Audit Trail and Provenance Export

An append-only, cryptographically chained log records every external action and every material quantity's origin, so any claim the plant makes is reconstructable.

Reconstructable by construction

Trust in a plant's numbers depends on being able to trace any figure back to its origin. L7 maintains an append-only audit trail: every external API call, every dispatch command, every isotope movement, and every compliance report is logged with the caller identity, the deciding policy, the inputs, and the outcome. Entries are chained by hash so the log cannot be silently altered; tampering breaks the chain and is detectable.

Provenance of a quantity

Beyond actions, L7 records provenance for physical quantities. A shipped kilogram of tritium can be traced to the breeding periods that produced it, the measurements that assayed it, the decay corrections applied, and the custody events that moved it. Provenance is a directed graph from a delivered quantity back to its physical origin and every transformation between.

# hash-chained audit entry (tamper-evident)
def append(entry):
    entry['prev']  = head_hash()
    entry['ts']    = now()
    entry['hash']  = sha256(canonical(entry))   # over content + prev
    store(entry)                                 # append-only
    set_head(entry['hash'])
# verify: recompute each hash; any break => tamper between here and there

Provenance export is a first-class product of L7. A regulator, an auditor, or an isotope customer can request the provenance of a specific quantity or the audit trail over a period, and receive a self-verifying document: the hash chain lets the recipient confirm the export was not altered after leaving the plant. Because entries are signed at the gateway, authenticity is verifiable independently of Kronos.

The audit trail and provenance graph are what let every other L7 claim be honest. A firm-power forecast, an isotope assay, or a compliance figure is only as trustworthy as its traceability, and here each is anchored to an immutable record with stated uncertainty and method.

The trail runs today over twin-driven, design-stage operations, so the provenance and audit machinery is exercised end to end before real material and real regulatory scrutiny arrive at FOAK ~2030.