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.
1
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
Assembly Process Analysis
Outer Tube
α
Deformation
Zone
Inner
Tube
Do
Df
Punch
Drawing Force
•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.
Mechanical and Aerospace Engineering
UNIVERSITY OF MISSOURI-COLUMBIA
Dr. Sherif El-Gizawy, July 11, 2011
3
σz
σh
Fz
σr
Draw Stress, sdr = sfmQdr = sfm .Qfr. 
Where Qfr = (1+mcota)
 = ln(Ao/A1)
h
  0.88  0.12
L
Drawing Force, Fdr = sdr* A
Power, P  F *
Torque,  P / 
Mechanical and Aerospace Engineering
UNIVERSITY OF MISSOURI-COLUMBIA
Dr. Sherif El-Gizawy, July 11, 2011
4
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
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.
Inner Tube
Outer
Tube
Drawing Die
Plug
Outer Tube
Drawing Die Set
Uranium
Foil
Nickel
Foil
Inner
Tube
LEU Foil inside the Nickel Envelop
Typical Floating Conical Plug Design
FEM Simulation Results for Target
Drawing Using Floating Conical Plug
Design
7
System Overview
Cylinder
Punch
Linear Guide Bearing
Push Rod
Hydraulic Ram
Hydraulic Pump
Quality Control Gauge
Swaging Process Cut Away
Swaging Process Cut Away
RAM Force
Removal
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): 1Integrity of the Target
(visual) , 2-Thermal
Contact Resistance, 3Forming Pressure, 4- Gap
Size at the Contact with
Target Walls (SEM
measurements of
sectioned targets).
Factors
Punch Angle
Experiment Punch Diam.
alpha
relief thickness (t) per side
1
1
1
1
2
1
2
2
3
1
3
3
4
2
1
2
5
2
2
3
6
2
3
1
7
3
1
3
8
3
2
1
9
3
3
2
Target Material
1
2
3
3
1
2
2
3
3
Outer
Aluminu
m Tube
Inner
Aluminum
Tube
Foil Materials Aliened
inside
The Relief area
B
A
A- Significant Voids Exist
(Unsuccessful) Case
B- Zero Gap Case
Intimate Contact Evaluated by SEM for Gap Observation
Mechanical and Aerospace Engineering
UNIVERSITY OF MISSOURI-COLUMBIA
Dr. Sherif El-Gizawy, July, 11, 2011
14
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
Y   0  1 x1   2 x2  11 x1   22 x2  12 x1 x2  
2
2
Fitted Surface; Variable: TORQUE
TORQUE in Titanium (lb.ft)
Example of Typical Results
0.267
0.284
0.301
0.319
0.336
0.353
0.371
0.388
0.405
0.423
above
z=-3.086263241604+.010844907560897*x-.0000078517515508477*x^2
+605.22238525195*y+98596.285487694*y^2-1.46482990521*x*y+0.
Fitted 3-D surface and equation of the Torque, (lb.ft), in Titanium
Fitted Surface; Variable: TORQUE
TORQUE in Titanium (lb.ft)
0.0016
0.0015
0.0014
0.267
0.284
0.301
0.319
0.336
0.353
0.371
0.388
0.405
0.423
above
FEED (ipr)
0.0013
0.0012
0.0011
0.0010
0.0009
0.0008
460
480
500
520
540
560
580
600
620
640
SPEED (rpm)
Process contour maps of torque, (lb.ft), during drilling Titanium
Future Work by the Production Process Design Group
Mechanical and Aerospace Engineering
UNIVERSITY OF MISSOURI-COLUMBIA
Dr. Sherif El-Gizawy, July, 11, 2011
19
Sealing Ends of the Annular Targets
TIG
EB
Forming
20
Target Disassembly Device
SEVEN Degrees of Freedom
Robotic Arm for Handling
Targets inside Hot Cell