05000482/LER-2008-006
| Docket Numbersequential Revmonth Day Year Year Month Day Yearnumber No. 05000 | |
| Event date: | 05-07-2008 |
|---|---|
| Report date: | 07-03-2008 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4822008006R00 - NRC Website | |
PLANT CONDITIONS PRIOR TO EVENT:
MODE — 4 Power — 000
EVENT DESCRIPTION:
The NRC issued a requirement to perform full flow testing (design flow verification) via 10 CFR 50.55a for all pumps listed under the In-service Testing (1ST) program in 2005. A Design Change Package was developed to enable full flow testing of the containment spray pumps [EIIS Code: BE-P] without the adverse consequences of spraying down containment. The modification would install a new recirculation flow path line to enable full flow testing of the containment spray pumps.
The modification was originally scheduled for Refueling Outage (RF)15 and a Mode 4 restraint Work Order was created to implement the modification. Sub Work Orders (SWO) were initiated for the containment spray modification to have Quality Control (QC) perform a VT-2 examination of the bypass lines installed on trains "A" and "B". The Shutdown Mode Code for the "A" train SWO was incorrectly changed from Mode 4 Hot Shutdown, to Mode 7 No Restraint. The "B" train SWO was then copied from the "A" train SWO also with a Mode 7 No Restraint.
A one-time Relief Request was submitted to the NRC to postpone the containment spray modification until RF 16.
The NRC approved the relief request and the containment spray modification was then removed from the RF15 scope and moved into the developing RF16 schedule.
During the modification work in RF 16, the VT-2 examinations were correctly accounted for in the outage schedule.
Issues with the alignment on flanges in the containment spray system occurred. The "A" train flange alignment issues were worked according to the outage schedule. The VT-2 test was completed satisfactorily.
On the "B" train, the decision was made to machine spacer rings to compensate for the misalignments. The refueling outage schedule was changed to support the completion of the spacer ring work prior to the plant entering Mode 4.
The VT-2 examination was inadvertently dropped from the schedule when this occurred. Since the SWO for the VT-2 examination was a Mode 7 restraint, it was not accounted for during the Mode 4 Work Order Review or on the Mode 4 checklist.
The plant entered Mode 4, at 1844 on 05/07/08. The missed examination was discovered early on 05/08/08 when the nightshift IST Coordinator and QC were reviewing the remaining open work requests. Operations was notified and entry into Technical Specification 3.6.6. Limiting Condition for Operation (LCO) 3.6.6, which requires two containment spray trains and two containment cooling trains to be Operable in Modes 1 through 4, was made at 0145 on 5/8/08. The VT-2 examination was scheduled and successfully performed by QC. The "B" train containment spray system was declared operable at 0313 on 5/8/08.
BASIS FOR REPORTABILITY:
The plant entered Mode 4 without confirming that the containment spray system was operable. This is reportable per 10CFR50.73(a)(2)(i)(B) for any operation or condition which was prohibited by the plant's Technical Specifications.
ROOT CAUSE:
The Sub Work Order was miscoded as a Mode 7 restraint instead of a Mode 4 restraint. The miscoding led to the missed operability determination when the 'B' train containment spray system was returned to service.
CORRECTIVE ACTIONS:
A method for reviewing Open Work Orders against Technical Specification related systems before making an Operability Determination will be developed. This action shall be incorporated in procedure AP 22D-001, "Refueling Outage Planning and Implementation," by 12/15/08.
SAFETY SIGNIFICANCE:
The safety significance of this event was low. Nuclear safety had the potential for being affected if the VT-2 examination had identified any flaws. The successful completion of the surveillance tests confirmed the containment spray system would perform its safety function per the license design basis. There was no affect to plant reliability, personnel safety, radiological safety, or environmental safety.
OPERATING EXPERIENCE/PREVIOUS EVENTS:
None.