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Creators/Authors contains: "Shonka Research Associates, Inc., Marietta, GA"
  1. The regulatory release of sites and facilities (property) for restricted or unrestricted use has evolved beyond prescribed levels to model-derived dose and risk based limits. Dose models for deriving corresponding soil radionuclide concentration guidelines are necessarily simplified representations of complex processes. It is not practical to obtain data to fully or accurately characterize transport and exposure pathway processes. Similarly, it is not possible to predict future conditions with certainty absent durable land use restrictions. To compensate for the shortage of comprehensive characterization data and site specific inputs to describe the projected 'as-left' contaminated zone, conservative default values are used tomore » derive acceptance criteria. The result is overly conservative criteria. Furthermore, implementation of a remediation plan and subsequent final surveys to show compliance with the conservative criteria often result in excessive remediation due to the large uncertainty. During a recent decommissioning project of a site contaminated with thorium, a unique approach to dose modeling and remedial action design was implemented to effectively manage end-point uncertainty. The approach used a dynamic feedback dose model and soil segregation technology to characterize impacted material with precision and accuracy not possible with static control approaches. Utilizing the remedial action goal 'over excavation' and subsequent auto-segregation of excavated material for refill, the end-state (as-left conditions of the refilled excavation) RESRAD input parameters were re-entered to assess the final dose. The segregation process produced separate below and above criteria material stockpiles whose volumes were optimized for maximum refill and minimum waste. The below criteria material was returned to the excavation without further analysis, while the above criteria material was packaged for offsite disposal. Using the activity concentration data recorded by the segregation system and the as-left configuration of the refilled excavation, the end state model of the site was prepared with substantially reduced uncertainty. The major projected benefits of this approach are reviewed as well as the performance of the segregation system and lessons learned including: 1) Total, first-attempt data discovery brought about by simultaneously conducted characterization and final status surveys, 2) Lowered project costs stemming from efficient analysis and abstraction of impacted material and reduced offsite waste disposal volume, 3) Lowered project costs due to increased remediation/construction efficiency and decreased survey and radio-analytical expenses, and 4) Improving the decommissioning experience with new regulatory guidance. (authors)« less
  2. This report describes development of a significant new method for monitoring radioactive surface contamination. A floor monitor prototype has been designed which uses position sensitive proportional counter based radiation detectors. The system includes a novel operator interface consisting of an enhanced reality display providing the operator with 3 dimensional contours of contamination and background subtracted stereo clicks. The process software saves electronic files of survey data at very high rates along with time stamped video recording and provides completely documented surveys in a visualization oriented data management system. The data management system allows simple re-assembly of strips of data thatmore » are taken with a linear PSPC and allows visualization and treatment of the data using algorithms developed for processing images from earth resource satellites. This report includes a brief history of the development path for the floor monitor, a discussion of position sensitive proportional counter technology, and details concerning the process software, post processor and hardware. The last chapter discusses the field tests that were conducted at five sites and an application of the data management system for data not associated with detector systems.« less
  3. A data management system oriented toward the visualization of large data sets has been developed. The system, which runs under the Windows{trademark} operating environment, provides most of the image-based algorithms developed by NASA for space-based imaging. When used in conjunction with large data sets, such as those acquired using position-sensing proportional counter based survey methods, the system can show images of survey data and subject those images to numerous mathematical transformations. The application of such mathematical treatments allows radiological survey data to be analyzed to an unprecedented extent. Visualization of survey data permits a user to see minor artifacts thatmore » would have been missed using only conventional survey techniques. The imaged survey data can be subjected to many different treatments, such as filters, smoothing, thresholding, color mapping, and statistical analyses. A variety of radioactive objects and areas have been surveyed using this system in conjunction with a novel floor monitor described elsewhere. Collection and examination of data in this fashion poses a new paradigm for assessing surface contamination. This research demonstrated that new methods for assessing survey performance are needed.« less
  4. This report summarizes research which demonstrates the use of position sensitive proportional counters in contamination monitoring systems. Both laundry monitoring and portal monitoring systems were developed. The laundry monitor was deployed at a nuclear power plant where it was used to monitor clothing during an outage. Position sensitive proportional counter based contamination monitoring systems were shown to have significant advantages over systems using conventional proportional counters. These advantages include the ability to directly measure the area and quantity of contamination. This capability permits identification of hot particles. These systems are also capable of self calibration via internal check sources. Systemsmore » deployed with this technology should benefit from reduced complexity, cost and maintenance. The inherent reduction of background that occurs when the counter is electronically divided into numerous detectors permits operation in high background radiation fields and improves detection limits over conventional technology.« less
  5. This report summarizes research which demonstrates the use of position sensitive proportional counters in contamination monitoring systems. Both laundry monitoring and portal monitoring systems were developed. The laundry monitor was deployed at a nuclear power plant where it was used to monitor clothing during an outage. Position sensitive proportional counter based contamination monitoring systems were shown to have significant advantages over systems using conventional proportional counters. These advantages include the ability to directly measure the area and quantity of contamination. This capability permits identification of hot particles. These systems are also capable of self calibration via internal check sources. Systemsmore » deployed with this technology should benefit from reduced complexity, cost and maintenance. The inherent reduction of background that occurs when the counter is electronically divided into numerous detectors permits operation in high background radiation fields and improves detection limits over conventional technology.« less
  6. The Transportation Energy Data Book: Edition 10 is a statistical compendium prepared and published by Oak Ridge National Laboratory (ORNL) under contract with the Office of Transportation Systems in the Department of Energy (DOE). Designed for use as a desk-top reference, the data book represents an assembly and display of statistics and information that characterize transportation activity, and presents data on other factors that influence transportation energy use. The purpose of this document is to present relevant statistical data in the form of tables and graphs. Each of the major transportation modes - highway, air, water, rail, pipeline - ismore » treated in separate chapters or sections. Chapter 1 compares US transportation data with data from seven other countries. Aggregate energy use and energy supply data for all modes are presented in Chapter 2. The highway mode, which accounts for over three-fourths of total transportation energy consumption, is dealt with in Chapter 3. Topics in this chapter include automobiles, trucks, buses, fleet automobiles, federal standards, fuel economies, and household data. The last chapter, Chapter 4, covers each of the nonhighway modes: air, water, pipeline, and rail, respectively. 60 figs., 87 tabs.« less
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