David J. LePoire

User's manual for RESRAD version 6.

This manual provides information on the design and application of the RESidual RADioactivity (RESRAD) code. It describes the basic models and parameters used in the RESRAD code to calculate doses and risks from residual radioactive materials and the procedures for applying these models to calculate operational guidelines for soil contamination. RESRAD has undergone many improvements to make it more realistic in terms of the models used in the code and the parameters used as defaults. Version 6 contains a total of 145 radionuclides (92 principal and 53 associated radionuclides), and the cutoff half-life for associated radionuclides has been reduced to 1 month. Other major improvements to the RESRAD code include its ability to run uncertainty analyses, additional options for graphical and text output, a better dose conversion factor editor, updated databases, a better groundwater transport model for long decay chains, an external ground radiation pathway model, an inhalation area factor model, time-integration of dose and risk, and a better graphical user interface. In addition, RESRAD has been benchmarked against other codes in the environmental assessment and site cleanup arena, and RESRAD models have been verified and validated.

Application of logistic analysis to the history of physics

Abstract Recently, two analyses have tried to put technological progress in a larger context. One interpretation hypothesizes that technological progress is likely to continue at increasingly higher rates of change. Another interpretation, which includes data from the beginning of the universe to the present, suggests that the universe is approaching a transition point in a logistic development of complexity. This logistic development is similar to the way ideas or products diffuse in a population, i.e., the rate of discovery in a field of knowledge is proportional to the amount discovered and the amount to be discovered. To test a part of this hypothesis, a leading indicator field (fundamental physics) was identified and the events in the history of this field were analyzed. Twelve subfields were identified and grouped into six stages. Each stage seemed to demonstrate a logistic-like development. By analyzing both the median time of development and the characteristic time of development of these stages, the overall development of this one field was found to suggest logistic development. These data seem to indicate that development in fundamental physics is slowing down, with at least one subfield beyond string physics yet to be developed. The data tend to support the hypothesis that a knowledge field can develop logistically.

External exposure model in the RESRAD computer code.

An external exposure model has been developed for the RESRAD computer code that provides flexibility in modeling soil contamination configurations for calculating external doses to exposed individuals. This model is based on the dose coefficients given in the U.S. Environmental Protection Agency’s Federal Guidance Report No. 12 (FGR-12) and the point kernel method. It extends the applicability of FGR-12 data to include the effects of different source geometries, such as cover thickness, source thickness, source area, and shape of contaminated area of a specific site. A depth factor function was developed to express the dependence of the dose on the source thickness. A cover-and-depth factor function, derived from this depth factor function, takes into account the dependence of dose on the thickness of the source region and the thickness of the cover above the source region. To further extend the model for realistic geometries, area and shape factors were derived that depend not only on the lateral extent of the contamination, but also on source thickness, cover thickness, and radionuclides present. Results obtained with the model generally compare well with those from the Monte Carlo N-Particle transport code.

Exploring ethical approaches to evaluate future technology scenarios

The integration of technology into the workplace has resulted in a long trend of changing working conditions, from agriculture to today’s growing “knowledge economy.” This latest development depends on information technology, which may continue to evolve through eventual convergence with nanotechnology and biotechnology. Knowledge work places more emphasis on an expanded skill set, as opposed to the smaller set of specialized skills typically needed in an industrial economy. Future technological progress might lead to further enhancement of human potential or to even greater inequality (individual and national) in income distribution, generating even larger pressures toward the divisions in society. This is illustrated by recently proposed scenarios of accelerated and logistic growth of technological progress. In an attempt to understand these dynamics, a simple model is constructed to clarify a possible relationship between technology and social systems. The model, based on the technology maturation proc...

Web-based training course for evaluating radiological dose assessment in NRC's license termination process.

As part of the requirement for terminating the licenses of nuclear power plants or other nuclear facilities, license termination plans or decommissioning plans are submitted by the licensee to the U.S. Nuclear Regulatory Commission (NRC) for review and approval. Decommissioning plans generally refer to the decommissioning of nonreactor facilities, while license termination plans specifically refer to the decommissioning of nuclear reactor facilities. To provide a uniform and consistent review of dose modeling aspects of these plans and to address NRC-wide knowledge management issues, the NRC, in 2006, commissioned Argonne National Laboratory to develop a Web-based training course on reviewing radiological dose assessments for license termination. The course, which had first been developed in 2005 to target specific aspects of the review processes for license termination plans and decommissioning plans, evolved from a live classroom course into a Web-based training course in 2006. The objective of the Web-based training course is to train NRC staff members (who have various relevant job functions and are located at headquarters, regional offices, and site locations) to conduct an effective review of dose modeling in accordance with the latest NRC guidance, including NUREG-1757, Volumes 1 and 2. The exact size of the staff population who will receive the training has not yet been accurately determined but will depend on various factors such as the decommissioning activities at the NRC. This Web-based training course is designed to give NRC staff members modern, flexible access to training. To this end, the course is divided into 16 modules: 9 core modules that deal with basic topics, and 7 advanced modules that deal with complex issues or job-specific topics. The core and advanced modules are tailored to various NRC staff members with different job functions. The Web-based system uses the commercially available software Articulate, which incorporates audio, video, and animation in slide presentations and has glossary, document search, and Internet connectivity features. The training course has been implemented on an NRC system that allows staff members to register, select courses, track records, and self-administer quizzes.

