Deuterium Supply Tracking

Deuterium fuels both machines; L7 tracks its inventory, purity, and consumption rate against burn plans so fuel never becomes the limiting constraint.

The common feedstock

Deuterium is the one feedstock both machines share. The breeder burns deuterium with tritium; the burner burns deuterium with helium-3. Deuterium is abundant and separable from water, so the supply question is not scarcity but continuity, purity, and matching delivery to burn rate. L7 tracks deuterium as an inventory with assay and a consumption model tied to each unit's operating plan.

Purity gating and consumption modeling

Fuel purity matters to plasma performance and to the diagnostics that infer plasma state; contaminants raise effective charge and radiation. Inbound deuterium is assayed and gated before it enters the fuel cycle, and the assay is recorded so a later performance anomaly can be correlated with a fuel batch. Consumption is modeled from the twin's burn state, not from nameplate, so inventory projections track what the machine actually uses.

# days-of-supply projection per unit
inv    = deuterium_inventory(unit)          # kg, assayed
rate   = twin_burn_rate(unit)                # kg/day from L3 state
inbound = scheduled_deliveries(unit)         # (day, kg) list
def days_of_supply(horizon):
    stock = inv
    for d in range(horizon):
        stock += delivered(inbound, d) - rate(d)
        if stock < reserve_floor(unit):
            return d                         # trigger reorder before floor
    return horizon

L7 keeps a reserve floor per unit and triggers reorder before inventory approaches it, so a delivery slip never forces an unplanned burn stop. Because deuterium serves both machine types, a fleet view aggregates demand across the breeder foundry and burner fleet and smooths ordering.

Deuterium supply is the least constrained node in the material graph; the binding constraints are lithium-and-TBR for the breeder and helium-3 for the burner. L7 nonetheless tracks it with the same rigor so that fuel is never the reason a unit under-produces.

Consumption figures today are twin-simulated at design-stage burn rates. The tracking interface is exercised now so that, from construction start Q2 2027 through FOAK, real deliveries and burns flow through the same accounting.