Modeling and Characterization

Radiological Modeling and Characterization Services for Operational and Decommissioning Radiological Sites

RSCS has expertise in modeling and characterization of radioactive materials.  From assessing high radiologically impacted areas, to performing  shielding calculations or source characterizations, our staff has the experience and solutions you need.

Advanced Radiological Assessment Technologies

RSCS deploys advanced characterization technologies for remote monitoring and assessment of hazardous radiological conditions.  Technologies include robotics and sensors for the assessment of  surface contamination levels, dose rates, isotopic distributions and mapping of elevated readings.  Learn more about technologies deployed that support operational and decommissioning nuclear sites by viewing the video “RSCS Advanced Radiological Assessment” above. 

Building Information Models

RSCS builds powerful 3D Building Information Models (BIM) for our nuclear utility clients based upon  facility designs and standard operational survey data sets, which are used to develops dynamic and interactive asset inventories for these sites. These complex models are augmented with imaging and data collected from advanced technologies, such as CZT radiological mapping.  BIMs are then coupled to site and regional Geographic Information Systems (GIS) in one Common Data Environment (CDE), resulting in highly detailed 3D maps of radiological conditions within nuclear plants, their sub-surfaces, and surrounding regions. 

Radiation Transport Modeling

RSCS can perform shielding and dose evaluations for complex geometries and various source terms. We use state of the art radiation transport codes; such as Monte Carlo N-Particle (MCNP) from Los Alamos National Laboratory and GEANT4 from the European Organization for Nuclear Research (CERN). These codes use the latest physics models (1eV up to 100 GeV) and allow single or coupled transport of Gamma / X-rays, Electrons / Betas, Neutrons, Protons, Alphas and heavy nuclei. 

Dose Reconstruction

We offer complex dose reconstruction for accident scenarios and potential contamination events. Our staff has extensive experience calculating dose from exposure pathways including inhalation, ingestion, and external radiation fields. In addition, RSCS has the ability to calculate internal dosimetry kinetic modeling from bioassay data.


RSCS performs simulations and modeling using Monte Carlo N- Particle (MCNP) for many Health Physics applications. Our specialists employ parametric studies and a dedicated computational system to allow for fast turn around of modeling. Data can be used for further calculations or processed using 2 and 3-D contouring software.

Source Design – RSCS has provided modeling support for design of medical and industrial sources. The MCNP support through the design phase allows custom field profiles for dose and fluence without having to go through expensive trial and error design iterations. Benchmarking performed using radiochromic dosimetry or other NIST traceable techniques.



cyclotron shielding - RSCSCyclotron Shielding – installation of shielded and unshielded cyclotrons can be modeled including all bolus transport lines, mazes, and stack exhaust. HPC used for fast engineering cycles.

Waste Packaging – Potential packaging of waste containers up to and including Greater Than Class C for dose impacts and required shielding to support storage and shipment.


dose reconstruction -  RSCSDose Reconstruction – Dose reconstruction for whole body, skin, or organ specific can be performed for uniform fields and hot particles. This method is recommended by EPRI and the USNRC.

Shielding and ALARA Planning – facility designs to support shielding installations or source configurations can be performed prior to work. This enables a better ALARA plan when there is little to no information available to start from.

Activation of Effluents – neutron activation of effluents can be determined and transported through the processes to determine the final source term.

Activation of Materials – Neutron activation of materials for new build or decommissioning planning.

     Detector Modeling – Instrument response for new instrumentation or existing instrumentation in unique applications.

heat distributionHeat Deposition – Heat deposition from radiation for material studies. Heat from heavy ion, alpha, neutron, photon, and electron modeled at various temperatures to various materials to determine optimum cooling needs.



Photon Characterizations

A-3 Chamber - RSCS

RSCS performs gamma characterizations using Exradin secondary standards coupled to a Keithley Model 617 electrometer with our custom computer controlled software.  Our characterization of gamma calibration sources also include a detailed data analysis and curve-fitting process that results in easy-to use techniques to help simplify your instrument calibration facility.

RSCS performs measurements for source and field characterization. All measurements are traceable to NIST and with instrumentation that is calibrated in accordance to ISO/IEC-17025:2017. Measurements include full propagation of uncertainties. Error analyses are performed for characterizations in accordance to ANSI/NCSL Z540 GUM and NCRP112 methodology.


scaffolding with detector - RSCSPhoton field characterizations are performed with reference grade ionization chambers and electrometers, scintillation systems with GPS, and in situ gamma spectroscopy for the following applications:

  • Calibration Sources
  • Environmental studies
  • Turbine Shine
  • Waste assay for disposal or free release

Neutron and Beta Field Characterizations

Detectors - RSCSRSCS performs neutron characterization projects using both TEPC and Bonnersphere Measurement Systems which use the most recent spectral unfolding software. Neutron characterizations are performed for the following applications:

  • Calibration sources
  • Neutron Dosimetry evaluations per ANI Bulletin 11-02
  • Environmental studies
  • Shielding evaluations

Radiographic film - RSCSBeta field characterizations are performed with radiochromic dosimetry or extrapolation chambers for the following applications:

  • Calibration sources
  • Medical source plaques
  • Hot particles