US-based Entergy will shutdown the 680MW Pilgrim nuclear power station in Plymouth, Massachusetts by June 2019.
Poor market conditions, reduced revenues and higher operational costs have been cited by the operator as the reason for this decision.
Entergy has informed the independent system operator of the electric grid, ISO New England (ISO-NE), that the power plant will no longer serve as a capacity resource in the market.
An exact time for the shutdown process is expected to be confirmed in the first half of 2016; however, it will depend on several factors such as further discussions with ISO-NE.
The firm may close plant operations as early as 2017, if it opts against the scheduled refueling.
Entergy chairman and CEO Leo Denault said: “The decision to close Pilgrim was incredibly difficult because of the effect on our employees and the communities in which they work and live.
“But market conditions and increased costs led us to reluctantly conclude that we had no option other than to shutdown the plant.”
The announcement follows a month after the US Nuclear Regulatory Commission (NRC) indicated Pilgrim facility as one of the three least-safe reactors in the US.
The nuclear facility has been operational since 1972 and generates almost carbon-free power for more than 600,000 homes.
Although this step is welcomed by opponents of the plant, it raises concerns about how the US state will replace its chief power source offering around 84% of its non-carbon emitting energy.
The plant will remain under enhanced NRC inspection until it closes operations, when it will be transitioned to the decommissioning phase.
Pilgrim nuclear decommissioning trust recorded a balance of $870m as of 30 September, Entergy said.