On 03/03/06, Susquehanna Unit 1 operators began the process of shutting down the unit for the 14th Refueling and Inspection Outage. It was expected that during this evolution, 'slow to settle'
control rods would be encountered, and rather than delay the continuance of the shutdown to perform operability testing, it was determined that these
control rods would conservatively be declared inoperable. Based on previous testing data and trending analysis of operability testing performed during the cycle,
PPL believes that the subject
control rods would have passed operability tests.
Accordingly, at 0517 EDT, Technical Specification 3.1.3.f was entered which requires the unit to be taken to Mode 3 in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> when nine or more control rods are inoperable. The inoperable control rods are fully inserted and disarmed, shutdown margin requirements are met, and the control rod system was always fully capable of performing its safety function.
At the time when the ninth control rod was declared inoperable, Unit One was operating at 0% Power. Unit Two is continuing operation at 100% power.
PPL is reporting this event as a Technical Specification Required Shutdown per
10CFR 50.72(b)(2)(i). The NRC Resident Inspector was notified by the licensee.
