Simulation Library

The software behind fusion and nuclear engineering.

Reviewed entries for open simulation software: what each code does, which engineering questions it helps answer, where its documentation and source live, who develops it, and what evidence Morton Labs actually holds. Start from a question, a category, or the credited source collection.

Activation & inventory · Nuclear data

ALARA

ALARA is an activation code that works out which radionuclides build up in the materials of a nuclear system under neutron irradiation, following every chain of transmutation and decay through an arbitrary pulsed irradiation schedule and set of cooling times, and choosing an analytic or Laplace-transform solution per chain. From the inventory it reports number densities, specific activity, decay heat, photon sources, contact dose and waste-disposal ratings, and it can run in reverse to find which starting nuclides produce a chosen target.

How much decay heat and activity will a first wall, blanket or vessel component carry at given cooling times after shutdown?

ListedReference listing
Multiphysics · Particle transport · CFD & heat transfer

Cardinal

Cardinal is an open-source MOOSE application that embeds the GPU spectral-element CFD code nekRS and the Monte Carlo code OpenMC inside the MOOSE framework, so they exchange temperatures, densities, heat fluxes and tallied power with MOOSE and other MOOSE-based solvers through in-memory transfers rather than files. It targets high-resolution coupling on CSG or CAD geometry for fission and fusion component analysis.

What is the coupled neutronics–thermal steady state of a component when Monte Carlo transport is iterated with heat conduction or CFD?

Upstream exampleHub integration planned
Geometry & CAD · Particle transport

DAGMC

DAGMC is a C++ geometry layer that lets Monte Carlo transport codes track particles directly through faceted CAD solid models instead of hand-built constructive solid geometry, using bounding-box trees for fast ray tracing and an automatically generated implicit complement for unmodelled space. It has been coupled to OpenMC, MCNP, Geant4, FLUKA, Tripoli4 and Shift, and its unified workflow lets one tagged geometry carry materials and tallies into several of them.

What flux, nuclear heating or dose does a geometrically complex blanket, shield or port assembly receive when modelled straight from its engineering CAD?

ListedHub beta
Nuclear data

endf-python

endf-python, published on PyPI as `endf`, is a Python library with a compiled extension that opens ENDF-6 evaluated nuclear data files and ACE continuous-energy tables and exposes their contents as Python objects. It offers a raw view of the MF/MT sections in a material and an interpreted incident-neutron view in which reactions, cross sections, Q-values and emitted products can be queried, interpolated and plotted.

What is the cross section for a specific reaction on a nuclide at a given energy in a particular evaluated library?

ListedReference listing
Particle transport · Nuclear data

Geant4

Geant4 is a C++ toolkit for Monte Carlo simulation of particles and radiation passing through matter: the user describes geometry and materials, chooses a physics list, fires primaries, and Geant4 tracks every particle and its secondaries through electromagnetic, hadronic, decay and optical processes from thermal-neutron energies up to the TeV range. It ships navigation, field tracking, scoring, visualisation, multithreading and a large set of example applications.

How much energy is deposited, and what dose is received, in a volume behind a shield or inside a detector for a given source?

ListedRuns in the Hub
Verification & validation · Nuclear data · Particle transport

JADE

JADE is an open-source Python framework that automates verification and validation of nuclear data libraries and transport codes: it builds benchmark inputs for each library and code combination, runs them, parses the outputs into a code-independent form, and produces comparison tables and plot atlases so libraries or codes can be checked against each other and against experiment. It drives MCNP, OpenMC and Serpent, plus shutdown-dose and activation variants.

How do leakage, heating, tritium production and damage in fusion-relevant materials change when switching from one evaluated nuclear data library to another?

ListedReference listing
Multiphysics · CFD & heat transfer · Materials

MOOSE

MOOSE is an open-source C++ framework from Idaho National Laboratory for building parallel finite-element and finite-volume simulations in which several physics are solved as one fully coupled implicit system on PETSc and libMesh. Engineers write small pluggable objects or assemble ready-made physics modules, link models across scales with MultiApps and Transfers, and run the same input from a laptop to tens of thousands of cores.

