Nuclear Power Plant 1 Nuclear Power Plant 2 Nuclear Power Plant 3 Nuclear Power Plant 4 Control Room Fall 2019 RAMP Meeting Attendees
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Welcome to the U.S. Nuclear Regulatory Commission RAMP Website
RAMP is a program for training, developing, maintaining, and distributing the U.S. NRC`s radiation protection, dose assessment and emergency response computer codes.

Welcome to the U.S. NRC RAMP Website

What is RAMP?

The purpose of Radiation Protection Computer Code Analysis and Maintenance program (RAMP) is to develop, maintain, improve, distribute and provide training on NRC-sponsored radiation protection and dose assessment computer codes.

RAMP includes user groups of domestic and international code users that share costs, analysis, and experiences to facilitate maintenance and usage of high quality radiation protection codes.

The NRC allows distribution of its Radiation Protection Codes to domestic organizations (utilities, vendors, academic institutions, commercial enterprises) and international organizations located in countries that participate in the RAMP programs.

Goals of RAMP:

  • To ensure codes are appropriately updated.
  • To ensure codes reflect computer programming language updates.
  • Updates are in accord with International Regulations and Guidance Documents.
  • Codes are updated based on lessons learned from events such as Fukushima.
  • Costs are shared among users of the codes.
  • Centralized management structure for reporting, prioritizing and resolving code issues.

Membership Benefits:

  • Access to the most current versions of the code.
  • Code maintenance, development, benchmarking, and uncertainty studies.
  • A cooperative forum to resolve code errors and inefficiencies.
  • Technical basis documents and user guidelines for applying the codes, and Periodic meetings to share experiences, discuss code development.
  • Periodic training on the codes.

Click here to join RAMP.

RASCAL slideshow GENII slideshow GALE slideshow DandD slideshow HABIT slideshow VARSKIN Slide SNAP RADTRAD PiMal Mildos Toolbox slideshow XOQDOQ slideshow PAVAN slideshow ARCON96 slideshow



The RASCAL code is a tool used by the Protective Measures Team in the U.S. Nuclear Regulatory Commission's (NRC's) Operations Center for making independent dose and consequence projections during radiological incidents and emergencies.


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.


The FORTRAN based gaseous and liquid effluent (GALE) code estimates the quantities of radioactivity released by a plant through liquid and atmospheric discharges during routine operations for pressurized-water reactors (PWR) and boiling-water reactors (BWR).


The Decontamination and Decommissioning (DandD) software package, developed by NRC, assesses compliance with the dose criteria. DandD embodies NRC's guidance on screening dose assessments to allow licensee s to perform simple estimates of the annual dose from residual radioactivity in soils and on building surfaces.


Computer code for evaluating control room HABIT-ability. The HABIT 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.


VARSKIN is a computer code for calculating skin dose. The code is used to perform confirmatory calculations of licensees' submittals regarding skin dose (from both electron and photon emissions) estimates at any skin depth or skin volume, with point, disk, cylindrical, spherical, or slab (rectangular) sources, and even enables users to compute doses from multiple sources.


SNAP/RADTRAD, was developed for the NRC Office of Nuclear Reactor Regulation, and is used as a licensing analysis code to show compliance with nuclear plant siting criteria for the radiation doses at the exclusion area boundary (EAB) and the low population zone and to assess the occupational radiation doses in the control room or emergency offsite facility for various loss-of-coolant accidents (LOCA) and non-LOCA design-basis accidents (DBAs).


The PIMAL code is a graphical user interface with pre-processor and post-processor capabilities which assists users in developing MCNP input decks and running the codes.It allows users to easily generate quantitative figures of merit regarding positioning arms and legs in difference geometries. PIMAL software is considered an efficient and accurate tool for performing dosimetry calculations for radiation workers and exposed members of the public.


The MILDOS-AREA 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 transport of radon and export of agricultural produce are also estimated.

Radiological Toolbox

The Radiological Toolbox provides ready access to data of interest in radiation safety and protection of workers and members of the public. The data include dose coefficients for intakes of radionuclides, external exposure to radionuclides distributed in environments, and for exposures to photon and neutron radiation fields.


XOQDOQ is a computer code used to evaluate routine or anticipated, intermittent releases of radionuclides at nuclear power plants. These assessments are required by 10 CFR Part 50 and 10 CFR Part 100. Relative atmospheric dispersion (X/Q) and deposition factors (D/Q) are calculated for 22 specific distances out to 50 miles from the site in each directional sector.


PAVAN is a computer code used to estimate relative ground-level air concentrations (X/Q) for the assessment of potential accidental releases of radioactive material from nuclear facilities. These assessments are required by 10 CFR Part 50 and 10 CFR Part 100. PAVAN uses joint frequency distributions of wind direction and wind speed by atmospheric stability to estimate relative air concentration values for specific averaging time periods at specified distances.


ARCON is a computer code used to calculate atmospheric relative concentrations (X/Q) in support of control room habitability assessments required by 10 CFR Part 50, Appendix A, General Design Criterion 19. It uses hourly meteorological data and the atmosphere's influence (i.e., dilution and dispersion) in the vicinity of buildings to calculate the relative concentration at control room air intakes.

RAMP Partner logos: U.S. NRC, RAMP, PNNL
Fall 2020 Users Group Virtual Meeting
October 26-30, 2020
November 4-6, 2020

RAMP Users' Meeting

The RAMP program holds two meetings annually. These meetings bring together participants and users from all over the world to discuss code usage and development. Attendees are able to participate in open discussions with developers, provide suggestions for code improvements, and learn more about code upgrades or future releases. Click here for past meetings  »

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Users Worldwide: 1,700 & Counting


RAMP International Partners

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