Topic: what happen to Knox vaults access if reinstall OS X

Yes, Knox vaults work fine across different Mac OS X installs.

After you install Mac OS X and Knox, whole-disk vaults just work normally. Knox also automatically discovers any vaults that you have in the Documents/Knox and Library/Knox folders under your home folder.

For vaults stored elsewhere, you need to open them with Knox first (by double-clicking on the vault file or by dragging the vault file onto the Knox icon)—after that, they will appear in Knox’s Vaults menu.

Note that there is a bug in the current Knox version that affects this. In trial mode, Knox currently refuses to open vaults that were created over 30 days before the trial began. This will be fixed in a future release.