58 Matching Results

Search Results

Advanced search parameters have been applied.

Exposure and risk calculations for disposal of wastes having minimal radioactivity

Description: The US Nuclear Regulatory Commission is currently considering revision of rules 10 CFR 20 and 10 CFR 61, which cover disposal of solid wastes containing minimal activity radioactivity. In support of these revised rules, we have evaluated the consequences of disposing of four waste streams at four types of disposal areas located in three different geographic regions. Consequences are expressed in terms of human exposures and associated health effects. Each geographic region has its own climate and geology. Example waste streams, waste disposal methods, and geographic regions chosen for this study are clearly specified. The PRESTO-II methodology was used to evaluate radionuclide transport and health effects. This methodology was developed to assess radiological impacts to a static local population for a 1000-year period following disposal. The modeling of pathways and processes of migration from the trench to exposed populations included the following considerations: groundwater transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, deposition, inhalation, and ingestion of contaminated beef, milk, crops, and water. 9 references, 2 figures, 3 tables.
Date: January 1, 1984
Creator: Fields, D.E.
Partner: UNT Libraries Government Documents Department

Computation of health risk associated with radionuclide transport and human exposure

Description: A methodology to characterize the physical site, the chemical and physical properties of radionuclides, and the human response to radionuclides following their ingestion, inhalation, or external exposure in the evaluation of health risks associated with surface deposition or shallow burial of contaminated materials is described. PRESTO-II simulates the transport of radionuclides from the disposal site and predicts radionuclide exposures and cancer risks for the 1000-year period following the end of burial operations. 10 references. (ACR)
Date: January 1, 1984
Creator: Fields, D.E.
Partner: UNT Libraries Government Documents Department

Selected approaches to pathway analysis

Description: Prediction of potential radionuclide exposure and the resulting health risk to individuals working on the site of a mining operation as well as to off-site individuals located down-wind or down-stream of such an operation, is facilitated by applying well-defined models and well-documented computer codes. Such methodologies and codes may have the advanages of being previously verified and applied, of having readily available data bases, of having supporting codes that may be used to prepare data sets or graph predictions, and of generating hard copy summaries containing intermediate calculations and the results of simulations. Several methodologies and codes developed for application to shallow-land disposal of radioactive wastes are of particular interest. One such methodology and code, PRESTO-II (Prediction of Radiation Effects from Shallow Trench Operations) is designed to evaluate possible doses and risks (health effects) from shallow-land disposal operations. This code, its supporting codes and data bases are discussed, together with several applications. 16 refs., 2 tabs.
Date: January 1, 1988
Creator: Fields, D.E. & Uslu, I.
Partner: UNT Libraries Government Documents Department

PHYSICS OF POLARITY AT RHIC-VOLUME 10.

Description: The RBRC Workshop on Physics of Polarimetry at RHIC was held from Aug 4 to 7, 1998 at BNL. The primary motive of the workshop is (1) to discuss the RHIC polarimeter using the elastic proton-carbon scattering at Coulomb-nuclear interference region (p-C CNI polarimeter) in detail and write a proposal for the test experiment a t the AGS, (2) to discuss the related physics, (3) and to discuss other options for the RHIC polarimetry. The idea of the p-C CNI polarimeter was proposed last year as a simple, inexpensive and efficient polarimeter for RHIC. In order to establish this polarimeter, we have decided to carry out a test experiment by using a polarized beam at the AGS. We have made a draft of the proposal during the workshop. For the p-C CNI polarimeter, a telescope detector using both the micro-channel plate (MCP) and the SSD was proposed to detect low energy recoil carbon ions, based on the test measurements at IUCF and Kyoto, where the carbon ions as low as 200 keV were successfully detected. The kinetic energy of carbon ion is measured with the SSD, and the velocity is measured by TOF between the two detectors and between the accelerator rf pulse and the two detectors. Counting rates for the background and true events were estimated. With the proposed polarimeter, one can expect to measure the beam polarization at the AGS and RHIC at an accuracy of 10% within a reasonable time period. We will test this detector system at Kyoto as soon as possible and install it in the AGS ring for the test measurement of A{sub N} during E880 which is scheduled early in the next year.
Date: August 4, 1998
Creator: IMAI,K. & FIELDS,D.
Partner: UNT Libraries Government Documents Department

