Protecting used fuel from damage during periods of operations involving high thermal or mechanical loadings is a key challenge in devising dry storage and transport systems.
Maintaining the fuel in an undamaged state is important to assuring that, in the future, it can be retrieved from storage, if need be, by normal means. As is well known to dry storage specialists, the greatest risk of damage to used fuel occurs during its transition from the wet to the dry state when it is often subjected to intense heat to extract its moisture. As reactor operators have, in recent years, gained improved power generating efficiencies by driving fuel to higher burnups – meaning that it is subject to the effects of bombardment by a greater number of neutrons – increased attention has been placed on the challenge of maintaining fuel integrity after it leaves the reactor.
To minimize the risk to used fuel, the USNRC has established a stringent set of criteria for drying that has been instrumental in mitigating fuel failures while drying fuel. The classical method for drying the canister/cask – vacuum drying – has been in use for well over three decades.
Seeking to provide a method to further minimize the possibility of used fuel damage during drying, Holtec International dedicated focused research to develop a new drying technology that would subject the fuel to significantly lower stresses during the drying process. The USNRC approved this new technology in 2002 as a part of the certification to store high burnup fuel in Holtec’s storage systems. Since then, all high burnup fuel placed in Holtec systems has been dried using the new technology. This new technology, known as Forced Helium Dehydration (FHD), is commercially protected by an array of patents owned by Holtec International – thus making it unavailable to users of non-Holtec storage systems.
In light of the growing attention now being placed on high burnup used fuel, Holtec International hereby announces that the Company will share its drying technology under an appropriate license with any dry storage facility owner interested in using the technology. Technical advice to adapt the Owner’s canister/cask to use the (low-stress-producing) Forced Helium Dehydration (FHD) technology will also be provided.
“As the challenges of long-term used fuel management continue to grow, it is important that we help our industry deal with this important technical issue in the best manner possible. Therefore, we offer to share our patented technology with all reactor operators who need to place high burnup fuel in dry storage under an appropriate licensing agreement. Our HI-STORM customers, in the U.S. and abroad, have already, by and large, made the transition to FHD”, says Holtec’s CNO Pierre Oneid.