This paper presents selected preliminary results obtained during the first 54 days of the Prototype Engineered Barrier System Field Tests (PEBSFT) that are being performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT). The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The PEBSFTs are being conducted to evaluate the applicability of measurement techniques, numerical models, and procedures for future investigations that will be conducted in the Exploratory Shaft Facilities of the Yucca Mountain Project (YMP). The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures, gas pressures, and rock mass gas-phase humidity. 10 refs., 12 figs.

Efforts to more effectively monitor the Comprehensive Nuclear-Test-Ban Treaty (commonly referred to as the CTBT) include research into methods of seismic discrimination. The most common seismic discriminants exploit differences in seismic amplitude for differing source types. Amplitude discriminants are quite effective when wave-propagation (a.k.a. path) effects are properly accounted for. However, because path effects can be exceedingly complex, path calibration is often accomplished empirically by spatially interpolating amplitude characteristics for a set of calibration earthquakes with techniques like Bayesian kriging. As a result, amplitude discriminants can be highly effective when natural seismicity provides sufficient event coverage to characterize a region. However, amplitude discrimination can become less effective for events that are far from historical (path-calibration) events. It is intuitive that events occurring at a distance from historical seismicity patterns are inherently suspect. However, quantifying the degree to which a particular event is unexpected could be of great utility in CTBT monitoring. Epicenter location is commonly used as a qualitative discriminant. For instance, if a seismic event is located in the deep ocean, then the event is generally considered to be an earthquake. Such qualitative uses of seismic location have great utility; however, a quantitative method to differentiate events from the …

Magnitude estimation forms an integral part in any seismic monitoring endeavor. For monitoring compliance of the Comprehensive Nuclear-Test-Ban Treaty, regional seismic discriminants are often functions of magnitude such as m{sub b}:M{sub 0} high-to-low spectral ratios, and nuclear yield estimation. For small-to-moderate magnitude events that cannot be studied by a large regional or global network of stations, there is a need for stable magnitudes that can be obtained from as few as one station. To date, magnitudes based on coda envelopes are by far the most stable because of the coda's averaging properties. Unlike conventional magnitudes which utilize the direct phases such as P (P{sub n}, P{sub g}) or S (S{sub n}, L{sub g}), or M{sub g}, a coda envelope magnitude is not as sensitive to the undesirable effects of source radiation pattern, 3-D path heterogeneity, and constructive/destructive interference near the recording site. The stability of the coda comes from a time-domain measurement made over a large portion of the seismogram thereby averaging over the scattered wavefield. This approach has been applied to earthquakes in the western United States where it was found that a single-station coda magnitude was approximately equivalent to an average over a 64 station network which used …

The material control and accountancy system for the Fuel Conditioning Facility (FCF) initially uses calculated values for the mass flows of irradiated EBR-II driver fuel to be processed in the electrorefiner. These calculated values are continually verified by measurements performed by the Analytical Laboratory (AL) on samples from the fuel element chopper retained for each chopper batch. Measured values include U and Pu masses, U and Pu isotopic fractions, and burnup (via La and Tc). When the measured data become available, it is necessary to determine if the measured and calculated data are consistent. This verification involves accessing two databases and performing standard statistical analyses to produce control charts for these measurements. These procedures can now be invoked via a Web interface providing: a timely and efficient control of these measurements, a user-friendly interface, off-site remote access to the data, and a convenient means of studying correlations among the data. This paper will present the architecture of the interface and a description of the control procedures, as well as examples of the control charts and correlations.

Seismic stations at islands and continental margins will be an essential component of the International Monitoring System (IMS) for event location and identification in support of Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring. Particularly important will be the detection and analysis of hydroacoustic-to-seismic converted waves (T-phases) at island or continental margins. Acoustic waves generated by sources in or near the ocean propagate for long distances very efficiently due to the ocean sound speed channel (SOFAR) and low attenuation. When ocean propagating acoustic waves strike an island or continental margin they are converted to seismic (elastic) waves. We are using a finite difference code to model the conversion of hydroacoustic T-waves at an island or continental margin. Although ray-based methods are far more efficient for modeling long-range (> 1000 km) high-frequency hydroacoustic propagation, the finite difference method has the advantage of being able to model both acoustic and elastic wave propagation for a broad range of frequencies. The method allows us to perform simulations of T-phases to relatively high frequencies ({>=}10 Hz). Of particular interest is to identify factors that affect the efficiency of T-phase conversion, such as the topographic slope and roughness at the conversion point and elastic velocity structure within the …

