Holtec International Storage, Transport & Repository

HI-STAR(USNRC Certificate of Compliance No.9261 for Transport)
(USNRC Certificate of Compliance No.1008 for Storage)

The HI-STAR 100 is the nuclear industry’s first fully licensed all-purpose MPC technology-based, high capacity system for storage and transport of spent nuclear fuel and Greater than Class C waste.

Engineered to store spent nuclear fuel in the vertical orientation and to transport it horizontally, the HI-STAR 100 overpack melds the roles of a nuclear pressure vessel and a robust transport device. In external appearance, the HI-STAR overpack is a cylindrical vessel with a flat bottom and a removable lid. From the structural standpoint, the HI-STAR 100 cask is made up of three shells: an innermost shell that acts as the containment boundary, a series of thick steel intermediate shells for gamma shielding, and an outer or enclosure shell that houses the neutron shielding material.

The HI-STAR 100 package is fitted with AL-STAR Impact Limiters for off-site transport by road (heavy haul trailer), rail, and/or barge. Included with the package are a shipping frame, tiedowns, and a personnel barrier that envelops the cask during shipping operations. The HI-STAR 100 design is in full compliance with USNRC (10CFR71) and IAEA transport regulations.

To summarize, some key design features of the HI-STAR overpack are:

  • Cryogenic alloy steel in the containment boundary material eliminates brittle fracture concerns under sub-zero conditions (in storage or transport).
  • A layered shell construction using thin stabilized carbon steel shells provides total immunity against propagation of a crack induced by a sudden impulse impact (e.g., missile impact, pin puncture).
  • Bolted-end closure construction designed to ensure joint sealworthiness under pressure and external/internal mechanical loadings.
  • An extremely efficient heat rejection configuration using carbon steel shells as a gamma barrier which also maximizes the heat transmission capability.
  • Holtite-A neutron absorber that is radiation and thermal tested at a temperature well over the maximum temperatures experienced during its operating modes.
  • Engineered surface flexibility: The outer region of the overpack is composed of matrix deformable connectors and Holtite-A to maximize the surface flexibility of the HI-STAR overpack during a postulated drop and impact events (and thus minimize the inertia load on the contained fuel basket during a drop accident).