Indian Point Replacing O-Rings in Unit 3

CORTLANDT, NY — Indian Point's Unit 3 is shut down as workers replace leaky o-rings on the reactor. There was no threat to public or worker health or safety, so the operation was scheduled for Sunday. The two water seals sit between the lid of the reactor and the reactor vessel, according to Entergy officials.

Unit 3 returned to service on May 18 from its refueling and maintenance outage. Operators noted and began monitoring slight water leakage past the seals during the last few weeks. Entergy said it was acting conservatively and proactively to replace the seals out of an abundance of caution.

Nuclear Regulatory Commission staff will discuss the 2016 safety performance of Indian Point during a public meeting on June 14. The forum will be held in Tarrytown.

According to the NRC, o-rings are flexible gaskets that create a leak-proof sealed connection. They are usually made of flexible synthetic materials because of their elasticity and durability, but some are comprised of metal. In order to perform their function, they are compressed between parts to form a seal.

In the case of nuclear power reactors, o-rings are used to help seal the flange connection where multi-ton reactor vessel heads are attached to the vessel. They must be designed to withstand severe conditions, such as temperature and pressure fluctuations and radiation impacts.

NRC Resident Inspectors assigned to the plant on a full-time basis were apprised of the leakage and of the decision to conduct a forced outage to perform repairs. They will continue to follow those repair activities and will monitor the restart of the reactor once that work is completed, NRC officials said.

PHOTO: An o-ring that was to be installed at a nuclear power plant in the southern US/ NRC

SEE ALSO:

• Indian Point Closure: Westchester County Exec Sues
• NRC Sets Public Meeting On Indian Point's Safety Performance
• Indian Point Bolt Replacement, Refueling Done: Unit 3 Reactor Back In Service
• Leaky Water Seals: Indian Point 3 To Begin Maintenance Shutdown