Introductory technical guidance for Professional Engineers interested in tritium facilities engineering. Here is what is discussed: 1. INTRODUCTION, 2. SOURCES OF TRITIUM, 3. THE RELATIVE ABUNDANCE OF TRITIUM, 4. THE RADIOACTIVE DECAY OF TRITIUM, 5. THE CHEMICAL PROPERTIES OF TRITIUM, 6. FUSION TEST FACILITIES, 7. DESIGN OF FACILITIES TO FACILITATE ULTIMATE DECONTAMINATION AND DECOMMISSIONING, 8. VITRIFICATION, 9. FEED MAKE-UP AND CHEMICAL ADDITION.