looks like these guys had some fun, lol
Glen,
it is Fusion reactor and it is shut down - 0 emmision. i'm not sure what is half life of said californium isotope (it might be only couple of hours), but i would think people who work there are responsible enough to measure the levels before puting it out in the open
EDIT:
"Californium is only slightly radioactive, so the toy train did not glow green after its ride in the fusion reactor. "
slightly radioactive? tells me that the journalist here is not very verse in the subject or just being silly. and radioactive or contaminated materials don't glow by themself...