Analysis/plot generation code with significance levels computed using Kolmogorov-Smirnov statistics valid for both large and small samples

Description: This report describes a version of the TERPED/P computer code that is very useful for small data sets. A new algorithm for determining the Kolmogorov-Smirnov (KS) statistics is used to extend program applicability. The TERPED/P code facilitates the analysis of experimental data and assists the user in determining its probability distribution function. Graphical and numerical tests are performed interactively in accordance with the user's assumption of normally or log-normally distributed data. Statistical analysis options include computation of the chi-square statistic and the KS one-sample test statistic and the corresponding significance levels. Cumulative probability plots of the user's data are generated either via a local graphics terminal, a local line printer or character-oriented terminal, or a remote high-resolution graphics device such as the FR80 film plotter or the Calcomp paper plotter. Several useful computer methodologies suffer from limitations of their implementations of the KS nonparametric test. This test is one of the more powerful analysis tools for examining the validity of an assumption about the probability distribution of a set of data. KS algorithms are found in other analysis codes, including the Statistical Analysis Subroutine (SAS) package and earlier versions of TERPED. The inability of these algorithms to generate significance levels for sample sizes less than 50 has limited their usefulness. The release of the TERPED code described herein contains algorithms to allow computation of the KS statistic and significance level for data sets of, if the user wishes, as few as three points. Values computed for the KS statistic are within 3% of the correct value for all data set sizes.
Date: October 1, 1983
Creator: Kurtz, S.E. & Fields, D.E.
Partner: UNT Libraries Government Documents Department

Algorithm for computing significance levels using the Kolmogorov-Smirnov statistic and valid for both large and small samples

Description: The KSTEST code presented here is designed to perform the Kolmogorov-Smirnov one-sample test. The code may be used as a stand-alone program or the principal subroutines may be excerpted and used to service other programs. The Kolmogorov-Smirnov one-sample test is a nonparametric goodness-of-fit test. A number of codes to perform this test are in existence, but they suffer from the inability to provide meaningful results in the case of small sample sizes (number of values less than or equal to 80). The KSTEST code overcomes this inadequacy by using two distinct algorithms. If the sample size is greater than 80, an asymptotic series developed by Smirnov is evaluated. If the sample size is 80 or less, a table of values generated by Birnbaum is referenced. Valid results can be obtained from KSTEST when the sample contains from 3 to 300 data points. The program was developed on a Digital Equipment Corporation PDP-10 computer using the FORTRAN-10 language. The code size is approximately 450 card images and the typical CPU execution time is 0.19 s.
Date: October 1, 1983
Creator: Kurtz, S.E. & Fields, D.E.
Partner: UNT Libraries Government Documents Department

Interactive statistical-distribution-analysis program utilizing numerical and graphical methods

Description: The TERPED/P program is designed to facilitate the quantitative analysis of experimental data, determine the distribution function that best describes the data, and provide graphical representations of the data. This code differs from its predecessors, TEDPED and TERPED, in that a printer-plotter has been added for graphical output flexibility. The addition of the printer-plotter provides TERPED/P with a method of generating graphs that is not dependent on DISSPLA, Integrated Software Systems Corporation's confidential proprietary graphics package. This makes it possible to use TERPED/P on systems not equipped with DISSPLA. In addition, the printer plot is usually produced more rapidly than a high-resolution plot can be generated. Graphical and numerical tests are performed on the data in accordance with the user's assumption of normality or lognormality. Statistical analysis options include computation of the chi-squared statistic and its significance level and the Kolmogorov-Smirnov one-sample test confidence level for data sets of more than 80 points. Plots can be produced on a Calcomp paper plotter, a FR80 film plotter, or a graphics terminal using the high-resolution, DISSPLA-dependent plotter or on a character-type output device by the printer-plotter. The plots are of cumulative probability (abscissa) versus user-defined units (ordinate). The program was developed on a Digital Equipment Corporation (DEC) PDP-10 and consists of 1500 statements. The language used is FORTRAN-10, DEC's extended version of FORTRAN-IV.
Date: April 1, 1982
Creator: Glandon, S. R. & Fields, D. E.
Partner: UNT Libraries Government Documents Department

