Packaging refers to a container and all accompanying components or materials necessary to perform its containment function. Packagings used by DOE for hazardous materials shipments are either certified to meet specific performance requirements or built to specifications described in Department of Transportation (DOT) hazardous materials regulations (49 Code of Federal Regulations [CFR] Subchapter C). For relatively low-level radioactive materials, DOT Specification Type A packagings are used. These packagings are designed to retain their contents under normal transportation conditions. More sensitive radioactive materials shipments require use of highly sophisticated Type B packaging, designed and tested to prevent the release of contents under all credible transportation accident conditions.
Plutonium, HEU, and components containing tritium are DOE-unique hazardous materials that require special protection. In addition to meeting the stringent Type B containment and confinement requirements of NRC's 10 CFR 71 and DOT's 49 CFR, packaging for nuclear weapons and components must be certified separately by DOE. DOE employs a closed, Government-owned and -operated Transportation Safeguards System for the intersite transport of nuclear weapons and components, including plutonium and HEU. Specially designed safe secure trailers are utilized to ensure high levels of safety and physical protection. Limited-life components are transported almost exclusively by DOE's contract air carrier.
As a representation of a typical Type B packaging used to transport weapons components, the testing sequence for the 6M, Type B packaging used for the shipment of HEU is described below. Plutonium and tritium packaging requires a similar, high level of protection. Most other radioactive and hazardous materials, such as low-level waste, would be transported by commercial truck. Historical summaries of the hazardous and nonhazardous materials shipped to and from each of the candidate sites are presented in tables G.3-1, G.3-2, and G.3-3.
In addition to meeting standards demonstrating it can withstand normal conditions of transport without loss or dispersal of its radioactive contents, the model 6M, Type B packaging used for DOE shipments must survive certain severe hypothetical accident conditions that demonstrate resistance to impact, puncture, fire, and water submersion. Test conditions do not duplicate accident environments but, rather, produce damage equivalent to extreme and unlikely accidents. The 6M, Type B packaging is judged as surviving extreme sequential testing if it retains all of its contents except for minuscule allowable releases, and if the dose rate outside the packaging does not exceed 1 rem/hour at a distance of 1 m from the package surface. Drum sizes (outer package) can vary from 38 to 420 liters (10 to 110 gallons).
The complete sequence of tests is listed below:
The regulatory test conditions for the 6M, Type B packaging and other similar packagings are much more demanding than they might appear. For example, an impact on a very hard surface (desert caliche) at over 32 km (200 mi) per hour is not as likely to deform the packaging as would a drop of 9 m (30 ft) onto an unyielding target.
The 6M, Type B packaging is made up of several component parts each playing an integral engineered role in containment and confinement of the radioactive material being shipped. The applicable DOE Safety Analysis Report for Packaging provides additional detail that shows that the package provides a high level of public safety regardless of the accidental conditions it might encounter during transportation. A typical 6M, Type B packaging approved for use by DOE is covered by a Certificate of Compliance. Although 6M, Type B packagings have been involved in severe accidents, the integrity of the packaging has never been compromised. A representative 6M packaging is shown in figure G.2-1.
