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Large Scale Production of Mo-99 Production Process Design Group Sherif El-Gizawy, Brian Graybill, James Berlin, Emily Ferner, Annemarie Hoyer. Project Objectives.
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Large Scale Production of Mo-99 Production Process Design Group Sherif El-Gizawy, Brian Graybill, James Berlin, Emily Ferner, Annemarie Hoyer Project Objectives Development of Robust Technology and Designs for Handling LEU-Foil Annular Targets for Production of Mo-99 that shall Fulfil the following Requirements and Constraints: 1- Flexibility, in order to accommodate different target geometries, materials, and production volumes with minimum efforts and cost. 2- Affordability, for USA domestic production as well as for other countries. 3- Safety and Quality Assurance, for meeting rules and regulation. 4- Productivity, for meeting USA domestic needs for fission product Mo-99. 5- Training US Young Engineers and Scientists for developing effective nuclear technology for energy and biomedical applications of the future.
Design Analysis is Required as Part of “Safety Case” Documentation to Demonstrate Target’s Structural Integrity during Target Assembly The Followings are the Required Design Tasks • Develop model and perform Detailed Finite Element Analysis of an assembled LEU-foil target. • The model will include the target’s drawing process of all foils and the Aluminum tubes. • Experimental testing and Measurements to verify the developed models, (residual stresses, microstructure, surface roughness, waviness, and contact profile). • This design analysis is parametric and applicable to any target design and can be used to determine inner tube minimum wall thickness that will withstand the maximum predicted operating pressure in order to assure “zero” target structural failures during irradiation
Outer Tube Inner Tube Deformation Zone α Punch Df Do Drawing Force Assembly Process Analysis • Process design to allow for deformation zone that covers the entire inner tube thickness. • Force is applied through the punch. Deformation of the wall of the inner tube is • caused by Compressive stresses along axial, radial and hoop directions.
Fz σz σh σr Draw Stress,sdr = sfmQdr = sfm .Qfr . Where Qfr = (1+mcota) = ln(Ao/A1) Drawing Force, Fdr = sdr* A
Finite Element Analysis • Modeling of the target assembly is completed using the FEM ANSYS structural package. These analyses serve three major purposes: • 1) Determine the force necessary to plastically deform the inner tube against the outer tube, resulting in a bond that will be maintained throughout irradiation. • 2) Determine the residual stresses in the assembled target after assembly. It is critical that the tensile stress in the outer tube is maintained so that it will “spring open” when cut, resulting in easy removal of the inner tube and irradiated target. • 3) The development of a parametric model provides a platform for faster analysis for the investigation of target shapes/dimensions that vary from the Indonesian target
Inner Tube Drawing Die Outer Tube Plug Drawing Die Set Outer Tube Uranium Foil Nickel Foil Inner Tube Finite Element Models • The Workbench layout of ANSYS allows for easy alteration of the original model, allowing for several geometries to be investigated without significant input from the user. • Once a dimension has been changed upstream, the rest of the model simply needs to be refreshed and/or updated to achieve the new results. LEU Foil inside the Nickel Envelop
Typical Floating Conical Plug Design FEM Simulation Results for Target Drawing Using Floating Conical Plug Design
System Overview Cylinder Punch Linear Guide Bearing Push Rod Hydraulic Ram Hydraulic Pump Quality Control Gauge
Swaging Process Cut Away RAM Force
Swaging Process Cut Away RAM Force
Parametric Analysis of Annular Target/ Assembly Process Design Using Design of Industrial Experiments
Partial Factorial • Basic matrix setup • Partial factorial setup allows for fewer initial experiments • The initial setup will serve to direct a more focused, comprehensive experimental array • Quality Characteristics (Responses , Y): 1- Integrity of the Target (visual) , 2-Thermal Contact Resistance, 3- Forming Pressure, 4- Gap Size at the Contact with Target Walls (SEM measurements of sectioned targets).
Outer Aluminum Tube Inner Aluminum Tube Foil Materials Aliened inside The Relief area B A A- Significant Voids Exist B- Zero Gap Case (Unsuccessful) Case Intimate Contact Evaluated by SEM for Gap Observation
Work for the next 3 months • Complete the partial factorial • Determine which variables are most sensitive to change • Use results to develop and execute a comprehensive response-surface type experimental array, explore and characterize variable interactions (Phase II) • These results will produce a single predictive equation to determine desired outputs from the input variables shown here
Design of Experiment (Phase II) • Response Surface Method (RSM) • Two Parameter central composite design. • Parameters:Relief Size(x1), Punch Diameter(x2). • Responses (Y):1-Thermal Contact Resistance, 2-Fraction Volume of Voids or Gab at the Contact with Target Walls, • 3- Forming Pressure. Second Order Response surface models
Example of Typical Results Fitted 3-D surface and equation of the Torque, (lb.ft), in Titanium
Process contour maps of torque, (lb.ft), during drilling Titanium
TIG EB Forming Sealing Ends of the Annular Targets
SEVEN Degrees of Freedom Robotic Arm for Handling Targets inside Hot Cell