Progress and future plans for MPC and A at Chelyabinsk-70 (open access)

Progress and future plans for MPC and A at Chelyabinsk-70

This paper describes that portion of the Nuclear Materials Protection, Control, and Accounting (MPC and A) program that is directed specifically to the needs of the All Russian Scientific Research Institute of Technical Physics (VNIITF), also called Chelyabinsk-70. Chelyabinsk-70 is located in the Ural Mountains, approximately 2000 km east of Moscow and 100 km south of Ekaterinburg. The MPC and A work that has been completed, is underway and planned at the facility will be described. During the first two years of the VNIITF project, emphasis was on the Pulse Research Reactor Facility (PRR), which contains one metal and two liquid pulse reactors and associated nuclear material storage rooms and a control center. A commissioning of the PRR was held in May of 1998. With the completion of the MPC and A work in the PRR, new physical protection work is focusing on other areas. VNIITF-wide physical protection initiatives underway include access control and computerized badging systems, and a central MPC and A control system. Measured physical inventory taking is a high priority for the VNIITF Project Team. A VNIITF-wide computerized accounting system is also being developed for the large and diverse inventory of nuclear material subject to MPC and …
Date: July 8, 1999
Creator: Apt, K.; Blasy, J.; Bukin, D.; Cahalane, P.; Churikov, Y.; Curtis, D. et al.
Object Type: Article
System: The UNT Digital Library
Progress toward hydrogen peroxide micropulsion (open access)

Progress toward hydrogen peroxide micropulsion

A new self-pressurizing propulsion system has liquid thrusters and gas jet attitude control without heavy gas storage vessels. A pump boosts the pressure of a small fraction of the hydrogen peroxide, so that reacted propellant can controllably pressurize its own source tank. The warm decomposition gas also powers the pump and is supplied to the attitude control jets. The system has been incorporated into a prototype microsatellite for terrestrial maneuvering tests. Additional progress includes preliminary testing of a bipropellant thruster, and storage of unstabilized hydrogen peroxide in small sealed tanks.
Date: July 8, 1999
Creator: Whitehead, J. C.; Dittman, M. D. & Ledebuhr, A. G.
Object Type: Article
System: The UNT Digital Library
Air Kerma Calibration Factors and kch Values for PTW Soft X-ray, NACP and Roos Ionization Chambers at Very Low X-ray Energies (0.035 mm - 1.0 mm Al HVL) (open access)

Air Kerma Calibration Factors and kch Values for PTW Soft X-ray, NACP and Roos Ionization Chambers at Very Low X-ray Energies (0.035 mm - 1.0 mm Al HVL)

Several national and international protocols have been established for the dosimetry of x-ray beams used in radiotherapy. For the very low energy x-rays (0.035mm-1.0 mm Al HVL) only two codes are available: the UK IPEMB Code of Practice and the German standard, DIN 6809 Part 4. The measurement of very low energy x-ray beams is normally performed with parallel plate ionization chambers calibrated at a standards laboratory and characterized by an air kerma calibration factor N{sub k}. According to the IPEMB Code of Practice the absorbed dose in the user's beam should be determined by taking measurements with the parallel plate chamber positioned such that its entrance window is at the surface of a full-scatter water equivalent phantom. The absorbed dose to water can then be determined using an equation which includes a factor, k{sub ch}, which accounts for the change in response of the ionization chamber between the calibration in air and measurement at the surface of the phantom. N{sub k} and k{sub ch} values for the PTW soft X-ray, NACP and Roos ionization chambers are reported. It was found that k{sub ch} values varied from about 1.01 to 1.08 depending on the chamber, beam quality and phantom material. …
Date: July 8, 1999
Creator: Ipe, Nisy E.
Object Type: Report
System: The UNT Digital Library
Orientifolds, RG Flows, and Closed String Tachyons (open access)

