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Utilization of the noble gases in studies of underground nuclear detonations

Description: From symposium on noble gases; Las Vegas, Nevada, USA (24 Sep 1973). The Livermore Gas Diagnostics Program employs a number of rare gas isotopes, both stable and radioactive, in its investigations of the phenomenology of underground nuclear detonations. Radioactive gases in a sample are radiochemically purified by elution chromatography, and the separated gases are radioassayed by gamma-ray spectrometry and by internal or thin-window beta proportional counting. Concentrations of the stable gases are determined by mass-spectrometry, following chemical removal of the reactive gases in the sample. The most general application of the noble gases is as device fraction indicators to provide a basis for estimating totals of chimney-gas components. All of the stable rare gases except argon have been used as tracers, as have /sup 127/Xe and /sup 85/Kr. /sup 37/Ar and /sup 85/Kr have proven to be of particular value in the absence of a good tracer material as reference species for studies of chimney-gas chemistry. The rate of mixing of chimney gases and the degree to which the sampled gas truly represents the underground gas mixture can be studied with the aid of the fission- product gases. /sup 222/Ra and He are released to the cavity from the surrounding rock and are therefore useful in studies of the interaction of the detonation with the surrounding medium. (auth)
Date: September 17, 1973
Creator: Smith, C.F.
Partner: UNT Libraries Government Documents Department

Rio Blanco gas quality analysis and evaluation program status report

Description: >From joint meeting of the American Nuclear Society and the Atomic Industrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). A summary of the information currently available from the efforts of the Rio Blanco gas quality analysis and evaluation program is presented. (TFD)
Date: November 1, 1973
Creator: Smith, C.F. & Taylor, R.W.
Partner: UNT Libraries Government Documents Department

Critique of rationale for transmutation of nuclear waste

Description: It has been suggested that nuclear transmutation could be used in the elimination or reduction of hazards from radioactive wastes. The rationale for this suggestion is the subject of this paper. The objectives of partitioning-transmutation are described. The benefits are evaluated. The author concludes that transmutation would appear at best to offer the opportunity of reducing an already low risk. This would not seem to be justifiable considering the cost. If non-radiological risks are considered, there is a negative total benefit. (DC)
Date: July 1, 1980
Creator: Smith, C.F. & Cohen, J.J.
Partner: UNT Libraries Government Documents Department

Validation of predictive models for geologic disposal of radioactive waste via natural analogs

Description: The incorporation of toxic or hazardous material in the earth's crust is a phenomenon not unique to radioactive waste burial. Useful insights on the environmental transport and effects of underground toxic or radioactive material can be derived from comparative analysis against natural (mineral) analogs. This paper includes a discussion of the background and rationale for the analog approach, a descripton of several variations of the approach, and some sample applications to illustrate the concept, focusing on Radium-226 and Iodine-129 as specific case studies.
Date: March 1, 1981
Creator: Cohen, J.J. & Smith, C.F.
Partner: UNT Libraries Government Documents Department

Models and criteria for waste repository performance

Description: A primary objective of the Waste Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in assuring that this objective is met. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste management decision making. Criteria development needs and the relation between criteria and models are also discussed.
Date: March 1, 1981
Creator: Smith, C.F. & Cohen, J.J.
Partner: UNT Libraries Government Documents Department

Models and criteria for LLW disposal performance

Description: A primary objective of the Low Level Waste (LLW) Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in meeting this objective. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste mangement decision making. In addition, criteria development needs and the relation between criteria and models are discussed.
Date: December 1, 1980
Creator: Smith, C.F. & Cohen, J.J.
Partner: UNT Libraries Government Documents Department

Perspectives and reconciliation of viewpoints on risk assessment issues

Description: It is important to recognize the distinction between risk assessment and its components which include risk analysis, perspectives study, and decision analysis. Divergence of opinion within the scientific community as well as the public at large is a characteristic of issues related to nuclear power. The divergent opinions can largely be characterized as either optimistic or pessimistic in nature. Reconciliation of divergent viewpoints presents some difficult challenges. It is doubtful that issues which have an emotional or philosophical basis can be resolved through technical efforts. Public education on the technical issues might prove helpful.
Date: February 13, 1980
Creator: Smith, C.F. & Cohen, J.J.
Partner: UNT Libraries Government Documents Department

Hazard index for underground toxic material

Description: To adequately define the problem of waste management, quantitative measures of hazard must be used. This study reviews past work in the area of hazard indices and proposes a geotoxicity hazard index for use in characterizing the hazard of toxic material buried underground. Factors included in this index are: an intrinsic toxicity factor, formulated as the volume of water required for dilution to public drinking-water levels; a persistence factor to characterize the longevity of the material, ranging from unity for stable materials to smaller values for shorter-lived materials; an availability factor that relates the transport potential for the particular material to a reference value for its naturally occurring analog; and a correction factor to accommodate the buildup of decay progeny, resulting in increased toxicity.
Date: June 1, 1980
Creator: Smith, C.F.; Cohen, J.J. & McKone, T.E.
Partner: UNT Libraries Government Documents Department

