Pilgrim nuclear plant down temporarily

The Pilgrim Nuclear Power Station in Plymouth, Massachusetts, was shut down temporarily yesterday due to an apparent malfunction. Media reports suggest a problem with a condenser, a piece of equipment that converts the steam produced by the plant back into water.

Nuclear power plants typically produce electricity by using fissile nuclear material to produce heat. This thermal energy vaporizes water into steam. In turn, this steam spins one or more turbines, each of which is connected to an electric generator. In this regard, nuclear power plants' reliance on steam resembles other thermal power plants such as those fired by combustion fuels like coal or biomass.

As with many other steam-based power plants, nuclear power plants often include steam condensers. A steam condenser takes the steam that is passed through the turbines and converts it back into liquid water. This enables the turbines to extract more energy from the flow of steam, and improves plant efficiency. It appears that a condenser at the Pilgrim station stopped working, leading to a shutdown of the plant.

Any time major equipment at a nuclear power plant sales or malfunctions, operators typically take it very seriously.  Plant owner Entergy has reportedly said that it will not restart the plant until it figures out what went wrong.

Pilgrim Station is a relatively large generating facility, capable of producing up to 688 megawatts of power. The plant was reportedly operating at 30% of its capacity prior to yesterday's shutdown. As result, the short-term impacts on electricity markets in New England may be relatively minimal. However, if the plant continues to be down for an extended period of time, particularly as temperatures heat up and air-conditioning loads increase, the region may experience marginally higher power pricing as result of the shutdown.

The Pilgrim plant is also undergoing a relicensing process through the federal Nuclear Regulatory Commission.