The design shall include a containment system securely closed by a positive fastening device which
cannot be opened unintentionally or by a pressure which may arise within the package.
Special form radioactive material may be considered as a component of the containment system.
If the containment system forms a separate unit of the package, it shall be capable of being securely
closed by a positive fastening device which is independent of any other part of the packaging.
The design of any component of the containment system shall take into account, where applicable, the
radiolytic decomposition of liquids and other vulnerable materials and the generation of gas by
chemical reaction and radiolysis.
The containment system shall retain its radioactive contents under a reduction of ambient pressure
to 60 kPa.
All valves, other than pressure relief valves, shall be provided with an enclosure to retain any leakage
from the valve.
A radiation shield which encloses a component of the package specified as a part of the containment
system shall be so designed as to prevent the unintentional release of that component from the shield.
Where the radiation shield and such component within it form a separate unit, the radiation shield
shall be capable of being securely closed by a positive fastening device which is independent of any
other packaging structure.
A package shall be so designed that if it were subjected to the tests specified in 6.4.15, it would
(a) Loss or dispersal of the radioactive contents; and
(b) More than a 20% increase in the maximum radiation level at any external surface of the
The design of a package intended for liquid radioactive material shall make provision for ullage to
accommodate variations in the temperature of the contents, dynamic effects and filling dynamics.
Type A packages to contain liquids
A Type A package designed to contain liquid radioactive material shall, in addition:
(a) Be adequate to meet the conditions specified in 126.96.36.199 (a) above if the package is subjected to
the tests specified in 6.4.16; and
(i) be provided with sufficient absorbent material to absorb twice the volume of the liquid
contents. Such absorbent material shall be suitably positioned so as to contact the liquid
in the event of leakage; or
(ii) be provided with a containment system composed of primary inner and secondary outer
containment components designed to enclose the liquid contents completely and ensure
their retention, within the secondary outer containment components, even if the primary
inner components leak.
Type A packages to contain gas
A package designed for gases shall prevent loss or dispersal of the radioactive contents if the package
were subjected to the tests specified in 6.4.16. A Type A package designed for tritium gas or for noble
gases shall be excepted from this requirement.
Requirements for Type B(U) packages
Type B(U) packages shall be designed to meet the requirements specified in 6.4.2, and of 188.8.131.52 to
184.108.40.206, except as specified in 220.127.116.11 (a), and, in addition, the requirements specified in 18.104.22.168
A package shall be so designed that, under the ambient conditions specified in 22.214.171.124 and 126.96.36.199 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;
(c) In combination with moisture, accelerate corrosion.
A package shall be so designed that, under the ambient condition specified in 188.8.131.52 and in the
absence of insolation, the temperature of the accessible surfaces of a package shall not exceed 50 °C,
unless the package is carried under exclusive use.