| Subject | English | Spanish |
| gen. | computerized central nuclear materials accounting system | sistema central informático de contabilidad de material nuclear |
| gen. | defensive strategic nuclear weapon system | sistema defensivo de armas nucleares estratégicas |
| nucl.phys. | direct cycle boiling water reactor nuclear system | sistema nuclear de reactor de agua en ebullición de ciclo directo |
| el. | ESSOR Nuclear System | Instalación Nuclear ESSOR |
| IT, nucl.phys. | International Nuclear Information System | Sistema Internacional de Documentación Nuclear |
| polit. | International Nuclear Information System | Sistema Internacional de Información Nuclear |
| el. | international nuclear non-proliferation system | sistema internacional de no proliferación nuclear |
| nucl.phys. | nuclear material accountancy and control system | sistema de control y contabilidad de material nuclear |
| el. | nuclear materials accountancy and control system | proyecto relativo a la contabilidad y al control de materiales nucleares |
| nucl.phys. | nuclear steam supply system | sistema nuclear de suministro de vapor |
| transp., el. | spaceborne nuclear power system | sistema electronuclear a bordo de un vehículo espacial |
| energ.ind., el., nucl.phys. | State system of accounting for and control of nuclear material | Sistema nacional de contabilidad y control de materiales nucleares |
| energ.ind., el., nucl.phys. | State system of accounting for and control of nuclear material | SNCC |
| energ.ind., el., nucl.phys. | State System of Accounting for and Control of Nuclear Material | Sistema nacional de contabilidad y control de materiales nucleares |
| energ.ind., el., nucl.phys. | State System of Accounting for and Control of Nuclear Material | SNCC |
| gen. | thermal power of a nuclear steam supply system | potencia térmica de un generador nuclear de vapor |