This page contains information regarding Star Trek: Picard, and thus may contain spoilers.
The intermix reactor was a type of energy technology used aboard the Kaplan F17 Speed Freighter. When fully functional, the intermix reactor generated power for the freighter. This device could be replaced by a replicant produced by the maintenance replicator.
In 2399, after forced to the surface of the planet Coppelius by an orchid, the intermix reactor was fused. Using the fundamental field replicator, a device devised by the Coppelius androids, Cristóbal Rios rebuilt the intermix reactor and repaired the freighter. (PIC: "Et in Arcadia Ego, Part 2")