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User`s manual for the radioactive decay and accumulation code RADAC

User`s manual for the radioactive decay and accumulation code RADAC

Date: November 1, 1995
Creator: Salmon, R.; Loghry, S.L. & Ashline, R.C.
Description: The RADAC computer code calculates radioactive decay and accumulation of decayed products using an algorithm based on the direct use of the Bateman equations and referred to here as the yield factor method. This report explains the yield factor method, gives an overview of the various modules in the RADAC code system, and describes the decay and accumulation code in detail. The RADAC code has capacity for two waste types and can accommodate up to 60 years of annual waste inputs. Decay times as high as 1 million years can be calculated. The user supplies the undecayed composition and radioactivity of the waste placed in storage each year. The code calculates the decayed composition, radioactivity, and thermal power of the accumulated waste at the end of each year and gives the results in terms of grams and curies of individual radionuclides. Calculations can be made for up to 19 waste storage sites in a single run. For each site and each waste type, calculations can be made by 1-year steps up to 60 years, by 10-year steps to 160 years, and by 6 discrete steps to 1 million years. Detailed outputs can be printed for each waste site and each ...
Contributing Partner: UNT Libraries Government Documents Department
Initiation of environmentally-assisted cracking in low-alloy steels

Initiation of environmentally-assisted cracking in low-alloy steels

Date: June 1, 1996
Creator: Wire, G.L. & Li, Y.Y.
Description: Environmentally-Assisted Cracking (EAC) in low alloy steels is activated by a critical level of sulfide ions at the crack tip, which is produced from dissolution of sulfide inclusions (MnS, FeS, etc.) in the steel following exposure by a growing crack. EAC of concern herein is the increase of fatigue crack growth rate of up to 40 to 100 times the rate in air that occurs at 240--300 C in high temperature LWR or boiler water environments. The initiation of EAC is the onset of the higher fatigue crack growth rates in fully developed cracks already presumed to be present due to fatigue, stress corrosion cracking, or induced by fabrication. Initiation of EAC is induced by a change in loading parameters causing the fatigue crack growth rate to increase from a small multiple (2--4) to 40--100 times the air rate. A steady state theory developed by Combrade, suggests that EAC will initiate only above a critical crack velocity and cease below this same velocity. However, more recent tests show that EAC can persist down to much lower velocities (100 times lower) in low oxygen water at slightly lower temperatures. A special set of experiments on high sulfur plate material demonstrate that ...
Contributing Partner: UNT Libraries Government Documents Department
Stratigraphic data for wells at and near the Idaho National Engineering Laboratory, Idaho

Stratigraphic data for wells at and near the Idaho National Engineering Laboratory, Idaho

Date: May 1, 1996
Creator: Anderson, S.R.; Ackerman, D.J.; Liszewski, M.J. & Frieburger, R.M.
Description: A stratigraphic data base containing 230 stratigraphic units in 333 wells was constructed for deposits that make up the unsaturated zone and the Snake River Plain aquifer at and near INEL in eastern Idaho. Stratigraphic units, which were identified and correlated using data from numerous outcrops, 26 continuous cores, and 328 natural-gamma logs available in Dec. 1993, include 121 basalt-flow groups, 102 sedimentary interbeds, 6 andesite-flow groups, and 1 rhyolite dome. By volume, basalt flows make up about 90% of the deposits underlying most of this 890 mi{sup 2} area. Basalt, sediment, andesite, and rhyolite were identified from outcrops and cores that were selectively evaluated. Stratigraphic units were correlated using these data and natural-gamma logs. Best correlations were for basalt and sediment at Test Area North, the Naval Reactors Area, the Test Reactor Area, ICPP, and the Radioactive Waste Management Complex (RWMC), where most cores and 2/3 of the logs were obtained. Correlations range from good at the RWMC to uncertain the eastern half of the study area. A computer diskette containing the data is included.
Contributing Partner: UNT Libraries Government Documents Department
Analysis of hydrogen vehicles with cryogenic high pressure storage

Analysis of hydrogen vehicles with cryogenic high pressure storage

Date: June 19, 1998
Creator: Aceves, S. M. & Berry, G. D.
Description: Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LIQ) or ambient-temperature compressed hydrogen (CH2). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.
Contributing Partner: UNT Libraries Government Documents Department
A statistical mechanical description of biomolecular hydration

