scholarly journals Interface Characterization within a Nuclear Fuel Plate

2019 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
James Smith ◽  
Clark Scott ◽  
Brad Benefiel ◽  
Barry Rabin
Keyword(s):  
High Spatial Resolution ◽  
National Laboratory ◽  
Laser Shock ◽  
High Radiation ◽  
System A ◽  
Digital Instrumentation ◽  
Laser Sensing ◽  
Failure Loads ◽  
Shock System ◽  
Irradiated Fuel

To predict the performance of nuclear fuels and materials, irradiated fuel plates must be characterized efficiently and accurately in highly radioactive environments. The characterization must take place remotely and work in settings largely inhospitable to modern digital instrumentation. Characterization techniques based on non-contacting laser sensing methods enable remote operation in a robust manner within a hot-cell environment. Laser characterization instrumentation can offer high spatial resolution and remain effective for scanning large areas. A laser shock (LS) system is currently being developed as a post-irradiation examination (PIE) technique in the hot fuel examination facility (HFEF) at the Idaho National Laboratory (INL). The laser shock technique will characterize material properties and failure loads/mechanisms in various composite components and materials such as plate fuel and next-generation fuel forms in high radiation areas. The laser shock-technique induces large amplitude shock waves to mechanically characterize interfaces such as the fuel–clad bond. As part of the laser shock system, a laser-based ultrasonic C-scan system will be used to detect and characterize debonding caused by the application of the laser shock. The laser shock system has been used to characterize the resulting bond strength within plate fuels which have been fabricated using different fabrication processes. The results of this study will be to select the fabrication process that provides the strongest interface.

RCS Depressurization and Loss of Flow No Trip 3D Neutronic Transient Analyses

2008 ◽  
Author(s):  
Cenk Gu¨ler ◽  
Daniel H. Risher
Keyword(s):  
Nucleate Boiling ◽  
System A ◽  
Digital Instrumentation ◽  
Complete Failure ◽  
Core Height ◽  
Operator Action ◽  
Analog Systems ◽  
Digital Protection ◽  
And Control ◽  
Point Kinetics

To be able to correctly analyze an RCS Depressurization or Loss of Flow accident with no reactor trip, the Westinghouse 3D Transient Neutronics tool RAVE™ was used. Plants which utilize all-digital Instrumentation and Control (I&C) systems may be required to consider a complete failure of the digital protection system. A backup analog system is provided in the event of a failure of the digital system; however the backup analog systems do not carry all safety trip signals. Therefore, it is postulated that the plant might experience an accident event in which no immediate trip signal is generated and protection would rely on operator action. To allow adequate time for the operator to recognize the malfunction and take action to manually trip the plant, it is assumed that operator action will not occur for ten minutes from the initiation of the transient. These kinds of transients may be analyzed with point kinetic transient codes; however, due to the lack of 3D neutronic feedback with a core height dependent moderator temperature coefficient and its effect on the axial and radial power distributions, it may not be possible to show that Departure from Nucleate Boiling (DNB) does not occur. Using 3D Neutronic transient analyses methods (RAVE™), it was shown that neither of these transients (RCS Depressurization or Loss of Flow) would generate DNB violations, even though the point kinetics version is showing the opposite.

The BNL STEM Facility

1997 ◽  
Vol 3 (S2) ◽  
pp. 277-278
Author(s):  
Joseph S. Wall ◽  
Martha N. Simon ◽  
James F. Hainfeld
Keyword(s):  
National Laboratory ◽  
Computer Control ◽  
Large Angle ◽  
Brookhaven National Laboratory ◽  
Dark Field ◽  
Vacuum System ◽  
Vacuum Chambers ◽  
System A ◽  
Freeze Dried ◽  
Individual Particles