Possible lessons from a recent technology (Nuclear) for an emerging (Ubiquitous Embedded Systems) technology

Information Technology (IT) has ushered in not only large societal opportunities but also large uncertain ‐ ties and risks. Future developments, like ubiquitous networked embedded systems, are technologies society may face. Such technologies offer larger opportunities and uncertainties because of their ability to widely distribute power through their small, inexpensive, and ubiquitous characteristics. Many interpretations of how these technologies may develop have been postulated, ranging from the conservative Precautionary Principle, to uncontrolled development leading to “singularity.” With so much uncertainty and so many predictions about the benefits and consequences of these technologies, it is important to raise ethical questions, determine potential scenarios, and try to identify appropriate decision points and stakeholders. Rather than going along an unknown path, perhaps lessons could be learned from recently deployed technologies, such as nuclear technology, that were controversial but offered s...

Pathways to Enhance Environmental Assessment Information Systems

In the environmental field, modeling plays a critical role in connecting current data and knowledge with predictions of future events and environmental states. Environmental problems are quite challenging to solve because of the complex relationships among many contributing factors, both natural and man-made. Moreover, these problems need to be addressed not only by environmental engineers and regulators but also by a larger community consisting of concerned members of the public and nongovernmental organizations. Their demands on environmental modeling often conflict because predictions need to be accurate yet easily understood, communicated, and explored. The requirements for environmental modeling are generally identified as accuracy, defensibility, transparency, efficiency, and effectiveness. An approach to meet these requirements based on layered components, role assignments, and flexible integration strategies is identified, developed, and tested with prototypes. The results from the prototypes suggest possible enhancements for further advancing the use and communication of environmental modeling. Qualitative comparisons with other approaches are framed with identified criteria.

An approach to facilitating communication of expert arguments through visualisation

Many public issues, such as environmental actions, involve a large number of diverse stakeholders such as governments, corporations, organizations (e.g. NGOs), and concerned citizens. Discussions frequently become contentious as the stakeholders defend their potentially conflicting goals with various assumptions, views, and expert testimony. These issues also tend to involve a range of fields. For example, the disposition of nuclear waste includes issues of economics, science, engineering, politics, and intergenerational justice, each with large uncertainties due to dependences on indirect estimations and the long time periods involved. At the same time that these complex issues might increase in number, due to applications of new technologies, tools are being developed on the Internet to enable flexible learning, visualization, collaborative conferencing, distributed computing, and meaning‐based (semantic) context. These tools might enable improved techniques for debating and discussing these complex issues. A technique that might facilitate orderly discussion of various arguments would include explicit recording and visualization of the evidence, its assumptions and uncertainties, their relationships in constructing the overall argument, and the ways the evidence needs to be generalized to support the argument. A simple argument visualization approach is explored based on a combination of an argument logic framework and techniques for fusing generalized data that are similar to kriging in spatial analysis. This approach is then applied to a recently contested risk analysis of nuclear waste disposition that was debated in a peer‐reviewed journal, involving concerns about uses of data, complex computational models, uncertainty analysis, and expert judgment. The need for wider understanding of such complex issues might be addressed by a convergence of techniques to facilitate greater understanding and the advanced Internet technologies to lower barriers to their adoption.

Resrad-recycle: a computer model for analyzing radiation exposures resulting from recycling radioactively contaminated scrap metals or reusing radioactively surface-contaminated materials and equipment.

RESRAD-RECYCLE is a computer code designed by Argonne National Laboratory (ANL) to be used in making decisions about the disposition of radioactively contaminated materials and scrap metals. It implements a pathway analysis methodology to evaluate potential radiation exposures resulting from the recycling of contaminated scrap metals and the reuse of surface-contaminated materials and equipment. For modeling purposes, it divides the entire metal recycling process into six steps: (1) scrap delivery, (2) scrap melting, (3) ingot delivery, (4) product fabrication, (5) product distribution, and (6) use of finished product. RESRAD-RECYCLE considers the reuse of surface-contaminated materials in their original forms. It contains representative exposure scenarios for each recycling step and the reuse process; users can also specify scenarios if desired. The model calculates individual and collective population doses for workers involved in the recycling process and for the public using the finished products. The results are then used to derive clearance levels for the contaminated materials on the basis of input dose restrictions. The model accounts for radiological decay and ingrowth, dilution and partitioning during melting, and distribution of refined metal in the various finished products, as well as the varying densities and geometries of the radiation sources during the recycling process. A complete material balance in terms of mass and radioactivity during the recycling process can also be implemented. In an international validation study, the radiation doses calculated by RESRAD-RECYCLE were shown to agree fairly well with actual measurement data.