Among the needs identified during initial surveys of nuclear facilities in Ukraine was improved accounting software for reporting material inventories to the regulatory body. AIMAS (Automated Inventory/Material Accounting System) is a PC-based application written in Microsoft Access that was jointly designed by an US/Ukraine development team. The design is highly flexible and configurable, and supports a wide range of computing infrastructure needs and facility requirements including situations where networks are not available or reliable. AIMAS has both English and Russian-language options for displays and reports, and it operates under Windows 3.1, 95, or NT 4.0{trademark}. AIMAS functions include basic physical inventory tracking, transaction histories, reporting, and system administration functions (system configuration, security, data backup and recovery). Security measures include multilevel password access control, all transactions logged with the user identification, and system administration control. Interfaces to external modules provide nuclear fuel burn-up adjustment and barcode scanning capabilities for physical inventory taking. AIMAS has been installed at Kiev Institute of Nuclear Research (KINR), South Ukraine Nuclear Power Plant (SUNPP), Kharkov Institute of Physics and Technology (KIPT), Sevastopol Institute of Nuclear Energy and Industry (SINEI), and the Ministry of Environmental Protection and Nuclear Safety/Nuclear Regulatory Administration (MEPNS/NRA). Facility specialists are being trained …

Following the principles set by the National Biofuels Roundtable, a workshop was held in March 1995 which brought together a group of stakeholders and experts in the field of biomass energy and ecology. The mission of the workshop was to identify and set priorities for ecological research to ensure that large-scale biomass energy development in the North Central states occurs in an ecologically sound, sustainable manner. The workshop found that questions about the landscape-scale deployment of biomass plantations were most pressing. The workshop recommended that adaptive resource management principles be applied in a phased development of increasingly larger plantations. Each phase of development would help to answer questions about landscape-scale development; improving the design of subsequent phases. Principles of sustainable agriculture should also be applied to biomass plantations to minimize impact on soils and water quality, maintain productivity and benefit the rural economy. Results of the workshop will be helpful to natural resource and research agencies, as well as utilities and biomass energy developers.

Beginning in the 1930`s, both chemists and physicists became interested in synthesizing new artificial elements. The first transuranium element, Np, was synthesized in 1940. Over the past six decades, 20 transuranium elements have been produced. A review of the synthesis is given. The procedure of naming the heavy elements is also discussed. It appears feasible to produce elements 113 and 114. With the Berkeley Gas-filled Separator, it should be possible to reach the superheavy elements in the region of the spherical Z=114 shell, but with fewer neutrons than the N=184 spherical shell. 57 refs, 6 figs.

Tank waste characterization requires various analytical systems to identify and quantify the chemical composition and water content of Hanford Site high-level waste. Safe long-term storage of the waste depends on its chemical and physical data. An analytical database is also the key to the design and implementation of pre-treatment and disposal processes. To provide a faster, cheaper, and safer technique to monitor the moisture content of tank waste, two types of near-infrared (NIR) diffuse reflectance fiber optic probes interfaced to a Fouiier transform infrared (FTIR) spectrometry system were studied. Lower absorptivities in the NIR region enable longer pathlengths to be used leading to easier nondestructive sampling. Both overtone and combination bands Of Water can be used for moisture measurements. While a previous report` provides evidence for the feasibility of using fiber optic probes, the results were strictly qualitative. In this study, the fiber optic probe is installed in a hot cell making it possible to characterize highly radioactive mixed waste rapidly and quantitatively. In seeking a strategy to identify individual species in the waste with minimal sample preparation, a modular transfer optic system equipped with a mid-infrared diffuse reflectance sampler was assessed. Light pipes were used to present the sample …

The metal laminates proposed here for aircraft structures are Al alloy interlayers between Al alloy based metal matrix composite (MMC) plates reinforced with Si carbide particles. Properties to be tailored for jet engine fan containment and wing and auxiliary support structures include the important property fracture toughness. A method was developed for simulating and predicting crack initiation/growth using finite element analysis and fracture mechanics. An important key in predicting the failure is the tie- break slideline with prescribed (chosen based on J Integral calculations) effective plastic strain to failure in elements along the slideline. More development of the method is needed, particularly in its correlation with experimental data from various fracture toughness and strength tests of metal laminates. Results show that delamination at the interface of the ductile interlayer and MMC material can add significantly to the energy required to propagate a crack through a metal laminate. 11 figs, 7 refs.

