Risk Assessment Corporation (RAC) brought a new creative approach to risk assessment and scientific studies when Dr. John E. Till founded the company in 1977. John assembled a team of independent researchers possessing the broad skills required to tackle the technical issues involved with:

  • Source Term Analysis
  • Contaminant Transport Modeling
  • Exposure and Risk Analysis
  • Environmental Data Management and Analysis
  • Integrated Software Development
  • Technical Review and Audit
  • Risk Communication
  • Courses and Training

In those early days, RAC’s work included research on the environmental transport and fate of materials such as tritium, carbon-14, and technicium-99. RAC also focused on the development of user-friendly software for predicting concentrations of radioactive materials and chemicals in the environment. MICROAIRDOS ©, DECOM © and DECHEM were early prototypes of software now widely used in risk assessment. In 1983, Dr. Till co-edited with Dr. Robert Meyer Radiological Assessment: A Textbook on Environmental Dose Analysis, the first comprehensive textbook describing methods for environmental risk analysis, published by the U.S. Nuclear Regulatory Commission. A major update and revision of that textbook, Radiological Risk Assessment and Environmental Analysis (co-edited by Dr. Till and Dr. Helen A. Grogan), was published by Oxford Press in 2008.

In 1988 John was appointed chair of the Technical Steering Panel that was responsible for directing the Hanford Environmental Dose Reconstruction Project (HEDR) that reconstructed doses to members of the public from radionuclide releases from the operation of U.S. Government facilities at the Hanford Nuclear Site in Washington State since 1944. Under his leadership, HEDR was instrumental in helping lift the shroud of secrecy that enveloped the nuclear weapons complex in the U.S. For the first time, the public was given access to information about the activities that took place at the Hanford Nuclear Site, the analysis to characterize the magnitude and duration of releases of radioactive materials to the environment, and the human exposures and health effects that would have occurred.

RAC went on to complete dose reconstructions for the Fernald Feed Materials Plant in Ohio and for the Rocky Flats Plant near Denver, Colorado, as well as the early phases of the dose reconstruction for the Savannah River Site in South Carolina and Idaho National Laboratory in Idaho.

On May 1, 1998, the corporation’s name was changed to Risk Assessment Corporation (from Radiological Risk Assessment when originally incorporated in the state of South Carolina in 1979) to more accurately reflect its expanded mission to address both radionuclides and chemicals in the environment. In recent years, RAC has applied its skills to address a broad spectrum of issues, including:

  • Developing and implementing a multifaceted data management system that combines a comprehensive environmental monitoring database with analysis and reporting functions, accessible through a hosted web site called RACER, or Risk Analysis, Communication, Evaluation, and Reduction
  • Developing a human health assessment and decision support tool
  • Developing and presenting courses designed to enhance the general knowledge of the audience on such topics as risk assessment, pathway analysis, risk-based decisions for corrective action, risk communication, and other areas of specific or general interest
  • Estimating doses with uncertainties for military personnel who participated in U.S. atmospheric nuclear weapons tests from 1945 until the Limited Nuclear Test Ban Treaty in 1963
  • Investigating deposition velocities and atmospheric transport models used in radiological safety assessments
  • Analyzing source term and transport from a liquid radioactive waste release from a single-shell tank at the Hanford site
  • Establishing a robust approach to determine soil clean-up levels for the Rocky Flats site
  • Conducting a series of independent audits of Los Alamos National Laboratory in New Mexico to determine compliance with the Clean Air Act
  • Analyzing the exposure and risks to the public from radionuclides and chemicals released by the Cerro Grande Fire at Los Alamos in May 2000
  • Establishing a process to work with stakeholders and decision-makers to identify and reduce risks from contaminated sources
  • Calculating exposures and doses to plaintiffs in a number of legal cases

For more information about RAC’s experience and capabilities, visit our Skills webpage.

How RAC Works

RAC is incorporated in South Carolina where President John Till resides. Executive Officer Dr. Helen Grogan and other team members live in various locations around the country. One of John’s goals has been to minimize the bureaucratic and overhead costs of a large organization. RAC is a consortium of independent consultants possessing technical skills and problem-solving experiences from a wide variety of disciplines, each called on when their skills match the needs of a project. This format allows RAC to obtain the skills of talented scientists who may contribute to projects on a part- or full-time basis and are free to live and work where they choose, ensuring that RAC is competitive in the marketplace and provides high quality work as a team.

John is responsible for the overall management of the team, while Helen manages the technical aspects of projects and provides John with any assistance needed. Although team members live in many different parts of the U.S., they meet regularly at project locations to collect and analyze information and to discuss technical approaches. The team also meets at least three times a year to discuss each project under contract, evaluate progress, and make team business decisions.

Above all, RAC stresses resolving technical problems through high quality science and the clear communication of scientific information. Since RAC was formed in 1977, RAC team members have served in nationally and internationally recognized organizations including the National Academy of Sciences, the National Council on Radiation Protection and Measurements, the International Commission on Radiological Protection, the Atomic Energy Agency, the Environmental Protection Agency Science Advisory Board, and the United Nations Scientific Committee on the Effects of Atomic Radiation.

For more information about the independent consultants who make up the RAC team, visit our Staff webpage.