They have a engineering program that can accurately calculate for the number of tubes plugged...how all the other parameters will change. There are no surprises here. They been plugging tubes for years and they have needed a new condenser for years too.
Pilgrim powers down to meet discharge temperature limit
WednesdayPosted at 1:52 PM Updated at 1:52 PM
By Christine Legere
PLYMOUTH — Operators have powered down the reactor at Pilgrim Nuclear Power Station a bit to comply with temperature limits on water being discharged from the plant into Cape Cod Bay.
The Environmental Protection Agency's water discharge permit for Pilgrim, which allows 500 million gallons to be drawn daily, requires that water leaving the plant after use be no more than 32 degrees hotter than water temperature in the bay.
Bay temperatures were at 40.3 degrees Tuesday, limiting the exit temperature to 72.3 degrees. Plant workers powered Pilgrim down to 97 percent, where it will likely remain for at least one more day, according to Patrick O'Brien, spokesman for plant owner-operator Entergy Corp.
The increased discharge temperature is believed to be related to the work done on the plant's condenser system, which contains 35,000 tubes filled with seawater and converts steam back into water for the reactor.
After a single tube was found to be leaking, hundreds were plugged last month. In an email to the Times, O'Brien wrote that "with the proactive tube plugging, the condenser is working harder, which can increase temperatures."
"Reducing (reactor) power relieves that pressure/stress and helps keep temperatures reduced," O'Brien wrote.
Neil Sheehan, spokesman for the Nuclear Regulatory Commission, reported that the presence of seaweed, algae and small clams also could be affecting the condenser's heat exchange efficiency.
"A diver was being sent in to explore that possibility," Sheehan said in an email.
No comments:
Post a Comment