Does anyone know what the record retention period is for a vault log where we track who and what time we opened/closed the vault?
We also use safety deposit boxes to store our ATM cash and keep a log for opening those boxes. I have read that safety deposit box record retention is 5 years after close... Does that still apply if the bank is the owner of the box and is using it is a vault?

Unless your State law or banking regulations require some sort of retention, it is more of an internal decision as to how long to retain the records. I highly doubt that a bank owned box would be governed under the same principals as a customer's safe deposit box. Check with your State banking association. Most of those publish comprehensive retention schedules designed specifically for your State.