We have estimated interference from external background radiation for a computed tomography (CT) scanner. Our intention is to estimate the interference that would be expected for the high-resolution SkyScan 1072 desk-top x-ray microtomography system. The SkyScan system uses a Microfocus x-ray source capable of a 10-{micro}m focal spot at a maximum current of 0.1 mA and a maximum energy of 130 kVp. All predictions made in this report assume using the x-ray source at the smallest spot size, maximum energy, and operating at the maximum current. Some of the systems basic geometry that is used for these estimates are: (1) Source-to-detector distance: 250 mm, (2) Minimum object-to-detector distance: 40 mm, and (3) Maximum object-to-detector distance: 230 mm. This is a first-order, rough estimate of the quantity of interference expected at the system detector caused by background radiation. The amount of interference is expressed by using the ratio of exposure expected at the detector of the CT system. The exposure values for the SkyScan system are determined by scaling the measured values of an x-ray source and the background radiation adjusting for the difference in source-to-detector distance and current. The x-ray source that was used for these measurements was not the …

During the WBS4 review almost a year ago in January, and in more recent discussions of needed capsule characterization, I was struck by three pieces of information related to machined Be capsules: (1) that the speed of sound (and perhaps other properties) in Be grains is markedly different in orthogonal directions, (2) that the grain size in the best refined bulk Be samples is 10 to 15 {micro}m, and that these grains in the best case are randomly oriented, and (3) that we are concerned about capsule homogeneity on the level of 1 part in 10{sup 4}, presumably over angular length scales corresponding to the maximum in the growth curve. It seems to me that the first two points might be inconsistent with the third, and this led me to attempt to model the effect of randomly oriented Be grains on the radially dependent properties of a capsule.

The data evaluated in this qualification report have been cited in analysis and model reports (AMRs) in support of the Site Recommendation in determining the suitability of the Yucca Mountain Site for a repository for high level nuclear waste. The AMRs use these hydrochemical data as a basis for modeling the chemical interactions between groundwater and engineered materials, including waste forms, packages and materials in the engineered barrier system J-13 water is also used as a reactant in experiments performed to collect data on corrosion of waste packages and repository materials, on solubility of radionuclides, on waste form leach rates, and in simulations of the mobility of radionuclides in groundwater, among other applications. J-13 water serves effectively as a reference or surrogate water composition across the program. Establishing a qualified data set describing the composition of J-13 will help ensure commonality among the various studies.

Preliminary shielding calculations were performed to establish the dimensions of the radiation shielding surrounding the three Spallation Neutron Source (SNS) beam stops. Steel shielding thicknesses were sized to give dose levels of 1, 2, and 5 mrem/h at the top of the shield, and, to provide enough shielding along the sides and bottom of the beam dump so that soil activation is not a problem. It was concluded that 144 in. of steel shielding is needed above the beam stop. The thickness of the concrete floor in the service building above the dump was not a part of these calculations. This shielding design is current as of January 2000.

The purpose and scope of this report is to describe the analysis of available colloidal data from waste form corrosion tests at Argonne National Laboratory (ANL) to extract characteristics of these colloids that can be used in modeling their contribution to the source term for sparingly soluble radioelements (e.g., Pu). Specifically, the focus is on developing a useful description of the following waste form colloid characteristics: (1) composition, (2) size distribution, and (3) quantification of the rate of waste form colloid generation. The composition and size distribution information are intended to support analysis of the potential transport of the sparingly soluble radionuclides associated with the waste form colloids. The rate of colloid generation is intended to support analysis of the waste form colloid-associated radionuclide concentrations. In addressing the above characteristics, available data are interpreted to address mechanisms controlling colloid formation and stability. This report was developed in accordance with the ''Technical Work Plan for Waste Form Degradation Process Model Report for SR'' (CRWMS M&O 2000). Because the end objective is to support the source term modeling we have organized the conclusions into two categories: (1) data analysis conclusions and (2) recommendations for colloid source term modeling. The second category is …

The purpose of this report was to document the process leading to development of the Biosphere Dose Conversion Factors (BDCFs) for the postclosure nominal performance of the potential repository at Yucca Mountain. BDCF calculations concerned twenty-four radionuclides. This selection included sixteen radionuclides that may be significant nominal performance dose contributors during the compliance period of up to 10,000 years, five additional radionuclides of importance for up to 1 million years postclosure, and three relatively short-lived radionuclides important for the human intrusion scenario. Consideration of radionuclide buildup in soil caused by previous irrigation with contaminated groundwater was taken into account in the BDCF development. The effect of climate evolution, from the current arid conditions to a wetter and cooler climate, on the BDCF values was evaluated. The analysis included consideration of different exposure pathway's contribution to the BDCFs. Calculations of nominal performance BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. BDCFs for the nominal performance, when combined with the concentrations of radionuclides in groundwater allow calculation of potential radiation doses to the receptor of interest. Calculated estimates of radionuclide concentration in groundwater result from the saturated zone …