This paper summarizes an analysis of the US-Russian Nuclear Material Protection, Control and Accounting (MPC and A) Program, developed on the basis of extensive discussions with US laboratory participants as well as personal experience. Results of the discussions have been organized into three main areas: Technical/MPC and A Progress; Programmatic and Administrative Issues; and Professional Aspects, Implications for MPC and A effectiveness, for MPC and A sustainability, and for future relations and collaboration are derived. Suggested next steps are given.

The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth.

Information technology is being used to provide interactive access to data collected from the electro-metallurgical treatment of spent fuel. The data are results from many hundreds of experiments performed to better characterize the processes by which uranium is separated from the waste products. Web-based display and relational database query capabilities facilitate the identification of trends in the data and the relating of these trends to the underlying electrochemistry. The objectives are to ensure that the process behavior is well understood, to make readily accessible the necessary data for development and validation of models, and to identify unexpected trends in the data as indications of phenomena not yet represented in the models.

In an effort to better characterize and classify austenitic stainless steel resistance upset welds, standard methods have been examined and alternative methods investigated. Optical microscopy yields subjective classification due to deformation obscured bond lines and individual perception. The use of specimen preparations that better reveal grain boundaries aids in substantiating optical information. Electron microscopy techniques produce quantitative information in relation to microstructural constituents. Orientation Imaging Microscopy (OIM) is a relatively new technique for obtaining objective, quantitative information pertaining to weld integrity, i.e., percent grain boundary growth across the interface.

Phase-space analysis of neutron optics has revealed that neutron imaging by Bragg reflection from thick bent perfect crystals can be non-dispersive (independent of the neutron wavelength), like with an optical mirror. The corresponding devices, called Bragg mirrors (BM), can be used for neutron imaging at pulsed neutron sources. Using a position sensitive detector (PSD) and time-of-flight analysis (TOF), a BM imaging system will make it possible to collect both real space mapping data and scattering space data simultaneously. Each pixel of PSD will correspond to a point in the sample and will contain a segment of the diffraction pattern (useful for strain, texture or phase analysis), or of an inelastic spectrum. In this paper the resolution and efficiency of BM in TOF diffraction experiments are calculated and compared with the usual sequential method of mapping. Experimental tests performed at steady state neutron sources showed sub-millimeter spatial resolution in the one-dimensional case.

In K-edge densitometry (KED), a continuous-energy x-ray beam is transmitted through a liquid sample. The actinide content of the sample can be measured through analysis of the transmitted portion of the x-ray beam. Traditional methods for KED analysis allow the simultaneous calculation of, at most, two actinide concentrations. A generalized multi-edge KED analytical method is presented, allowing up to six actinide concentrations to be calculated simultaneously. Applications of this method for hybrid KED/x-ray fluorescence (HKED) systems are discussed. Current HKED systems require the operator to know the approximate actinide content of each sample, and manually select the proper analysis mode. The new multi-edge KED technique allows rapid identification of the major actinide components in a sample, independent of actinide content. The proper HKED analysis mode can be selected automatically, without requiring sample content information from the user. Automatic HKED analysis would be especially useful in an analytical laboratory setting, where samples with truly unknown characteristics are encountered. Because this technique requires no hardware modifications, several facilities that use HKED may eventually benefit from this approach.

Legacy plutonium residues often have inadequate item descriptions. Nondestructive characterization can help segregate these items for reprocessing or provide information needed for disposal or storage. Alpha particle-induced gamma-ray spectra contain a wealth of information that can be used for matrix characterization. We demonstrate how this information can be used for item identification. Gamma-ray spectra were recorded at the Los Alamos Plutonium Facility from a variety of legacy, plutonium-processing residues and product materials. The comparison and analysis of these spectra are presented.

A design goal for VULCAN, the SNS engineering diffractometer, is to enable spatial mapping with 0.1 mm resolution. Because the targeted applications often involve the use of large samples or special environment, slits cannot be used for this purpose. In this paper, methods to achieve 0.1 mm spatial resolution are outlined. For the incident beam, a new compact focusing device is proposed. The device is made of a stack of bent silicon wafers, each having a reflective multilayer (supermirror) deposited on one side and a neutron-absorbing layer on the other side. The optimal design to minimize the optical spatial aberrations is discussed and Monte-Carlo simulation results are presented. For the diffracted beam, imaging devices made from thick packets of diffracting bent silicon wafers (known as the Bragg Mirrors) could be used. The requirements to achieve a sharp imaging together with a large phase-space acceptance window are discussed and preliminary testing results are presented.

