Vernon, Vt. — A plan to speed up the storage of Vermont Yankee’s radioactive spent fuel poses “no significant environmental impacts,” federal regulators have ruled.

The Nuclear Regulatory Commission sees no environmental risk in allowing Entergy to load “hotter fuel” into sealed casks faster than previously had been permitted and in a different configuration designed to limit radiation exposure.

While the NRC still must complete a separate safety review, the environmental decision is important because Entergy’s accelerated fuel-storage project would clear the way for selling the idled Vernon plant to NorthStar Group Services.

“The NRC’s finding of no significant environmental impact is a key milestone for the fuel-movement campaign and for the decommissioning of Vermont Yankee,” said Joe Lynch, Entergy’s senior government affairs manager for decommissioning.

New York-based NorthStar wants to buy Vermont Yankee by the end of this year. The company has pledged to clean up most of the site as early as 2026, which is decades faster than Entergy has been planning

The deal is subject to ongoing reviews by the NRC and the Vermont Public Utility Commission.

While waiting on regulatory approvals for the sale, Entergy has moved ahead with a $143 million project to transfer all of Vermont Yankee’s spent fuel out of a cooling pool and into more secure “dry casks” stored on site.

The fuel move must be complete before NorthStar will buy the plant. But in order to meet that deadline, Entergy needs the NRC’s OK to put newer fuel in casks into service more quickly than initially had been planned.

One aspect of Entergy’s regulation-exemption request has to do with how long spent fuel is required to cool before being packed into casks. The minimum cooling period for the type of storage cask used at Vermont Yankee had been three years; Entergy asked to have that reduced to two years.

The company also has requested that the NRC approve a different loading pattern for spent fuel. The idea is to mix “hotter” fuel and damaged fuel assemblies with older, cooler fuel in the same cask.

“The low-burned, long-cooled assemblies on the periphery of the cask acts as shielding and blocks the radiation from the shorter-cooled, higher-burned fuels stored in the center of the cask,” NRC officials wrote. “As the result, it would reduce dose rate to (Vermont Yankee) onsite workers and at its site boundary.”

The NRC said there are advantages to speeding up Vermont Yankee’s fuel storage program, including reduced costs and the retention of existing staff to handle the project.

Changing the fuel-storage rules for Vermont Yankee “will allow (Entergy) to maintain its continuous loading campaign without interruption to wait for the fuel to meet both the heat loading and cooling time requirements,” federal officials wrote. “This could also avoid potential higher personal exposure and human errors due to loss of experienced workers.”

In granting environmental approvals for the accelerated storage plan, NRC officials said they expect “no significant increase in individual or cumulative radiation exposures, and no significant increase in the potential for or consequences of radiological accidents will occur.”