Thursday, January 17, 2008
Zinc sulfide forms the basis of many scintillation detectors, dating from practically the beginning of the science of radioactivity. The old radium dial clocks mixed radium with the zinc sulfide, to provide that "glow in the dark" wonderfulness. Few modern scintillation detectors use zinc sulfide, however, because other crystalline compounds such as NaI are better suited to electronic detection.
When doped with various elements, the color emitted by zinc sulfide scintillation varies, with silver (blue emission), manganese (reddish orange), and copper (green) being most common.
Suppose you were to mix a zinc sulfide powder, properly doped, with nuclear waste material. It would, of course, glow in the dark. Actually, it would glow all the time, but it would be most noticeable in the dark.
One way to do this would be to do the mixing at an intermediate step in a process of nuclear waste vitrification. One typical way of doing this is to convert the liquid waste into a silica gel, which is then and dried, followed by heating to melt the gel into a glassy substance. If zinc sulfide were added to the mix at the dry gel stage, the resultant glassy substance should scintillate with the radiation of the waste.
Now let's imagine surrounding the glassy material with fused quartz, a clear, hard substance. I'm figuring on getting a block that's maybe two meters on a side, which would weight around 24 tons, but one could easily create larger or smaller blocks if there were practical reasons to do so.
It's said that nuclear waste needs to be stored for hundreds of thousands of years, but that's waiting for the long-lived actinides to decay. Without the actinides, several centuries would do. Either way, stone pyramids in the middle of a desert have been shown to last for thousands of years to date, which is a good start. And it's always a good idea to keep things where you can keep track of them.
Imagine glowing pyramids in the middle of the Nevada desert. Any breach in containment would be easy to detect; the radiation has its own glowing tracer that would follow it. The radiation penetration through the blocks could be engineered to be minimal; if the quartz isn't enough, put a few layers of leaded glass around the center. God knows, we have plenty of leaded glass around from old CRT screens.
I figure it would be a tourist attraction. Properly managed, you might be able to build a casino or two nearby, where the gamblers could sit at night and watch our nuclear legacy glower in the dark. Just a little reminder of some of the other ways there are to gamble.