It doesn't really come as much of a shock that a small amount of radioactive material turned up in a salvage yard on
Beyond that, APG, being a proving ground, was, and remains, a place where a fair amount of experimentation on the latest findings of science is done. Experimentation results in waste and if something is little understood, that waste is likely as not to be regarded as harmless as scrap paper or an old coffee can, especially back in the day.
In modern times, a lot more precautions are taken when it comes to disposing of radioactive, chemical and biological contamination, and with good reason. All have the potential to trigger horrible sicknesses days, weeks, months or even years after initial exposure. Such things were poorly understood back in the days before dumps were replaced with sanitary landfills and wastewater treatment became the municipal standard for dealing with sewage before it is dumped into a public waterway.
The cavalier attitude toward dealing with potentially dangerous waste products has largely been replaced with caution after having had it proven time and again that what we don't know and can't see actually can hurt us, our children and our grandchildren.
So while it comes as no surprise that such things as old lighting systems that relied on radioactivity were left in with other more ordinary scrap, it's an issue of substantial concern. It's important to remember that unexpected finds are made with a fair degree of regularity on post, starting with old unexploded ordnance dating from the