05000483/FIN-2009002-02
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Intermediate Range Hi Flux Reactor Protection System Actuation While Shutdown |
| Description | The inspectors identified a self-revealing noncited violation of Technical Specification 5.4.1.a, Procedures, after maintenance on intermediate range nuclear Instrument N36 resulted in an unanticipated reactor trip signal and feedwater isolation. On December 12, 2008, Callaway instrumentation and controls maintenance personnel performed work to replace a circuit card associated with the intermediate range nuclear Instrument P-6 bistable. At the time of the maintenance, the plant was in Mode 3 with the reactor trip breakers open. Shortly after beginning work, an intermediate range high flux reactor trip signal was generated. The trip signal was generated because the bypass of the reactor trip bistables is removed upon removal of the control power fuses. With instrument power removed, the solid state protection system perceived a high intermediate range neutron flux condition and generated a reactor trip signal and feedwater isolation. Control room operators responded to the feedwater isolation by starting both motor-driven auxiliary feedwater pumps and restoring steam generator water levels to the program band. The licensee later determined that instrumentation and controls maintenance personnel were unaware that pulling the control power fuses would cause a reactor trip signal and that the step in the work instruction that directed the removal of the control power fuses had not received an adequate review. This finding was greater than minor because the finding impacted the Initiating Events cornerstone attribute of human performance and affected the cornerstone objective to limit the likelihood of those events that upset plant stability and challenge critical safety functions. Using Manual Chapter 0609.04, Phase 1 - Initial Screening and Characterization of Findings, this finding was determined to be of very low safety significance since it did not affect the Technical Specification limit for reactor coolant system leakage or mitigation systems safety function, did not contribute to both the likelihood of a reactor trip and mitigation equipment or functions not being available, and did not increase the likelihood of a fire or internal/external flooding. This issue was entered into the licensee\'s corrective action program as Callaway Action Request 200812681. The finding had a crosscutting aspect in the area of human performance associated with the work controls component because the licensee failed to coordinate the impact of changes to the work scope or activity, specifically, the licensee failed to fully evaluate the impact of removal of control power fuses on the work instructions H.3(b) |
| Site: | Callaway  |
|---|---|
| Report | IR 05000483/2009002 Section 4OA3 |
| Date counted | Mar 31, 2009 (2009Q1) |
| Type: | NCV: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | D Dumbacher P Elkmann V Gaddy J Groom |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
| ' | |
Finding - Callaway - IR 05000483/2009002 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Callaway) @ 2009Q1
Self-Identified List (Callaway)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||