Orientifolds, RG Flows, and Closed String Tachyons

We discuss the fate of certain tachyonic closed string theories from two perspectives. In both cases our approach involves studying directly configurations with finite negative tree-level cosmological constant. Closed string analogues of orientifolds, which carry negative tension, are argued to represent the minima of the tachyon potential in some cases. In other cases, we make use of the fact, noted in the early string theory literature, that strings can propagate on spaces of subcritical dimension at the expense of introducing a tree-level cosmological constant. The form of the tachyon vertex operator in these cases makes it clear that a subcritical-dimension theory results from tachyon condensation. Using results of Kutasov, we argue that in some Scherk-Schwarz models, for finely-tuned tachyon condensates, a minimal model CFT times a subcritical dimension theory results. In some instances, these two sets of ideas may be related by duality.
Date: July 8, 1999
Creator: Kachru, S
Object Type: Report
System: The UNT Digital Library
Electron transport phenomena and dense plasmas produced by ultra-short pulse laser interaction (open access)

Electron transport phenomena and dense plasmas produced by ultra-short pulse laser interaction

Recent experiments with femtosecond lasers provide a test bed for theoretical ideas about electron processes in hot dense plasmas. We briefly review aspects of electron conduction theory likely to prove relevant to femtosecond laser absorption. We show that the Mott-Ioffe-Regel limit implies a maximum inverse bremsstrahlung absorption of about 50% at temperatures near the Fermi temperature. We also propose that sheath inverse bremsstrahlung leads to a minimum absorption of 7-10% at high laser intensity.
Date: July 8, 1994
Creator: More, R.M.
Object Type: Article
System: The UNT Digital Library
Prediction of the lifetime integrity of a nuclear waste container material based on thermal stability studies (open access)

Prediction of the lifetime integrity of a nuclear waste container material based on thermal stability studies

The kinetics of precipitation in C-22 alloy (UNS N06022) was estimated through isothermal aging experiments at temperatures ranging from 427 C to 800 C for times up to 40,000 h. The phases that formed, at least after the longer aging times, were identified by transmission electron microscopy (TEM). Aged samples were also examined using scanning electron microscopy (SEM) to determine when precipitation began on grain boundaries, completely covered grain boundaries, and began forming within the grains. This data was used to evaluate the kinetics of precipitation at lower temperatures using a simple exponential temperature dependent. The corrosion resistance of aged samples was investigated using the ASTM Specification G28B technique. The time to cause a significant increase in corrosion rate was also determined as a function of temperature and was fit to an exponential temperature dependence. Preliminary results indicate that C-22 alloy base metal would remain a highly corrosion resistant, single-phase material for greater than 10,000 years at temperatures below approximately 300 C.
Date: July 8, 1999
Creator: Rebak, R B; Shen, T & Summers, T
Object Type: Article
System: The UNT Digital Library
Rotating crystal cube as a variable shutter for use with synchrotron radiation. (open access)

Rotating crystal cube as a variable shutter for use with synchrotron radiation.

A beam chopper together with the temporal structure of x-rays emitted by a synchrotrons storage ring can be utilized to generate x-ray bursts of variable length and time separation. A Si cube, cut for diffraction from the (220) planes, was mounted to a low-speed motor to produce a beam chopper based upon the Darwin width of the crystal. An x-ray pulse, consisting of an envelope of individual pulses characterizing the loading pattern of the storage ring, was transmitted. The width of the transmitted pulse and the time between pulses was varied by varying the rotation frequency of the Si cube. Pulses as short as {approx} 75 ps or as long as {approx} 4 {micro}s were transmitted with pulse separation spanning from 4 ms to 167 ms.
Date: July 8, 1998
Creator: McPherson, A.
Object Type: Article
System: The UNT Digital Library
Spray Forming Aluminum - Final Report (Phase II) (open access)

Spray Forming Aluminum - Final Report (Phase II)

