Three Mile Island

In this March photo, a pickup truck travels on Route 441 in the shadow of Three Mile Island cooling towers. The iconic clouds of water vapor are no longer seen, as TMI ceased producing electricity last month.

After 45 years of generation, Unit 1 of the Three Mile Island nuclear power plant will produce its last electricity on Friday.

The shutdown will fulfill the timetable set by plant owner Exelon, which said in May 2017 that the site would shut down by Sept. 30, absent a government bailout.

Exelon said at the time that Unit 1, with 675 employees, had lost $800 million in the past five years due to the emergence of cheaper energy sources such as shale gas.

A government rescue never materialized. In May, Exelon said it would pull the plug.

An Exelon spokesman on Thursday declined to disclose the current number of employees. He said that detail would be disclosed Friday.

However big the current workforce is, Exelon said earlier this year that the workforce would be reduced to 300 six months after the shutdown, to 200 in 2021 and to 50 in 2022.

As LNP previously reported, Exelon wants to decommission Unit 1 by using the “SafeStor” method, with an estimated cost of $1.2 billion.

This would allow the plant’s large components — including its reactor and landmark cooling towers — to sit idle for 55 years before they get dismantled. The radioactivity will diminish over time.

Its radioactive fuel rods would be dealt with much sooner, though. Rods would be moved to the unit’s spent-fuel pool, then into a dry cask storage area, to be constructed at TMI, by the end of 2022.

Fuel rods would be shipped to a Department of Energy permanent storage facility in 2034-2035.

The Exelon proposal can be read online at

(Three Mile Island’s Unit 2 has been closed since its reactor sustained a partial meltdown in 1979.)