SPECIFIC ZIRCONIUM ALLOY DESIGN PROGRAM. First Quarterly Progress Report, February-June 1962

A program was initiated for the design of steam-service Zr base cladding alloy. Specifications were derived for an acceptable alloy for such service based on considerations of neutron economy, cost, H/sub 2/ embrittlement, corrosion resistance, fabricability, and strength. The selection of the field of alloy compositions having promise for meeting these specifications was made. Thirty-one alloys whose compositions were chosen from the alloy field were arcmelted and are being fabricated to sheet. Specimens cut from the sheet will be tested for response to composition. The response parameters will measure corrosion resistance at 300, 400, and 500 deg C, mechanical properties before and after corrosion exposure, and H/sub 2/ take-up during corrosion. The experiment is designed to permit analysis of the results employing computer programing to determine the optimum composition within the selected alloy field. Fundamental studies in support of the alloy design were also initiated. Film stripping techniques were developed to permit partitioning studies of alloying element between the corrosion film and the alloy substrate. Hydrogen overvoltage measurements were made for the intermetallic phases Zr/sub 2/Cu, Zr/sub 2/Ni, for Zr-90% Nb and for crystal bar Zr. The diffusion of O/sub 2/ in bulk nonstoichiometric ZrO/sub 2/ was measured: D = 0.055 exp (33,400 plus or minus 3,100/RT) for ZrO/sub 1.955/ at 700 to 1000 deg C. The activation energy is in agreement with that for parabolic corrosion of Zr alloys indicating that bulk O/ sub 2/ diffusion in the corrosion films and not short circuiting diffusion paths are rate controlling. Oxygen diffusion in alloy oxide-doped ZrO/sub 2/ is now being studied. (auth

Simulations for experimental study of warm dense matter and inertial fusion energy applications on NDCX-II

The Neutralized Drift Compression Experiment II (NDCX II) is an induction accelerator planned for initial commissioning in 2012. The final design calls for a {approx}3 MeV, {approx}30 A Li{sup +} ion beam, delivered in a bunch with characteristic pulse duration of 1 ns, and ransverse dimension of order 1 mm. The purpose of NDCX II is to carry out experimental studies of material in the warm dense matter regime, and ion beam/hydrodynamic coupling experiments relevant to heavy ion based inertial fusion energy. In preparation for this new machine, we have carried out hydrodynamic simulations of ion-beam-heated, metallic solid targets, connecting quantities related to observables, such as brightness temperature and expansion velocity at the critical frequency, with the simulated fluid density, temperature, and velocity. We examine how these quantities depend on two commonly used equations of state