Run your own transport

You do not need this to explore the recorded study. Use it to run new fixed-source transport yourself, for example to record a case with your own seed or history count. It uses the same engine from the command line and from the desktop.

What you need

OpenMC 0.15.3 in an environment you provide. The run refuses any other version.
The nuclear data the study was audited against. The recorded runs use FENDL-3.2 neutron data and ENDF/B-VII.1 photon data. The photon data come from a local overlay that FARIS does not ship. Its acquisition is described in the repository’s photon library document.
A library audit of your own installation. The audit file in the repository records one workstation’s cache. Run integrations/openmc/audit_library.py on yours and supply its output. FARIS does not silently accept differences in library content.

The data stay outside the repository. They are not part of the package.

Run a case

faris reactor run \
  --scenario scenarios/arc-inspired/cold-coupled-control.scenario.json \
  --physics scenarios/arc-inspired/cold-coupled-control.reference.physics.json \
  --mesh-preset outboard-local \
  --audit references/openmc-library-audit.json \
  --cross-sections /path/to/cross_sections.xml \
  --python /path/to/openmc-env/bin/python --openmc /path/to/openmc-env/bin/openmc \
  --particles 10000 --batches 100 --seed 123456789 --threads 1 \
  --output runs/cold-coupled-control-reference-001

The scenario and physics files shown are the port-free arrangement with the reference allocation. The port arrangements use cold-reference-port.scenario.json and its matching physics files.

The limits are:

30 to 1000 batches, and at most 50 million histories in all.
At most 32 threads.
A timeout of 3,600 seconds by default (--timeout-seconds), at most 14,400.
--output must be a new directory. The command refuses an existing one.

--mesh-preset is coarse (the default), outboard-local-coarse, outboard-local or outboard-port-window. The recorded runs use the outboard-local mesh. Ctrl-C cancels the run and its solver processes. These limits bound resources. They are not a sandbox.

A run records the per-batch results behind the covariance that the uncertainty ensembles need. Small regions need many histories. At 10 million histories, the port-sector fast flux of a port-free control has a 36 to 54 % relative error. That is too poorly sampled for ensembles, which is why the recorded controls use 30 million. A 30 million history run took about 68 minutes at 7 threads on the reference laptop.

Check a run

faris reactor inspect \
  --scenario scenarios/arc-inspired/cold-coupled-control.scenario.json \
  --run runs/cold-coupled-control-reference-001/run.json

This rechecks the run’s recorded inputs, raw artifact, sampling, audit, adapter identity, volumes and normalization. Neither a completed process nor an accepted normalization is a scientific verdict. Scientific qualification stays not evaluated.

Replay or run in the desktop

faris-app \
  --scenario scenarios/arc-inspired/cold-coupled-control.scenario.json \
  --physics scenarios/arc-inspired/cold-coupled-control.reference.physics.json \
  --physics scenarios/arc-inspired/cold-coupled-control.breeder-emphasis.physics.json \
  --run runs/cold-coupled-control-reference-001/run.json --field-view flux-slice

Repeat --run for the other arrangement. Add --python, --openmc, --audit and --cross-sections to enable Run and review transport in the Simulate step, or set them under Transport configuration. Closing the app cancels its transport workers. Camera interaction stays available while a job runs.

A study started from --run records cannot be saved as a .faris file, because a study file holds recorded-transport bundles. faris transport pack packages a completed run into a portable bundle:

faris transport pack --run runs/cold-coupled-control-reference-001/run.json --output reference.transport-bundle.json

Where to read more

The repository documents the details: the cold-reference workflow covers the materials, the source, the recorded tallies and the verification steps, and the transport boundary covers the contracts, normalization and trust limits.

Next: Reading the numbers.