There are many, many sites where warheads are stored and, in fact, lots of sites where fissionable materials, like highly enriched uranium and plutonium, are absolutely not safe.
Hay muchos, muchos sitios donde se almacenan cabezas nucleares y, de hecho, muchos sitios donde hay materiales fisionables, como uranio y plutonio altamente enriquecidos, son completamente inseguros.