Moly-99 Work Group Meeting

1. Moly-99 Work Group Meeting • February 14, 2011 Molybdenum-99 Thermal/Mechanical/Hydraulic Experimental Tools Update • P. F. Makarewicz1 1University of Missouri, Department of Mechanical and Aerospace Engineering, Lafferre Hall, Columbia, MO, 65211

2. Problems and Resolutions • Heater Assembly • Current Measurement • Test Section Vibration

3. Heater Assembly • A heater that had been assembled at Y-12 this summer was recently sent to the University of Missouri for testing • Before testing, a problem was discovered with the heater; an electrical short was occurring between the Nichrome resistance heater and the Aluminum cladding • It was found that build-up on the edges of the resistance heater had occurred during the milling process. This build-up was cutting through the Kapton tape and causing the short.

4. Heater Assembly Aluminum Cladding Nichrome build-up from milling process Contact! Nichrome Kapton Aluminum Cladding

5. Heater Assembly • The heater was disassembled and time was spent to grind away at the build-up to create a smooth surface that would not penetrate through the Kapton tape. • The heater was then reassembled and work began in January towards testing • Additionally, strain gauges were added to the cladding of the target as previously discussed

6. Heater Assembly Flat Plate Strain Gage Laser Displacement Sensor Strain gauge configuration as discussed at the ANS Conference. Strain gauge configuration in physical application.

7. Heater Assembly • Initial testing began in January but issues were noticed right away • The power measurements were reading much higher than expected • After further testing, it was discovered a small short with a very high resistance exists somewhere within the target that is skewing the data • The target will need to be disassembled • A more precise procedure for target production has been created from these faults • Looking into possibly replacing Kapton tape with a Mica tape

8. Current Measurement • In order to calculate the power being produced by the resistance heater, one must know the current running through the heater • Current can be calculated from a known resistance and a voltage measurement • The NI module intended to measure the voltage for the current calculation does not have the necessary resolution • Exploration of a new method of measuring current is currently underway • A current clamp has been purchased and initial tests show it produces similar results to Keithley measurements but more fine tuning is needed

9. Test Section Vibrations • Water flow through the piping of the flow loop caused large vibrations across the unsupported test section • Keyence laser system, intended for deformation of surrogate target measurement, is very sensitive and will detect the vibrations through an unsupported test section • A truss support has been designed, built, and assembled at the University of Missouri to support the test section being used for the U-10Mo research. • The truss support has reduced vibrations and can be utilized to reduce vibrations in the Moly-99 test section as well.

10. Test Section Vibrations Truss Support System U-10Mo test section with truss support system

11. Test Section Vibrations Displacement due to vibration from U-10Mo test section during testing