ATOMIC TEST SITE, Nev. -- American scientists said today that it might be a 100 years before it would be safe for a human to enter a "secret-filled" cavern which served as a detonation chamber for a nuclear device deep under a desolate desert mesa.
The walls of a man-made tunnel leading to the blast chamber collapsed as expected yesterday, sealing the deadly radioactivity inside the chamber.
Scientists estimated that it would be a century before the radioactivity loses its intensity, allowing humans to inspect firsthand the secrets of the blast chamber. The Atomic Energy Commission plans to core-drill but it has little hope of uncovering more than samples of radioactive particles.
Scientists have speculated that artificial heat and pressure produced by the blast could have turned rocks and minerals into rubies, sapphires or even diamonds.