A statistical mechanical description of biomolecular hydration

Date: February 1, 1996
Creator: unknown
Description: We present an efficient and accurate theoretical description of the structural hydration of biological macromolecules. The hydration of molecules of almost arbitrary size (tRNA, antibody-antigen complexes, photosynthetic reaction centre) can be studied in solution and in the crystal environment. The biomolecular structure obtained from x-ray crystallography, NMR, or modeling is required as input information. The structural arrangement of water molecules near a biomolecular surface is represented by the local water density analogous to the corresponding electron density in an x-ray diffraction experiment. The water-density distribution is approximated in terms of two- and three-particle correlation functions of solute atoms with water using a potentials-of-mean-force expansion.
Contributing Partner: UNT Libraries Government Documents Department
Stress and Defect Control in GaN Using Low Temperature Interlayers

Stress and Defect Control in GaN Using Low Temperature Interlayers

Date: December 4, 1998
Creator: Akasaki, I.; Amano, H.; Chason, E.; Figiel, J.; Floro, J.A.; Han, J. et al.
Description: In organometallic vapor phase epitaxial growth of Gail on sapphire, the role of the low- temperature-deposited interlayers inserted between high-temperature-grown GaN layers was investigated by in situ stress measurement, X-ray diffraction, and transmission electron microscopy. Insertion of a series of low temperature GaN interlayers reduces the density of threading dislocations while simultaneously increasing the tensile stress during growth, ultimately resulting in cracking of the GaN film. Low temperature AIN interlayers were found to be effective in suppressing cracking by reducing tensile stress. The intedayer approach permits tailoring of the film stress to optimize film structure and properties.
Contributing Partner: UNT Libraries Government Documents Department
Evaluation of a non-cyanide gold plating process for switch tubes

Evaluation of a non-cyanide gold plating process for switch tubes

Date: January 1, 1996
Creator: Norwood, D.P. & Martinez, F.E.
Description: Switch tubes are used in nuclear weapon firing sets and are required to be reliable and impervious to gas permeation for many years. To accomplish this, a gold plated coating of approximately 25 microns is required over all metal surfaces on the tube exterior. The gold has historically been plated using gold cyanide plating chemistry. In this work we proposed to replace the cyanide plating bath with an environmentally friendlier sulfite gold plating bath. Low and high pH sulfite plating chemistries were investigated as possible replacements for the cyanide gold plating chemistry. The low pH plating chemistry demonstrated a gold plated coating which met the high purity, grain size, and hardness requirements for switch tubes. The high pH chemistry was rejected primarily because the hardness of the gold plated coatings was too high and exceeded switch tube coating requirements. A problem with nodule formation on the gold plated surface using the low pH chemistry had to be resolved during this evaluation. The nodule formation was postulated to be produced by generation of SO{sub 2} in the low pH bath causing gold to be precipitated out when the sulfite concentration falls below a minimum level. The problem was resolved by maintaining ...
Contributing Partner: UNT Libraries Government Documents Department
LANSCE beam current limiter

LANSCE beam current limiter

Date: June 1, 1996
Creator: Gallegos, F.R.
Description: The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.
Contributing Partner: UNT Libraries Government Documents Department
Formulation and make-up of simulate dilute water, low ionic content aqueous solution

Formulation and make-up of simulate dilute water, low ionic content aqueous solution

Date: April 4, 1997
Creator: Gdowski, G.
Description: This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate the effect of ionic concentrating due to elevated temperature water flowing through fractures where salts and minerals have been deposited due to evaporation and boiling.
Contributing Partner: UNT Libraries Government Documents Department
ORNL contribution to the IAEA bcnchmark problem on fission reactor decommissioning

ORNL contribution to the IAEA bcnchmark problem on fission reactor decommissioning

Date: May 1, 1996
Creator: Broadhead, B.L. & Childs, R.L.
Description: Recently the International Atomic Energy Agency (IAEA) selected a benchmark problem for calculation of radioactivity inventories and dose estimates necessary for fission reactor decommissioning. Several researchers were invited to participate in the solution of this benchmark problem set. The contribution from Oak Ridge National Laboratory (ORNL) is presented in this paper.
Contributing Partner: UNT Libraries Government Documents Department
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