Burnup credit is an ongoing issue in designing and licensing transportation and storage casks for spent nuclear fuel (SNF). To address this issue, in July 1999, the U.S. Nuclear Regulatory Commission (NRC), Spent Fuel Project Office, issued Interim Staff Guidance-8 (ISG-8), Revision 1 allowing limited burnup credit for pressurized water reactor (PWR) spent nuclear fuel (SNF) to be used in transport and storage casks. However, one of the key limitations for a licensing basis analysis as stipulated in ISG-8, Revision 1 is that ''burnup credit is restricted to intact fuel assemblies that have not used burnable absorbers''. Because many PWR fuel designs have incorporated burnable-absorber rods for more than twenty years, this restriction places an unnecessary burden on the commercial nuclear power industry. This paper summarizes the effects of in-reactor irradiation on the isotopic inventory of PWR fuels containing different types of integral burnable absorbers (BAs). The work presented is illustrative and intended to represent typical magnitudes of the reactivity effects from depleting PWR fuel with different types of burnable absorbers.

A goal of the Mesaverde project was to better define the depositional system of the Mesaverde in hopes that it would provide insight to new or by-passed targets for oil exploration. The new, detailed studies of the Mesaverde give us a better understanding of the lateral variability in depositional environments and facies. Recognition of this lateral variability and establishment of the criteria for separating deltaic, strandplain-barrier, and estuarine deposits from each other permit development of better hydrocarbon exploration models, because the sandstone geometry differs in each depositional system. Although these insights will provide better exploration models for gas exploration, it does not appear that they will be instrumental in finding more oil. Oil in the Mesaverde Group is produced from isolated fields on the Chaco slope; only a few wells define each field. Production is from sandstone beds in the upper part of the Point Lookout Sandstone or from individual fluvial channel sandstones in the Menefee. Stratigraphic traps rather than structural traps are more important. Source of the oil in the Menefee and Point Lookout may be from interbedded organic-rich mudstones or coals rather than from the Lewis Shale. The Lewis Shale appears to contain more type III organic matter …

Report on status of program to raise awareness and heighten interest in nuclear engineering and nuclear science, particularly among 7th through 12th grade students and pre-college freshmen.

This document is a revision of the document titled above, summarizing the technical baseline of the Tank Farm Contractor. It is one of several documents prepared by CH2M HILL Hanford Group, Inc. to support the U.S. Department of Energy Office of River Protection Tank Waste Retrieval and Disposal Mission at Hanford.

Atomic force microscopy was used to study changes in the surface step structure of GaInAsSb layers with varying degrees of phase separation. The layers were grown by organometallic vapor phase epitaxy on (001) GaSb substrates with 2{sup o} miscut angles toward (-1-11)A, (1-11)B, and (101). Alloy decomposition was observed by contrast modulations in plan-view transmission electron microscopy, and broadening in x-ray diffraction and photoluminescence peaks. GaInAsSb layers with a minimal degree of phase separation exhibit a step-bunched step structure. A gradual degradation in the periodicity of the step structure is observed as the alloy decomposes into GaAs- and InSb-rich regions. The surface eventually develops trenches to accommodate the local strain associated with composition variations, which are on the order of a few percent. The surface composition is affected by substrate miscut angle, and although phase separation cannot be eliminated, its extent can be reduced by growing on substrates miscut toward (1-11)B.

These valves are 1/2 inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as isolation valves for pressure instrumentation in the SCHe System between the helium bottle supply manifolds and safety class helium pressure instrumentation, and in lower pressure SCHe supply line.

Bent crystal monochromators were developed for the neutron scattering community: (1) doubly focusing bulk silicon, for high-resolution neutron diffraction; (2) doubly focusing multi-wafer silicon, for residual stress instruments; (3) silicon-wafer: (a) with pneumatic spherical bending, (b) with mechanical cylindrical bending, (c) with mechanical two-dimensional bending, for high-resolution three-axis spectrometry; (4) doubly focusing multi-wafer silicon, for epithermal (eV range) neutrons; (5) doubly focusing composite pyrolytic graphite (low-cost), for high-flux applications.

This document is a printout of the S-102 software for the Programmable Logic Controller (PLC) for Pumping, Instrumentation and Control Skid ''E''.

