Shielded containers for radioactive waste using recycled contaminated metals

A family of shielded containers constructed of recycled contaminated lead and stainless steel from the US Deptartment of Energy (DOE) stockpile have been developed as a joint effort by the Idaho National Engineering and Environmental Laboratory and Lockheed Martin Energy Systems-Oak Ridge. The containers were designed primarily for the transportation and storage of 30- or 55-gallon drums of remote handled transuranic solid waste (RH-TRU). The use of recycled construction materials fulfills two purposes: (1) waste transportation and storage and (2) a reduction in the quantity of contaminated metals that require both storage and disposal. Currently, the DOE complex has millions of pounds of contaminated lead and stainless steel. Non-linear, dynamic finite element analyses were used to simulate the drop tests onto a rigid surface required for US Deptartment of Transportation (DOT) 7A Type A certification. During and after these tests, the container contents must remain within the container and shielding must not be reduced. Loads in the major connections and strains in the stainless steel and lead were monitored as a function of time during dynamic impact analyses for three simulated drop orientations. Results were used to optimize the final design. Stainless steel and lead were found to have maximum strains well below ultimate levels except at an impact corner where additional deformation is acceptable. The predicted loads in the connections indicate that some yielding will occur but the containment and shielding will remain intact. The results provide assurance that the containers will pass the required DOT certification tests. The methods used can be applied to other waste shipping containers allowing for optimization of designs without the expense of actual impact testing.