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The Radiation Protection Computer Code Analysis and Maintenance Program (RAMP)

The NRC initiated the Radiation Protection Computer Code Analysis and Maintenance Program (RAMP) for the development, maintenance, improvement, and distribution of the NRC's collection of radiation protection, health physics, dose assessment, and emergency response computer codes. RAMP codes calculate dose for scenarios such as environmental assessment, nuclear power plant licensing, emergency response, atmospheric assessment, decommissioning, bioassay, and others.

RAMP provides a centralized management structure for code updates, distribution, modernization, applied research, training, and issue resolution. The RAMP user group of 3500+ active members include NRC staff, NRC and Agreement State licensees, private corporations, university/non-profit researchers, other U.S. federal agency staff, U.S. state/local officials, and national regulators across the world. Most RAMP codes are free for most users.

For the latest information on RAMP codes, user meetings, code access, and registration, visit the RAMP website.

RAMP's Premium Codes include:

  • IMBA: RAMP's IMBA code (formerly IMBA Pro) is a suite of software modules for internal dosimetry that implements respiratory tract, GI-tract, tissue dosimetry, biokinetic and bioassay models as recommended by the International Commission on Radiological Protection (ICRP). Originally designed by the UK's Health Security Agency, the IMBA modules can estimate single or multiple intakes of different radionuclides and calculate resulting doses in the body and/or excrement for workers based on ICRP Publications 26/30 and 60/68, as well as U.S. regulations outlined in 10 CFR 835. IMBA provides a platform for conducting customized dose calculations with different user set parameters. The suite has functionalities such as performing simple and more complex dose calculations, vapor inhalation modelling, intake estimation for multiple regimes, bioassay quantities at different times from a specified intake, 740 radionuclides, and more.

  • RASCAL: The Radiological Assessment System for Consequence Analysis computer code is used for making dose projections for atmospheric releases during radiological emergencies. RASCAL is used by the Protective Measures Team in the NRC's Operations Center for making independent dose and consequence projections during radiological incidents and emergencies. RASCAL was developed by NRC over 25 years ago to provide a tool for the rapid assessment of an incident or accident at an NRC-licensed facility and aid decision-making such as whether the public should evacuate or shelter in place. RASCAL evaluates atmospheric releases from nuclear power plants, spent fuel storage pools and casks, fuel cycle facilities, and radioactive material handling facilities. Its data is not the only criterion used by the local authorities during an accident, but certainly an important one.

  • SNAP/RADTRAD: The Symbolic Nuclear Analysis Package/ RADionuclide, Transport, Removal, and Dose estimation code is a licensing analysis code used to show compliance with nuclear plant siting criteria for the site boundary radiation doses at the Exclusion Area Boundary (EAB) and the Low Population Zone (LPZ) and to assess the occupational radiation doses in the control room (CR) and /or Emergency Offsite Facility for various loss-of-coolant accidents (LOCA) and non-LOCA design basis accidents (DBAs). RADTRAD uses a combination of tables and numerical models of source term reduction phenomena to determine the time-dependent dose at the CR, EAB and LPZ for given DBA scenarios.

RAMP base codes:

  • DandD: The DandD computer code is used by NRC licensees to demonstrate in an application for decommissioning a materials license (and the NRC to verify) that residual soil or building contamination at the licensed site following decontamination and decommissioning complies with the radiological dose criteria for license termination in 10 CFR 20, Subpart E. The computer code was designed to simplify decommissioning in cases where low levels of contamination exist.

  • GALE: The gaseous and liquid effluent computer code, for pressurized-water and boiling-water reactors, which estimate the quantities of radioactivity released by a plant through liquid and atmospheric discharges during routine operations.

  • GENII: GENII is a set of programs for estimating radionuclide concentrations in the environment and dose to humans from acute or chronic exposures from radiological releases to the environment or initial contamination conditions. It is part of a set of quality-assured and configuration-controlled safety analysis codes managed and maintained for the U.S. Department of Energy’s Safety Software Central Registry and the NRC.

  • HABIT: The HABIT computer code is an integrated set of computer programs used mainly to estimate chemical exposures that personnel in the control room of a nuclear facility would be exposed to in the event of an accidental release of toxic chemicals.

  • MILDOS: The MILDOS computer code calculates the radiological dose commitments received by individuals and the general population within an 80-km radius of an operating uranium recovery facility. In addition, air and ground concentrations of radionuclides are estimated for individual locations, as well as for a generalized population grid. Extra-regional population doses resulting from the transport of radon and export of agricultural produce are also estimated.