The recently discovered dynamical diffraction effect ''neutron camel'' was used for the residual stress measurements in a thick Si(111) crystal coated with a 2000 {angstrom} thick Ni film. The observed asymmetry of the back-face rocking curve corresponds to the bending radius of {approx} 19 km and the tension force applied to the Ni film is {approx} 90 N/m. Relative deformation of the Si crystallographic cells in the vicinity of diffractive surfaces is |{partial_derivative}u{sub z}/{partial_derivative}z| {approx} 1.6 x 10{sup -6}.

Understanding the exchanges of carbon between the atmosphere and ocean and the fate of carbon delivered to the deep sea is fundamental to the evaluation of ocean carbon sequestration options. An additional key requirement is that sequestration must be verifiable and that environmental effects be monitored and minimized. These needs can be addressed by carbon system observations made from low-cost autonomous ocean-profiling floats and gliders. We have developed a prototype ocean carbon system profiler based on the Sounding Oceanographic Lagrangian Observer (SOLO; Davis et al., 1999). The SOLO/ carbon profiler will measure the two biomass components of the carbon system and their relationship to physical variables, such as upper ocean stratification and mixing. The autonomous observations within the upper 1500 m will be made on daily time scales for periods of months to seasons and will be carried out in biologically dynamic locations in the world's oceans that are difficult to access with ships (due to weather) or observe using remote sensing satellites (due to cloud cover). Such an observational capability not only will serve an important role in carbon sequestration research but will provide key observations of the global ocean's natural carbon cycle.

A moving diffractor changes the energy of elastically diffracted neutrons by the Doppler effect. Depth-graded multilayers can diffract neutrons over a large band of energy. Using a pulsed neutron source, such a depth-graded multilayer, decelerating synchronously with the incident neutron pulse, can shift the reflected neutrons into a compressed energy window. This focusing in energy is associated with a broadening of the pulse in time, but the process does not involve a significant decrease in the neutron phase-space density. The proposed method can be used to design long pulse or quasi-continuous sources of cold, very cold or ultra cold neutrons (UCN). The analysis concentrates on enhanced production of UCN at pulsed neutron sources.

The design of high-power lasers such as those used for inertial confinement fusion demands accurate modeling of the interaction between lasers and plasmas. In inertial confinement fusion, initial laser pulses ablate material from the hohlraum, which contains the target, creating a plasma. Plasma density variations due to plasma motion, ablating material and the ponderomotive force exerted by the laser on the plasma disrupt smooth laser propagation, undesirably focusing and scattering the light. Accurate and efficient computational simulations aid immensely in developing an understanding of these effects. In this paper, we compare the accuracy of two methods for calculating the propagation of laser light through plasmas. A full laser-plasma simulation typically consists of a fluid model for the plasma motion and a laser propagation model. These two pieces interact with each other as follows. First, given the plasma density, one propagates the laser with a refractive index determined by this density. Then, given the laser intensities, the calculation of one time step of the plasma motion provides a new density for the laser propagation. Because this procedure repeats over many time steps, each piece must be performed accurately and efficiently. In general, calculation of the light intensities necessitates the solution of …

Development of an ANSI/ANS Standard for the training and qualification of criticality safety engineers has been underway for nearly one year. The working group for this Standard is comprised of criticality safety experts from regulatory, licensee and contractor organizations. Its goal is to develop a standard that can be uniformly adopted, that covers all criticality safety engineer qualification levels, and that includes all required competencies such that most of the qualifications can be easily transferred between sites. This status report is presented to let the general criticality safety community know of progress on the Standard, and to solicit feedback to the working group as it continues work on ANSI/ANS-8.26.

The basic theoretical aspects of the band anticrossing effects in highly electronegativity-mismatched semiconductor alloys are reviewed. The many-impurity Anderson model treated in the coherent potential approximation is applied to the semiconductor alloys, in which metallic anion atoms are partially substituted by atoms of a highly electronegative element. Analytical solutions for the Green's function describe dispersion relations and state broadening effects for the restructured conduction band. The solutions are identical to those obtained from the physically intuitive and widely used two-level band anticrossing model. It is shown that the model explains key experimental observations including the unusual composition and pressure dependence of the interband optical transitions and the large enhancement of the electron effective mass.