Radionuclide daughter inventory generator code: DIG

Description: The Daughter Inventory Generator (DIG) code accepts a tabulation of radionuclide initially present in a waste stream, specified as amounts present either by mass or by activity, and produces a tabulation of radionuclides present after a user-specified elapsed time. This resultant radionuclide inventory characterizes wastes that have undergone daughter ingrowth during subsequent processes, such as leaching and transport, and includes daughter radionuclides that should be considered in these subsequent processes or for inclusion in a pollutant source term. Output of the DIG code also summarizes radionuclide decay constants. The DIG code was developed specifically to assist the user of the PRESTO-II methodology and code in preparing data sets and accounting for possible daughter ingrowth in wastes buried in shallow-land disposal areas. The DIG code is also useful in preparing data sets for the PRESTO-EPA code. Daughter ingrowth in buried radionuclides and in radionuclides that have been leached from the wastes and are undergoing hydrologic transport are considered, and the quantities of daughter radionuclide are calculated. Radionuclide decay constants generated by DIG and included in the DIG output are required in the PRESTO-II code input data set. The DIG accesses some subroutines written for use with the CRRIS system and accesses files containing radionuclide data compiled by D.C. Kocher. 11 refs.
Date: September 1, 1985
Creator: Fields, D.E. & Sharp, R.D.
Partner: UNT Libraries Government Documents Department

Unrestricted disposal of minimal activity levels of radioactive wastes: exposure and risk calculations

Description: The US Nuclear Regulatory Commission is currently considering revision of rule 10 CFR Part 20, which covers disposal of solid wastes containing minimal radioactivity. In support of these revised rules, we have evaluated the consequences of disposing of four waste streams at four types of disposal areas located in three different geographic regions. Consequences are expressed in terms of human exposures and associated health effects. Each geographic region has its own climate and geology. Example waste streams, waste disposal methods, and geographic regions chosen for this study are clearly specified. Monetary consequences of minimal activity waste disposal are briefly discussed. The PRESTO methodology was used to evaluate radionuclide transport and health effects. This methodology was developed to assess radiological impacts to a static local population for a 1000-year period following disposal. Pathways and processes of transit from the trench to exposed populations included the following considerations: groundwater transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, deposition, inhalation, and ingestion of contaminated beef, milk, crops, and water. 12 references, 2 figures, 8 tables.
Date: August 1, 1984
Creator: Fields, D.E. & Emerson, C.J.
Partner: UNT Libraries Government Documents Department

PREREM: an interactive data preprocessing code for INREM II. Part I: user's manual. Part II: code structure

Description: PREREM is an interactive computer code developed as a data preprocessor for the INREM-II (Killough, Dunning, and Pleasant, 1978a) internal dose program. PREREM is intended to provide easy access to current and self-consistent nuclear decay and radionuclide-specific metabolic data sets. Provision is made for revision of metabolic data, and the code is intended for both production and research applications. Documentation for the code is in two parts. Part I is a user's manual which emphasizes interpretation of program prompts and choice of user input. Part II stresses internal structure and flow of program control and is intended to assist the researcher who wishes to revise or modify the code or add to its capabilities. PREREM is written for execution on a Digital Equipment Corporation PDP-10 System and much of the code will require revision before it can be run on other machines. The source program length is 950 lines (116 blocks) and computer core required for execution is 212 K bytes. The user must also have sufficient file space for metabolic and S-factor data sets. Further, 64 100 K byte blocks of computer storage space are required for the nuclear decay data file. Computer storage space must also be available for any output files produced during the PREREM execution. 9 refs., 8 tabs.
Date: May 1, 1981
Creator: Ryan, M.T. & Fields, D.E.
Partner: UNT Libraries Government Documents Department