This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular …

The Configuration Management Plan for the Tank Farm Contractor describes configuration management the contractor uses to manage and integrate its technical baseline with the programmatic and functional operations to perform work. The Configuration Management Plan for the Tank Farm Contractor supports the management of the project baseline by providing the mechanisms to identify, document, and control the technical characteristics of the products, processes, and structures, systems, and components (SSC). This plan is one of the tools used to identify and provide controls for the technical baseline of the Tank Farm Contractor (TFC). The configuration management plan is listed in the management process documents for TFC as depicted in Attachment 1, TFC Document Structure. The configuration management plan is an integrated approach for control of technical, schedule, cost, and administrative processes necessary to manage the mission of the TFC. Configuration management encompasses the five functional elements of: (1) configuration management administration, (2) configuration identification, (3) configuration status accounting, (4) change control, and (5 ) configuration management assessments.

This Phase I project was designed to demonstrate feasibility of in situ waste destruction and vitrification technology as a means of remediating hard-to-treat buried radioactive and hazardous wastes and focused on proving viability of the concentric graphite arc melter technique as a robust, safe, and economic tool for use as the IWDV process heat source. Oak Ridge National Laboratory provided technical support to Montec Research including the volatile behavior of elements during silicate melting operations and temperature viscosity modeling of silicate melts. Further research will be needed to develop this technology into a competitive remediation technique.

These pressure switches are located in the SCHe helium supply lines at the pressure bottles and upstream of the PRV. The switches monitor the SCHe supply bottle pressure and are set to alarm at 2200 psig. There is one switch for each SCHe supply (4). Electronic output signal is NON-SAFETY (GS).

This revision notes the supersedure of the subject document by concurrent issuance of HNF-1901 ''Technical Baseline Summary Description for the Tank Farm Contractor'', Revision 2. Safe storage mission technical baseline information was absorbed by the new revision of HNF-1901.

There has been considerable work accomplished internationally examining the effects of drill and blast excavation on rock masses surrounding emplacement openings of proposed nuclear waste repositories. However, there has been limited discussion tying the previous work to performance confirmation models such as those proposed for Yucca Mountain, Nevada. This paper addresses a possible approach to joining the available information on drill and blast excavation and performance confirmation. The method for coupling rock damage data from drill and blast models to performance assessment models for fracture flow requires a correlation representing the functional relationship between the peak particle velocity (PPV) vibration levels and the potential properties that govern water flow rates in the host rock. Fracture aperture and frequency are the rock properties which may be most influenced by drill and blast induced vibration. If it can be shown (using an appropriate blasting model simulation) that the effect of blasting is far removed from the waste package in an emplacement drift, then disturbance to the host rock induced in the process of drill and blast excavation may be reasonably ignored in performance assessment calculations. This paper proposes that the CANMET (Canada Center for Mineral and Energy Technology) Criterion, based on properties …

These gas bottles and associated valves provide the safety grade helium source for emergency MCO purge.

We describe a new class of directory coherence protocols called delta coherence protocols that use network guarantees to support a new and highly concurrent approach to maintain a consistent shared memory. Delta coherence protocols are more concurrent than other coherence protocols in that they allow processes to pipeline memory accesses without violating sequential consistency; support multiple concurrent readers and writers to the same cache block; and allow processes to access multiple shared variables atomically without invalidating the copies held by other processes or otherwise obtaining exclusive access to the referenced variables. Delta protocols include both update and invalidate protocols. In this paper we describe the simplest, most basic delta protocol, an update protocol called the home update protocol. Delta protocols are based on isotach network guarantees. An isotach network maintains a logical time system that allows each process to predict and control the logical time at which its messages are received. Processes use isotach guarantees to control the logical time at which their requests on shared memory appear to be executed. We prove the home update protocol is correct using logical time to reason about the order in which requests are executed.

A nonradioactive chemical vapor space source term for tanks on the Phase 1 and the extended Phase 1 delivery, storage, and disposal mission was determined. Operations modeled included mixer pump operation and DST waste transfers. Concentrations of ammonia, specific volatile organic compounds, and quantitative volumes of aerosols were estimated.

MCNP Monte Carlo radiation transport computations were performed exploring the capability of low-yield nuclear fusion and fission warheads to neutralize biological warfare agents with the radiation dose deposited in the agent by the prompt neutron output. The calculations were done for various typical storage configurations on the ground in the open air or in a warehouse building. This application of nuclear weapons is motivated by the observation that, for some military scenarios, the nuclear collateral effects area is much smaller than the area covered with unacceptable concentrations of biological agent dispersed by the use of conventional high explosive warheads. These calculations show that biological agents can be radiation-neutralized by low-yield nuclear warheads over areas that are sufficiently large to be useful for military strikes. This report provides the calculated doses within the stored agent for various ground ranges and heights-of-burst.