The Department of Energy (DOE) has developed a design concept for a set of standard canisters for the handling, interim storage, transportation, and disposal in the national repository, of DOE spent nuclear fuel (SNF). The standardized DOE SNF canister has to be capable of handling virtually all of the DOE SNF in a variety of potential storage and transportation systems. It must also be acceptable to the repository, based on current and anticipated future requirements. This expected usage mandates a robust design. The canister design has four unique geometries, with lengths of approximately 10 feet or 15 feet, and an outside nominal diameter of 18 inches or 24 inches. The canister has been developed to withstand a drop from 30 feet onto a rigid (flat) surface, sustaining only minor damage - but no rupture - to the pressure (containment) boundary. The majority of the end drop-induced damage is confined to the skirt and lifting/stiffening ring components, which can be removed if de sired after an accidental drop. A canister, with its skirt and stiffening ring removed after an accidental drop, can continue to be used in service with appropriate operational steps being taken. Features of the design concept have been …

A program is being carried out for the US Nuclear Regulatory Commission (NRC) by the Idaho National Engineering and Environmental Laboratory (INEEL), to conduct an independent risk assessment of the consequences of failures initiated by intergranular stress corrosion cracking (IGSCC) of the reactor vessel internals of boiling water reactor (BWR) plants. The overall project objective is to assess the potential consequences and risks associated with the failure of IGSCC-susceptible BWR vessel internals, both singly and in combination with the failures of others, with specific consideration given to potential cascading and common mode effects on system performance. This paper presents a description of the overall program that is underway to modify an existing probabilistic risk assessment (PRA) of the BWR/4 plant to include IGSCC-initiated failures, subsequently to complete a quantitative PRA.

BWR core shrouds and other reactor internals important to safety are experiencing intergranular stress corrosion cracking (IGSCC). The United States Nuclear Regulatory Commission (NRC) has followed the problem, and as part of its investigations, contracted with the Idaho National Engineering and Environmental Laboratory (INEEL) to conduct a risk assessment. The overall project objective is to assess the potential consequences and risks associated with the failure of IGSCC-susceptible BWR vessel internals, with specific consideration given to potential cascading and common mode effects. The paper presents an overview of the program, discusses the results of a preliminary qualitative assessment, and summarizes a simplified risk assessment that was conducted on sequences resulting from failures of jet pump components of a BWR/4 plant.

One method of increasing automotive energy efficiency is through mass reduction of structural components by the incorporation of composite materials. Significant use of glass reinforced polymers as structural components could yield a 20--30% reduction in vehicle weight while the use of carbon fiber reinforced materials could yield a 40--60% reduction in mass. Specific areas of research for lightweighting automotive components are listed, along with research needs for each of these categories: (1) low mass metals; (2) polymer composites; and (3) ceramic materials.

This paper presents a viscoplasticity model taking into account the effects of change in grain or phase size and damage on the characterization of creep damage in 60Sn-40Pb solder. Based on the theory of damage mechanics, a two-scalar damage model is developed for isotropic materials by introducing the free energy equivalence principle. The damage evolution equations are derived in terms of the damage energy release rates. In addition, a failure criterion is developed based on the postulation that a material element is said to have ruptured when the total damage accumulated in the element reaches a critical value. The damage coupled viscoplasticity model is discretized and coded in a general-purpose finite element program known as ABAQUS through its user-defined material subroutine UMAT. To illustrate the application of the model, several example cases are introduced to analyze, both numerically and experimentally, the tensile creep behaviors of the material at three stress levels. The model is then applied to predict the deformation of a notched specimen under monotonic tension at room temperature (22 C). The results demonstrate that the proposed model can successfully predict the viscoplastic behavior of the solder material.

We describe a very-low power consumption circuit for processing the pulses from a semiconductor radiation detector. The circuit was designed for use with a cadmium zinc telluride (CZT) detector for unattended monitoring of stored nuclear materials. The device is intended to be battery powered and operate at low duty-cycles over a long period of time. This system will provide adequate performance for medium resolution gamma-ray pulse-height spectroscopy applications. The circuit incorporates the functions of a charge sensitive preamplifier, shaping amplifier, and peak sample and hold circuit. An application specific integrated circuit (ASIC) version of the design has been designed, built and tested. With the exception of the input field effect transistor (FET), the circuit is constructed using bipolar components. In this paper the design philosophy and measured performance characteristics of the circuit are described.

Z-cut lithium tantalate (LiTaO{sub 3}) ferroelectric single crystals were irradiated with 200 keV Ar{sup ++} ions. LiTaO{sub 3} possesses a structure that is a derivative of the corundum (Al{sub 2}O{sub 3}) crystal structure. A systematic study of the radiation damage accumulation rate as a function of ion dose was performed using ion-beam channeling experiments. An ion fluence of 2.5 x 10{sup 18} Ar{sup 2+} ions/m{sup 2} was sufficient to amorphize the irradiated volume of a LiTaO{sub 3} crystal at an irradiation temperature of approximately 120K. This represents a rather exceptional susceptibility to ion-induced amorphization, which may be related to a highly disparate rate of knock-on of constituent lattice ions, due to the large mass difference between the Li and Ta cations. The authors also observed that the c{sup {minus}} end of the ferroelectric polarization exhibits slightly higher ion dechanneling along with an apparent greater susceptibility to radiation damage, as compared to the c{sup +} end of the polarization.