The U.S. Department of Energy - Office of Industrial Technology (DOE) has an objective to increase energy efficient and enhance competitiveness of American metals industries. To support this objective, ALCOA Inc. entered into a cooperative program to develop spray forming technology for aluminum. This Phase II of the DOE Spray Forming Program would translate bench scale spray forming technology into a cost effective world class process for commercialization. Developments under DOE Cooperative Agreement No. DE-FC07-94ID13238 occurred during two time periods due to budgetary constraints; April 1994 through September 1996 and October 1997 and December 1998. During these periods, ALCOA Inc developed a linear spray forming nozzle and specific support processes capable of scale-up for commercial production of aluminum sheet alloy products. Emphasis was given to alloys 3003 and 6111, both being commercially significant alloys used in the automotive industry. The report reviews research performed in the following areas: Nozzel Development, Fabrication, Deposition, Metal Characterization, Computer Simulation and Economics. With the formation of a Holding Company, all intellectual property developed in Phases I and II of the Project have been documented under separate cover for licensing to domestic producers.
Date: July 8, 1999
Creator: Leon, D. D.
Object Type: Report
System: The UNT Digital Library
Spin-Polarized Electron Transport and Emission from Strained Superlattices (open access)

Spin-Polarized Electron Transport and Emission from Strained Superlattices

Polarized electron emission from a series of new strained short-period AlInGaAs/AlGaAs superlattices (SL) is investigated. The In layer content was chosen to give minimal conduction-band offset with large strain splitting of the V-band. Simultaneous changing of Al content in both SL layers provides variation of the structure band gap. We demonstrate that tuning of the SL to the excitation energy can be achieved without loss of the electron polarization. The polarization of up to 84% was measured at room temperature.
Date: July 8, 1999
Creator: Clendenin, James E
Object Type: Report
System: The UNT Digital Library
Plutonium immobilization project development and testing technical project office quality assurance program description (open access)

Plutonium immobilization project development and testing technical project office quality assurance program description

The Plutonium Immobilization Project (PIP) is one of several fissile materials disposition projects managed by the Department of Energy (DOE) Office of Fissile Materials Disposition (OFMD). The PIP is expected to evolve from the current Development and Testing (D and T) effort, to design, to construction, and finally to operations. Overall management and technical management of the D and T effort resides at the Lead Laboratory, Lawrence Livermore National Laboratory (LLNL), through the LLNL Manager, Fissile Materials Disposition Program (FMDP). Day to day project activities are managed by the D and T Technical Project Office (TPO), which reports to the LLNL Manager, FMDP. The D and T TPO consists of the Technical Manager, the TPO Quality Assurance (QA) Program Manager, and TPO Planning and Support Staff. This Quality Assurance Program Description (QAPD) defines the QA policies and controls that will be implemented by these TPO personnel in their management of D and T activities. This QAPD is consistent with and responsive to the Department of Energy Fissile Materials Disposition Program Quality Assurance Requirements Document (FMDP QARD). As the Project and upper level requirement's documents evolve, this QAPD will be updated as necessary to accurately define and describe the QA Program …
Date: July 8, 1999
Creator: Gould, T H; MacLean, L M & Ziemba, J M
Object Type: Report
System: The UNT Digital Library
The development of Sn-Li coolant/breeding material for APEX/ALPS applications. (open access)

The development of Sn-Li coolant/breeding material for APEX/ALPS applications.

A Sn-Li alloy has been identified to be a coolant/breeding material for D-T fusion applications. The key feature of this material is its very low vapor pressure, which will be very useful for free surface concepts employed in APEX, ALPS and inertial confinement fission. The vapor is dominated by lithium, which has very low Z. Initial assessment of the material indicates acceptable tritium breeding capability, high thermal conductivity, expected low tritium volubility, and expected low chemical reactivities with water and air. Some key concerns are the high activation and material compatibility issues. The initial assessment of this material, for fission applications, is presented in this paper.
Date: July 8, 1999
Creator: Sze, D.-K.
Object Type: Article
System: The UNT Digital Library
Developing a cross-platform port simulation system. (open access)

Developing a cross-platform port simulation system.

