Transport index (TI) and package category for shipping radioactive material
What the transport index is
The transport index (TI) characterises the external radiation level of a package of radioactive material and is used in carriage (Class 7): it drives the package category, the labels and the stowage rules in the conveyance. TI equals the maximum dose rate at 1 metre from the external surface of the package, expressed in mSv/h, multiplied by 100, rounded up to the first decimal place (to 0.1). If the computed value does not exceed 0.05, the transport index is taken as zero. The calculator finds TI from the dose rate at 1 m and solves the inverse problem — the dose rate at 1 m for a given TI.
Package categories: I-WHITE, II-YELLOW, III-YELLOW
The package category is set by two criteria at once — the transport index and the dose rate at the package surface; the higher (worse) of the two is assigned. I-WHITE (label 7A): TI = 0 and surface ≤ 5 µSv/h. II-YELLOW (7B): TI ≤ 1 and surface ≤ 0.5 mSv/h. III-YELLOW (7C): TI ≤ 10 and surface ≤ 2 mSv/h. With TI > 10 or a surface dose rate up to 10 mSv/h, carriage is allowed only under exclusive use (a dedicated conveyance); the rules set no TI ceiling for a single package, and 50 is the maximum TI sum per conveyance outside exclusive use. A surface dose rate above 10 mSv/h means routine transport is not possible and special arrangements are required.
Russian regulation (NP-053-16)
In Russia the carriage of radioactive material is governed by NP-053-16 “Safety rules for the transport of radioactive material” (Rostekhnadzor), section 5.3. The document is harmonised with the IAEA SSR-6 regulations — the transport-index formula and the package-category thresholds coincide, with no separate Russian values. For road carriage across Russia, ADR also applies. For fissile material the criticality safety index (CSI) is used instead of the transport index — that is a separate calculation.
Limitations and related calculators
The calculator gives a screening estimate: shipment documents need the actually measured dose rates at the surface and at 1 metre and the current edition of the rules. The transport index applies to the loaded package (a container with specific contents), not to the container as a product. To estimate the dose rate from a source by its activity, use the dose-rate calculator and the gamma-shielding calculator in this service.
