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Radiological Dose & Risk Assessments

When the safety of your workers and the public is at stake, accurate and reliable health physics expertise is necessary to demonstrate compliance with federal and/or state regulations and guidelines regarding radiological exposure. ORAU’s highly-qualified health physicists perform site-specific radiation dose and risk assessments, using methods consistent with industry standards, to meet these regulatory requirements.

ORAU personnel have derived authorized limits for the U.S. Department of Energy per Order 458.1, dose-based screening values for the U.S. Nuclear Regulatory Commission per NUREG-1757, and derived concentration guideline levels (DCGLs) for the U.S. Army Corps of Engineers and the U.S. Defense Logistics Agency, among others.  

Dose models have included those for buildings and similar structural media, as well as environmental media including air, soil, sediment, rocks, surface water, and groundwater. Both retrospective and prospective assessments have been performed to determine radiation doses to past and current receptors, or hypothetical receptors based on central tendency or reasonable maximum exposure (i.e., critical group) scenarios. ORAU uses a variety of assessment tools to perform radiological dose assessments, including RESRAD, RESRAD-BUILD, DandD, MCNP and MicroShield.

Health physicist conducting radiation dose assessment

ORAU offers dose modeling and assessment services in support of:

  • Safety evaluations
  • Regulatory compliance evaluations
  • Standards development
  • Regulatory rulemaking

Select Publications

Health physicist performing radium sampling test

Radium contamination from manufacturing is focus of survey work for NRC

Since 2016, ORAU survey teams have provided technical assistance to the NRC Radium Program by determining the radiological status of more than 40 sites. Surveyors perform radiation scans and collect soil, dust, water and radon sampling at the decommissioned sites. These samples are analyzed by a radioanalytical laboratory and radium concentration results are used by ORAU health physicists to perform dose assessments.

Our Expert

David King

David King

Health Physicist

Expertise: More than 20 years of experience in human health risk/dose assessment, environmental studies and project management

  • Serves as project manager and technical lead for the assessment of various environmental and non-environmental media, derivation of site-specific cleanup goals, MARSSIM training and technical consultation covering a range of health physics related topics.
  • Member: Health Physics Society and Project Management Institute
  • Co-author, 2015. “Lessons Learned on the Presentation of Scan Data,” Operational Radiation Safety, Vol. 109, No. 5, S212-S218.
  • Co-author, 2013. “An Approach for Addressing Hard-to-Detect Hot Spots,” Operational Radiation Safety, Vol. 104, No. 5, S52-S59.
  • Co-author, 2012. “Minimum Detectable Concentration as a Function of Gamma Walkover Survey Technique,” Operational Radiation Safety, Vol. 102, No. 2, S22-S27.

Certifications: Certified Health Physicist, Project Management Professional

Contact us

For more information about contracting with ORAU, contact Kathy Rollow at 865.574.4390 or