Zirconium is best known to the public as the ring you get your fiancée if you don’t love her enough to invest in a blood diamond. Popular as it is in “fake” jewelry, zirconium is more often used in power plants and space shuttles, because it has a remarkable resistance to damage by radiation.
Cubic zirconia are made of zirconium dioxide—two oxygen atoms and one zirconium atom. They’re the bright, translucent, and cheap substitute for diamonds. But zirconium has more than one trick up its sleeve, and more than one material to which it can bind itself. Various zirconium alloys are found in space, around crucial parts of spaceships, and in nuclear power plants. Whether they’re in space or on the ground, they’re there for the same purpose—to protect equipment from damage done by radiation.
As cosmic rays and neutrons go streaking through equipment, they wrench atoms out of place. Over time, this leads to more and more corruption until the material is shredded and the equipment fails. Zirconium alloys have the ability to repair themselves. Zirconium and its alloys tend to form ionic bonds—bond that tends to pry electrons away from one atom, and deliver them to the other atom, leaving two joined ions. These bonds leave the atoms more mobile than they usually would be, so they can creep back into place when radiation knocks them away.
There are drawbacks to zirconium alloys. When zirconium is heated up and exposed to water, the zirconium strips the oxygen in the water away, leaving hydrogen gas. Hydrogen gas, when in the presence of oxygen, can catch fire and explode. Power stations need to regularly vent hydrogen gas, and if they don’t, it can—and has—led to explosions.