05000483/FIN-2014002-03: Difference between revisions
Jump to navigation
Jump to search
StriderTol (talk | contribs) (Created page by program invented by Mark Hawes) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
| (One intermediate revision by the same user not shown) | |||
| Line 12: | Line 12: | ||
| identified by = Self-Revealing | | identified by = Self-Revealing | ||
| Inspection procedure = IP 71153 | | Inspection procedure = IP 71153 | ||
| Inspector = N O | | Inspector = N O'Keefe, P Elkmann, T Hartman, Z Hollcraft | ||
| CCA = H.13 | | CCA = H.13 | ||
| INPO aspect = DM.1 | | INPO aspect = DM.1 | ||
| description = The inspectors reviewed a self-revealing finding involving the failure to correct a design deficiency known to represent s single point plant trip vulnerability. Specifically, Procedure EDP-ZZ-01131, Callaway Plant Health Program, required documenting and correcting Health Issues, which included single point vulnerabilities. Health Issue 2005028 was written to identify that dampers in the main generator bus duct cooling system were not designed for the flow rate they experienced. This document was subsequently closed without correcting the single point vulnerability it was written to address. Also, in 2011, after Callaway Action Request 201108672 identified that this concern still existed, the licensee failed to document the condition as a new Health Issue or correct the condition. As a result, the damper blades came loose and entered the bus duct, which resulted in a fault on the auxiliary transformer and a subsequent unit trip in July 2013. As a result of the trip, the site performed a modification to remove the single point vulnerability and documented the issue in their corrective action program as Callaway Action Request 201305943. The inspectors determined that failure to correct a design deficiency known to represent a single point plant trip vulnerability was a performance deficiency. This performance deficiency was more than minor because it is associated with the design control attribute of the Initiating Events Cornerstone and affects the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the failure to correct a long term design issue resulted in an electrical fault and subsequent reactor trip. The inspectors assessed the finding in accordance with NRC Inspection Manual 0609, Appendix A, Exhibit 1, Initiating Event Screening Questions, and determined the finding required a detailed risk evaluation because the performance deficiency caused an initiating event and affected some mitigating equipment. Therefore, a senior reactor analyst performed a detailed risk evaluation. The analyst determined that the finding was of very low safety significance (Green). The bounding change to the core damage frequency was approximately 4.2E-7/year. The dominant core damage sequences involved transients that led to anticipated transient without scram events. The recovery of the startup transformer, the recovery of the circulating water pumps, and the availability of the auxiliary feedwater system helped minimize the risk significance. This finding has a cross-cutting aspect in the consistent process component of the human performance cross-cutting area because the licensee failed to use a consistent, systematic approach to make decisions and risk insights were not incorporated as appropriate. Specifically, despite identifying a single point vulnerability that could have caused a plant trip in 2011, the licensees processes were not properly utilized to address the issue and risk insights were not used properly to elevate the importance of the issue to ensure the licensee took appropriate action. | | description = The inspectors reviewed a self-revealing finding involving the failure to correct a design deficiency known to represent s single point plant trip vulnerability. Specifically, Procedure EDP-ZZ-01131, Callaway Plant Health Program, required documenting and correcting Health Issues, which included single point vulnerabilities. Health Issue 2005028 was written to identify that dampers in the main generator bus duct cooling system were not designed for the flow rate they experienced. This document was subsequently closed without correcting the single point vulnerability it was written to address. Also, in 2011, after Callaway Action Request 201108672 identified that this concern still existed, the licensee failed to document the condition as a new Health Issue or correct the condition. As a result, the damper blades came loose and entered the bus duct, which resulted in a fault on the auxiliary transformer and a subsequent unit trip in July 2013. As a result of the trip, the site performed a modification to remove the single point vulnerability and documented the issue in their corrective action program as Callaway Action Request 201305943. The inspectors determined that failure to correct a design deficiency known to represent a single point plant trip vulnerability was a performance deficiency. This performance deficiency was more than minor because it is associated with the design control attribute of the Initiating Events Cornerstone and affects the cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown as well as power operations. Specifically, the failure to correct a long term design issue resulted in an electrical fault and subsequent reactor trip. The inspectors assessed the finding in accordance with NRC Inspection Manual 0609, Appendix A, Exhibit 1, Initiating Event Screening Questions, and determined the finding required a detailed risk evaluation because the performance deficiency caused an initiating event and affected some mitigating equipment. Therefore, a senior reactor analyst performed a detailed risk evaluation. The analyst determined that the finding was of very low safety significance (Green). The bounding change to the core damage frequency was approximately 4.2E-7/year. The dominant core damage sequences involved transients that led to anticipated transient without scram events. The recovery of the startup transformer, the recovery of the circulating water pumps, and the availability of the auxiliary feedwater system helped minimize the risk significance. This finding has a cross-cutting aspect in the consistent process component of the human performance cross-cutting area because the licensee failed to use a consistent, systematic approach to make decisions and risk insights were not incorporated as appropriate. Specifically, despite identifying a single point vulnerability that could have caused a plant trip in 2011, the licensees processes were not properly utilized to address the issue and risk insights were not used properly to elevate the importance of the issue to ensure the licensee took appropriate action. | ||
}} | }} | ||
Latest revision as of 23:21, 21 February 2018
| Site: | Callaway  |
|---|---|
| Report | IR 05000483/2014002 Section 4OA3 |
| Date counted | Mar 31, 2014 (2014Q1) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | N O'Keefe P Elkmann T Hartman Z Hollcraft |
| CCA | H.13, Consistent Process |
| INPO aspect | DM.1 |
| ' | |