GLASS is the matrix of choice of every major country involved with long-term management of high-level radioactive waste (HLW). There are many reasons why glass is preferred. Among the most important considerations is the ability of glass structures to accommodate and immobilize the many different types of constituents present in HLW, and to produce a product that not only has excellent technical properties, but also processes good processing features.

Having laser intensities of 10{sup 21} W/cm{sup 2} yield electrical field strengths of 10{sup 12} V/cm which is comparable to the field strength at the K-shell of neon. Instant field ionization becomes part of the laser-matter interaction allowing to transfer most of the photons momenta directly onto the ions by driving an electrostatic shock through the target equivalent to pressures of several 100 Gbar. Utilization of these high-pressure conditions in form of equation of state measurements, however, strongly depends on the contrast of the femtosecond laser pulse. Currently, the Livermore USP and JanUSP lasers reach contrast values up to 10{sup 8}. This is sufficient to explore near-isochorically heated materials at moderate intensities (10{sup 13}-10{sup 15} W/cm{sup 2}) attaining pressures around 100 Mbar.

Under the APEX program the He-cooled system design task is to evaluate and recommend high power density refractory alloy first wall and blanket designs and to recommend and initiate tests to address critical issues. We completed the preliminary design of a helium-cooled, W-5Re alloy, lithium breeder design and the results are reported in this paper. Many areas of the design were assessed, including material selection, helium impurity control, and mechanical, nuclear and thermal hydraulics design, and waste disposal, tritium and safety design. System study results show that at a closed cycle gas turbine (CCGT) gross thermal efficiency of 57.5%, a superconducting coil tokamak reactor, with an aspect ratio of 4, and an output power of 2 GWe, can be projected to have a cost of electricity at 54.6 mill/kWh. Critical issues were identified and we plan to continue the design on some of the critical issues during the next phase of the APEX design study.

This paper presents a description of the National Ignition Facility, some of the physics experiments that will be performed on it and a description of some of the diagnostics needed to complete these experiments. Experiments are presented under the headings of: ignition physics, weapons physics or high-energy-density experimental science, weapons effects, and basic science and inertial fusion energy. The diagnostics discussed are primarily those that will be provided for early operation.

This paper presents a description of the National Ignition Facility, some of the physics experiments that will be performed on it and a description of some of the diagnostics needed to complete these experiments. Experiments are presented under the headings of: ignition physics, weapons physics or high-energy-density experimental science, weapons effects, and basic science and inertial fusion energy. The diagnostics discussed are primarily those that will be provided for early operation.

This paper presents a description of the National Ignition Facility, some of the physics experiments that will be performed on it, and a description of some of the diagnostics needed to complete these experiments. Experiments are presented under the headings of: ignition physics, weapons physics or high-energy-density experimental science, weapons effects, and basic science and inertial fusion energy. The diagnostics discussed are primarily those that will be provided for early operation.

CP violation is a crucial component in the creation of the matter - anti matter asymmetry of the universe. An important open question is whether the CP violating phenomena observeable in terrestrial experiments have any relation with those responsible for baryogenesis. We discuss two mechanisms of baryogenesis where this question can be meaningfully posed: ''electroweak baryogenesis'' and ''baryogenesis via leptogenesis''. We show how these scenarios can be constrained by existing and forthcoming experimental data. We present a specific example of both these scenarios where the CP violating phase in the Cabbibo Kobayashi Maskawa matrix is related in a calculable way to the CP violating phase responsible for baryogenesis.

This paper presents a new computer system, PROSPECT, for protein threading. PROSPECT employs an energy function that consists of three additive terms: (1) a singleton fitness term, (2) a distance-dependent pairwise-interaction preference term, and (3) alignment gap penalty; and currently uses FSSP as its threading template database. PROSPECT uses a divide-and-conquer algorithm to find an alignment between a query protein sequence and a protein fold template, which is guaranteed to be globally optimal for its energy function. The threading algorithm presented here significantly improves the computational efficiency of our previously-published algorithm, which makes PROSPECT a practical tool even for large protein threading problems. Mathematically, PROSPECT finds a globally-optimal threading between a query sequence of n residues and a fold template of m residues and M core secondary structures in O(nm + MnN{sup 1.5C{minus}1}) time and O(nm + nN{sup C{minus}1}) space, where C, the topological complexity of the template fold as we term, is a value which characterizes the overall structure of the considered pairwise interactions in the fold; and N represents the maximum number of possible alignments between an individual core of the fold and the query sequence when its neighboring cores are already aligned. PROSPECT allows a user to …

A NRC-BNL benchmark program for evaluation of state-of-the-art analysis methods and computer programs for seismic analysis of coupled structures with non-classical damping is described. The program includes a series of benchmarking problems designed to investigate various aspects of complexities, applications and limitations associated with methods for analysis of non-classically damped structures. Discussions are provided on the benchmarking process, benchmark structural models, and the evaluation approach, as well as benchmarking ground rules. It is expected that the findings and insights, as well as recommendations from this program will be useful in developing new acceptance criteria and providing guidance for future regulatory activities involving licensing applications of these alternate methods to coupled systems.