With the advent of networked computer systems that connect disparate computer hardware and operating systems, it is important for port simulation systems to be able to run on a wide variety of computer platforms. This paper describes the design and implementation issues in reengineering the PORTSIM model in order to field the model to Windows-based systems as well as to Unix-based systems such as the Sun, Silicon Graphics, and HP workstations. The existing PORTSIM model was written to run on a Sun workstation running Unix. The model was initially implemented in MODSIM and C and utilized embedded SQL to retrieve port, ship, and cargo data from back-end OMCLE databases. Output reports, graphs, and tables for model results were written in C, utilizing third-party graphics libraries. This design and implementation worked well for the intended hardware platform and configuration, but as the number of model users grew and as the capabilities of the model expanded, a need developed to field the model to varying hardware configurations. This new requirement demanded that the existing design be modified to more easily allow for model fielding and maintenance. A phased approach is described that (1) identifies the existing model from which cross-platform development began, …
Date: July 8, 1999
Creator: Nevins, M. R.
Object Type: Article
System: The UNT Digital Library
Compared performances of ENDF/B-VI and JEF-2.2 for MOX core physics. (open access)

Compared performances of ENDF/B-VI and JEF-2.2 for MOX core physics.

The US is currently evaluating the use of MOX fuel in commercial LWR's for reducing weapons grade Pu stockpiles. The design and licensing processes will require that the validity of the nuclear data libraries and codes used in the effort be demonstrated. Unfortunately, there are only a very limited number of relatively old and non representative integral experiments' freely available to the US programs. This lack of adequate experimental data can be partially remediated by comparing the results of well validated European codes with the results of candidate US codes. The demonstration can actually be divided in two components: a code to code (Monte Carlo) comparison can easily demonstrate the validity and limits of the proposed algorithms; and the performances of nuclear data libraries should be compared, major trends should be observed, and their origins should be explained in terms of differences in evaluated nuclear data; In this paper, we have compared the performances of the JEF-2.2 and ENDF/B-VI.4 libraries for a series of benchmarks for k{sub eff}, void worth, and pin power distributions. Note that JEF-2.2 has been extensively validated for MOX applications.
Date: July 8, 1998
Creator: Finck, P. J.
Object Type: Article
System: The UNT Digital Library
Assessment of the effects of microbially influenced degradation on a massive concrete structure. Final report, Report 5 (open access)

Assessment of the effects of microbially influenced degradation on a massive concrete structure. Final report, Report 5

There is a need to estimate the effect of environmental conditions on construction materials to be used in the repository at Yucca Mountain. Previous reports from this project have demonstrated that it is important to develop an understanding of microbially influenced degradation (MID) development and its influence on massive concrete structures. Further, it has been shown that the most effective way to obtain quantitative data on the effects of MID on the structural integrity of repository concrete is to study manmade, analog structures known to be susceptible to MID. The cooling tower shell located at the Ohaaki Power Station near Wairakei, New Zealand is such a structure.
Date: July 8, 1995
Creator: Rogers, R.D.
Object Type: Report
System: The UNT Digital Library
Synchrotron Environmental Science-I Workshop Report. (open access)

Synchrotron Environmental Science-I Workshop Report.

Attendees of the Synchrotrons Environmental Science 1 (SES-1) workshop represented a broad spectrum of environmental science research areas and expertise in all of the current synchrotrons techniques (X-ray scattering and diffraction, X-ray absorption spectroscopy, and two- and three-dimensional X-ray imaging). These individuals came together to discuss current measurement obstacles in environmental research and, more specifically, ways to overcome such obstacles by applying synchrotrons radiation techniques. Significant obstacles in measurement affect virtually all of the research issues described. Attendees identified synchrotrons approaches of potential value in their research. A number of the environmental research studies discussed are currently being addressed with some success by synchrotron-based approaches. Nevertheless, improvements in low-Z measurement capabilities are needed to facilitate the use of synchrotrons radiation methodologies in environmental research.
Date: July 8, 1999
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Nanohardness and Chemical Bonding of Boron Nitride Films (open access)

