Transport of High Activity Isotopes in the BEA Research Reactor Package

The BEA Research Reactor Package has been in use for nine years in the DOE complex as a workhorse for moving used research reactor fuels. Over its lifetime, the packaging’s NRC approval has been amended to include a broad range of research reactor and materials test reactor (MTR) fuels. Because the packaging has very heavy shielding, it is also readily amenable for use with high-activity payloads such as cobalt-60. Because such isotopes with their high heat generation were not part of the original design specification, some design challenges were presented when the Isotope Program Office of Nuclear Physics, Office of Science, U.S. Department of Energy (DOE-SC IP) requested the addition of cobalt 60 to the approved payloads. The first problem addressed was the movement of the decay heat out of the package without generating excessive temperatures in the important-to-safety components of the package, such as the basket, the structural shells, and the shielding. The thermal limit of the payload itself was a particular challenge, since it was made of aluminum. Next, since an early payload target design had experienced a rupture failure in the past, it was necessary to design a target holder to preclude loss of control of the individual activated pellets in the event of target rupture. The use of the target holder ensures safe transport of the target. For added safety, the target was redesigned to eliminate the rupture failure. Finally, the concentration of the heat source meant that the cask surface temperature would exceed regulatory limits in the shade, and consequently a personnel barrier needed to be included. This paper will describe these challenges and the design approaches taken to meet them.