Tritium Offtake and Logistics

Exportable tritium from the breeder is scheduled, assayed, and moved under full chain of custody, with self-consumption and decay accounted before anything ships.

From breeding surplus to shipment

The breeder's headline product is tritium, near the ~4 kg/yr class depending on the TBR lever. Tritium is valuable, radioactive, and decays (half-life ~12.3 years), so offtake logistics must account for time as a first-class variable. L7 schedules offtake from the true surplus (bred minus self-consumption minus decay and process loss) and never from gross breeding.

Assay, custody, and decay accounting

Each shipment is assayed for quantity and purity, tagged with an isotopic composition, and entered into a chain of custody that follows it from the plant boundary onward. Because tritium decays continuously, the recorded quantity is stamped with its measurement time, and any quoted delivery quantity is decay-corrected to the delivery date so the customer receives what was promised, not a stale figure.

import math
LAMBDA = math.log(2) / (12.32*365.25*24*3600)  # tritium decay const (1/s)
def decay_correct(q0, t0, t_deliver):
    dt = (t_deliver - t0).total_seconds()
    return q0 * math.exp(-LAMBDA * dt)          # quantity at delivery
# exportable surplus = bred - self_burn - process_loss, then decay-corrected
surplus = bred - self_burn - process_loss
quote   = decay_correct(surplus, now, delivery_date)

Offtake scheduling is coupled to plant operation. Tritium inventory must never fall below the level the breeder needs to sustain its own burn and startup reserve; L7 enforces this floor as a hard constraint on how much may be committed for export. A customer order that would breach the floor is queued to a later window, not fulfilled from operating inventory.

Every tritium movement is a byproduct-material event under the compliance framework. The offtake record and the byproduct-material accountancy record are the same underlying data, so a shipment cannot leave without a complete, auditable compliance entry attached.

No tritium is offered for delivery before the breeder produces it. Through construction (from Q2 2027) and up to FOAK first tritium ~2030, offtake logistics run against twin-projected surplus so the process, custody chain, and decay accounting are proven before the first real gram exists.