At
1834 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.97837e-4 months <br /> on 7/14/10, the Unit 1 'C' Reactor Coolant Loop was declared inoperable due to small unisolable leaks on the 'C'
Steam Generator secondary side surface sample line. Two small through-wall flaws were identified in the piping upstream of 1 -SS-217, 'C'
Steam Generator surface sample line manual isolation valve. The piping is Class 2 and the non-conforming condition could not be evaluated with the
steam generator pressurized. Based on the condition of the piping and the inability to evaluate the flaw, the 'C'
Steam Generator was declared inoperable per Technical Requirements Manual 3.4.6,
ASME Code Class 1, 2 and 3 Components. Subsequently,
Technical Specification 3.4.4 was entered to place Unit 1 in Mode 3 within
6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
At 1934 hours0.0224 days <br />0.537 hours <br />0.0032 weeks <br />7.35887e-4 months <br /> on 7/14/10, North Anna Unit 1 initiated a shutdown in accordance with Technical Specification 3.4.4. The unit will be shutdown and the line will be evaluated and repaired.
The licensee is presently at 82% power and coasting down in power. All safety systems are fully operable.
The licensee has notified the NRC Resident Inspector.
North Anna Unit 1 entered mode 3 at 2353 hrs. There were no complications during shutdown. One source range monitor failed downscale low. The other source range monitor is operating correctly. The failure of this source range monitor did not affect shutdown capabilities.
Notified R2DO (Seymour).
