The decision is triggered by the unfavorable market conditions, increased operational costs and reduced revenues, the company said.
The closure, however, is subject to several factors, including further discussion with independent system operator of the electric grid, ISO New England (ISO-NE).
Entergy expects to announce a final closure date of the power plant in the first half of 2016.
Commenting on the decision, Nuclear Matters co-chair Judd Gregg said: "Today’s announcement creates an even greater sense of urgency around the need to implement public policies that ensure existing nuclear plants continue to provide long-term sustainability of the electric system and an adequate power supply for the 21st century electric grid.
Gregg said that the retirement of Pilgrim station, which accounts to 12% of the state’s power generation capacity, would affect more than 600 employees.
"The closure will clearly hamstring Massachusetts’ ability to meet the emissions targets set forth by the Environmental Protection Agency’s recently finalized Clean Power Plan to reduce carbon emissions and ensure a cleaner energy future for the country."
Commissioned in 1972, the power plant is designed to generate electricity to meet power demand of more than 600,000 homes and it had operational license till 2032.
Over the next several years, many other nuclear power plants in the US are expected to face potential closure primarily due to low natural gas and power prices, reported Reuters.
Entergy wholesale commodities head Bill Mohl was cited by Wall Street Journal as saying that the company is also planning to decide in the next two weeks on whether to close or continue operations at the FitzPatrick nuclear plant located in New York.
