Trying to securely erase hard drive, but Security Options not available (Mavericks)
Yes, it is possible to re-enable secure erase. All you need to do is to format the partition once again. Just make sure you select "Mac OS Extended (Journaled, Encrypted)", with any password that you will remember (just in case). Once formatted, the "Security Options" button will be available again, and you can securely wipe out the partition!