Chemical Safety Incidents
After Leak, MA Nuke Back Online
Wednesday, March 1, 2017 @ 10:03 AM gHale
Equipment problems continue to plague the Pilgrim nuclear power station in Plymouth, MA, as this time a valve leaked in the feedwater system which provides hot water to the reactor.
The reactor was at 20 percent of full power while workers addressed the problem. But it is now back at full power.
The 45-year-old plant had not operated at full power since Feb. 6, when an unrelated leak discovered in the condenser system – a closed network of seawater-filled pipes used to cool steam from the reactor – forced operators to power down to 30 percent.
Workers found the faulty tube within 15 minutes, said Patrick O’Brien, spokesman for the plant’s owner, Entergy Corp.
He said the duration of the leak would have meant a release of about 225 gallons. O’Brien said the demineralization filters would have captured most of it “before it got far into the system.”
The plant maintained the 30 percent power level for the first three days of that week. Operators fully shut down the reactor Feb. 9 based on forecasts of a snowstorm.
With the reactor shut down, workers plugged the leaking tube as well as hundreds of other tubes in the condenser system to prevent a repeat of the problem.
Pilgrim began to power back up at 2 a.m. Feb. 12. The reactor never went above 20 percent, until Feb. 15 when it returned to full power.
The plant has six feedwater heating tanks. The tank with the leaking line ended up isolated from the others and now workers have to fully drained it, O’Brien said.
Neil Sheehan, spokesman for the federal Nuclear Regulatory Commission (NRC), described the work that will occur to address the faulty valve.
“Instead of replacing it, plant personnel are cutting the valve out, putting a threaded cap on the line and welding it closed,” Sheehan said. “The line will be abandoned in place at that point.”
“We’ll fix it again in the outage,” O’Brien said, referring to April’s scheduled shutdown of the reactor for refueling.
Operators are keeping the power level low until they have finished work on the faulty line. When the work wraps up, the feedwater heating tank will end up refilled and put back into service.
Pilgrim will shut down permanently before May 31, 2019.