Massachusetts officials have dropped a lawsuit against Holtec International, now site owner and intended cleanup manager of the closed Pilgrim Nuclear Plant near Plymouth that allows the $1.13 billion-decontamination and decommissioning of the 670-MW site to move forward to be completed in 2027.

The state also dropped its challenge to the U.S. Nuclear Regulatory Commission’s transfer of the site operating license from Entergy Nuclear to Holtec.

Under the agreement reached June 16, Holtec will set aside $193 million of the plant’s decommission trust fund to pay for cost increases, project delays and possible hidden contamination.

Once cleanup is competed, $38.8 million will be set aside to cover the cost to transport spent nuclear fuel stored at the site to out-of-state storage.

“I’m pleased we were able to work with the Commonwealth of Massachusetts to find common ground that provides Holtec the certainty needed to safely complete decommissioning on the projected timeline,” Pam Cowan, CEO of Holtec Decommissioning International, said in a statement. Holtec also must comply under the agreement with state standards to clean up hazardous materials such as oil and polychlorinated biphenyl (PCBs).

The Massachusetts Dept. of Environmental Protection and Dept. of Public Health will oversee the cleanup.

“This agreement provides critical protections, includes compliance measures stricter than federal requirements,” Attorney General Maura Healey said in a statement. Deconstruction of buildings and structures outside the controlled area of the nuclear power station began immediately after Holtec completed acquisition of the plant’s assets last August. The plant ceased operating in May 2019.

A joint venture of Holtec and SNC-Lavalin Group will complete demolition and site cleanup. Used nuclear fuel now located in a spent fuel pool is being moved to an on-site dry storage system designed by Holtec. The process will be completed in less than three years.

Other contaminated parts of the reactor will be dismantled and transferred to high capacity transport packages, the company said.

Holtec will use the NRC’s DECON method of decommissioning the plant rather than Entergy’s planned SAFESTOR method, which will shave about 60 years off the cleanup.

All but 50 of the site’s 1,600 acres will be available for commercial or industrial development. Dry storage casks will be held on the 50 acres until they can be moved to an interim storage site.

Entergy has agreed to sell two other nuclear plants to Holtec for decommissioning—two nuclear units totaling 1,060 MW at the Indian Point site in New York state north of New York City and the single unit 805-MW Palisades nuclear plant in Covert, Mich. on Lake Michigan.

Indian Point units will shut down in 2020 and 2021. Palisades will cease operation in 2022.

Holtec last year also acquired Exelon’s 636-MW Oyster Creek nuclear plant in New Jersey to decommission at a cost of $826 million, which is expected to be completed in 2035.