Guidance for Gas-Generation Considerations for Shipping and Storage of Type B or Fissile Material Packages

This guidance applies only to DOE elements or persons working under contract to DOE elements

DOE elements means programs, operations offices, field/site offices, and other organizational units of the Department of Energy, excluding those of the National Nuclear Security Administration.  The list of DOE elements is hereexternal (link to DOE Directives website).

This guidance briefly addresses how acceptable shipping periods are determined for Type B or fissile radioactive material packages certified by the Department of Energy (DOE), based on flammable gas compliance considerations.  The scope of this guidance is for packages that have not been inerted with a diluent.  The guidance also includes a WARNING for non-transportation uses of Type B or fissile radioactive material packages.

According to 49 CFR 173.7(d), Type B or fissile radioactive material (RAM) “…packagings made by or under the direction of the U.S. Department of Energy may be used for the transportation of Class 7 materials when evaluated, approved, and certified by the Department of Energy against packaging standards equivalent to those specified in 10 CFR Part 71”, Packaging and Transportation of Radioactive Material.  The Part 71 packaging standards and criteria for flammable gases are discussed below.

The §71.43(d) compliance evaluation in a Safety Analysis Report for Packaging (SARP) for Normal Conditions of Transport assumes the package is closed for period of 1 year under the heat conditions specified in §71.71(c)(1) in order to:

  1. Calculate the maximum normal operating pressure (MNOP) from all possible sources of gases and 
  2. Demonstrate that hydrogen or other flammable gases will not result in a flammable mixture within any confined volume of the package.  

Under the heat conditions of §71.71(c)(1) [Ref DOE Packaging Review Guide for Reviewing Safety Analysis Reports for Packagings (SARP)], the criterion for a “flammable mixture” is hydrogen and other flammable gases compose less than 5% by volume of the total gas inventory within any confined volume in the package over a period of 1 year.  However, if hydrogen and other flammable gases compose 5% or greater by volume of the total gas inventory within any confined volume in the package in 1 year, the SARP may evaluate the actual time to reach 5% and then propose controls to demonstrate equivalent safety for the shipment [see §71.41.(d)].

 In 2009, the Nuclear Regulatory Commission (NRC) issued Information Notice 84-72, Clarification of Conditions for Waste Shipments Subject to Hydrogen Gas Generation (  IN 84-72 provided clarification and guidance with respect to an acceptable safety margin applied to the shipment period, that is, half the time to reach 5% where the time begins when the package is prepared (i.e., confined volume is sealed).  For example, if the SARP demonstrates that 5% flammable gas is generated in 4 months, then the shipping period reflected in the SARP Chapter 7 for Package Operations and in the CoC as a condition-of-use would be 2 months. 

Based on IN 84-72, and for consistency with NRC CoCs, DOE CoCs will only include a specific condition-of-use to limit the shipping period if flammable gases reach 5% in less than 2 years.

DOE packages users are reminded that the shipping period begins WHEN the confined volume is sealed, as defined by the SARP and CoC, which is typically when the package containment boundary is sealed, and not when the package is offered for shipment.  Consequently, the shipping period includes storage of the package pending shipment. 

Non-transportation use (e.g., indefinite storage or disposal) of a Type B or fissile material package is outside the scope of Part 71 and the DOE Certifying Official's package certification authority under Order 460.1D, Hazardous Materials Packaging and Transportation Safety; therefore, it is responsibility of package users (i.e., shipper/consignor and receiver/consignee) to understand and comply with the applicable safety requirements for non-transportation uses of a Type B or fissile material package.  DOE PCP strongly advises package users to consult with the Certificate Holder and their subject matter expert for safe use of packages outside the scope of transportation.  


Questions or comments? Contact the DOE Packaging Certification Program Manager, Dr. Shuler, (301) 903-5513,

Added July 9, 2020

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