CORTLANDT, NY — Unit 2 at the Indian Point nuclear power plant was offline for two weeks. It returned to service Dec. 23, said spokesman Jerry Nappi.
It was taken offline due to leakage from a reactor coolant pump, said Neil Sheehan, spokesman for the Nuclear Regulatory Commission. “It stayed down not only for those repairs but also to address other issues, including o-ring leakage on the reactor vessel head (the o-rings help create a seal between the head and the vessel). O-ring leakage has been an ongoing issue for both Indian Point units.”
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.