The purpose of this task was to perform an Independent Validation Review to evaluate the successful implementation and effectiveness of Safety Basis controls, including new and revised controls, to support the implementation of a new DSA/TSR for B239. This task addresses Milestone 2 of FY10 PEP 7.6.6. As the first IVR ever conducted on a LLNL nuclear facility, it was designated a pilot project. The review follows the outline developed for Milestone 1 of the PEP, which is based on the DOE Draft Guide for Performance of Independent Verification Review of Safety Basis Controls. A formal Safety Basis procedure will be developed later, based on the lessons learned with this pilot project. Note, this review is termed a ''Validation'' in order to be consistent with the PEP definition and address issues historically raised about verification mechanisms at LLNL. Validation is intended to confirm that implementing mechanisms realistically establish the ability of TSR LCO, administrative control or safety management program to accomplish its intended safety function and that the controls are being implemented. This effort should not, however, be confused with a compliance assessment against all relevant DOE requirements and national standards. Nor is it used as a vehicle to question …

This paper extends studies of ion beam transport through a background plasma along a solenoidal magnetic field [I. Kaganovich et al., Phys. Plasmas 15, 103108 (2008)] to the important regime of moderate magnetic field strength satisfying ωce > 2βbωpe . Here, ωce and ω pe are the electron cyclotron frequency and electron plasma frequency, respectively, and βb = vb/ c is the directed ion beam velocity normalized to the speed of light. The electromagnetic field perturbations excited by the ion beam pulse in this regime are calculated analytically, and verified by comparison with the numerical simulations. The degrees of beam charge neutralization and current neutralization are estimated, and the transverse component of the Lorentz force associated with the excited electromagnetic field is calculated. It is found that the plasma response to the ion beam pulse is significantly different depending on whether the value of the solenoidal magnetic field is below or above the threshold value specified by ω cr ce = 2βbωpe, and corresponding to the resonant excitation of large-amplitude whistler waves. The use of intense whistler wave excitations for diagnostic purposes is also discussed.

Savannah River Remediation (SRR) is preparing Tank 6F for closure. The first step in preparing the tank for closure is mechanical sludge removal. In mechanical sludge removal, personnel add liquid (e.g., inhibited water or supernate salt solution) to the tank to form a slurry. They mix the liquid and sludge with pumps, and transfer the slurry to another tank for further processing. Mechanical sludge removal effectively removes the bulk of the sludge from a tank, but is not able to remove all of the sludge. In Tank 6F, SRR estimated a sludge heel of 5,984 gallons remained after mechanical sludge removal. To remove this sludge heel, SRR performed chemical cleaning. The chemical cleaning included two oxalic acid strikes, a spray wash, and a water wash. SRR conducted the first oxalic acid strike as follows. Personnel added 110,830 gallons of 8 wt % oxalic acid to Tank 6F and mixed the contents of Tank 6F with two submersible mixer pumps (SMPs) for approximately four days. Following the mixing, they transferred 115,903 gallons of Tank 6F material to Tank 7F. The SMPs were operating when the transfer started and were shut down approximately five hours after the transfer started. SRR collected a …

Li(Ni{sub 0.4}Co{sub 0.2-y}Al{sub y}Mn{sub 0.4})O{sub 2} with y=0.05 was investigated to understand the effect of replacement of the cobalt by aluminum on the structural and electrochemical properties. The effect of the substitution was studied by in-situ X-ray absorption spectroscopy (XAS), utilizing a novel in situ electrochemical cell, specifically designed for long-term X-ray experiments. The cell was cycled at a moderate rate through a typical Li-ion battery operating voltage range (1.0-4.7 V). XAS measurements were performed at different states-of-charge (SOC) during cycling, at the Ni, Co, and the Mn edges, revealing details about the response of the cathode to Li insertion and extraction processes. The extended X-ray absorption fine structure region of the spectra revealed the changes of bond distance and coordination number of Ni, Co, and Mn absorbers as a function of the SOC of the material. The oxidation states of the transition metals in the system are Ni{sup 2+}, Co{sup 3+}, and Mn{sup 4+} in the as-made material (fully discharged), while during charging the Ni{sup 2+} is oxidized to Ni{sup 4+} through an intermediate stage of Ni{sup 3+}, Co{sup 3+} is oxidized towards Co{sup 4+} and Mn was found to be electrochemically inactive and remains as Mn{sup 4+}. The …