We have undertaken a study of ion mobility resolution in a miniature ion mobility spectrometer with a drift channel 1.7 mm in diameter and 35 mm in length. The device attained a maximum resolution of 14 in separating ions of NO, O{sub 2}, and methyl iodine. The ions were generated by pulses from a frequency-quadrupled Nd:YAG laser. Broadening due to Coulomb repulsion was modeled theoretically and shown experimentally to have a major effect on the resolution of the miniature device.

Structure within thin epoxy films is investigated by neutron reflectivity (NR) as a function of resin/crosslinker composition and cure temperature. Variation in the crosslink density normal to the substrate surface is examined by swelling the films with the good solvent d-nitrobenzene (d-NB). The principle observation is a large excess of d-NB near the air surface. This is not a wetting layer,but rather indicates a lower crosslink density in the new-surface region. This effect is due to preferential segregation of the crosslinker to the air surface, driven by the lower surface energy of the crosslinker relative to the epoxide oligamers. The magnitude of the effect is a function of composition and cure temperature. Exclusion of d-N13from the region immediately adjacent to the substrate surface is also observed, possibly indicating a tightly bound layer of epoxy. Regarding swelling in the bulk of the films, the behavior is non-symmetric with departure from the stoichiometric ratio. The films deficient in curing agent show greater equilibrium swelling and faster swelling kinetics than the films with an excess of curing agent.

Scattered light at three-halves of the incident laser frequency from solid targets is observed at five different angles. When the incident laser intensity is low enough, rescattering of two plasmon decay (TPD) instability electron plasma waves by ion acoustic waves is not significant. In this regime, Thomson scattering measurements of the electron temperature and the plasma flow velocity allow quantitative comparison of the angular dependence of the spectrum to theory.

A universal solvent extraction process is being evaluated for the simultaneous separation of Cs, Sr, and the actinides from acidic high-activity tank waste at the Idaho National Engineering and Environmental Laboratory (INEEL) with the goal of minimizing the high-activity waste volume to be disposed in a deep geological repository. The universal solvent extraction process is being developed as a collaborative effort between the INEEL and the Khlopin Radium Institute in St. Petersburg, Russia. The process was recently demonstrated at the INEEL using actual radioactive, acidic tank waste in 24 stages of 2-cm-diameter centrifugal contactors located in a shielded cell facility. With the testing, removal efficiencies of 99.95%, 99.985%, and 95.2% were obtained for Cs-137, Sr-90, and total alpha, respectively. This is sufficient to reduce the activities of Cs-137 and Sr-90 to below NRC Class A LLW requirements. The total alpha removal efficiency was not sufficient to reduce the activity of the tank waste to below NRC Class A non-TRU requirements. The lower than expected removal efficiency for the actinides is due to loading of the Ph2Bu2CMPO in the universal solvent with actinides and metals (Zr, Fe, and Mo). Also, the carryover of aqueous solution (flooding) with the solvent exiting the …

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Neural networks (NNs) provide a powerful and flexible tool for selecting a signal from a larger background. The D0 collaboration has used them extensively in studying t{anti t} decays. NNs were essential to the measurement of the t{anti t} production cross section in the all-jets channel (t{anti t} {yields} b {anti b}qqqq), and were also used in the measurement of the mass of the top quark in the lepton+jets channel (t{anti t} {yields} b{anti b}l{nu}q{anti q}). This paper will describe two new applications of neural networks to top quark analysis: the search for single top quark production, and an effort to increase the sensitivity in the dilepton channel t{anti t} {yields} b{anti b}e{anti {mu}}{nu}{anti {nu}} beyond that achieved in the published analysis.

The Silicon Vertex Tracker is the CDF online tracker which will re- construct 2D tracks using hit positions measured by the Silicon Vertex Detector and Central Outer Chamber tracks found by the eXtremely Fast Tracker. The precision measurement of the track impact parameter will allow triggering on events contain- ing B hadrons. This will allow the investigation of several important problems in B physics, like CP violation and B_s mixing, and to search for new heavy particles decaying to b{anti b}.

NMR spectroscopy is expanding the horizons of structural biology by determining the structures and describing the dynamics of blobular proteins in aqueous solution, as well as other classes of proteins including membrane proteins and the polypeptides that form the aggregates diagnostic of prion and amyloid diseases. Significant results are also emerging on DNA and RNA oligomers and their complexes with proteins. This meeting focused attention on key structural questions emanating from molecular biology and how NMR spectroscopy can be used to answer them.