We maintain our reputation as leaders in evaluating the fate, transport, and effects of radionuclides and chemicals by looking beyond traditional methods to identify new ways to resolve technical issues efficiently. We emphasize thorough and responsive research, careful and accessible documentation, and the flexibility to respond to changing conditions and concerns while fulfilling schedule and budget agreements.


Source Term Analysis

We specialize in reviewing and estimating releases of chemical and radioactive materials to the environment (source terms). Such estimates are part of a process that enables their impact to the surrounding population to be determined. Our source-term analysis can address historical, present day, or future releases. We have studied facilities that began operation more than 60 years ago and estimated the releases from them. Using such release estimates, coupled with transport analysis and contemporary environmental measurements, allows us to understand the effects of the operations on environmental concentrations and whether other nearby sources or natural processes also contributed to them. RAC also assists facilities in assessing future emissions, whether from new facilities or the result of process or effluent treatment modifications to existing plants. Careful analyses of releases and their movement in the environment can provide a sound basis for determining the validity of claims regarding historic or current public exposures.

Relevant projects: Rocky Flats Historical Public Exposures Project, Fernald Dosimetry Reconstruction Project, Savannah River Site Historical Dose Reconstruction, Uravan Historical Dose Reconstruction, INEEL

Selected Publications


Exposure and Risk Analysis

RAC has a great deal of experience in developing and applying methods to determine how people are exposed to contaminants in the environment and the health effects associated with such exposures. Depending on the situation, this may involve piecing together evidence to evaluate past exposures, a process called historical dose reconstruction, or evaluating the present-day situation at a facility or location and, if appropriate, the likely future impacts, or assessing the potential impact of planned or unplanned releases.

RAC is recognized for developing the benchmark for dose reconstructions in the U.S. Our experience in analyzing a number of the U.S. nuclear weapon facilities has advanced the science of source-term analysis, uncertainty analysis, and model validation and redefined the practice of gathering and evaluating historical data. In addition, RAC team members have breadth and depth of knowledge and expertise in estimating health risks and identifying uncertainties in risks for people exposed to chemical and radioactive materials. We use state-of-the-art methods to conduct exposure and toxicological assessments and risk characterizations, and we excel at presenting results to technical audiences and the public alike.

Relevant projects: Assessment of Cerro Grande Fire, Risk-based screening for releases to the Columbia River at Hanford, Doses from Short-Lived Radionuclides at Hanford, Rocky Flats Historical Public Exposures Project, Fernald Dosimetry Reconstruction Project

Selected Publications


Contaminant Transport Modeling

Contaminant transport modeling provides a quantitative estimate of contaminant concentrations in environmental media (soil, ambient air, surface water, groundwater, and biota) in the past, present, or future. These concentrations can then be used to estimate impacts on human health and the environment. The RAC team has used off-the-shelf models when appropriate, but also has developed custom numerical models that fit the specific needs, circumstances, and objectives of the project. Our team understands the limitations of numerical models and has developed empirical models when appropriate field data are available. Moreover, RAC has extensive experience in uncertainty analysis so the limitations of model-estimated contaminant concentrations in the environment are more fully understood and appreciated.

Relevant projects: Rocky Flats Historical Public Exposures Project, Uravan Historical Dose Reconstruction, Fernald Dosimetry Reconstruction Project, Risk-based screening for releases to the Columbia River at Hanford

Selected Publications


Environmental Data Management and Analysis

RAC develops data management applications that facilitate easy access to and use of environmental measurement data for a variety of applications, ranging from basic data evaluation to more complex risk calculations. This is in contrast to many data management applications that are developed around managing the entire data life cycle, rather than on using the data to reach meaningful conclusions. The data life cycle ranges from sample collection and preparation to result verification and validation and is sufficiently complex so that functions aimed at actual data use are often limited.

One example of such an application is the RACER@LANL data analysis tool (DAT). The DAT provides access to environmental measurement data (air, soil/sediment, biota, surface/storm water, groundwater) collected in and around the LANL site. A variety of features and functions are provided for analyzing, displaying, mapping, and interpreting the measurement data. The tool allows you to access and evaluate measurement data collected from any area that you specify on a map of the LANL area. Furthermore, the option to download selected data for additional analysis is available. In the past, this information was located in a series of databases, often with incompatible formats. Analyzing the data was a cumbersome, if not, impossible task. With the DAT, you can now efficiently summarize and evaluate these data.

Relevant projects: RACER, San Ildefonso Tribal Risk Assessment

Selected Publications


Integrated Software Development

RAC specializes in the development of customized software for environmental transport and risk analysis. We do not believe in forcing off-the-shelf applications to fit a situation. Therefore we frequently develop computer models to ensure the tool is tailored to answering the client’s needs. This is possible because RAC team members are not only skilled in the science of risk assessment but also in computer programming, database development, and GIS development. The net result is a product that gets to the heart of the client’s issue.

