6.4.8.2

a package shall be so designed that, under the ambient conditions specified in 6.4.8.5 and 6.4.8.6 heat

generated within the package by the radioactive contents shall not, under normal conditions of

carriage, as demonstrated by the tests in 6.4.15, adversely affect the package in such a way that it

would fail to meet the applicable requirements for containment and shielding if left unattended for a

period of one week. particular attention shall be paid to the effects of heat, which may cause one or

more of the following:

(a) alter the arrangement, the geometrical form or the physical state of the radioactive contents or,

if the radioactive material is enclosed in a can or receptacle (for example, clad fuel elements),

cause the can, receptacle or radioactive material to deform or melt;

(b) lessen the efficiency of the packaging through differential thermal expansion or cracking or

melting of the radiation shielding material;