Two nuclear plants reported unplanned reactor shutdowns Tuesday after water level irregularities in steam generators.
At PSEG's Salem plant in New Jersey, operators manually tripped unit 1 when a steam generator feed pump malfunctioned. According to a report filed with the Nuclear Regulatory Commission, the lost pump resulted in a drop in steam generator water levels, which also caused the automatic start of auxiliary feedwater pumps. Safety systems performed as designed, and the shutdown from full power proceeded normally. PSEG reported that no major equipment had been tagged for maintenance before the trip.
At Southern Co.'s Plant Vogtle, unit 2 tripped automatically from full power when water levels in one of four steam generators fell below a set point. Feedwater alarms activated for all four steam generators, according to the NRC, and operators manually controlling a main feedwater regulating valve were unable to recover water levels in one of them. Auxiliary feedwater and feedwater isolation systems actuated and the shutdown proceeded normally. Southern Co. has dispatched a forced outage response team to investigate the trip.