Science: The Bomb Site

Cattle and sheep graze over the vast domain of the Atomic Energy Commission’s Nevada Test Site northwest of Las Vegas, which saw its last nuclear explosion in 1958 when the U.S. and Russia informally agreed to stop testing. But the specter of the bomb still hangs over the landscape: the man who cares for the cattle rides the range with a radiation counter clipped to his shirt pocket. Last week, with resumption of testing still in the balance, the atomic cowpoke had plenty of company. Never abandoned by the AEC, the test site has blossomed with activity.

Tunnels & Towers. Streams of skilled workers and a continual coming and going of scientists from many laboratories create the air of important things afoot. The number of employees of Reynolds Electrical & Engineering Co., which supplies nonscientist help, has jumped to 1,600 from 878 in 1960. Total employment at the site is now about 2,500. On the great barren area (40 miles by 30 miles), the AEC is testing a nuclear rocket engine, Project Rover, and a nuclear ramjet, Project Pluto (so far non-explosively), is also using chemical explosives to make studies of craters. Since most nuclear authorities agree that any further bomb testing will be done underground to avoid contaminating the atmosphere or the ocean, a force of hard-rock miners is busily digging tunnels into the mountains.

The first new set of explosions (if any are authorized) may not involve any new nuclear devices. Instead, they may be part of Project Vela, a new group whose purpose is to discover how far away underground nuclear explosions can be detected. Such tests would probably use old-style bombs, and the Russians and others might be invited to participate or observe. But on dry Broom Lake in the isolated northeast corner of the range, a 1,500-ft. tower is under construction for far more advanced testing. On its top will soon perch a small, unshielded nuclear reactor designed to give powerful bursts of neutrons and gamma rays for short periods. There will be no explosion, but scientists will be able to observe the effect of the radiation on test objects (and perhaps animals) arranged around the tower. Thus, they should be able to estimate the killing effect of the still-unachieved neutron bomb and figure how soon humans can reoccupy a place that has been showered with neutrons.

Scraped Soil. Large areas of the test site are still littered with bomb-twisted steel and wrecked buildings, but the site’s radioactivity has notably declined since the start of the test moratorium. “Hot” debris has been removed from the dangerous places where bombs exploded; in some cases several inches of soil have been scraped up with bulldozers. But caution has not relaxed. All workers wear radiation-detecting devices and are carefully checked in and out of their jobs.

A chief center of scientific interest is a tunnel cut into a mountain of soft rock, its mouth now blocked with a complex ventilating system. Four years ago a bomb exploded in that tunnel, and as the cavity that it made cooled down (both in temperature and radioactivity), scientists studied it intensively. It can now be entered without danger, is serving as a guide for future underground tests. Other tunnels, still too hot to enter, are explored chiefly by drilling.

The living things of the desert—such as they are—have also made a comeback. Great disks of land that nuclear explosions wiped clear of plants are now covered again. Seeds in the ground apparently were not killed: some bomb-denuded places bloomed during the following spring with unusually luxuriant growths of tumbleweed. Biologist Lora Shields of New Mexico Highlands University, who is studying the site’s resurgent biology, says that the spherical tumbleweeds rolled across the denuded sites scattering their seeds, and found the atomized soil exactly to their liking. So far, no atom-induced plant mutations have appeared, and trees on a nearby mesa show no radiation damage. The local animals (red foxes, snakes, rodents) are doing fine—for the time being.