Surface contaminated object (SCO) means a solid object which is not itself radioactive but which has radioactive material distributed on its surface.
SCO is classified in one of three groups:
- SCO-I: A solid object on which:
- the non-fixed contamination on the accessible surface averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 4 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 0.4 Bq/cm2 for all other alpha emitters; and
- the fixed contamination on the accessible surface averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 4 × 104 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 4 × 103 Bq/cm2 for all other alpha emitters; and
- the non-fixed contamination plus the fixed contamination on the inaccessible surface averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 4 × 104 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 4 × 103 Bq/cm2 for all other alpha emitters;
- SCO-II: A solid object on which either the fixed or non-fixed contamination
on the surface exceeds the applicable limits specified for SCO-I in (a) above and on which:
- the non-fixed contamination on the accessible surface averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 400 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 40 Bq/cm2 for all other alpha emitters; and
- the fixed contamination on the accessible surface, averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 8 × 105 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 8 × 104 Bq/cm2 for all other alpha emitters; and
- the non-fixed contamination plus the fixed contamination on the inaccessible surface averaged over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed 8 × 105 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 8 × 104 Bq/cm2 for all other alpha emitters.
- SCO-III: A large solid object which, because of its size, cannot be transported in a
type of package described in these Regulations and for which:
- all openings are sealed to prevent release of radioactive material during conditions defined in 4.1.9.2.4 e) (ADR, RID, ADN) or 4.1.9.2.4.5 (IMDG Code);
- the inside of the object is as dry as practicable;
- the non-fixed contamination on the external surfaces does not exceed the limits specified in 4.1.9.1.2; and
- the non-fixed contamination plus the fixed contamination on the inaccessible surface averaged over 300 cm2 does not exceed 8 × 105 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, or 8 × 104 Bq/cm2 for all other alpha emitters.