| Kernreaktor | nuclear reactor |
| Kernreaktion | nuclear reaction |
| Korrektor | proofreader |
| Atomreaktor | nuclear reactor |
| Brutreaktor | fast breeder fast breeder reactor |
| Reaktor | reactor |
| Klirrfaktor | distortion factor |
| Refraktor | refracting telescope refractor |
| Kernpunkt | issue |
| Kernzeit | core hours |
| Kernbeißer | hawfinch grosbeak |
| Kernkraft | nuclear power |
| Kernsatz | kernel sentence |
| Sternentor | stargate |
| Fernverkehr | long-distance traffic |
| Gegenreaktion | counterreaction |
| Kettenreaktion | chain reaction |
| Überreaktion | overreaction |
| Kreatur | creature wight |
| Formfaktor | form factor |