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| Entered date | Event description | |
|---|---|---|
| ENS 50597 | 6 November 2014 04:30:00 | Six (6) U2 CRD (Control Rod Drive) HCU (Hydraulic Control Unit) accumulators were identified with riser brackets that were installed incorrectly. This issue impacts U2 CRD HCU accumulators only. The incorrect riser bracket installation could challenge the ability of the CRD hydraulic control unit to perform its design function during a seismic event. Identified U2 control rods associated with HCU accumulators that had riser brackets installed incorrectly were declared inoperable. This condition has been corrected since initial identification, restoring all control rods to operable status. Reference IR 2407342. This notification is made pursuant to 10CFR 50.72(b)(3)(v) regarding the reportability of multiple failures that could have prevented fulfillment of a safety function. The NRC Resident Inspector will be notified.
The purpose of this notification is to retract the ENS notification made on November 6, 2014 (ENS 50597). An Engineering Evaluation has determined that the function of the affected U2 CRD HCU Accumulators was not affected as discussed in Chapters 6 and 15 of the Updated Final Safety Analysis Report. Therefore, the threshold for reporting the issue as an event or condition that could have prevented the fulfillment of a safety function was not met (NUREG 1022, Revision 3, Event Report Guidelines Section 3.2.7). The NRC Resident Inspector has been notified. Notified R3DO (Dickson). |
| ENS 45333 | 8 September 2009 23:56:00 | On September 8, 2009, during performance of quarterly Core Spray (CS) system flow rate testing, a pinhole leak was identified in the 1B Core Spray Minimum Flow Line. The pinhole leak is located just downstream of the 1B CS minimum flow valve (1-1402-38B) and cannot be isolated from primary containment. At 1935, hours it was determined that structural integrity of the piping could not be assured. Technical Specification 3.6.1.1, Required Action B.1, was entered and a plant shutdown was initiated at 2010 hours. In addition, the 1B Core Spray system was declared inoperable. All other ECCS systems remain operable. The NRC Resident Inspector has been notified. This event is being reported under 50.72(b)(2)(i) due to the initiation of a shutdown required by the plant's Technical Specifications. The licensee estimates reactor shutdown will be achieved at 0130 CDT. |