Tobias J. Romero

The Accelerator Production of Tritium Materials Test Program

A materials qualification program has been developed to irradiate and test candidate materials (alloy 718, Type 316L, and Type 304L stainless steel, modified Fe9Cr-1Mo(T91), Al-6061-T6, and Al-5052-O) for use in the Accelerator Production of Tritium (APT) target and blanket. The irradiations were performed in prototypic proton and neutron spectra at prototypic temperatures (50 to 160°C). The study used the 800-MeV, 1.0-mA proton accelerator at the Los Alamos Neutron Science Center, which produces a Gaussian beam with 2 sigma = 3 cm. The experiment geometry is arranged to contain near-prototypic modules of the tungsten neutron source and the lead and aluminum blanket as well as mechanical test specimens of candidate APT materials. The particle spectrum varies throughout the irradiation volume; specimens are exposed to protons and a variety of mixed proton and neutron spectra, depending on the specimen’s position relative to the beam center. These specimens have been irradiated for >3600 h to a maximum proton fluence of 4 × 1021 p/cm2 in the center of the proton beam. Specimens will yield data on the effect of proton irradiation, to high dose, on material properties from tensile tests, three-point bend tests, fracture toughness tests, pressurized tubes, U-bend stress corrosion cracking specimens, corrosion measurements, and microstructural characterization using transmission electron microscopy specimens. Results from these studies are applicable to all spallation neutron sources now in operation and under consideration, including the Spallation Neutron Source, the European Spallation Source, and The Accelerator Transmutation of Waste project.

Testing of Neutron-Irradiated Ceramic-to-Metal Seals

This paper reports on ceramic-to-metal seals prepared by sputtering a titanium metallizing layer onto ceramic disks and then brazing to metal tubes. The ceramics used were alumina, MACOR, spinel, AlON, and a mixture of Al{sub 2}O{sub 3} and Si{sub 3}N{sub 4}. Except for the MACOR, which was brazed to a titanium tube, the ceramics were brazed to niobium tubes. The seals were leak tested and then sent to Los Alamos National Laboratory, where they were irradiated using the spallation neutron source at the Los Alamos Meson Physics Facility. Following irradiation for {approx} 90 days to a fluence of 2.8 {times} 10{sup 23} n/m{sup 2}, the samples were moved to hot cells and again leak tested. Only the MACOR samples showed any measurable leaks. One set of samples was then pressurized to 6.9 MPa (1000 psi) and subsequently leak tested. No leaks were found. Bursting the seals required hydrostatic pressures of at least 34 MPa (5000 psi). The high seal strength and few leaks indicate that ceramic-to-metal seals can resist radiation-induced degradation.

High Temperature Mechanical Properties, Fractography and Synchrotron Studies of ATF clad materials from the UCSB-NSUF Irradiations.

A variety of tensile samples of Ferritic and Oxide Dispersion Strengthened (ODS or nanostructured ferritic) steels were placed the ATR reactor over 2 years achieving doses of roughly 4-6 dpa at temperatures of roughly 290°C. Samples were shipped to Wing 9 in the CMR facility at Los Alamos National Laboratory and imaged then tested in tension. This report summarizes the room temperature tensile tests, the elevated temperature tensile tests (300°C) and fractography and reduction of area calculations on those samples. Additionally small samples were cut from the undeformed grip section of these tensile samples and sent to the NSLS synchrotron for high energy X-ray analysis, initial results will be described here.

UCSB ATR-­NSUF Irradiation DMC Sample Inspection Report

A variety of tensile samples of Ferritic and Oxide Dispersion Strengthened (ODS or nanoferritic) steels were placed the ATR reactor over 2 Years achieving doses of roughly 4-6 dpa at temperatures of roughly 290°C. After irradiation, samples were shipped from the MFC hot cells at Idaho National Laboratory (INL) to the Wing 9 hot cells in the CMR facility at Los Alamos National Laboratory. Samples were cleaned to removed alpha contamination from the MFC hot cells, and then, as needed removed from their irradiation containers, sorted and inspected. This report will summarize the inspection of the Disc Multipurpose Coupon (DMC) inspection from packet 7-1.

2012-13 Blue Room Low Enriched Uranium Sample Irradiation, Associated Gas Handling System, and Subsequent Separation Chemistry

Author(s): May, Iain; Anderson, Aaron S.; Bitteker, Leo J. Jr.; Connors, Michael A.; Copping, Roy; Cover, Matthew; Crooks, William J.; Dale, Gregory E.; Dalmas, Dale A.; Gallegos, Michael J.; Garcia, Eduardo; Gioia, Jack G.; Gonzales, Robert; Graves, Debra; Hollis, W. Kirk; Janicke, Michael T.; Kelsey, Charles T. IV; Mocko, Michal; Pieck, Martin; Rawool-Sullivan, Mohini; Reilly, Sean D.; Rios, Daniel; Romero, Tobias J.; Stephens, Francis H.; Taw, Felicia L.; Thorn, David L.; Woloshun, Keith A.