Some 40 years ago, as environmental reporter for the Norfolk Ledger-Star, I asked some top authorities on atomic energy what would happen if a nuclear power plant lost all the cooling water in its reactor core.

The answer from a spokesman for the Atomic Energy Commission — then the watchdog agency for domestic as well as military nuclear power: “The probability of a total failure of the entire system is so small that we have not found it necessary to postulate the consequences.” He added, however, that those consequences would be “very, very serious.”

Since then, Three Mile Island and Chernobyl have come close to drawing us a picture of how “very, very serious” such an event would be. We’re on the edge of our seats now, wondering whether Fukushima Daiichi Nuclear Power Station in Japan will complete the picture.

The question I asked back then was more than academic. Virginia Electric and Power Co. at the time was building a 1,600-megawatt nuclear power plant at Surry, on the banks of the James River across from the site of the first permanent English settlement in America. A few miles downstream lay the Hampton Roads metropolitan complex, with about a million people, not to mention the headquarters for the Navy’s Atlantic Fleet, Fifth Naval District and the naval arm of Nato.

I had spoken with Carl W. Houston of Johnson City, Tenn., who had been fired as a welding superintendent at the Surry plant because he insisted that the welding in the core cooling system was defective and could result in disaster.

The Atomic Energy Commission spokesmen said Houston was correct in his assessment of the welding, but not all of his concerns about the dangers of a nuclear disaster were valid.

Later, at a seminar in Oak Ridge, Tenn., I was able to talk to Ralph Lapp, Ph.D., who had worked on the Manhattan Project that produced the first nuclear bomb. Lapp knew something about nuclear power plants. He is credited with coining the term “China accident” to describe a situation in which molten nuclear fuel might melt its way into the ground toward the center of the earth. Lapp assured me that anything that threatened the integrity of the core cooling system was not to be taken lightly, and explained why:

The core cooling system is what keeps the reactor from melting. It pours cooling water through the nuclear fuel rods through stainless steel pipes that are 2 inches thick. These pipes channel water under  pressure of 1,200 to 1,800 pounds per square inch. At this pressure, the water can absorb heat from the reactor core and use it to turn water in a secondary loop into steam. It’s this steam that drives the generators that produce electricity.

Lapp told me that if the reactors were to lose all the cooling water, the plant operators would have about 12 seconds to replace it. Otherwise, the reactor would overheat. It would melt down, and then melt through any container, including the reactor domes that housed it. These domes were constructed of steel sheathed in concrete. After the nuclear fuel melted its way out of the containment structure, no one was sure where it would go. It wouldn’t end up in China or anywhere else on the other side of the earth. But wherever it went, it would take it 10 to 12 years to cool.

Because the pipes were stainless steel, they required special care in welding. The right kind of metal had to be used in the welds, and they had to be welded at the right temperature. Since carbon is one constituent of stainless steel, welding at excessive temperatures could cause the carbon to separate into tiny droplets. This would “sensitize” the steel, meaning that it would be vulnerable to corrosive elements such as halogen gases. Halogen gases are among the byproducts of nuclear fission. An independent engineering company inspected the welds, and those found to be defective were repaired.

Officials at Vepco acknowledged the dire consequences should a “China accident” happen, but they assured me that the plant was designed to withstand any plausible accident. They called it the “maximum credible accident,” and took me through another plant under construction to show me their impressive safeguards. Should the plant suddenly lose its cooling water, replacement water would immediately be pumped back in. Diesel-powered generators would automatically spring into action to provide electricity for the emergency cooling system.

The Atomic Energy Commission conducted a hearing into the defective welds before granting the Surry plant a license to operate. At its conclusion, it reported that there was “reasonable assurance” that the plant would operate safely. It allowed it to open on schedule, but required a stepped-up frequency for inspections and mandated close federal surveillance of the plant.

There was considerable pressure to get the plant on line at the time. During the late ’60s and early ’70s, the nation was alerted to an impending energy crisis. The Surry plant and Duke Power Co.’s Oconee plant near Clemson, S.C., were being counted on to stave off the shortage.

So the plant opened, and for nearly 40 years it has been providing us with reliable energy.

There has been no “maximum credible accident.”

What we’re watching in Japan is an incredible accident: a 9.0 level earthquake followed by an epic tsunami that rocked the Fukushima Daiichi plant to the limits of its endurance.

We don’t have tsunamis here on the East Coast of the United States. Nor is an earthquake likely to shake Surry or Oconee or any other nuclear plant in our vicinity.

Our nuclear plants, like those in Japan, are designed to survive the maximum credible accident.

Let’s just hope an incredible accident doesn't come along. And we’re not forced to learn from experience how disastrous a reactor melt-down could be.

Readers may write Gene Owens at 315 Lakeforest Circle, Anderson SC 29625 or  at WadesDixieco@AOL.com.