Entergy’s Vermont Yankee (VY), undergoing complete defueling of its pool as a prelude to decommissioning, has its second storage pad built by Holtec that will provide ample space to store all the remaining MPCs needed to make the reactor building free of fuel. It is with great pride that we announce the early completion of all major civil construction work associated with the Independent Spent Fuel Storage Installation (ISFSI) expansion project at Vermont Yankee handily beating Entergy’s accelerated target schedule.
As part of the site construction effort, Holtec has decommissioned several existing site structures, such as the North Warehouse and Auxiliary Diesel Generator, and reconfigured and upgraded electrical, service air, and potable water supply systems. In addition to expanding the ISFSI through the addition of a second pad, the site work included installation of a new Diesel Generator, and its blast protection structure that houses the generator. At this point, Holtec has loaded six HI-STORM 100 casks with steadily declining crew dose as the Company deploys creative ALARA solutions to compensate for the elevated background radiation levels inherent to an inactive BWR. The technologies being developed at VY to minimize crew dose will be valuable in decommissioning other BWRs in the future.
Tennessee Valley Authority’s (TVA) Browns Ferry site now has eight additional large capacity MPC-89s that were loaded in the site’s 10th loading campaign. Like the ongoing VY pool-to-pad effort mentioned above, the loadings have been characterized by the “Four zeros”- zero recordable incident, zero contamination, zero handling mishap, and zero procedure violation.
“Our pool-to-pad loading duration, reflecting our core emphasis on long term Canister integrity and ALARA is deliberately programmed to occur in 5 days. This approach has enabled our MPC’s field closure weld size to be made four times that of any peer supplier, and the Canister dried to a greater level of vacuum than any other in the industry. Eschewing economy in favor of reliability, we don’t use neutron absorbers that trap moisture and pose the risk of in-process swelling or carbon steel in the fuel basket that led to many a loading debacle in the 1990s or use a loading process that may gouge the Canister. Protecting public health and safety, minimizing crew dose and engineering the storage facility to facilitate an effective long-term aging management are the three cardinal goals that guide our dry storage program,” says Dr. Stefan Anton, Holtec’s VP of Engineering and an eminent nuclear engineer.