An expansion tank high level warning has been added to the T1/T2 control system under Work Request #4011.  The purpose for this new warning is to alert staff of an unexpected water increase in the unlikely scenario that a leak develops in the heat exchanger between the two fluids and CuALCW on the secondary side enters the target water system.  The new thresholds for high level warn, low level warn, and low level trip have been set at 40cm, 30cm, and 25cm respectively.  The nominal water level is 35cm.  All thresholds were tested by adding water to the tank, or removing it.  All responded as expected.