A boiler tube ruptured at Wisdom Station on July 6, resulting in a six-day forced outage.
The tube leaked approximately 9,000 gallons of water down three floors of the plant and left up to a half an inch of standing water in the emissions monitoring room and most offices. Plant employees responded quickly to prevent significant electrical equipment damage.
The investigation found that a small hole in a nearby superheater steam tube was likely the cause of the adjacent tube rupture.
Mike Thatcher, vice president of generation, says there were a number of factors contributing to the length of the outage. "Employees had to allow time to pass for the boiler to cool down before anyone could safely investigate the inside and we worked to repair additional leaks found in the superheater loops and a second boiler tube."
Instead of going offline in the future, crews also took advantage of the outage and replaced worn parts on the pulverizer this week to help with the continuous burn of the remaining coal stockpile.
Thatcher says, "We made good use of the outage time and plant employees worked safely during the event and in subsequent clean up and repairs."