Portable, remotely operated, computer-controlled, quadrupole mass spectrometer for field use

Description: A portable, remote-controlled mass spectrometer was required at the Nevada Test Site to analyze prompt post-event gas from the nuclear cavity in support of the underground testing program. A Balzers QMG-511 quadrupole was chosen for its ability to be interfaced to a DEC LSI-11 computer and to withstand the ground movement caused by this field environment. The inlet system valves, the pumps, the pressure and temperature transducers, and the quadrupole mass spectrometer are controlled by a read-only-memory-based DEC LSI-11/2 with a high-speed microwave link to the control point which is typically 30 miles away. The computer at the control point is a DEC LSI-11/23 running the RSX-11 operating system. The instrument was automated as much as possible because the system is run by inexperienced operators at times. The mass spectrometer has been used on an initial field event with excellent performance. The gas analysis system is described, including automation by a novel computer control method which reduces operator errors and allows dynamic access to the system parameters.
Date: April 1, 1982
Creator: Friesen, R.D.; Newton, J.C. & Smith, C.F.
Partner: UNT Libraries Government Documents Department

Nuclear waste issues: a perspectives document

Description: This report contains the results of systematic survey of perspectives on the question of radioactive waste management. Sources of information for this review include the scientific literature, regulatory and government documents, pro-nuclear and anti-nuclear publications, and news media articles. In examining the sources of information, it has become evident that a major distinction can be made between the optimistic or positive viewpoints, and the pessimistic or negative ones. Consequently, these form the principal categories for presentation of the perspectives on the radioactive waste management problem have been further classified as relating to the following issue areas: the physical aspects of radiation, longevity, radiotoxicity, the quantity of radioactive wastes, and perceptual factors.
Date: February 1, 1983
Creator: Cohen, J.J.; Smith, C.F. & Ciminese, F.J.
Partner: UNT Libraries Government Documents Department

Hazard index for underground toxic material

Description: A geotoxicity hazard index was developed for radioactive wastes buried in geologic media. Parameters are: toxicity, persistance, availability, and correction for progeny buildup. (DLC)
Date: January 11, 1980
Creator: Smith, C.F.; Cohen, J.J. & McKone, T.
Partner: UNT Libraries Government Documents Department

Summary: beyond fault trees to fault graphs

Description: Fault Graphs are the natural evolutionary step over a traditional fault-tree model. A Fault Graph is a failure-oriented directed graph with logic connectives that allows cycles. We intentionally construct the Fault Graph to trace the piping and instrumentation drawing (P and ID) of the system, but with logical AND and OR conditions added. Then we evaluate the Fault Graph with computer codes based on graph-theoretic methods. Fault Graph computer codes are based on graph concepts, such as path set (a set of nodes traveled on a path from one node to another) and reachability (the complete set of all possible paths between any two nodes). These codes are used to find the cut-sets (any minimal set of component failures that will fail the system) and to evaluate the system reliability.
Date: September 1, 1984
Creator: Alesso, H.P.; Prassinos, P. & Smith, C.F.
Partner: UNT Libraries Government Documents Department

Carbon-14 in waste packages for spent fuel in a tuff repository

Description: Carbon-14 is produced naturally by cosmic ray neutrons in the upper atmosphere. It is also produced in nuclear reactors, in amounts much smaller than the global inventory. About one-third of this is released directly to the atmosphere, and the other two-thirds remains in the spent fuel. Both the Environmental Protection Agency and the Nuclear Regulatory Commission have established limits on release of the {sup 14}C in spent fuel. This is of particular concern for the proposed repository in tuff, because of the unsaturated conditions and the consequent possibility of gaseous transport of {sup 14}C as CO{sub 2}. Existing measurements and calculations of the {sup 14}C inventory in spent fuel are reviewed. The physical distribution and chemical forms of the {sup 14}C are discussed. Available data on the release of {sup 14}C from spent fuel in aqueous solutions and in gaseous environments of air, nitrogen, and helium are reviewed. Projected {sup 14}C behavior in a tuff repository is described. It is concluded that {sup 14}C release measurements from spent fuel into moist air at temperatures both above and below the in situ boiling point of water as well as detailed transport calculations for the tuff geological environment will be needed to determine whether the 10CFR60 and 40CFR191 requirements can be met. 56 refs., 1 tab.
Date: October 14, 1986
Creator: Van Konynenburg, R.A.; Smith, C.F.; Culham, H.W. & Smith, H.D.
Partner: UNT Libraries Government Documents Department

Behavior of carbon-14 in waste packages for spent fuel in a repository in tuff. Revision 1

