Unmount/ Disable access to a partition to a particular user on Mac

I have two user accounts in my Mac.

1. Admin


2. Account managed by parental controls

I also have two partitions

1. Mac OS(system partition)


2. LocalDisk

I want to restrict the users of second account to access LocalDisk.

How can I do that ?

I am on Yosemite 10.10.1