05000387/FIN-2011002-01
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | |
| Description | Inspectors identified a Green finding of MT-AD-605, Maintenance and Calibration of Installed Plant lnstrumentation (lPl), Revision 11, when as-found calibration results of the refueling water storage tank (RWST) level transmitter were discovered outside tolerance and not captured in the CAP. Consequently, RWST level was later discovered to be 25 percent lower than indicated in the control room and below emergency operating procedure (EOP) procedural expectations. The inspectors concluded that finding the level transmitter oUt of tolerance by more than twice the asfound tolerance should have been entered into the CAP as a Level 3 condition adverse to quality (CAO) Cause CR with a due date not to exceed September 28,2010, and that the CR would have directed PPL to investigate the issue earlier, avoided inaccurate level indications to control room operators, and prevented RWST levelfrom ultimately lowering below EOP normal levels. This issub was entered into PPL\'s CAP as CR 1371594. The finding was more than minor since it affected the Mitigating Systems cornerstone objective to maintain the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences and was associated with its equipment performance and configuration control attributes. Specifically, the lack of accurate level indication caused operators to believe that more RWST inventory was available than actually present and an EOP procedural decision is based, in part, on the available RWST inventory. The finding was {etermined to be of very low safety significance in accordance with IMC 0609, Appendix A, Determining the Significance of Reactor Inspection Findings for At-Power Situations using SDP Phases 1,2, and 3. Phase 1 screened the finding to Phase 2 bec0use it represented an actual loss of safety function to makeup to the condensate storage tank (CST)from the RWST per 10CFR50.65, for greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. A Region I Senior Reactor Analyst (SRA) conducted a Phase 3 analysis because the Pfiase 2 analysis, conducted by the inspectors using the Susquehanna pre-solved Risk-lnformed lnspection Notebook, indicated that the finding could be of more thdn very low safety significance. In conducting the Phase 3 analysis the SRA determined that refilling the CST from the RWST was not modeled in the Susquehanna Standardized Plant Analysis Risk (SPAR) model, Revision 8.15. The SRA reviewed a FPl-completed risk significance analysis which included the increase of both core dampge and large early event release frequencies (i.e., delta CDF and delta LERF) bssuming that the RWST was not available for a year. This PPL analysis, which appeare! conservative given the actual volume of water in the RWST during the approximately 6 months that the RWST level instruments were not functioning properly, indicated that the delta CDF and delta LERF were in the very low safety significance range. The finding was determined to have a cross-dutting aspect in Human Performance, Work Practices, in that the licensee defined ahd communicated expectations regarding procedural compliance, however, personnel did not follow procedures. Specifically, PPL technicians did not enter the out-of{olerance level instrument calibration into the CAP in accordance with procedures. (H.4 (b)) |
| Site: | Susquehanna  |
|---|---|
| Report | IR 05000387/2011002 Section 1R13 |
| Date counted | Mar 31, 2011 (2011Q1) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | E Dipaolo J Furia A Rosebrook P Finney J Tomlinson J Greives D Molteni |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
| ' | |
Finding - Susquehanna - IR 05000387/2011002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Susquehanna) @ 2011Q1
Self-Identified List (Susquehanna)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||