Mark I - Basic Layout This Mark I is a very basic and safe configuration as it only uses two Uranium Cells and the Reactor has no additional chambers. The two cells are evenly spaced apart, the sides of each Uranium Cell has an Integrated Heat Disperser and the rest of the space is occupied by Coolant Cells. This layout produces 18 EU/t.
Mark I - Basic 6-Chamber Layout
Also a Mark I because it is a safe design at the cost of efficiency. Heat in this layout will not exceed the life of the Uranium Cells so there is no risk of an explosion. This design is basically the same as the one above except that it now utilizes 6 Reactor Chambers. The spacing of the Uranium Cells is the same, as is the placement of the Dispersers. It is the same thing expanded twice more. The power output is 59 EU/t.
Mark II Layout
This layout places two sets of three Uranium Cells adjacent to each other which increases the efficiency but generates more heat. It is a safe design because it will still take a long while to deplete the Coolant Cells. The Dispersers and Coolant Cells are placed in a checkerboard fashion around the Uranium cells for maximum cooling efficiency. The power output is 139 EU/t.