Questions Remain About Oyster Creek Nuclear Plant Post-Shutdown

Jul 18, 2018

The Nuclear Regulatory Commission July 17 took questions from the public regarding the Oyster Creek Nuclear Generating Station’s plan after it comes permanently offline, which is slated for almost 10 weeks from now. One of the questions that remains is whether Exelon Corp., which owns the Lacey Township-based plant, will sell the generating station post-shutdown to a company specializing in the decommissioning of nuclear plants.

“It’s a new business model,” Bruce Watson, chief of the reactor decommissioning branch of the NRC Office of Nuclear Materials and Safeguards, said recently, noting there are currently six units at four nuclear sites across the country in active decommissioning.

Neil Sheehan, public information officer for the NRC Region 1, said a prospective buyer would need to apply to the federal agency to transfer the plant’s license.

“Only if we were to approve that could the sale take place,” he explained, noting other agencies, such as the state Board of Public Utilities, would also likely have oversight of such a proposal. “We would want to ensure the prospective new owner had the technical and financial wherewithal to safely and effectively decommission the plant it wanted to acquire.”

The NRC is currently reviewing a proposed license transfer for Vermont Yankee, Sheehan said.

“That plant ceased operations at the end of 2014 and a company called NorthStar wants to buy the plant, decommission it in the near time, rather than several decades down the road as was earlier proposed, and then continue to own the site,” Sheehan said.

If the NRC approves the license transfer for Vermont Yankee, the only building left on the property, located on the Connecticut River in Vernon, Vt., would be the dry cask storage facility unless Yucca Mountain or an interim federal spent fuel repository opened in the meantime, he said.

With no federal repository on the horizon, spent nuclear fuel would also remain on site at Oyster Creek following shutdown until at least 2023 with the remainder of decommissioning, including demolishing the reactor building and off-gas stack, beginning in 2075. The NRC continues to look at two interim sites for spent fuel, one in Texas and the other in New Mexico.

In the meantime, the only option for U.S. nuclear power plants is to store spent fuel from the reactor vessel on site, federal officials said. Dry cask storage permits spent fuel that has cooled in the spent fuel pool for at least one year to be surrounded by inert gas, generally helium, inside a container called a cask.

Whenever spent fuel is moved, all of the steps are carefully orchestrated to ensure safety, Sheehan said. The process begins with placing the stainless-steel canister holding the bundles of fuel rods into the spent fuel pool. The fuel assemblies are lifted by a crane from the metal racks located at the bottom of the pool before being inserted into the canister. A lid is then placed on it.

“After the canister is lifted out of the pool, the water is drained and the lid is welded into place,” Sheehan said, noting an inert gas is injected into the canister to alleviate heat transfer and prevent corrosion. “The fuel is then placed into a transfer cask and moved using a special transporter to the dry cask storage pad, where it is inserted into a concrete vault.”

At the top and bottom of the vault, vents allow for convective airflow that removes heat from the canister, he said. The vents are inspected on a daily basis to ensure there is no blockage, Sheehan said. Each steel cylinder is encompassed by additional steel, concrete or other material to provide radiation shielding to workers and the general public. Some of the cask designs can be used for storage and transportation.

In May, Exelon announced its intention to place the nuke in safe storage for nearly six decades after it permanently takes Oyster Creek offline this year, more than 14 months earlier than initially anticipated when it agreed to cease operations in 2019 instead of building cooling towers on the site. In safe storage a facility is left intact or it may be partially dismantled, but the fuel is removed from the reactor vessel, radioactive liquids are drained from the systems and components then processed. The radioactive decay during safe storage lowers the level of contamination and radioactivity that must be disposed of during decontamination and dismantlement.

The company has said the primary objectives for decommissioning the plant are to take it out of service, reduce residual radioactivity to levels permitting unrestricted release, restore the site, perform the work safely, and complete the work in a cost-effective manner.

In addition to the six U.S. nuclear power plants in active decommissioning, there are 14 units in safe storage. Exelon began planning for decommissioning Oyster Creek in 2014, according to the NRC.

For those unable to attend the July 17 public hearing, the NRC is accepting written comments for consideration until Sept. 10.

— Gina G. Scala

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