ECCS ACTUATION DURING RCS HEATUP
"At 2258 (CST) on 02/11/04, Callaway Plant was performing a heat up of the Reactor Coolant System in Mode 3 using plant procedure, OTG-ZZ-00001. When performing Section 6.4 of OTG-ZZ-00001, a Steam Line Pressure Safety Injection was initiated due to the automatic resetting of permissive P-11 at 1970 psig Reactor Coolant System pressure with steam line press less than 615 psig. Actual steam pressure was approximately 600 psig, 15 psig below the Steam Line Pressure Safety Injection set point. As a result of the Safety Injection [signal], the following safety related systems actuated: Safety Injection, Residual Heat Removal, Auxiliary Feedwater, Essential Service Water, and both of the Emergency Diesel Generators. During the injection phase, Pressurizer water level increased to approximately 98 percent and pressurizer pressure increased above the Pressurizer Power Operated Relief Valve (PORV) set point causing the PORVs to operate. During the operation of the PORVs, an open alarm for a Pressurizer Safety Relief Valve actuated, however, there are no indications that this valve actually opened. Initial indications are that a valve position limit switch has malfunctioned.
"All systems responded as expected during the event with the exception of the above mention Pressurizer Safety valve position indication problem and one Steam Generator Atmospheric Safety Valve that would not operate properly in Manual. At present, the plant is being stabilized using plant procedures. Both Emergency Diesel Generators are in standby and the primary system is at 500 degrees F and 1900 psig with Pressurizer level at 25%."
The licensee notified the NRC Resident Inspector. |