Nanohardness and Chemical Bonding of Boron Nitride Films

Boron-nitride (BN) films are deposited by the reactive sputter deposition of fully dense, boron targets utilizing a planar magnetron source and an argon-nitrogen working gas mixture. Near-edge x-ray absorption fine structure analysis reveals distinguishing features of chemical bonding within the boron is photoabsorption cross-section. The hardness of the BN film surface is measured using nanoindentation. The sputter deposition conditions as well as the post-deposition treatments of annealing and nitrogen-ion implantation effect the chemical bonding and the film hardness. A model is proposed to quantify the film hardness using the relative peak intensities of the p*-resonances to the boron 1s spectra.
Date: July 8, 1998
Creator: Jankowski, Alan Frederic
Object Type: Article
System: The UNT Digital Library
Striped-double cavity fabry-perot interferometers using both glass and air cavities (open access)

Striped-double cavity fabry-perot interferometers using both glass and air cavities

We have used piezo-driven Fabry-Perot interferometers in the past far many continuous velocity-time measurements of fast moving surfaces. In order to avoid the annoying drift of some of these devices, we have developed and used inexpensive, solid glass, striped etalons with lengths up to 64 mm. Usable apertures are 35 mm by 80 mm with a finess of 25. A roundabout technique was devised for double cavity operation. We built a passive thermal housing for temperature stability, with tilt and height adjustments. We have also developed and used our first fixed etalon air-spaced cavity with a rotatable glass double- cavity insert. The rotation allows the referee cavity fractional order to be adjusted separately from that of the main cavity. It needs very little thermal protection, and eliminates the need for a roundabout scheme for double cavity operation, but is more costly than the solid glass version I
Date: July 8, 1998
Creator: Perry, S. & Steinmetz, L.
Object Type: Article
System: The UNT Digital Library
Status of special reactor process tube loadings, July 1, 1968 (open access)

Status of special reactor process tube loadings, July 1, 1968

This report gives the status of production tests control tube loadings in reactor process tubes containing significant amounts of SS material. Data are given in table form. For further description of column headings and the current discharge goal exposure plan refer to Document DUN-3443.
Date: July 8, 1968
Creator: Walton, R. P.
Object Type: Report
System: The UNT Digital Library
Affinity functions for modeling glass dissolution rates (open access)

Affinity functions for modeling glass dissolution rates

Glass dissolution rates decrease dramatically as glasses approach "saturation" with respect to the leachate solution. This effect may lower the dissolution rate to 1/100 to 1/1000 of the unsaturated rate. Although rate controls on glass dissolution are best understood for conditions far from saturation, most repository sites are chosen where water fluxes are minimal, and therefore the waste glass is most likely to dissolve under conditions close to saturation. Our understanding of controls on dissolution rates close to saturation, versus far from saturation, are therefore of greater significance for assessing release rates of radionuclides from repositories. The key term in the rate expression used to predict glass dissolution rates close to saturation is the affinity term, which accounts for saturation effects on dissolution rates. The form of the affinity term and parameters used to model glass dissolution are clearly critical for accurate estimates of glass performance in a repository. The concept of saturation with respect to glass dissolution is problematic because of the thermodynamically unstable nature of glass. Saturation implies similar rates of forward (dissolution) and back (precipitation) reactions, but glasses cannot precipitate from aqueous solutions; there can be no back reaction to form glass. However experiments have shown that …
Date: July 8, 1998
Creator: Bourcier, W L
Object Type: Article
System: The UNT Digital Library
Management of unconverted light for the National Ignition Facility target chamber (open access)

Management of unconverted light for the National Ignition Facility target chamber

