On April 19, 2012, Holtec International presented a new subterranean multi-purpose canister (MPC) based storage system in a pre-submittal briefing to the USNRC. In development since 2010, HI-STORM UMAX (for Underground MAXimum capacity) is physically sized to store all of the used nuclear fuel produced in the United States and all canisters currently licensed in dry storage in the country making it a truly universal on-site storage facility. HI-STORM UMAX, like its forerunner HI-STORM 100U certified by the USNRC in 2009, stores the MPC entirely below-ground and emits virtually zero dose. HI-STORM UMAX (Docket Number 72-1040) has heat rejection capacity in excess of 47 kW and stores up to 37 PWR and 89 BWR assembly MPCs. Like HI-STORM 100U, HI-STORM UMAX is “security-friendly”, providing a clear, unobstructed view of the entire ISFSI (see figure below) from any location and the closure lid is a massive steel weldment filled with concrete.
The licensing application for HI-STORM UMAX is scheduled to be submitted in June of this year. The Company informed the USNRC that the analysis methodologies and computer codes used in the safety analyses of HI-STORM UMAX are identical to those used in the recently certified HI-STORM FW storage system (Docket Number 72-1032) and HI-STORM 100U (Docket Number 72-1014). The HI-STORM UMAX FSAR, CoC, and Technical Specification contain all relevant details on the VVM (the “overpack” portion of the system) while the MPCs and HI-TRACs technical details, such as approved contents, are maintained in their separate licensing bases (HI-STORM 100 and HI-STORM FW FSAR, CoC, and Technical Specifications) and are not repeated in the HI-STORM UMAX licensing documents. This approach reduces the NRC review scope for the HI-STORM UMAX.
In light of its close similarity with the HI-STORM 100U system and the use of previously approved analysis methods in its safety analyses, Holtec’s President and CEO, Dr. Kris Singh, requested the NRC to complete the safety evaluation of HI-STORM UMAX by January 2013, which would handily beat the Agency’s own prior record of 10 months achieved in 2010 in certification of the HI-STORM FW System. Final certification is anticipated by August 2013.