Holtec International is pleased to announce that, following the record-breaking defueling of the Oyster Creek and Pilgrim Nuclear spent fuel pools, both facilities’ high-level waste parts have been safely and successfully loaded into Holtec’s HI-SAFE storage systems and securely stored at the respective sites. 

Known as Greater-than-Class C (GTCC) waste, highly radioactive components within the facilities’ reactor vessels were remotely segmented and placed into the Company’s HI-SAFE storage systems. Designed for low-dose- accreting storage of highly activated metal components, the HI-SAFE systems enabled Oyster Creek and Pilgrim to remove their activated components despite the unavailability of a viable disposal facility for this type of waste. 

Oyster Creek was the first of the two sites to fully load and store its GTCC waste into four HI-SAFE systems. The final unit was filled and placed on the site’s Independent Spent Fuel Storage Installation (ISFSI) pad last August. 

Pilgrim completed the placement of all its GTCC waste into three HI-SAFE systems earlier in March of this year, using best practices from Oyster Creek’s campaign, and by utilizing an improved HI-SAFE systems design. “The improved HI-SAFE system introduced at Pilgrim is a piece of our relentless drive for minimizing crew dose and maximizing worker safety,” says Holtec’s SVP of Operations, Mr. PK Chaudhary. 

A Canister Storing GTCC Waste Being Transferred to a HI-SAFE Storage System at Oyster Creek (Left); 
HI-SAFE Storage System and HI-STORM 100 Dry Storage Systems on the Pilgrim ISFSI Pad (Right)

The process to load the canisters and then store them within the Oyster Creek and Pilgrim ISFSIs was essentially the same method as how their used fuel assemblies were removed from the spent fuel pools at both locations and then placed on their respective ISFSIs. 

The HI-SAFE system design is based on Holtec’s HI-STORM dry storage system for used nuclear fuel. The HI-SAFE system consists of the overpack that provides the requisite shielding and an internal canister that serves as the primary confinement boundary for the radioactive material. The system provides robust, low-dose interim storage of non-fuel waste. The extent of shielding around the HI-SAFE storage system depends on the type of waste being stored. In addition to highly activated metal components from reactor operations and decommissioning, the HI-SAFE storage system is adaptable for storage of all Class B, Class C and GTCC waste. A Non-Fuel Waste Canister serves as the confinement enclosure for the waste and the steel-concrete-steel HI-SAFE overpack provides the biological shield and physical protection for years of onsite storage until a viable disposal facility becomes available.

The HI-SAFE Storage System is a member of Holtec’s HI-STORM family of storage overpacks, allowing use of the same ancillary equipment that is used to load Holtec’s HI-STORM dry storage system. This allows the site to leverage in-house expertise and trained personnel in the performance of a successful HI-SAFE loading campaign. 

All components of the HI-SAFE system are fabricated at Holtec’s manufacturing facilities based in the U.S.