  • NRCDOSE3: NRCDose3 is a software suite that integrates the functionality of three individual Fortran codes: LADTAP II, GASPAR II and XOQDOQ that were developed by the NRC and have been in use by NPP licensees and the NRC staff for assessments of routine liquid radioactive releases and offsite doses, routine gaseous radioactive effluents and offsite doses, and meteorological transport and dispersion, respectively. NRCDose3 is primarily used to support reactor licensing in the confirmatory evaluation on the environmental dose impacts of routine liquid and gaseous radiological effluent releases.

  • NRC-RADTRAN: The NRC-RADTRAN computer code is used for risk and consequence analysis associated with routine, incident-free, transportation of radioactive materials and accidents that might occur during radioactive material transportation. NRC-RADTRAN will produce estimates of incident-free population dose, accident dose-risk, non-radiological traffic mortality, and a suite of individual dose estimates.

  • PIMAL: The Phantom with Moving Arms and Legs is a graphical user interface that allows users to develop input decks for the Monte Carlo N-Particle (MCNP) code. PiMAL contains humanoid, equine, feline and canine phantom models which are considered an efficient and accurate tool for developing exposure models and performing dosimetry calculations for radiation workers and exposed members of the public.

  • SIERRA ATD Module: The Software Integration for Environmental Radiological Release atmospheric transport and dispersion code used for analysis in siting, licensing, and environmental reviews for evaluating releases in cases of design-based accidents (from 100s of meters to 10 km), as well as normal effluent releases for sensitive receptors and populations up to 80 km. This module consolidates and modernizes the scientific functions of ARCON, PAVAN, and XOQDOQ into a single user interface and allows users to estimate relative concentrations based on hourly meteorological data for all three codes, rather than use of joint frequency distributions.

  • Table Calculator: The Table Calculator is a user-friendly tool to facilitate a more comprehensive understanding of the calculations used to develop the low-level radioactive waste classification tables. The tool runs in the GoldSim Player, and it allows users to trace the original calculations and observe the effects of changes in parameter values by running the original calculations with the original or updated data.

  • V+: The V+ (formerly VARSKIN+) computer code is a comprehensive radiation dose assessment tool designed to evaluate occupational and medical exposure scenarios. The software includes six specialized modules, each tailored to a specific type of radiation dose calculation: SkinDose, WoundDose, NeutronDose, EyeDose, Radiological Toolbox, and ExtravDose. V+ is RAMP’s most popular code.

RAMP joint-sponsored codes:

  • RESRAD: The Residual Radioactivity family of codes analyze potential human and biota radiation exposures from the environmental contamination of residual radioactive materials. The codes use pathway analysis to evaluate radiation exposure and associated risks, and to derive cleanup criteria or authorized limits for radionuclide concentrations in the contaminated source medium. This code is jointly sponsored with and distributed by Argonne National Laboratory.

  • VSP: The Visual Sample Plan computer code is a tool that helps ensure the right type, quality, and quantity of data are gathered to support confident decisions and provides statistical evaluations of the data with decision recommendations. VSP couples' site, building, and sample location visualization capabilities with optimal sampling design and statistical analysis strategies. This code is jointly sponsored with and distributed by Pacific Northwest National Laboratory.

RAMP-affiliated codes:

  • CAP88: CAP88-PC (Clean Air Act Assessment Package - 1988) is a computer code for estimating the dose and risk from emissions of radioactive material to the air. Version 4.1.1 is the most current CAP88-PC and is a regulatory compliance tool under the National Emissions Standard for Hazardous Air Pollutants (NESHAPs), Subpart H. The CAP88–PC program is a well-established and validated code for the purpose of making comprehensive dose and risk assessments. The Gaussian plume model used in CAP88–PC to estimate dispersion in air is one of the most used models for dispersion modeling. CAP 88-PC estimates the average dispersion of radionuclides released from up to six sources, that may be either elevated stacks, such as smokestack, or uniform area sources, such as pile of uranium mill tailings. It produces results that agree with experimental data as well as any model, is easy to work with, and is consistent with the random nature of turbulence. This code is distributed by the U.S. Environmental Protection Agency.

  • Turbo FRMAC: Turbo FRMAC code performs complex calculations to quickly evaluate radiological hazards during an emergency response by assessing impacts on the public, workers, and the food supply. Turbo FRMAC can be used to evaluate the hazard from a wide variety of radiological incidents, such as a nuclear power plant emergency. Turbo FRMAC calculations are based on methods established by the Federal Radiological Monitoring and Assessment Center (FRMAC). This code is distributed by Sandia National Laboratories.

Page Last Reviewed/Updated Wednesday, August 13, 2025