A finding of very low safety significance was self-revealed when improper installation of insulation surrounding the
main turbine bearing number two oil deflector caused the
main turbine to be taken off-line due to smoking insulation. An insulation blanket was blocking normal air flow used for cooling the oil deflector, causing oil to carbonize and clog the oil deflector screen. This issue was caused by the lack of procedural guidance for the installation and removal of insulation from the turbine. A corrective action was initiated to create a procedure which incorporates specific guidance for removing and installing the insulation. This finding was more than minor because the issue is associated with the design control attribute of the
initiating events cornerstone and affects the cornerstone objective of limiting the likelihood of events that upset plant stability. The finding was not a loss of coolant accident (
LOCA) initiator and did not contribute to both the likelihood of a
reactor trip and the likelihood that mitigation equipment or functions will not be available. The finding was not considered an external event initiator. Therefore, the finding was determined to be of very low safety significance. (Section 4OA2
