Fuel Rod (MOX)
MOX Fuel Rods last 1/2 a reactor cycle (10,000 seconds).
MOX Fuel Rods become more efficient as reactor heat increases (up to 5 times normal efficiency at 99.9% maximum heat). MOX reactors can reach up to 35 times 1-rod efficiency with sufficient cooling.
Pressure Vessel Reactor
MOX Fuel Rods behave rather more sedately in the fluid reactor, outputting normal efficiency at reactor heat <50% and 2 times normal efficiency for reactor heat >50%.
While more difficult to build stably, a proper MOX fluid reactor can be much more efficient than an EU reactor, with optimized designs reaching above 40x efficiency.
MOX Fuel Rods can be crafted into more powerful fuel rod assemblies.