See ticket 1367 where a hung reaping cfthread could cause thousands of extra reaping threads to be created. Look into one of the two ideas:
1) Creating a flag in the object store that keeps track of when reaping starts that the reaping thread sets back when it's finished.
2) A way to check and see if the reaping thread is still running prior to starting a new one. That way if the reap errors our for some reason the app won't just stop reaping forever.