US-based Holtec International announced on 13 August that its HI-STAR 100MB transport package had been certified by the US Nuclear Regulatory Commission (NRC) and was "destined to become America's workhorse for transporting used nuclear fuel". Holtec submitted its application for the HI-STAR 100MB to the NRC in February 2018. It is an enhanced version of the HI-STAR 100 package licensed in 1998 to transport high burn-up fuel in either a multipurpose canister (MPC) or in a basket. The HI-STAR 100MB is based on the HI-STAR 190 cask designed for retrieval of large-diameter canisters from US NPPs with on-site storage facilities. “We expect this cask to be employed to transport used fuel of all different sizes and lengths from the nuclear plant sites around the country to our consolidated interim storage facility, HI-STORE CIS (under licensing) in southeastern New Mexico, or directly to a repository,” said Holtec.

According to Holtec, the HI-STAR 100MB has the ability to ship contents packaged in an MPC or in a “bare basket,” to transport both moderate burn-up and high burn-up fuel in the various sizes employed in light water reactors, and to transport fuel with as little as 3.5 years of decay after discharge from the reactor.

“Certification of HI-STAR 100MB at present includes the high capacity Canister, MPC-32M, and “bare baskets” F-24M and F-32M, all using Metamic-HT as basket material for optimal performance. The cask is however sized to hold any canister loaded in the industry up to 68-1/2 inches in diameter which means almost every canister commissioned into dry storage in the US before 2014,” the company noted. A dual purpose (capable of transport and on-site storage) and dual use (capable of holding both unpackaged and canisterised fuel) makes HI-STAR 100MB industry’s first cask of the “double dual” genre.

“Together with its larger cousin, the HI-STAR 190 universal cask (sized to transport the extra-large Canisters deployed in the past five years, and some large legacy canisters), HI-STAR 100MB will provide the means to safely transport all of America’s fuel from the nation’s nuclear plants.”

In March 2017, Holtec submitted a licence application to the NRC for the HI-STORE CIS facility in New Mexico where it proposes to install its Hi-Storm UMax system, which would see casks of used fuel placed below ground in a concrete lot. The initial storage capacity of HI-STORE CIS is 10,000 storage canisters. “We also expect HI- STAR100MB to elicit a strong demand from our overseas clients,” Holtec said. In March 2018, it announced that the design had won an international tender launched by China National Nuclear Corporation.