Description: Analysis of gas from a heated air-filled canister containing a spent fuel assembly before and after rupture of a fuel rod shows that about 1.5 mCi of {sup 14}C from the external surface of the assembly was rapidly oxidized and released as {sup 14}CO{sub 2} in excess oxygen at 275{sup 0}C and 10{sup 4}/sup rad/h. After rupture, an additional 0.3 mCi was released, probably also from the external surface. The total {sup 14}C inventory in the entire 15 x 15 rod assembly including structural hardware is estimated to be 690 mCi. These measurements indicate that account will have to be taken of the time distribution of lifetimes of the canisters, and a broad definition of the "engineered system" may be necessary, in order to meet 10CFR60 requirements with spent fuel in a repository in tuff. 22 refs., 1 tab.
Date: November 7, 1984
Creator: Van Konynenburg, R.A.; Smith, C.F.; Culham, H.W. & Otto, C.H. Jr.
Partner: UNT Libraries Government Documents Department

An assessment of issues related to determination of time periods required for isolation of high level waste

Description: A commonly held perception is that disposal of spent nuclear fuel or high-level waste presents a risk of unprecedented duration. The EPA requires that projected releases of radioactivity be limited for 10,000 years after disposal with the intent that risks from the disposal repository be no greater than those from the uranium ore deposit from which the nuclear fuel was originally extracted. This study reviews issues involved in assessing compliance with the requirement. The determination of compliance is assumption dependent primarily due to uncertainties in dosimetric data, and relative availability of the radioactivity for environmental transport and eventual assimilation by humans. A conclusion of this study is that, in time, a spent fuel disposal repository such as the projected Yucca Mountain Project Facility will become less hazardous than the original ore deposit. Only the time it takes to do so is in question. Depending upon the assumptions selected, this time period could range from a few centuries to hundreds of thousands of years considering only the inherent radiotoxicities. However, if it can be assumed that the spent fuel radioactivity emplaced in a waste repository is less than 1/10 as available for human assimilation than that in a uranium ore deposit, then even under the most pessimistic set of assumptions, the EPA criteria can be considered to be complied with. 24 refs., 5 figs., 2 tabs.
Date: June 1, 1989
Creator: Cohen, J.J.; Daer, G.R.; Smith, C.F.; Vogt, D.K. & Woolfolk, S.W.
Partner: UNT Libraries Government Documents Department

The secure, transportable, autonomous reactor (STAR): a small proliferation-resistant reactor system for developing countries

Description: The Secure, Transportable, Autonomous Reactor (STAR), is an integrated concept for a small, proliferation-resistant nuclear power system capable of meeting the growing power demands of many regions of the developing world. The STAR approach builds on earlier work investigating the features required for implementation of such a system. The STAR approach includes establishing overall system requirements, conducting research into issues common to four reactor concepts (gas, liquid metal, light water and molten salt), and defining and performing the down-selection to a preferred concept that will serve as the basis for continued development leading to an eventual prototype. The paper indicates that a number of unique and distinguishing innovations are needed to both meet the energy demands of most of the world's developing regions and address growing nuclear proliferation concerns. These technical innovations form much of the basis underlying the STAR concept and include: eliminating on-site refueling and fuel access; incorporating a systems approach to nuclear energy supply and infrastructure design, with all aspects of equipment life, fuel and waste cycles included; small unit size enabling transportability; replaceable standardized modular design; resilient and robust design concepts leading to large safety margins, high reliability and reduced maintenance; simplicity in operation with reliance on autonomous control and remote monitoring; and waste minimization and waste form optimization.
Date: May 27, 1999
Creator: Brown, N W; Hassberger, J A & Smith, C F
Partner: UNT Libraries Government Documents Department

Geotoxic materials in the surface environment

Description: The toxicology and natural occurrence of several recognized geotoxic elements including arsenic, cadmium, chromium, nickel, lead, selenium, uranium, and vanadium is reviewed. The behavior of these elements in the environment and in biological systems is examined. The properties of these eight toxic elements are summarized and presented in a toxicity matrix. The toxicity matrix identifies each of the elements in terms of average crustal abundance, average soil concentration, drinking water standards, irrigation water standards, daily human intake, aquatic toxicity, phytotoxicity, mammalian toxicity, human toxicity, and bioaccumulation factors for fish. Fish are the major aquatic environment contribution to the human diet and bioaccumulation in aquatic ecosystems has been demonstrated to be an important factor in the cycling of elements in aquatic ecosystems. The toxicity matrix is used as a first approximation to rank the geotoxicity of elements for the purpose of focusing future efforts. The ranking from highest to lowest toxicity with respect to the toxicity parameters being discussed is as follows: arsenic, cadmium, lead, selenium, chromium, vanadium, nickel, and uranium.
Date: December 7, 1981
Creator: Koranda, J.J.; Cohen, J.J.; Smith, C.F. & Ciminesi, F.J.
Partner: UNT Libraries Government Documents Department