2. Testing During Use
ANSI N14.5, Leakage Tests on Packages for Shipment, specifies that the acceptable
maximum leak rate is 1 x 10 std. mm /sec (1 x 10 std. cm /sec) of dry air at one
atmosphere [ANSI 1997]. Full penetration weld closures provide the highest integrity
and longest life seals possible. Welds eliminate gaskets, which may degrade and
leak. Mechanical seals using bolts or screwed connections are susceptible to wear,
creep relaxation, seizure, or other mechanical failure.
1. Identification markings are required on all storage containers to facilitate
maintenance of an inventory data base and management of stored materials.
2. The outer container will be placed in and moved through contamination-free areas.
It is important that the container not compromise the contamination-free nature of
those areas. Further, the outer container, when open prior to filling or loading,
should still be capable of placement in, or transport through contamination-free
The inner container is the innermost barrier to release of radioactive materials. To
ascertain that this barrier has been adequately established, the container is tested to
confirm that it is leak-tight. Removable contamination should be minimized, within
the bounds of ALARA principles, but should not exceed 2000 dpm/100 cm , which is
the threshold between a "contamination area" and a "high contamination area."
In earlier versions of this Standard, there was a requirement that, at the time of
closure of the outer container, the exterior surface of the inner container be
contamination-free, as defined in Appendix D to 10 CFR 835. That requirement has
now been removed and replaced with the requirement stated above. The reasons
for the change are as follows:
Once the outer container has been sealed, there is no way to determine whether
the inner is contaminated or not. On opening the outer, the assumption must be
made that the inner is contaminated. Thus, a contamination-free inner provides
no benefit after the outer is closed.