In the late 1990s, Metamic® emerged to become the nuclear power industry’s definitive solution to the age-old problem of neutron absorber performance. The mechanical properties of Metamic® have fueled its use to rehabilitate spent fuel storage racks with malperforming neutron absorbers and propelled its use in the latest generation of high-density fuel storage racks. All active cask designers have sought (and some have already received) the NRC’s approval to equip their fuel baskets with Metamic®. Metamic® is being used virtually exclusively in the U.S. in wet storage applications to avert the physical stability problems of the old generation neutron absorbers.

Conceived and developed in the Reynolds Metal Company’s research laboratories, Metamic® was tested ad nauseam for its adequacy by the Electric Power Research Institute in the late 1990s and subsequently by cask system designers. Holtec International conducted a 4 year testing program ending in 2003 and incorporated Metamic® in the company’s wet and dry product lines. Metamic® is a fitting symbol of American ingenuity and an apt affirmation of the adage, “necessity is the mother of invention”. In addition to serving as the ultimate device to ensure reactivity control whether in a plant’s fuel pool, in a dry storage cask, or in the long-term repository, Metamic® also holds out the promise to become a preferred material in the aircraft, automobile, and other industries where a high strength-to-weight ratio, good ductility and weldability (all strong points of Metamic® are considered premium material attributes).