Simulations of long-term health risk from shallow land burial of low-level radioactive waste

Description: PRESTO (Prediction of Radiation Effects from Shallow Trench Operations) is a computer code developed under U.S. Environmental Protection Agency (EPA) funding to evaluate possible health effects from shallow land burial of low-level radioactive wastes. The model is intended to assess radionuclide transport, ensuing exposure, and health impact to a static local population for up to 1000 years following the end of burial operations. Human exposure scenarios that may be considered by model include normal releases (including leaching and operational spillage), human intrusion, and near site farming. Pathways and processes of transit from the trench to an individual or population include:groundwater transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, overland flow, erosion, surface water dilution, resuspension, atmospheric transport, deposition, inhalation, and ingestion of contaminated beef, milk, crops, and water. Off-site population and individual doses and cancer risks may be calculated as well as doses and risks to the intruder and farmer. Data have been compiled for three extant shallow land burial sites: Barnwell, South Carolina; Beatty, Nevada; and West Valley, New York. Some simulation results for the Barnwell site are presented. 13 references, 3 figures, 3 tables.
Date: January 1, 1982
Creator: Little, C.A. & Fields, D.E.
Partner: UNT Libraries Government Documents Department

Calculations of sodium aerosol concentrations at breeder reactor air intake ports

Description: This report describes the methodology used and results obtained in efforts to estimate the sodium aerosol concentrations at air intake ports of a liquid-metal cooled, fast-breeder nuclear reactor. A range of wind speeds from 2 to 10 m/s is assumed, and an effort is made to include building wake effects which in many cases dominate the dispersal of aerosols near buildings. For relatively small release rates on the order of 1 to 10 kg/s, it is suggested that the plume rise will be small and that estimates of aerosol concentrations may be derived using the methodology of Wilson and Britter (1982), which describes releases from surface vents. For more acute releases with release rates on the order of 100 kg/s, much higher release velocities are expected, and plume rise must be considered. Both momentum-driven and density-driven plume rise are considered. An effective increase in release height is computed using the Split-H methodology with a parameterization suggested by Ramsdell (1983), and the release source strength was transformed to rooftop level. Evaluation of the acute release aerosol concentration was then based on the methodology for releases from a surface release of this transformed source strength.
Date: January 1, 1985
Creator: Fields, D.E. & Miller, C.W.
Partner: UNT Libraries Government Documents Department

Methodology for estimating sodium aerosol concentrations during breeder reactor fires

Description: We have devised and applied a methodology for estimating the concentration of aerosols released at building surfaces and monitored at other building surface points. We have used this methodology to make calculations that suggest, for one air-cooled breeder reactor design, cooling will not be compromised by severe liquid-metal fires.
Date: January 1, 1985
Creator: Fields, D.E. & Miller, C.W.
Partner: UNT Libraries Government Documents Department

User's manual for DWNWND: an interactive Gaussian plume atmospheric transport model with eight dispersion parameter options

Description: The most commonly used approach for estimating the atmospheric concentration and deposition of material downwind from its point of release is the Gaussian plume atmospheric dispersion model. Two of the critical parameters in this model are sigma/sub y/ and sigma/sub z/, the horizontal and vertical dispersion parameters, respectively. A number of different sets of values for sigma/sub y/ and sigma/sub z/ have been determined empirically for different release heights and meteorological and terrain conditions. The computer code DWNWND, described in this report, is an interactive implementation of the Gaussian plume model. This code allows the user to specify any one of eight different sets of the empirically determined dispersion paramters. Using the selected dispersion paramters, ground-level normalized exposure estimates are made at any specified downwind distance. Computed values may be corrected for plume depletion due to deposition and for plume settling due to gravitational fall. With this interactive code, the user chooses values for ten parameters which define the source, the dispersion and deposition process, and the sampling point. DWNWND is written in FORTRAN for execution on a PDP-10 computer, requiring less than one second of central processor unit time for each simulation.
Date: May 1, 1980
Creator: Fields, D.E. & Miller, C.W.
Partner: UNT Libraries Government Documents Department

