Science: Swords into Plowshares

Even before an atomic bomb leveled Hiroshima, scientists dreamed of the day when nuclear explosives might be used to build, not to destroy. They talked about moving mountains with nuclear blasts, digging harbors and tunnels, constructing canals. Huge oil caches, they said, could be recovered with underground explosions.

In 1957 the U.S. Government finally got to work on Project Plowshare,* a program for developing the peaceful uses of nuclear explosives. Last week, after a 2½-year moratorium on testing, the first nonmilitary nuclear bomb test ever conducted in the U.S. rocked the flat floor of the New Mexico desert with a mighty underground blast. And what had begun as a bright scientific dream almost turned into a nightmare. For a few minutes, minor accidents and miscalculations suggested disaster.

Man-Made Quake. Scientists had worked hard to make a success of Project Gnome, an offspring of Plowshare. An elevator shaft had been sunk 1,216 ft. below the New Mexico desert, just 25 miles from Carlsbad. At the bottom of the shaft (see diagram), a horizontal tunnel had been cut through 1,116 ft. of rock salt, silt and clay stone. The plan was to explode a 5-kiloton nuclear charge at a crook in the end of the tunnel. If all went according to theory, the tunnel would collapse; some 1,200 ft. underground, a huge cylindrical, salt-lined cavern would be formed. Conceivably, heat from the blast could turn moisture to steam for the production of electrical power. In the future, such atom-produced power might even be economical enough for general use.

Also programmed for the $5,500,000 blast were some other experiments. Such elements as tritium and americum were to be exposed to nuclear particles released by the explosion; scientists hoped to recover the elements in radioactive form. “Wheels” which revolve at high speed and contain various elements on their rims were lowered into the shaft in the expected path of neutrons; scientists planned to study the wheels, find out how the neutrons affected the elements. At many spots around “ground zero” (the point directly above the blast), instruments were set to measure shock waves, temperature and radioactivity. Around the globe, seismologists monitored the countdown on short-wave radio and then watched their instruments to record the effect of the man-made quake. There was a cache of TNT near by, to be detonated five minutes after the blast. Instruments were to compare the wave from the underground nuclear blast with the wave from a known quantity of TNT. Project Gnome’s big blast was easily the most heavily instrumented U.S. nuclear test in the short history of the atom.

Rattling the Snakes. But even as newsmen and observers from 13 nations (Russia had turned down an invitation to attend) were waiting for the countdown, saboteurs were at work; gophers chewed away the plastic coverings on electronic cables, putting a pair of radiation detectors out of action. At “zero” minute, the bomb exploded with more force than the experts had anticipated. The shock wave rolled through sandy desert and rock-strewn mountains, rattling dishes and Christmas tree ornaments and rippling the waters of Mirror Lake at Carlsbad Caverns 34 miles away. Physicist Edward Teller, viewing ground zero from a helicopter, thought he saw the ground heave 2 ft. (later measurements showed it to be better than 4 ft.). Watching a thin blanket of dust rise across the test site, a booted rancher yelped: “That shook up your rattlesnakes.”

Somehow, the 2,400-lb. surface charge of TNT exploded prematurely, sending an ominous-looking mushroom cloud aloft. White-suited squads raced for the blast area. The first site-entry crew arrived on the scene in less than two minutes to take control of temperature and pressure gauges. “Request permission to enter the area,” radioed their chief. “We’re getting a buildup at the bottom of the tunnel,” was the anxious answer from the control center. “You’ll have to get out of there.”

The blast had failed to close off the underground “teakettle.” Radioactive vapor escaped from the site’s elevator shaft. After flying into the billowing cloud of fallout in a helicopter to take measurements, a Public Health Service technical crew sent word that the exit road from the test site had to be shut down. Roadblocks were set up. Cars in the area, although not exposed to much radiation, were washed down as a precautionary measure.

Back at the test site, much scientific equipment was in disarray. It was feared that the neutron wheels at the bottom of the shaft had been damaged. Film in cameras used to photograph instruments near the elevator shaft was fogged by radiation. Chemical samplers over ground zero were severely damaged. Data cables running out of the shaft had somehow been cut.

At week’s end, as radiation subsided, the scientists, who had not been altogether unprepared for the unexpected, were convinced that some 70% of the data could be salvaged. Probably the neutron wheels could be recovered. There still might be a cavity beneath the earth; the leak in the teakettle might yet be plugged with blastfurnace clay. Some radioactive isotopes could still be retrieved. Some data might be obtained from fogged camera film. A pair of drilling rigs had been moved over ground zero; two holes would be drilled—one to pump water into the teakettle, another to draw off steam.

Already the scientists are making detailed plans on two new Plowshare tests in Nevada—one to produce isotopes, the other to gather information on cratering, possibly for the digging of a canal. The hopeful dream that nuclear bombs may some day be used for the good of mankind is inching toward fulfillment.

*After the Biblical quotation in Isaiah 2:4: “They shall beat their swords into plowshares, and their spears into pruninghooks . . . neither shall they learn war any more.”