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Title: Developing a laser shockwave model for characterizing diffusion bonded interfaces

Abstract

The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) with the goal of reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU in high-power research reactors. The new LEU fuel is a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to support the fuel qualification process, the Laser Shockwave Technique (LST) is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However, because the deposition of laser energy into the containment layer on a specimen's surface is intractably complex, the shock wave energy is inferred from the surface velocity measured on the backside of the fuel plate and the depth of the impression left on the surface by the high pressure plasma pulse created by the shock laser. To help quantify the stresses generated at the interfaces, a finite elementmore » method (FEM) model is being utilized. This paper will report on initial efforts to develop and validate the model by comparing numerical and experimental results for back surface velocities and front surface depressions in a single aluminum plate representative of the fuel cladding.« less

Authors:
; ;  [1]
  1. Idaho National Laboratory, Idaho Falls, ID (United States)
Publication Date:
OSTI Identifier:
22391206
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1650; Journal Issue: 1; Conference: 41. Annual Review of Progress in Quantitative Nondestructive Evaluation, Boise, ID (United States), 20-25 Jul 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; ALUMINIUM; CLADDING; COMPARATIVE EVALUATIONS; DIFFUSION; FINITE ELEMENT METHOD; FUEL PLATES; HIGHLY ENRICHED URANIUM; INTERFACES; LASER-PRODUCED PLASMA; MATHEMATICAL MODELS; MOLYBDENUM ALLOYS; NUCLEAR FUEL CONVERSION; SHOCK WAVES; SLIGHTLY ENRICHED URANIUM; SOUND WAVES; SPENT FUELS; SURFACES; URANIUM ALLOYS

Citation Formats

Lacy, Jeffrey M., E-mail: Jeffrey.Lacy@inl.gov, Smith, James A., E-mail: Jeffrey.Lacy@inl.gov, and Rabin, Barry H., E-mail: Jeffrey.Lacy@inl.gov. Developing a laser shockwave model for characterizing diffusion bonded interfaces. United States: N. p., 2015. Web. doi:10.1063/1.4914752.
Lacy, Jeffrey M., E-mail: Jeffrey.Lacy@inl.gov, Smith, James A., E-mail: Jeffrey.Lacy@inl.gov, & Rabin, Barry H., E-mail: Jeffrey.Lacy@inl.gov. Developing a laser shockwave model for characterizing diffusion bonded interfaces. United States. doi:10.1063/1.4914752.
Lacy, Jeffrey M., E-mail: Jeffrey.Lacy@inl.gov, Smith, James A., E-mail: Jeffrey.Lacy@inl.gov, and Rabin, Barry H., E-mail: Jeffrey.Lacy@inl.gov. Tue . "Developing a laser shockwave model for characterizing diffusion bonded interfaces". United States. doi:10.1063/1.4914752.
@article{osti_22391206,
title = {Developing a laser shockwave model for characterizing diffusion bonded interfaces},
author = {Lacy, Jeffrey M., E-mail: Jeffrey.Lacy@inl.gov and Smith, James A., E-mail: Jeffrey.Lacy@inl.gov and Rabin, Barry H., E-mail: Jeffrey.Lacy@inl.gov},
abstractNote = {The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) with the goal of reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU in high-power research reactors. The new LEU fuel is a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to support the fuel qualification process, the Laser Shockwave Technique (LST) is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However, because the deposition of laser energy into the containment layer on a specimen's surface is intractably complex, the shock wave energy is inferred from the surface velocity measured on the backside of the fuel plate and the depth of the impression left on the surface by the high pressure plasma pulse created by the shock laser. To help quantify the stresses generated at the interfaces, a finite element method (FEM) model is being utilized. This paper will report on initial efforts to develop and validate the model by comparing numerical and experimental results for back surface velocities and front surface depressions in a single aluminum plate representative of the fuel cladding.},
doi = {10.1063/1.4914752},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1650,
place = {United States},
year = {Tue Mar 31 00:00:00 EDT 2015},
month = {Tue Mar 31 00:00:00 EDT 2015}
}
  • 12. Other advances in QNDE and related topics: Preferred Session Laser-ultrasonics Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces 41st Annual Review of Progress in Quantitative Nondestructive Evaluation Conference QNDE Conference July 20-25, 2014 Boise Centre 850 West Front Street Boise, Idaho 83702 James A. Smith, Jeffrey M. Lacy, Barry H. Rabin, Idaho National Laboratory, Idaho Falls, ID ABSTRACT: The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) which is assigned with reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEUmore » to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU. The new LEU fuel is based on a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to complete the fuel qualification process, the laser shock technique is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. The Laser Shockwave Technique (LST) is being investigated to characterize interface strength in fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However the deposition of laser energy into the containment layer on specimen’s surface is intractably complex. The shock wave energy is inferred from the velocity on the backside and the depth of the impression left on the surface from the high pressure plasma pulse created by the shock laser. To help quantify the stresses and strengths at the interface, a finite element model is being developed and validated by comparing numerical and experimental results for back face velocities and front face depressions with experimental results. This paper will report on initial efforts to develop a finite element model for laser shock.« less
  • The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process.more » Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.« less
  • Microstructure development at solid-state diffusion-bonded Cu/[alpha]-Al[sub 2]O[sub 3] interfaces has been studied using optical and electron microscopy. High-purity Cu foil was bonded between basal-oriented [alpha]-Al[sub 2]O[sub 3] single-crystal plates at 1,040 C for 24 h in a vacuum of [approximately]1.3 [times] 10[sup [minus]4] Pa (1 [times] 10[sup [minus]6] torr). Optical microscopy of as-bonded specimens revealed a large Cu grain size, fine pores, and long needles of Cu[sub 2]O at the interface. Bulk specimens were annealed at 1,000 C for various times under controlled oxygen partial pressures in CO/CO[sub 2] mixtures. Consistent with a thermochemical analysis, CuAlO[sub 2] could be formedmore » at the interfaces. The CuAlO[sub 2] was acicular and discontinuous, but occurred in a uniform distribution over the bulk specimen interfaces.« less
  • The ability to join ceramics with and to metals is a limiting aspect of many plans for the future use of both structural and functional ceramics. The distinctive technologically interesting characteristics of ceramics such as hardness or refractoriness are due to the ionicity or covalency of their lattice structures which lack the delocalized electrons that bind together metals. Hence ceramic-metal interfaces can be energetically unfavorable regions of severe electronic discontinuity. Special interfacial chemistries are needed if continuity is to be achieved and high integrity interfaces produced, and this paper comments on important chemical effects during brazing and diffusion bonding.
  • A double laser pulse heating scheme has been applied to generate plasmas with enhanced emission in the extreme ultraviolet (EUV). The plasmas were produced by focusing two laser beams (prepulse and main pulse) with a small spatial separation between the foci on a xenon gas jet target. Prepulses with ps-duration were applied to obtain high shockwave densities, following indications of earlier published results obtained using ns prepulses. EUV intensities around 13.5 nm and in the range 5-20 nm were recorded, and a maximum increase in intensity exceeding 2 was measured at an optimal delay of 140 ns between prepulse andmore » main pulse. The gain in intensity is explained by the interaction of the shockwave produced by the prepulse with the xenon in the beam waist of the main pulse. Extensive simulation was done using the radiative magnetohydrodynamic code Z{sup *}.« less