As early as the 1980s RAC was developing desktop solutions to solve specific problems. We conceived, developed, and tested the first pathway analysis models for determining decontamination requirements for soil containing radioactive materials (DECOM©) and chemicals (DECHEM©). Recognizing the need for an easy-to-use microcomputer model for dose assessment, we developed the MICROAIRDOS© computer code, which has been approved by the U.S. Environmental Protection Agency for demonstrating compliance with the Clean Air Act. We built an Individual Risk Calculator application to provide users the ability to estimate doses related to historic airborne releases from Rocky Flats, based on their residence history, age, and other information specific to them.

As part of the RACER project at LANL, we are developing a suite of integrated software tools that focus on efficiently using available information to better understand site conditions and assist with establishing sensible priorities and making defensible decisions. The data analysis tool is designed to be a user-friendly and intuitive application to provide regulators, facility personnel, and community members with dynamic access to very large and complex sets of environmental measurement data, along with various options to assist with interpreting the data. The risk calculation and ranking tool is designed to use existing measurement data selected using the data analysis tool, or supplied by the user, to rank the importance of identified sources of chemicals and radionuclides at a facility based on both current and potential future human health risks or ecological impacts. Finally, the decision-support tool uses output from the risk-calculation and ranking tool to provide a framework for evaluating and ranking sources of chemicals and radionuclides based on criteria other than risk, like cost or feasibility, as well as a mechanism to compare alternative approaches for reducing risks for those sources identified as most important.

Relevent projects: RACER, Tungsten Operational Risk Assessment

Selected Publications


Technical Review and Audit

RAC provides audits and technical reviews for facility programs in risk analysis and environmental monitoring. Our multi-disciplinary team includes the skills needed to thoroughly evaluate every aspect of your program. We have the expertise to cover complex facilities and to address both chemicals and radioactive materials. External audits (informal or formal) are a requirement for some environmental regulations. We have performed audits for compliance with the Clean Air Act at Los Alamos National Laboratory and Oak Ridge National Laboratory. Independent technical reviews are frequently requested as part of a company’s ongoing quality assurance or periodic evaluation of the state of the art of methods being used. One example is RAC’s review of the environmental monitoring program and annual environmental report for the Savannah River Site. Our comments and suggestions resulted in significant changes to the format and content of the annual report, improvements in data management, and recommendations to increase the efficiency of monitoring locations.

Relevant projects: Audit of Los Alamos National Laboratory for Compliance with the Clean Air Act


Risk Communication

Risk communication is a crucial component of any dose reconstruction or risk assessment. RAC works hard to maintain open communication among all stakeholders for each project and has found this to be particularly important in public studies. We learned early on that public credibility is earned by a commitment to constant public involvement. RAC’s past work on public dose reconstruction studies (Hanford Environmental Dose Reconstruction (HEDR), Fernald Dosimetry Reconstruction Project, Rocky Flats Dose Reconstruction, Cerro Grande Fire Risk Assessment) has provided team members with the technical knowledge and experience working with stakeholders to foster open communication among scientists, decision-makers, and citizen groups. RAC's policy is simple and consistent: work hard to involve all potentially interested parties in the project early and often; make certain that key research staff, properly trained in public participation, are involved in all public interactions; and respond to stakeholder concerns quickly and positively.

Relevant projects: RACER, Assessment of Cerro Grande Fire, Soil Action Levels

Selected Publications


Courses and Training

RAC is passionate about our work and we believe in sharing our knowledge with anyone keen to learn. We have developed and presented courses designed to enhance the general knowledge of the audience on such topics as risk assessment, risk communication, and other areas of specific or general interest. We have organized and conducted technical workshops for local, state, and federal organizations and have incorporated workshops as part of risk communication activities to supplement and support stakeholder understanding of technical information and explain the process and findings of risk assessments. Such workshops have greatly increased the level of communication among the scientific community, decision makers, and the public.

Our courses and technical workshops are focused on general topics or specific areas of interest and provide appropriate resources to enhance the learning process. Our courses include hands-on training activities to enhance the learning process and recognized experts to address specific issues of interest. Where appropriate, software products conceived, developed, and tested by RAC are applied during our courses and workshops. Depending on the topic and content, we develop courses and workshops that are board-certified for continuing education credits from American Board of Industrial Hygiene, American Association for Clinical Chemistry, American Academy of Health Physics, and the American Academy of Environmental Engineers.

Examples of courses that we have designed and taught include: