During the performance of
Service Water Essential
header swap, SWN-6 (Supply to Turbine Building Oil Coolers) valve stem became disconnected from its gear box at 85% open and could not be operated. Therefore, the non-essential
service water system was inoperable.
LCO 3.0.3 was entered at 0930 [EDT] with required actions to be in Mode 3 in
7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, Mode 4 in
13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br /> and Mode 5 in
37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br />. Repair efforts were successful at shutting SWN-6, and
LCO 3.0.3 was exited at 1305 [EDT] before adding any negative reactivity in support of shutdown. ('TS Required S/D' box not checked.)
This condition constituted a loss of safety function which requires an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> report [in accordance with] IAW 50.72(b)(3)(v)(B): Without the ability to close SWN-6, the non-seismic portion of the conventional Service Water System could not be isolated as required in the event of either a seismic event or as required in the EOPs. The nonessential service water system is required to support the recirculation phase post [Design Basis Accident] DBA for accident mitigation.
The licensee notified the NRC Resident Inspector and the State of
New York.
