Palisades Suffers Reactor Coolant Pressure Boundary Leakage

Palisades Suffers Reactor Coolant Pressure Boundary Leakage

by C.Harris

Palisades nuclear power plant owned and operated by Exelon Nuclear in Covert Michigan, suffered yet another black eye Sunday, August 12, 2012. On that morning operators determined that an Unidentified Reactor Coolant leak existed, amounting to .3 Gallons Per Minute. Technical Specifications were invoked which forced the operators to expeditiously shutdown the Reactor and Cooldown to Mode 5. A Containment Entry Team found steam issuing forth from a Control Rod Guide Tube, indicating that this was the smoking gun.
Control Rod Guide Tubes enclose the Control Rod Drive Mechanisms which allow Control Rods to insert or withdraw from the Reactor Core. They are an extension of the Reactor Coolant System Pressure Boundary. As such, NO leakage is tolerated.
Repair to this component is likely to be complicated because the Event Report states that the leak is in a section of the Control Rod Guide Tube where there are no welds or threaded joints.  A detailed Failure Mechanism investigation will have to be performed in order to pin point the cause of the leak. Further, an Extent of Condition Analysis will have to determine how many other of the 45 Control Rod Guide Tubes may be susceptible to the same Failure. Other Combustion Engineering Plants will have to apply the results of the Investigation to their plants to determine whether they could occur there.http://enformable.com/2012/08/palisades-suffers-reactor-coolant-pressure-boundary-leakage/