Surrounding uranium cells with as much cooling components as possible makes it output less heat. I removed external cooling to show you the impact. Design1Design2 So putting cells into a corner is generally a bad idea.
Another thing to keep in mind is the layout of Coolant cells. Coolant cells = cooling, while HDs only mean heat distribution. Every HD that doesn't need to be contained in design means lower cooling. Your design contains 5 free slots, so I added 2 cells to the best slots available. Design3 I recreated it, but maintained uranium configuration. Again 5 free slots, 2 UCs added. Design4 My version is performing better because I used 2 less HDs to cover the same area as you did (5 free slots). This means better cooling and desing lasting longer.
Hope it helps. (It may have nothing to do with with your request, but when I saw those Uranium Cells in the corner, I thought it might be helpful a little.)