TS 5.4.1.a requires that maintenance activities be performed in accordance with documented instructions. Procedure FHP-0003, Refuel Platform Operation, requires the grapple control operator to appropriately exercise the grapple controls to raise and lower fuel. On January 13, 2008 and January 14, 2008, while moving irradiated fuel within the reactor vessel, the refueling bridge driver inadvertently lowered a grappled fuel bundle that contacted the top of the reactor core. There was no radiological or industrial consequence as a result of this event. The root cause evaluation determined that the primary factors in both events was the failure to appropriately use the human performance tools including self-checking, peer- checking, and three leg communications. This event is described in the licensees
CAP as
CR-RBS-2008-0326. This finding was more than minor because the finding is related to the human performance attribute of the
barrier integrity cornerstone and negatively impacts the cornerstone objective to provide reasonable assurance that physical design barriers (
fuel cladding) protect the public from radio nuclide releases caused by accidents or events. The inspectors completed a Phase 1 significance determination using
IMC 0609 Appendix A,
Significance Determination Process Phase 1 Screening Worksheet, and determined the finding to be of very low safety significance (Green) because the performance issue only degraded the
fuel cladding barrier and its associated cornerstone.