The STEM facility at Brookhaven National Laboratory has been in operation since Oct. ‘77, using a custom-built instrument (STEM1) with cold field emission source, 2.5Å probe, -150°C cold stage, efficient dark field detectors and computer control & data acquisition system. A specimen changing air lock and several portable vacuum chambers permit vacuum transfer of specimens from a separate vacuum system where they were freeze dried overnight.The large angle dark-field signal produced by the STEM is directly proportional to the total mass within the probed area. STEM mass mapping is based on this linear relationship and the fact that only specimen-specific atoms remain on the substrate after washing with volatile buffer and freeze drying. All images are digital and available via Internet. PC software can be provided for analysis.STEM mass accuracy ranges from a fraction of a percent on well-defined individual particles such as viruses in the 50 MDa to 10 GDa range, to ∼1% around 1 MDa and ∼10% in the 50 kDa range.

scholarly journals A Solution-Based Approach for Mo-99 Production: Considerations for Nitrate versus Sulfate Media

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Amanda J. Youker ◽  
Sergey D. Chemerisov ◽  
Michael Kalensky ◽  
Peter Tkac ◽  
Delbert L. Bowers ◽  
...  
Keyword(s):  
Uranyl Nitrate ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Fission Products ◽  
Sulfate Solution ◽  
Medical Community ◽  
High Radiation ◽  
Uranyl Sulfate ◽  
Sulfate Solutions ◽  
Nitrate Solutions

Molybdenum-99 is the parent of Technetium-99m, which is used in nearly 80% of all nuclear medicine procedures. The medical community has been plagued by Mo-99 shortages due to aging reactors, such as the NRU (National Research Universal) reactor in Canada. There are currently no US producers of Mo-99, and NRU is scheduled for shutdown in 2016, which means that another Mo-99 shortage is imminent unless a potential domestic Mo-99 producer fills the void. Argonne National Laboratory is assisting two potential domestic suppliers of Mo-99 by examining the effects of a uranyl nitrate versus a uranyl sulfate target solution configuration on Mo-99 production. Uranyl nitrate solutions are easier to prepare and do not generate detectable amounts of peroxide upon irradiation, but a high radiation field can lead to a large increase in pH, which can lead to the precipitation of fission products and uranyl hydroxides. Uranyl sulfate solutions are more difficult to prepare, and enough peroxide is generated during irradiation to cause precipitation of uranyl peroxide, but this can be prevented by adding a catalyst to the solution. A titania sorbent can be used to recover Mo-99 from a highly concentrated uranyl nitrate or uranyl sulfate solution; however, different approaches must be taken to prevent precipitation during Mo-99 production.

Microscale Laser Shock Peening of Thin Films, Part 2: High Spatial Resolution Material Characterization

2004 ◽  
Vol 126 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Wenwu Zhang ◽  
Y. Lawrence Yao ◽  
I. C. Noyan
Keyword(s):  
Thin Films ◽  
Spatial Resolution ◽  
Strain Field ◽  
High Spatial Resolution ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Stress Strain ◽  
Crystal Silicon ◽  
X Ray ◽  
Shock Peening

Microscale Laser Shock Peening (LSP) is a technique that can be potentially applied to manipulate the residual stress distributions in metal film structures and thus improve the reliability of micro-devices. This paper reports high-spatial-resolution characterization of shock treated copper thin films on single-crystal silicon substrates, where scanning x-ray microtopography is used to map the relative variation of the stress/strain field with micron spatial resolution, and instrumented nanoindentation is applied to measure the distribution of hardness and deduce the sign of the stress/strain field. The measurement results are also compared with 3-D simulation results. The general trends in simulations agree with those from experimental measurements. Simulations and experiments show that there is a near linear correlation between strain energy density at the film-substrate interface and the X-ray diffraction intensity contrast.

scholarly journals Uganda's New National Laboratory Sample Transport System: A Successful Model for Improving Access to Diagnostic Services for Early Infant HIV Diagnosis and Other Programs

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e78609 ◽  
Author(s):  
Charles Kiyaga ◽  
Hakim Sendagire ◽  
Eleanor Joseph ◽  
Ian McConnell ◽  
Jeff Grosz ◽  
...  
Keyword(s):  
Transport System ◽  
National Laboratory ◽  
Laboratory Sample ◽  
Hiv Diagnosis ◽  
Successful Model ◽  
System A ◽  
Early Infant
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