How do heat conduction, stresses and fluid flow in a component interact when solved as a single coupled implicit system?

Upstream exampleHub beta
CFD & heat transfer

NekRS

nekRS is an open-source, GPU-first spectral-element CFD solver from Argonne that solves the incompressible and low-Mach Navier–Stokes equations with scalar transport on high-order hexahedral elements, running through MPI and the OCCA portability layer on CUDA, HIP, SYCL and CPU backends. It adds LES and RANS models, moving meshes, overset grids, conjugate heat transfer and Lagrangian particles, targeting exascale machines.

What are the resolved velocity, pressure and temperature fields in a turbulent coolant channel or blanket flow path, and what wall heat flux and pressure drop follow?

ListedHub integration planned
CFD & heat transfer · Multiphysics

OpenFOAM

OpenFOAM is a GPL-licensed C++ finite-volume toolbox for computational continuum mechanics with solvers and utilities for incompressible, compressible, multiphase, reacting, heat-transfer and solid-stress problems, plus meshing, decomposition and post-processing tools that run in parallel with MPI. Two separately maintained lines share the name: the OpenFOAM Foundation line (openfoam.org, yearly numbered releases) and the OpenCFD line (openfoam.com, six-monthly releases).

What are the coolant flow distribution, pressure drop and wall heat-transfer coefficients in a blanket, divertor or first-wall cooling channel?

ListedRuns in the Hub
Particle transport · Nuclear data · Activation & inventory

OpenMC

OpenMC is an open-source Monte Carlo code that tracks neutrons and photons through models built from constructive solid geometry or CAD (through DAGMC), using continuous-energy or multigroup nuclear data, in fixed-source, eigenvalue and subcritical modes with MPI and OpenMP parallelism. Its Python API drives model building, depletion and activation workflows (including R2S and D1S shutdown dose rate), nuclear-data processing and tally analysis.

What neutron flux, nuclear heating, tritium breeding ratio or damage-driving reaction rates does a blanket, divertor or shield see for a given fusion source?

Morton reproducedRuns in the Hub
Uncertainty quantification · Workflow & orchestration

RAVEN

RAVEN is an Idaho National Laboratory framework that drives external simulation codes to perform sampling-based uncertainty quantification, sensitivity analysis, probabilistic risk assessment, surrogate-model construction, optimisation and data mining, with the analysis defined in an XML input and executed in parallel on workstations or clusters. It is not a physics solver; it wraps codes through a generic external interface or bundled code interfaces.

How uncertain is a figure of merit given distributions on the inputs, and which inputs drive that uncertainty?

ListedReference listing
Tritium transport · Multiphysics · Materials

TMAP8

TMAP8 (Tritium Migration Analysis Program, version 8) is a MOOSE-based open-source application from Idaho National Laboratory for hydrogen-isotope transport in materials and systems: diffusion with trapping and release, surface and interface conditions, and coupled heat transfer, solved as finite-element problems on the MOOSE framework.

How much tritium is retained in a plasma-facing component, and how much permeates to the coolant, under cyclic heat and particle loads?

Upstream exampleHub integration planned
Workflow & orchestration

WATTS

WATTS (Workflow and Template Toolkit for Simulation) is a small MIT-licensed Python library from Argonne for driving simulation codes from a script: it fills Jinja placeholders in a code's text input from a parameters mapping, runs the code in an isolated temporary directory, and files inputs, outputs and parameters into a local results database. Code-specific plugins add unit conversion and light post-processing.

How does a result change when sweeping a geometry or material parameter across many runs without hand-editing input files?

ListedReference listing

Entries are an editorial selection, not an endorsement, and not a claim that Morton Labs runs or has validated a tool. Each project is credited to its own team under its own licence. Catalog release 2026-11-02.1.