June 24 (Reuters) - Constellation Energy ( CEG ) on May

31 permanently shut down the natural gas-fired Mystic Generating

Station located in Charlestown, Massachusetts, the Energy

Information Administration (EIA) said in a report on Monday.

The agency added Mystic's future had been uncertain when in

2018 its then-owner, Exelon ( EXC ), sought to retire the plant

due to profitability concerns.

However, recognizing its role in ensuring fuel security and

system reliability during the peak winter demand season, grid

operator Independent System Operator New England (ISO-NE)

mandated the plant remain operational until May 31, 2024, the

report said.

The retirement of Mystic also raised concerns about the

future of the adjacent Everett LNG terminal, also owned and

operated by Constellation and which supplied 100% of the plant's

natural gas, EIA added.

However, under new long-term supply contracts secured with

regional utilities, Constellation will keep the Everett terminal

operational through winter 2029-2030, according to the EIA

report.

The contracts ensure a steady supply of natural gas for New

England, particularly during the critical winter months when

natural gas price spikes are common due to pipeline limitations,

EIA said.