Faulty relays lead to NRC inspection at Waterford 3

7 relay failures reported in past year, but spokesman says public never in danger

On June 22, a faulty electrical relay at Waterford 3 gave operators problems starting a high-pressure safety injection pump that is used to supply cooling water to the plant’s reactor core in case of an accident.

It was the seventh electrical relay failure at Waterford in the past year, according to the U.S. Nuclear Regulatory Commission (NRC).

Waterford reported the incident to the NRC because the faulty equipment is also used at other nuclear facilities. The NRC then conducted a special inspection at the plant at the end of July.

“There was never a threat to the public or to employees at any time,” Waterford 3 spokesman Carl Rhode said. “We promptly shared what we learned with the vendor and with the NRC. The NRC wanted to thoroughly understand the failure and its significance because of the nature of the issue and the importance of the equipment.”

Rhode said that Waterford worked closely with the NRC to investigate the issue and also formed a Root Cause Analysis team that included site personnel, a vendor representative and two consultants who were experts on the matter.

“The RCA team continues to work closely with the manufacturer to understand the issue and to ensure the reliability of the relays installed in the plant,” Rhode said. “We aggressively removed the equipment in question and worked with the supplier and other sites to understand the nature of the problem.”

Rhode said that Waterford 3 now uses enhanced pre-installation inspections to make sure future relay replacements work and employees have now ensured that reliable and properly functioning relays are installed at the plant

“The NRC team identified a few minor technical regulatory matters in how we handled the information, but overall, did not have any issues with our response,” Rhode said.

The most recent problem occurred when operators tried to start the high-pressure safety injection pump during testing. When the pump didn’t start, the operators traced the problem to a faulty electrical relay, replaced it, and were able to start the pump.

Waterford 3 has received numerous safety awards over the years, including being named a Region VI “Super Star” in 2008 by the Occupational Safety and Health Administration’s Voluntary Protection Program. Waterford received the award because its workers have put in more than 15 million hours without a lost time accident.