APORT: a program for the area-based apportionment of county variables to cells of a polar grid. [Airborne pollutant transport models]

Description: The APORT computer code was developed to apportion variables tabulated for polygon-structured civil districts onto cells of a polar grid. The apportionment is based on fractional overlap between the polygon and the grid cells. Centering the origin of the polar system at a pollutant source site yields results that are very useful for assessing and interpreting the effects of airborne pollutant dissemination. The APOPLT graphics code, which uses the same data set as APORT, provides a convenient visual display of the polygon structure and the extent of the polar grid. The APORT/APOPLT methodology was verified by application to county summaries of cattle population for counties surrounding the Oyster Creek, New Jersey, nuclear power plant. These numerical results, which were obtained using approximately 2-min computer time on an IBM System 360/91 computer, compare favorably to results of manual computations in both speed and accuracy.
Date: November 1, 1978
Creator: Fields, D.E. & Little, C.A.
Partner: UNT Libraries Government Documents Department

Applicability of Gaussian plume dispersion parameters to acute radionuclide releases

Description: The Gaussian plume atmospheric dispersion model is one of the most widely used models for assessing the impact of radionuclides released to the atmosphere. This model is a statistical solution to the basic atmospheric diffusion equation. As a result, the Gaussian model should give more accurate results when used to calculate average air concentrations from long-term releases rather than for short-term concentrations from acute releases. However, the Gaussian model is routinely applied to such short-term radionuclide releases. The purpose of this paper is to examine the applicability of standard plume dispersion parameters for calculations of air concentrations resulting from such acute releases.
Date: January 1, 1980
Creator: Miller, C.W. & Fields, D.E.
Partner: UNT Libraries Government Documents Department

HTGR fuel reprocessing pilot plant: results of the sequential equipment operation

Description: The second sequential operation of the HTGR fuel reprocessing cold-dry head-end pilot plant equipment has been successfully completed. Twenty standard LHGTR fuel elements were crushed to a size suitable for combustion in a fluid bed burner. The graphite was combusted leaving a product of fissile and fertile fuel particles. These particles were separated in a pneumatic classifier. The fissile particles were fractured and reburned in a fluid bed to remove the inner carbon coatings. The remaining products are ready for dissolution and solvent extraction fuel recovery.
Date: May 1, 1979
Creator: Strand, J.B.; Fields, D.E. & Kergis, C.A.
Partner: UNT Libraries Government Documents Department

Validation of annual average air concentration predictions from the AIRDOS-EPA computer code

Description: The AIRDOS-EPA computer code is used to assess the annual doses to the general public resulting from releases of radionuclides to the atmosphere by Oak Ridge National Laboratory (ORNL) facilities. This code uses a modified Gaussian plume equation to estimate air concentrations resulting from the release of a maximum of 36 radionuclides. Radionuclide concentrations in food products are estimated from the output of the atmospheric transport model using the terrestrial transport model described in US Nuclear Regulatory Commission Regulatory Guide 1.109. Doses to man at each distance and direction specified are estimated for up to eleven organs and five exposure modes. To properly use any environmental transport model, some estimate of the model's predictive accuracy must be obtained. Because of a lack of sufficient data for the ORNL site, one year of weekly average /sup 85/Kr concentrations observed at 13 stations located 30 to 150 km distant from an assumed-continuous point source at the Savannah River Plant, Aiken, South Carolina, have been used in a validation study of the atmospheric transport portion of AIRDOS-EPA. The predicted annual average concentration at each station exceeded the observed value in every case. The overprediction factor ranged from 1.4 to 3.4 with an average value of 2.4. Pearson's correlation between pairs of logarithms of observed and predicted values was r = 0.93. Based on a one-tailed students's test, we can be 98% confident that for this site under similar meteorological, release, and monitoring conditions no annual average air concentrations will be observed at the sampling stations in excess of those predicted by the code. As the averaging time of the prdiction decreases, however, the uncertainty in the prediction increases.
Date: January 1, 1981
Creator: Miller, C.W.; Fields, D.E. & Cotter, S.J.
Partner: UNT Libraries Government Documents Department

