Two reactor units, one in New Jersey and one in Georgia, experienced unplanned outages on April 8, according to incident report filed with the Nuclear Regulatory Commission (NRC).
The Public Service Enterprise Group (NYSE:PEG) Salem Unit 1was manually tripped following the loss of an operating steam generator feed pump, according to the preliminary NRC report posted April 9.
A situation with a steam generator also figured into the Vogtle Unit 2 being taken offline. Vogtle 2 is part of Southern (NYSE:SO) subsidiary Georgia Power.
At the PSEG Salem plant, “The trip was initiated due to loss of Steam Generator water level [SGWL] following the loss of one of the running SGFPs (#11 Steam Generator Feed Pump),” according to the NRC notice.
One of the feedwater pumps stopped working after 9 p.m., a PSEG spokesperson said in an email to GenerationHub. “This led to low water levels inside the steam generators. Control room operators made the conservative decision to manually remove the reactor from service prior to water levels reaching a low set point that would have caused an automatic reactor trip,” said the PSEG spokesperson.
“Troubleshooting is in progress” to determine why the feedwater pump stopped operating,” said the PSEG representative. The last refueling outage for Salem 1 was spring of 2013. A refueling outage for Salem 2 is scheduled for this spring.
Salem 1 is a pressurized water reactor (PWR) with an operating capacity of roughly 1,150 MW.
As for Vogtle 2, it was operating at 100% power “when digital feedwater trouble alarms were received,” according to the NRC notice.
The Vogtle 2 shutdown occurred at 4:30 a.m. ET on April 8.
“Operating crew entered abnormal operating procedure for feedwater malfunction when SG [steam generator] #3 level began rapidly lowering,” according to the NRC event report. “Operators attempted to take manual control of SG #3 main feedwater regulating valve and were unable to raise SG #3 level. SG #3 level lowered to the Lo-Lo Level setpoint causing an automatic reactor trip,” NRC noted.
A “forced outage response team” has been formed to determine the cause of the low steam generator water level” and determine restart criteria, NRC said of the Vogtle situation.
Vogtle 2 is a roughly 1,150-MW PWR. Unit 1 remains in a planned refueling and maintenance outage. Unit 2 last went offline Oct. 19, 2013, and returned to service on Oct. 29, 2013.
For competitive reasons, companies like Southern and PSEG routinely don’t announce the date when they offline units to return to service.
The Vogtle complex, located less than 30 miles from Augusta, Ga., is where the company is building the first new reactors ordered in the United States in more than 30 years. Vogtle 3 is currently scheduled to start commercial operation in 2017 and Vogtle 4 in 2018.