Holtec International this week revealed a “cutting-edge” decommissioning approach it said will allow utilities to convert nuclear plant sites to greenfield status about five-and-a-half years after reactor shutdown.
The “proto-prompt” system features a friction-stir welded Metamic HT fuel basket, which the Nuclear Regulatory Commission licensed in 2008. The nuclear waste company developed the concept to address the risks of accidental pool drain-downs, which cause zirconium fires. A drain down involves a loss of spent fuel pool water, “uncovering” the pool. These risks, the company said in a press release, impact a utility’s decisions in reducing its workforce following cessation of operations, because more staff is needed when spent fuel remains in the pool.
Following reactor shutdown, spent fuel remains in the facility’s pool until it’s cool enough to be prepared for storage or disposal. The five-and-a-half-year timeline for greenfield conversion requires that the contents of the spent fuel pool be transferred to dry storage no more than two-and-a-half years after reactor shutdown.
A fuel basket is a spent fuel support structure located within the spent fuel canister. Holtec said the Metamic HT basket’s thermal conductivity is 10 times greater than traditional stainless steel baskets, shortening the cooling period of spent fuel from seven years to two-and-a-half years. The system allows utilities to avoid years of delay in decommissioning nuclear plants, decreasing upkeep costs and the reliance on volatile trust fund appreciation to finance the decommissioning, according to Holtec.
“The proto-prompt decommissioning strategy espoused herein will eliminate the fuel and high level waste as the obstacle to demolishing the plant and restoring the site for other productive purposes on an expedited calendar,” Holtec stated in the release. “We like to call it a cutting-edge fuel storage technology in the service of accelerated environmental cleanup!”