PRESTO-II computer code for safety assessment on shallow land disposal of low-level wastes

Description: The PRESTO-II (Prediction of Radiation Effects from Shallow Trench Operations) computer code has been applied for the following sites; Koteyli, Balikesir and Kozakli, Nevsehir in Turkey. This site selection was based partially on the need to consider a variety of hydrologic and climatic situations, and partially on the availability of data. The results obtained for the operational low-level waste disposal site at Barnwell, South Carolina, are presented for comparison. 6 refs., 2 figs., 1 tab.
Date: January 1, 1987
Creator: Uslu, I.; Fields, D.E. & Yalcintas, M.G.
Partner: UNT Libraries Government Documents Department

Impact of the Chernobyl accident on Turkey

Description: In this paper, we present and discuss measurements of radionuclide concentrations made in Turkey during the Chernobyl event and perform preliminary analyses of the internal and external doses associated with exposure to these materials. 15 refs., 1 tab.
Date: January 1, 1987
Creator: Fields, D.E.; Ozluoglu, N. & Yalcintas, M.G.
Partner: UNT Libraries Government Documents Department

Local transport of vertically- and horizontally-emitted sodium oxide aerosols

Description: Liquid-metal cooled breeder reactors are expected to use large quantities of sodium or sodium-potassium alloy, and evaluation of the possible consequences of a liquid-metal fire, henceforth referred to as a sodium fire, is an important consideration. Of particular interest is the sodium aerosol concentration at the air intake ports that are used for reactor cooling, and which might suffer restricted flow under high aerosol concentrations. We have devised and applied a methodology for estimating the concentration of aerosols released vertically and horizontally from building surfaces and monitored at other building surface points. We have used this methodology to make calculations that indicate the time-development of aerosol build-up, and the maximum aerosol concentrations, at air intake ports. Building wake effects, momentum-driven plume rise, and density-driven plume rise are considered.
Date: January 1, 1986
Creator: Fields, D.E.; Miller, C.W. & Cooper, A.C.
Partner: UNT Libraries Government Documents Department

Studies involving proposed waste disposal facilities in Turkey

Description: Today principal sources of radioactive wastes are hospitals, research institutions, biological research centers, universities, industries and two research reactors in Turkey. These wastes will be treated in a pilot waste treatment facility located in Cekmece Nuclear Research and Training Center, Istanbul. In this temporary waste disposal facility, the wastes will be stored in 200 liter concrete containers until the establishment of the permanent waste disposal sites in Turkey, in 1990. The PRESTO - II (Prediction of Radiation Effects From Shallow Trench Operations) computer code was applied for the general probable sites for LLW disposal in Turkey. The model is non-site specific screening model for assessing radionuclide transport, ensuring exposure, and health impacts to a static local population for a chosen time period, following the end of the disposal operation. The methodology that this codes takes into consideration is versatile and explicitly considers infiltration and percolation of surface water into the trench, leaching of radionuclides, vertical and horizontal transport of radionuclides and use of this contaminated ground water for farming, irrigation, and ingestion.
Date: January 1, 1987
Creator: Uslu, I.; Fields, D.E. & Yalcintas, M.G.
Partner: UNT Libraries Government Documents Department

Estimation of doses to individuals from radionuclides disposed of in Solid Waste Storage Area 6

Description: A simple methodology has been applied to estimate possible doses to individuals from exposure to radionuclides released from Solid Waste Storage Area No. 6. This is the only operating shallow-land disposal site for radioactive waste at the Oak Ridge National Laboratory. The methodology is based upon simple, conservative, assumptions. A data base of radionuclides disposed of in trenches and auger holes was prepared, and several radionuclide transport and ingestion scenarios were considered. The results of these simulations demonstrate the potential for adverse health effects associated with this waste disposal area, and support the need for further calculations using more complete and realistic assumptions. 5 refs., 6 tabs.
Date: January 1, 1984
Creator: Fields, D.E.; Boegley, W.J. Jr. & Huff, D.D.
Partner: UNT Libraries Government Documents Department