MODULE 5.0: FUEL FABRICATION Introduction Welcome to Module 5.0 of the Fuel Cycle Processes Directed Self-Study Course! This is the fifth of nine modules available in this directed self-study course. The purpose of this module is to assist the trainee in describing fuel fabrication and Nuclear Regulatory Commission (NRC) regulation of fuel fabrication facilities; the ammonium diuranate (ADU) wet conversion and intergrated dry route (IDR) chemical processes; ceramic process conversion; loading of rods and assemblies; scrap recovery; radiological and nonradiological hazards; administrative and engineering controls and preventive measures; key contributing factors for fuel fabrication accidents; and mixed-oxide (MOX) fuel. There are 12 learning objectives in this module. This self-study module is designed to assist you in accomplishing the learning objectives at the beginning of the module. The module has self-check questions and an activity to help you access your understanding of the concepts presented in the module. Before you Begin It is recommended that you have access to the following materials: ◙ Trainee Guide ◙ 10 CFR Part 70, Domestic Licensing of Special Nuclear Material Complete the following prerequisites: ◙ Module 1.0: Overview of the Nuclear Fuel Cycle How to Complete this Module 1. Review the learning objectives. 2. Read each section within the module in sequential order. 3. Complete the self-check questions and activities in this module. 4. Check off the tracking form as you complete each activity. 5. Contact your administrator as prompted for a progress review meeting. 6. Contact your administrator as prompted for any additional materials and/or specific assignments. 7. Complete all assignments. If no other materials or assignments are given to you by your administrator, you have completed this module. 8. Ensure that you and your administrator have dated and initialed your progress on the tracking form. 9. Go to the Trainee Self-Study Course Guide and review the steps for course completion. This page has been intentionally left blank. MODULE 5.0: FUEL FABRICATION TABLE OF CONTENTS LEARNING OBJECTIVES ................................................................................................................. 5-1 FUEL FABRICATION OVERVIEW .................................................................................................... 5-2 Fuel Fabrication Facilities ......................................................................................................... 5-9 NRC Regulation ...................................................................................................................... 5-11 Self-Check Questions 5-1 ....................................................................................................... 5-14 CHEMICAL PROCESS: WET OR ADU PROCESS ............................................................................ 5-16 Vaporization ........................................................................................................................... 5-17 Hydrolysis ............................................................................................................................... 5-18 Precipitation ........................................................................................................................... 5-19 Separation .............................................................................................................................. 5-20 Calcination ............................................................................................................................. 5-20 Reduction ............................................................................................................................... 5-20 Self-Check Questions 5-2 ....................................................................................................... 5-22 CHEMICAL PROCESS: DRY OR DIRECT CONVERSION OR INTEGRATED DRY ROUTE (IDR) PROCESS ..................................................................................................................................... 5-24 Vaporization ........................................................................................................................... 5-26 Hydrolysis ............................................................................................................................... 5-26 Defluorination/Calcination .................................................................................................... 5-26 Self-Check Questions 5-3 ....................................................................................................... 5-29 CERAMIC PROCESS: PELLET PRODUCTION ................................................................................ 5-31 PRETREATMENT STEPS............................................................................................................... 5-32 Conversion of Enriched UO2 Powder to Pellets ..................................................................... 5-32 Hammer Milling ..................................................................................................................... 5-32 Blending ................................................................................................................................. 5-33 Direct Conversion (DC) ........................................................................................................... 5-35 PELLET PRODUCTION STEPS ....................................................................................................... 5-35 Pelletizing ............................................................................................................................... 5-35 Sintering ................................................................................................................................. 5-36 Grinding .................................................................................................................................. 5-36 Washing, Drying, and Inspection of Pellets ........................................................................... 5-38 BURNABLE POISONS .................................................................................................................. 5-38 Self-Check Questions 5-4 ....................................................................................................... 5-39 MECHANICAL PROCESS: LOADING OF UO2 PELLETS INTO RODS/ASSEMBLIES ......................... 5-41 Cleaning/Inspection of Tubing ............................................................................................... 5-42 Lower End-Plug Welding ........................................................................................................ 5-42 Pellet Loading ......................................................................................................................... 5-42 Upper End-Plug Welding ........................................................................................................ 5-42 Laser Drilling ........................................................................................................................... 5-43 Helium Charge ........................................................................................................................ 5-43 Final Weld .............................................................................................................................. 5-43 USNRC Technical Training Center 3/10 Rev 4 i Fuel Cycle Processes Directed Self-Study Course MODULE 5.0: FUEL FABRICATION Helium Testing ....................................................................................................................... 5-43 Inspection ............................................................................................................................... 5-44 Fuel Assembly ........................................................................................................................ 5-44 Inspection/Storage ................................................................................................................. 5-55 Loading of Shipping Container ............................................................................................... 5-55 Self-Check Questions 5-5 ....................................................................................................... 5-56 SCRAP RECOVERY ....................................................................................................................... 5-58 Head End Treatment—Dry/Calcine ....................................................................................... 5-61 Acid Dissolution ..................................................................................................................... 5-61 Filtration ................................................................................................................................. 5-62 Solvent Extraction .................................................................................................................. 5-62 Uranium Concentration ......................................................................................................... 5-63 Return of Uranium to Powder Production ............................................................................ 5-63 Self-Check Questions 5-6 ....................................................................................................... 5-64 ACCIDENTS ................................................................................................................................