nuclear-news

Seawater heating up causes partial shutdown for Pilgrim nuclear station

Rising seawater temperatures force Pilgrim to reduce power, Cape Cod Times, 11 Aug 15,  Rising temperatures in bay force reduction in power  

To cool its reactors, Pilgrim Nuclear Power Station draws up to 500 million gallons of saltwater a day from Cape Cod Bay through an inlet created by two breakwaters. Merrily Cassidy/Cape Cod Times File  By Christine Legere  clegere@capecodonline.com  

PLYMOUTH — The owner of Pilgrim Nuclear Power Station had been planning to ask for a license adjustment that would allow the plant to draw warmer water from Cape Cod Bay than is currently allowed.But the request was not made soon enough.Pilgrim operators were forced to begin preparation for a shutdown late Sunday afternoon, when the temperature of the seawater used to cool the reactor edged above the 75-degree limit set by the Nuclear Regulatory Commission…….

Millstone Nuclear Power Plant in Connecticut, which draws water from Long Island Sound, was the first in the Northeast to shut down because of rising water temperatures, which have become an issue in this region within the past five years. The plant has since secured a maximum intake temperature of 80 degrees on its operating license.“Pilgrim is still looking to increase the maximum saltwater temperature to a higher value, but the supporting analysis is not yet complete,” Lauren Burm, spokeswoman for Entergy Corp., the plant’s owner-operator, said.Last week’s hot spell likely contributed to the rise in the bay’s water temperature, but a spokesman for the Nuclear Regulatory Commission said the plant’s discharge of hot water into the bay also may have been a contributing factor.

“The ballpark estimate on water discharge temperatures at Pilgrim (Sunday) would be about 95 degrees Fahrenheit,” Neil Sheehan said in an email.Under its license, water discharged from the plant may be no hotter than 102 degrees, a level set by the Environmental Protection Agency as part of a water discharge permit…….

Pilgrim draws up to 500 million gallons of saltwater daily from Cape Cod Bay through an inlet created by two breakwaters. The water is circulated through the plant’s condenser via a network of thousands of tubes, cooling down the steam from the reactor and returning it to its water form, Sheehan said.“The higher water temperature affects the efficiency of the heat removal,” Sheehan said.http://www.capecodtimes.com/article/20150811/NEWS/150819916

August 12, 2015 - Posted by Christina Macpherson | climate change