05000482/FIN-2008005-01
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Finding | |
|---|---|
| Title | Maintenance Causes Unplanned Increase in Reactor Power |
| Description | On September 24, 2008, inspectors identified a noncited violation of 10 CFR 50.54(j) in which the fix it now team manipulated limit switches for Valve ACPV186C that caused the reactor to exceed the licensed thermal power limit of 3565 MWt for 27 minutes until reactor operators reduced power. The fix it now superintendent designated this work as tool pouch maintenance which required no prior planning. When the instrumentation and controls technician recoupled the limit switch to the stem linkage, position indication of Valve ACPV186C changed from open to closed. Unknown to the control room or the fix it now team, Valve ACPV186C is interlocked with Valve ACHV256D which is a dump valve from Moisture Separator Reheater C to the condenser. When Valve ACHV256D opened, it caused a positive reactivity addition which exceeded the licensed thermal power limit. The failure to adequately plan a work activity that resulted in an unexpected positive reactivity addition is a performance deficiency. The inspectors determined that the finding was more than minor because it is associated with the configuration control attribute for the Barrier Integrity Cornerstone; and it affected the cornerstone objective of providing reasonable assurance that physical design barriers, such as fuel cladding, protect the public from radionuclide releases caused by accidents or events. Specifically, this issue relates to the reactor manipulation example of the configuration control attribute. The inspectors evaluated the significance of this finding using Phase 1 of Inspection Manual Chapter 0609.04, Phase 1 Initial Screening and Characterization of Findings, and determined that the finding was of very low safety significance or Green because the fuel cladding barrier was affected but did not affect the reactor coolant system or containment barriers. The inspectors determined that this finding has a crosscutting aspect in the area of Human Performance associated with the Decision Making component because Wolf Creek used flawed assumptions in the work planning process for Valve ACPV186C to demonstrate that the Tool Pouch course of action was safe H.1.b] (Section 1R13) |
| Site: | Wolf Creek  |
|---|---|
| Report | IR 05000482/2008005 Section 1R13 |
| Date counted | Dec 31, 2008 (2008Q4) |
| Type: | NCV: Green |
| cornerstone | Barrier Integrity |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.13 |
| Inspectors (proximate) | B Baca C Long G Apger M Peck P Elkmann P Jayroe S Garchow S Hedger V Gaddy W Schaup |
| CCA | H.14, Conservative Bias |
| INPO aspect | DM.2 |
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Finding - Wolf Creek - IR 05000482/2008005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Wolf Creek) @ 2008Q4
Self-Identified List (Wolf Creek)
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