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FARIS 0.1.0: ARC-inspired demo study

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@Connoravila1 Connoravila1 released this 06 Oct 03:28
· 68 commits to main since this release
v0.1.0
a238f94

The first public release, a deliberately narrow demo that is complete for one
study: an ARC-inspired compact D-T tokamak, studied from 3D Monte Carlo
transport through 30 years of operation, with the transport sampling
uncertainty carried into every year. What comes next is in the README, "Where
FARIS is going".

Study

  • Five-step workspace: Design, Simulate, Operate, Compare, Evidence (keys 1 to 5),
    with a first-run tour that can be replayed.
  • Four recorded arrangements: two blanket/shield allocations, each with a finite
    outboard service port and a matched port-free control. Coupled neutron/photon
    OpenMC fixed-source transport with FENDL-3.2 neutron and ENDF/B-VII.1 photon
    data.
  • A seven-point blanket/shield allocation sweep.
  • A 30-year operating history that recalculates in about a second from sliders:
    tritium inventory and losses, fuel-limited operation and restart, planned
    outages, exposure-triggered component replacements, and signed net
    electricity.

Uncertainty

  • Transport records the covariance between all scalar responses from per-batch
    results, so correlated quantities (tritium production and heating, say) move
    together when sampled.
  • History ensembles: up to 2,000 histories on transport rates sampled from that
    covariance. Every output gets a median, a 90 % range with order-statistic
    confidence limits, and event probabilities. Ensembles fail closed: if more than
    1 % of draws are non-physical, the result is not evaluated and says why and
    what to do next.
  • Paired comparison of two arrangements' ensembles from independent transport
    runs.

Magnets

  • Fast-neutron (above 0.1 MeV) flux on the magnet's inboard half, outboard
    half and the 20° sector behind the port, each with its own service limit.
    The first limit reached triggers the replacement and is named in the event.
  • The default preset treats the magnet as demountable at a literature REBCO
    screening fluence of 3 × 10²² n/m² (Sorbom et al. 2015).

Files and export

  • .faris study files: one file holds both arrangements, the recorded transport,
    the sweep, the assumptions, stored ensembles and the view. Recorded bytes are
    checked by hash on every open; a damaged file is refused and the damaged part
    named.
  • Export to a 3-page PDF brief, CSV tables, and SVG/PNG charts, stamped with the
    study file's SHA-256. The same export runs from the desktop and from
    faris study-file export.
  • Every PDF page, CSV, chart and the export manifest carry the research-screening
    statement.

Evidence

  • Studies compile and run through Avila Core, which records hash-bound receipts;
    saved cases reopen only if every recorded byte still matches.

Known limits

  • Linux only. The binaries are not signed.
  • Idealised geometry: concentric tori and one outboard port. Not the published
    ARC design.
  • The outboard port is an open 0.30 m × 0.30 m duct with no shield plug, so it
    is a bounding streaming case. With the demountable-magnet preset the
    port-sector magnet limit is reached 0.65 years into operation and the magnets
    are replaced about 30 times in 30 years; without the port, at most once. A
    shield plug would reduce the streaming; FARIS has not modelled one.
  • Recorded transport: port-free controls at 30 million histories, port and
    sweep cases at 10 million. Monte Carlo standard errors are below 0.04 % for
    tritium production and heating, and 5 % to 24 % for regional magnet fast
    flux (up to 30 % for the port-sector region of the port-free controls).
  • Only transport sampling uncertainty is propagated. Nuclear-data, geometry,
    material and model uncertainty are not.
  • Magnet fluence is a regional average, not a local peak. A true peak needs
    variance reduction aimed at the magnet (planned for 0.2).
  • No activation, decay heat or shutdown dose yet (planned for 0.2).
  • Service limits, outage durations and plant efficiencies are authored
    assumptions, not material allowables or measured values.

SHA-256 of FARIS-0.1.0-linux-x86_64.tar.gz: 5f6d7455f41ba89d07e48f1e3a40722b7854733ea3de49c710ea64a60c0da060

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