Contamination means the presence of a radioactive substance on a surface in quantities in excess of 0.4 Bq/cm2for beta and gamma emitters and low toxicity alpha emitters, or 0.04 Bq/cm2for all other alpha emitters.Non-fixed contamination means contamination that can be removed from a surface during routine conditions of carriage.Fixed contamination means contamination other than non-fixed contamination.

A1 and A2

A1 means the activity value of special form radioactive material which is listed in the Table in 2.2.7.2.2.1 or derived in 2.2.7.2.2.2 and is used to determine the activity limits for the requirements of ADR.

A2 means the activity value of radioactive material, other than special form radioactive material, which is listed in the Table in 2.2.7.2.2.1 or derived in 2.2.7.2.2.2 and is used to determine the activity limits for the requirements of ADR.

Fissile nuclidesmeans uranium-233, uranium-235, plutonium-239 and plutonium-241. Fissile materialmeans a material containing any of the fissile nuclides. Excluded from the definition of fissile material are the following:

(a)Natural uranium or depleted uranium which is unirradiated;

(b)Natural uranium or depleted uranium which has been irradiated in thermal reactors only;

(c)Material with fissile nuclides less than a total of0.25g;

(d)Any combination of (a), (b) and/or (c).

These exclusions are only valid if there is no other material with fissile nuclides in the package or in the consignment if shipped unpackaged.

Low dispersible radioactive materialmeans either a solid radioactive material or a solid radioactive material in a sealed capsule, that has limited dispersibility and is not in powder form.

Low specific activity (LSA) materialmeans radioactive material which by its nature has a limited specific activity, or radioactive material for which limits of estimated average specific activity apply. External shielding materials surrounding the LSA material shall not be considered in determining the estimated average specific activity.

Low toxicity alpha emittersare: natural uranium; depleted uranium; natural thorium; uranium-235 or uranium-238; thorium-232; thorium-228 and thorium-230 when contained in ores or physical andchemical concentrates; or alpha emitters with a half-life of less than 10 days.

Special form radioactive materialmeans either:

(a)An indispersible solid radioactive material; or

(b)A sealed capsule containing radioactive material.

Specific activity of a radionuclidemeans the activity per unit mass of that nuclide. The specific activity of a material shall mean the activity per unit mass of the material in which the radionuclides are essentially uniformly distributed.

Surface contaminated object (SCO) means a solid object which is not itself radioactive but which has radioactive material distributed on its surface.Unirradiated thoriummeans thorium containing not more than 10-7g of uranium-233 per gram of thorium-232.

Unirradiated uraniummeans uraniumcontaining not more than 2 ×103Bq of plutonium per gram of uranium-235, not more than 9×106Bq of fission products per gram of uranium-235 and not more than 5 ×10-3g of uranium-236 per gram of uranium-235.

Uranium - natural, depleted, enrichedmeansthe following:

Natural uraniummeans uranium (which may be chemically separated) containing the naturally occurring distribution of uranium isotopes (approximately 99.28% uranium-238, and 0.72% uranium-235 by mass).

Depleted uraniummeans uranium containing a lesser mass percentage of uranium-235 than in natural uranium.

Enriched uraniummeans uranium containing a greater mass percentage of uranium-235than0.72%.

In all cases, a very small mass percentage of uranium-234 is present.