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[en] Under this Annex, a research program on the near-field performance assessment related to the geological disposal of radioactive waste will be carried out at the Lawrence Livermore National Laboratory (LLNL) in close collaboration with the Power Reactor and Nuclear Fuel Development Corporation of Japan (PNC). This program will focus on activities that provide direct support for PNC's near-term and long-term needs that will, in turn, utilize and further strengthen US capabilities for radioactive waste management. The work scope for two years will be designed based on the PNC's priorities for its second progress report (the H12 report) of research and development for high-level radioactive waste disposal and on the interest and capabilities of the LLNL. The work will focus on the chemical modeling for the near-field environment and long-term mechanical modeling of engineered barrier system as it evolves. Certain activities in this program will provide for a final iteration of analyses to provide additional technical basis prior to the year 2000 as determined in discussions with the PNC's technical coordinator. The work for two years will include the following activities: Activity 1: Chemical Modeling of EBS Materials Interactions--Task 1.1 Chemical Modeling of Iron Effects on Borosilicate Glass Durability; and Task 1.2 Changes in Overpack and Bentonite Properties Due to Metal, Bentonite and Water Interactions. Activity 2: Thermodynamic Database Validation and Comparison--Task 2.1 Set up EQ3/6 to Run with the Pitzer-based PNC Thermodynamic Data Base; Task 2.2 Provide Expert Consultation on the Thermodynamic Data Base; and Task 2.3 Provide Analysis of Likely Solubility Controls on Selenium. Activity 3: Engineered Barrier Performance Assessment of the Unsaturated, Oxidizing Transient--Task 3.1 Apply YMIM to PNC Transient EBS Performance; Task 3.2 Demonstrate Methods for Modeling the Return to Reducing Conditions; and Task 3.3 Evaluate the Potential for Stress Corrosion Cracking in PNC Waste Packages. Activity 4: Coupled Displacement and Degradation Analysis of Carbon Steel Overpack Embedded in Bentonite--Task 4.1 Demonstration of NIKE-2D/ALE-3D Mesh Adaptation Capability; Task 4.2 Demonstration of NIKE-2D/ALE-3D Code Capability to Compute Realistic Repository Problems; Task 4.3 Implementation and Verification of the Cam Clay Model in NIKE-2D/ALE-3D Code; and Task 4.4 Estimation of the Timing and Spatial Distribution of Rewetting

[en] In Nd:glass laser systems used for inertial confinement fusion experiments, such as the Nova laser at Lawrence Livermore National Laboratory, the amplifiers use hundreds to thousands of flashlamps. It is critical that flashlamp explosion rates be low, since explosions can disrupt operation of the system and cause extensive damage to amplifier components. The authors have modeled dynamic stresses in the envelopes of pulsed xenon flashlamps, treating stresses produced by three different sources: the heating of the envelope by the plasma; the pressure rise of the xenon gas; and magnetic forces, due to currents flowing in nearby lamps. The heat-induced stresses were calculated by the finite element method, using uniform heating rates for the inside surface of the envelope that were inferred from flashlamp radiant efficiency measurements. Pressure-induced stresses were calculated analytically, using empirical relationships for temperature and pressure in terms of current density. Magnetically-induced stresses were also calculated analytically, for flashlamps packed parallel to each other in linear arrays