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 cm2, 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.
Contamination levels up to 2000 dpm/100 cm2 do not pose a significant health
threat in this application.
Contamination levels up to 2000 dpm/100 cm2 do not limit disposal of the outer,
which could become contaminated by contacting the inner, as low level waste.
Originally (in DOE-STD-3013-94), the packaging concept was that the package
would be acceptable for both storage and transportation. It considered the
plutonium-bearing materials to be placed into a "boundary container" and that
packaged into a "primary containment vessel." The boundary container was
required to withstand 150% of the "worst case" internal pressure. The primary
containment vessel was expected to pass the same pressure test, all the DOT
tests (various drop tests, a crush test, etc.) and to be reusable. The current
concept of the 3013 package, which is only for storage, uses the boundary
container as the outer and has added a pressure indicating inner container. The
outer is not expected to be reused. In short, although the packaging concept has
changed dramatically, the criteria regarding removable contamination did not
change to reflect the different role that the inner container now fulfills.
In summary, then, allowing a slightly contaminated inner container does not sacrifice
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