While playing around with the reactor planner I noticed a strange oddity in this design
If you look at the top row, the 2nd and 4th cooling cell, as well as those cells at the bottom with the free spot adjacent, they are marked as cooling cells although there isn't anything around them to cause them to heat up. Additional information shows that they are receiving 0 heat, yet they are included in the cooling calculation.
Is this a bug in the tool or is this some secret nuclear engineering that I wasn't aware of?