Pyrophoric reagents represent an important class of reactants because they can participate in many different types of reactions. They are very useful in organic synthesis and in industrial applications. The Occupational Safety and Health Administration (OSHA) and the National Fire Protection Association (NFPA) define Pyrophorics as substances that will self-ignite in air at temperatures of 130 F (54.4 C) or less. However, the U.S. Department of Transportation (DOT) uses criteria different from the auto-ignition temperature criterion. The DOT defines a pyrophoric material as a liquid or solid that, even in small quantities and without an external ignition source, can ignite within five minutes after coming in contact with air when tested according to the United Nations Manual of Tests and Criteria. The Environmental Protection Agency has adopted the DOT definition. Regardless of which definition is used, oxidation of the pyrophoric reagents by oxygen or exothermic reactions with moisture in the air (resulting in the generation of a flammable gas such as hydrogen) is so rapid that ignition occurs spontaneously. Due to the inherent nature of pyrophoric substances to ignite spontaneously upon exposure to air, special precautions must be taken to ensure their safe handling and use. Pyrophoric gases (such as …

The purpose of the ASME/DOE Gen IV Task 7 Part I is to review the current experience on various high temperature reactor intermediate heat exchanger (IHX) concepts. There are several different IHX concepts that could be envisioned for HTR/VHTR applications in a range of temperature from 850C to 950C. The concepts that will be primarily discussed herein are: (1) Tubular Helical Coil Heat Exchanger (THCHE); (2) Plate-Stamped Heat Exchanger (PSHE); (3) Plate-Fin Heat Exchanger (PFHE); and (4) Plate-Machined Heat Exchanger (PMHE). The primary coolant of the NGNP is potentially subject to radioactive contamination by the core as well as contamination from the secondary loop fluid. To isolate the radioactivity to minimize radiation doses to personnel, and protect the primary circuit from contamination, intermediate heat exchangers (IHXs) have been proposed as a means for separating the primary circuit of the NGNP (Next Generation Nuclear Plant) or other process heat application from the remainder of the plant. This task will first review the different concepts of IHX that could be envisioned for HTR/VHTR applications in a range of temperature from 850 to 950 C. This will cover shell-and-tube and compact designs (including the platefin concept). The review will then discuss the maturity …

The proper representation of particulate phenomena is important for the simulation of many non-ideal particle loaded explosives. These explosives present severe numerical difficulties to simulate because numerical approaches for packed particle beds often behave poorly for the dilute regime and the reverse is often true for methods developed for the dilute regime. This paper presents a multiphase framework for the simulation of these non-ideal explosives that accurately accounts for the particulate behavior in both of these regimes. The capability of this framework is enhanced by the use of prescribed PDF methods for both particle size distributions and the representation of chemical processes. We have validated this framework using several experimental methods that accommodate the separation of momentum flux measurements in two-phase blast flows.

Extending spatial resolution in laser-based chemical analysis to the nanoscale becomes increasingly important as nanoscience and nanotechnology develop. Implementation of femtosecond laser pulses arises as a basic strategy for increasing resolution since it is associated with spatially localized material damage. In this work we study femtosecond laser far- and near-field processing of silicon (Si) at two distinct wavelengths (400 and 800 nm), for nanoscale chemical analysis. By tightly focusing femtosecond laser beams in the far-field we were able to produce sub-micrometer craters. In order to further reduce the crater size, similar experiments were performed in the near-field through sub-wavelength apertures, resulting to the formation of sub-30 nm craters. Laser Induced Breakdown Spectroscopy (LIBS) was used for chemical analysis with a goal to identify the minimum crater size from which spectral emission could be measured. Emission from sub-micrometer craters (full-with-at-half-maximum) was possible, which are among the smallest ever reported for femtosecond LIBS.