aside from the fact that 'breaking open a refrigerator' doesn't remotely sound like something a child would ever do to me, let's assume the worst and the child somehow opens up a refrigerator.
a conventional fridge has electric motors/pumps , live a/c wiring, and gas under pressure. It's not radiation-spilling-everywhere unsafe, but it's not really safe for the kid, either.
That refrigerator is discarded. It ends up in a scrapyard. Someone comes, sees the shielded capsule containing radioactive material and harvests the lead. The remains are eventually sold to someone else and it ends up in that person's home where children are likely to become fascinated by it or even eat it.
Everyone who went near this thing is likely to become ill at the very least.
Yes. Sounds like something a child would do.