nuclear-news

11 USA nuclear reactors may have unsafe cooling systems

Nuclear Regulatory Commission says accident models could be amiss, By Mike M. Ahlers, CNN February 18, 2012 — The models may underestimate how much nuclear fuel would heat up during system failures
The commission is asking 11 U.S. nuclear power plants for more information
There is no immediate threat to public safety
Washington  — The Nuclear Regulatory Commission has asked 11 nuclear power plants for information about the computer models they use to test different accident scenarios, saying those models may underestimate how much nuclear fuel will heat up during cooling system
failures….
At issue is a phenomenon known as “thermal conductivity degradation,” or TCD, the NRC said. TCD refers to the fact that nuclear fuel loses its capacity to transfer heat as it ages.
The NRC said it is concerned that some computer models may not account for TCD. If the plants are not considering TCD, the possibility exists that fuel rods could heat up 100 degrees more than anticipated in an accident scenario, exceeding the 2,200-degree limit considered safe,the NRC said. That could damage the fuel rods’ outer layer, leading to
reactor damage, the NRC said……
The plants have until March 19 to provide the information to the NRC
staff. http://edition.cnn.com/2012/02/17/us/nuclear-accident-models/index.html

February 18, 2012 - Posted by Christina Macpherson | Reference, safety, USA