The NIF target chamber beam dumps must survive high x-ray, laser, ion, and shrapnel exposures without excessive generation of vapors or particulate that will contaminate the final optics debris shields, thereby making the debris shields susceptible to subsequent laser damage. The beam dumps also must be compatible with attaining and maintaining the required target chamber vacuum and must not activate significantly under high neutron fluxes. Finally, they must be developed, fabricated, and maintained for a reasonable cost. The primary challenge for the beam dump is to survive up to 20 J/cm{sup 2} of lpm light and 1 - 2 J/cm{sup 2} of nominally 200 - 350 eV blackbody temperature x rays. Additional threats include target shrapnel, and other contamination issues. Designs which have been evaluated include louvered hot-pressed boron carbide (B{sub 4}C) or stainless steel (SS) panels, in some cases covered with transparent Teflon film, and various combinations of inexpensive low thermal expansion glasses backed by inexpensive absorbing glass. Louvered designs can recondense a significant amount of ablated material that would otherwise escape into the target chamber. Transparent Teflon was evaluated as an alternative way to capture ablated material. The thin Teflon sheet would need to be replaced after each …
Date: July 8, 1998
Creator: Anderson, A. T.; Bletzer, K.; Burnham, A. K.; Dixit, S; Genin, F. Y.; Hibbard, W. et al.
Object Type: Article
System: The UNT Digital Library
Four in. three jaw type connector suitable for vertical mounting sample for job 11 (open access)

Four in. three jaw type connector suitable for vertical mounting sample for job 11

As authorized by purchase order No. 11-2532 dated March 11, 1949 of the Kellex Corp., the first sample of a 4 inch three jaw type connector for Job 11 was fabricated. The design of the connector was per Crane Co. drawing DR-25126-D except vertical mounting. The materials were per Crane Co. drawing A-24491-C. As instructed in verbal conversation with Dr. D.D. Jacobus and as requested in Mr. J.J. Cuniffe`s letter of May 6, 1949, and Ingersoll-Rand Company`s 1 1/4 inch 534 impact wrench with suitable socket to fit the hexagon head of the operating screw of the 4 inch connector was procured on loan to make some preliminary tests. Engineering drawings are listed in a second report on the data base.
Date: July 8, 1949
Creator: Grubbe, A.C.
Object Type: Report
System: The UNT Digital Library
Landscape paradigms in physics and biology: Introduction and overview (open access)

Landscape paradigms in physics and biology: Introduction and overview

A brief introductory overview in general terms is given of concepts, issues and applications of the paradigm of rugged landscapes in the contexts of physics and biology.
Date: July 8, 1996
Creator: Sherrington, D.
Object Type: Article
System: The UNT Digital Library
Micronized coal-fired retrofit system for SO{sub x} reduction. Technical progress report No. 1, [April--June 1996] (open access)

Micronized coal-fired retrofit system for SO{sub x} reduction. Technical progress report No. 1, [April--June 1996]

The Project proposes in install a new TCS micronized coal fired heating plant for the PHRO Greenhouse Complex in the Town of Krzeszowice, Poland (near Krakow). PHRO utilizes 14 heavy oil-fired boilers to produce heat for its greenhouse facilities and also home heating to several adjacent housing cooperatives. The boilers currently burn a high-sulfur content heavy oil, called Mazute. The new micronized coal fired boiler would: (1) provide a significant portion of the heat load for PHRO, and a portion of the adjacent residential heating, (2) dramatically reduce sulfur dioxide air pollution emissions, while satisfying new Polish air regulations, and (3) provide attractive savings to PHRO, based on the quantity of displaced oil. TCS, Inc. will maintain primary responsibility for Project implementation and for supply of micronization equipment. Currently, the Town of Krzeszowice is considering a district heating program that would replace some, or all, of the 40 existing small in- town heating boilers that presently burn high-sulfur content coal. Potentially the district heating system can be expanded and connected into the PHRO boiler network; so that, PHRO boilers can supply all, or a portion of, the Town`s heating demand. The new TCS micronized coal system could provide a portion …
Date: July 8, 1996
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Effects of a spray leak inside the unloading area of the 204-AR waste unloading facility. Revision 1 (open access)

Effects of a spray leak inside the unloading area of the 204-AR waste unloading facility. Revision 1

This document presents the radiological dose and toxicological exposure calculations for a spray leak inside the unloading area of the 204-AR Waste Unloading Facility.
Date: July 8, 1997
Creator: Ryan, G. W. & Huang, C. H.
Object Type: Report
System: The UNT Digital Library