Support journalism that matters to you

Since COVID-19 impacts us all and we want everyone in our community to have the important information they need, we have decided to make all coronavirus related stories free to read on While we are providing free access to articles, they are not free to produce. The newsroom is working long hours to provide you the news and information you need during this health emergency. Please consider supporting our work by subscribing or donating.

Millstone 2 reactor shut down after pump shuts off during maintenance

Waterford – Dominion, the owner of Millstone Power Station, is investigating the unexpected shutdown of a water pump in the Unit 2 reactor Sunday that triggered an automatic shut down of the reactor itself.

“We’re investigating the cause,” said Dominion Spokesman Ken Holt. “We’re troubleshooting and testing while at the same time making preparations to restart.”

The shutdown occurred at 3:15 p.m. Sunday as plant workers were backwashing the reactor’s condenser, which is used to cool down and condense into water the steam that has already passed through the turbine, said Neil Sheehan, a spokesman for the Nuclear Regulatory Commission, in an email.

One of two water pumps was placed out of service while the work was being performed, as is customary, but the second pump suddenly and independently “tripped,” or shut itself off, Holt and Sheehan said.

The plant safely shut down, there were no complications and the cause of the pump trip is being investigated, Sheehan said.

In a pressurized water reactor like this one, the reactor keeps water under pressure so that it heats, but does not boil, according to the NRC. The reactor coolant system transfers heat produced in the reactor core to the steam generators. At that point, heat is produced for the turbine-generator, which in turn produces electricity.


Loading comments...
Hide Comments