Clarification of Certain Requirements for Exclusive-Use Shipments
See IE Information Notice No. 80-32, Rev. 1, entitled as above and dated February 12, 1982.
This document clarifies guidance on radiation limits for open exclusive use vehicles and use of packages within an outer shield. In some cases, the inner container plus shield is the "package" while in others, the outer shield may constitute a closed transport vehicle.
The radiation limits that apply to shipments being transported by an open exclusive-use transport vehicle must follow the constraints of 49 CFR 173.393 (j) (3) and (4); e.g., 10 mrem/hr at 2 meters from the open planes projected by the outer lateral edges of the vehicle and 2 mrem/hr in any normally occupied area of the vehicle (or cab).
NRC has been informed by DOT that the existing language of 49 CFR 173.393 (j) does not clearly reflect the original intent of the regulation; i.e., to limit the radiation level at the accessible exterior surface of a package on an open exclusive-use vehicle to 200 mrem/hr (such as the same limit applied to the surface of a closed transport vehicle) and is taking steps to revise 49 CFR 173.393 (j). In the interim, NRC licensees are cautioned to adhere to a surface radiation level limit of 200 mrem/hr on a package transported by an open exclusive-use transport vehicle. [Note: This problem was addressed in the current revision of 40 CFR 173. See 49 CFR 173.441 (b) and also 10 CFR 71.47 (a).]
A definition of what constitutes a "package" is illustrated in the enclosures to IE Information Notice No. 80-32, Rev. 1. Generally speaking, the criteria considered include the following: whether any single inner container has a radiation level of less than 1 rem/hr at 3 feet [49 CFR 173.393 (j) (1)]; and whether any single inner container, if bearing LSA material, has a quantity of radioactivity exceeding Type A [10 CFR 71.7 (b), 71.11 (b) (1), 71.12 (b), and 71.35].
With the above considerations and the DOT definitions of "closed transport vehicle" [49 CFR 173.389 (q)] and "packaging" [49 CFR 171.8], each inner drum within an outer shield integrally attached to the vehicle may be considered a "package" provided that each inner drum complies with 10 CFR 173.393 (j) (1) [1 rem/hr at 3 feet], and also provided that the content within any single inner drum does not exceed a Type A quantity of LSA material.
In this configuration, the outer enclosure may be considered as the closed transport vehicle and may incorporate integral shielding to meet the vehicle limit of 173.393 (j) (2) [200 mrem/hr]. The inner drums are marked as packages and the outer enclosure placarded as a vehicle. The combination of inner container plus the outer shield are considered the "package" if any single inner container has a quantity of radioactivity as LSA exceeding Type A or if any single inner container must be certified as Type A by the NRC Office of Nuclear Materials Safety and Standards.
Regulatory references: 10 CFR 71, 49 CFR 173
Subject codes: 7.1, 12.17