic. The administration building that stood between us and the heart of the plant was protected by big concrete jersey barriers. Later we were to see hydraulic pop-up barriers that can stop a speeding tractor-trailer truck cold. Once inside that building we had to be approved by another armed squad, pass through metal detectors, and have our belongings X-rayed while being scrutinized by even bigger, burlier, and more heavily beweaponed guards on the other side.

All this took place in a room that was partitioned at one end by a big one-way mirror-walled cubicle. Once we passed through the detectors I could see through an open door the dim interior. There, several people were watching video monitors. Others were watching us. Our escort showed an official some documents and a laminated pass. We were then issued passes that were electronically linked to her pass. Next we each had to put a hand in a box that instantly makes thousands of measurements of the geometry of the palm. Each palm is unique. And, our escort assured us, you can't use a severed hand as ID in the palm sensor because the lack of circulation changes the measurements. We then successively swiped our cards and one by one passed through a floor-to-ceiling turnstile made of case-hardened steel bars.

Our guide told us to remain within her sight at all times. Now we entered the enclosure where the plant made reliable, around-the-clock electricity, without producing greenhouse gases, for about a million people. The whole area was enclosed by an earthen bulwark with motion sensors and cameras, multiple razor-wire barriers, and concentric rows of high hurricane fences, and all these lines of defense were inspected by foot patrols with guard dogs. Above us rose reactor containment buildings with walls of dense concrete reinforced with steel bars the thickness of a man's arm. This defensive construction was tested long ago in bunkers built to protect observers from thermonuclear explosions at the Nevada Test Site. Each containment building, negatively pressurized, was perhaps six stories high. But the reactor itself was about 10 stories underground, anchored in bed rock and enclosed in a pressure vessel of steel five inches thick. The actual core where the fuel rods produced the heat that was carried away to make steam to turn turbines was twelve feet by twelve feet. Very few employees are permitted to enter the reactor building, and the airlock is seldom opened. The temperature is very high. If a trespasser could somehow find a way to get down to the pressure vessel, where water circulates among the fuel rods, cooling them, and if he had access to special equipment necessary to move the extremely heavy fuel rods out of the reactor, he would perish within minutes from their radiation.

In an experiment, a fighter jet rammed at five hundred miles an hour into a thick concrete wall only made a scratch two centimeters deep before pancaking. (A link to a video of this is in the FAQ section of my website.) An airliner -- a big tin can full of fuel, as one engineer describes it -- would make even less of an impact on a containment building. Rip Anderson and other experts told me that about the only way to breach the reactor containment and the pressure vessel would be by dropping a thermonuclear weapon directly on them.

But I know of a scarier threat that's not hypothetical. It's happening all the time. North of the plant, in the Four Corners Area, huge coal-fired plants belch out brown plumes that stream on for hundreds of miles. Arizonans were worried about radioactivity might take note that coal combustion releases 100 to 400 times the low-dose radiation that a nuclear plant does. In fact, if you eat one banana you're getting much more radiation exposure from its potassium-40 isotopes than you would from living next to a nuclear plant for a year. But I'm not concerned about low-dose radiation; I grew up in New Mexico, where natural background radiation is higher than in most states, and yet the state has one of the lowest incidences of cancer in the nation. And people living near Spokane in Washington State are more than three times the exposure from nature that New Mexicans do. No, I am worried about the fine particulates, mercury, and noxious and global-warming gases these behemoths spew into the environment.

By the end of the tour it became obvious to me that the slightest incident at a nuclear plant, even if it occurs far from any reactor and poses no risk to the public, is usually given three-alarm treatment by the media, whereas the large-scale, relentless, ongoing risks from fossil fuel combustion are ignored. Our biggest reliable sources of our basic electricity supply are fossil fuel plants and nuclear plants. There is nothing speculative about the fact that as coal combustion provides half of our electricity it causes the premature deaths of more than 24,000 Americans a year in addition to hundreds of thousands of cases of lung and heart disease. Is this acceptable?

Nuclear power, while providing one-fifth of our electricity and three-quarters of our emissions-free electricity, has never caused a single death to a member of the American public.

Gwyneth Cravens is the author of the recently published Power to Save the World: The Truth About Nuclear Energy.