Type B U packages

Radioactive material in a non-dispersible form or sealed in a strong metallic capsule presents a minimal contamination hazard, although the direct radiation hazard still exists. Additional protection provided by the special form definition is sufficient to ship special form material by air in a Type B(U) package up to an activity of 3000 Aj but not more than 100 000 of the special form nuclide. French studies indicated that some special form material approved under current standards may retain its containment function under test conditions for air accidents [9]. 

Eor low dispersible material the airborne release of radioactive material in gaseous or particulate form is limited to 100 A2 when subjecting the contents of a Type B(U) package to the mechanical and thermal tests. This 100 limit refers to all particle sizes up to 100 pm AED. Airborne releases can lead to radiation exposure of persons in the downwind direction from the location of an aircraft accident via several exposure pathways. Of primary concern is a short term intake of radioactive... 

The concept of a Type B(U) package is that it is capable of withstanding most of the severe accident conditions in transport without loss of containment or increase in external radiation level to an extent which would endanger the general public or those involved in rescue or cleanup operations. It should be safely recoverable (see paras 510 and 511), but it would not necessarily be capable of being reused. 

Type B(U) package should be avoided. However, since absolute containment cannot be guaranteed, the purpose of specifying maximum allowable activity leak rates is to permit the specification of appropriate and practical test procedures which are related to acceptable radiological protection criteria. The model used in the derivation of the release rate of A2 x 10 per hour is discussed in Appendix 1. 

The Regulations require Type B(U) packages to be designed to restrict loss... 

In many cases of Type B(U) package design, the need to meet other sections of the Regulations will result in a containment system which is completely unimpaired by immersion in 200 m of water. 

The surface temperature limit of 85°C for Type B(U) packages under exclusive use, where potential damage to adjacent cargo can be well controlled, is required... 

The intent is that the safety standards of Type B(M) packages, so designed and operated, provide a level of safety equivalent to that provided by Type B(U) packages. 

In order to provide safety equivalent to that which would be provided by a Type B(U) package, the design may include requirements that only gaseous materials should be allowed to be vented, that filters or alternative containment might be used, or that venting may only be performed under the direction of a qualified health physicist. 

Since this test is intended to be analogons to the Type B(U) package 9 m drop test (see para. 603.1), the specimen shonld be dropped so as to suffer maximnm damage. 

RADIOACTIVE MATERIAL, TYPE B(U) PACKAGE, non-fissile or fissile-excepted ... 

Type B(U) packages containing radioactive material with an activity greater than 3000 4 or 3000 2, as appropriate, or 1000 TBq, whichever is the lower ... 

Type B(U) packages shall be designed to meet the requirements specified in paras 606-616, the requirements of paras 617-619 if carried by air, and of paras 634-647, except as specified in para. 646(a), and, in addition, the requirements specified in paras 651-664. 

Type B(M) packages shall meet the requirements for Type B(U) packages specified in para. 650, except that for packages to be transported solely within a specified country or solely between specified countries, conditions other than those given in paras 637,653-655 and 658-664 above may be assumed with the approval of the competent authorities of these countries. Notwithstanding, the requirements for Type B(U) packages specified in paras 653 and 658-664 shall be met as far as practicable. 

An application for approval of a Type B(M) package design shall include, in addition to the information required in para. 807 for Type B(U) packages ... 

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