05000382/FIN-2014007-05
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Identify and Correct Through Wall Corrosion on Emergency Diesel Generator A and B Day Tank Vents |
| Description | The team identified an apparent violation of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, which states, in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformance are promptly identified and corrected. Specifically, prior to October 22, 2014, the licensee failed to identify and correct through-wall corrosion on the emergency diesel generator A and B day tank vents, a condition adverse to quality. Prior to discovery by the team, the licensee had been unaware of the corrosion, which was significant enough that a through-wall hole had formed at the base of the each vent pipe where it penetrates the roof. Consequently, any water that collects on the roof of the building would have the potential to drain into the day tanks. The licensee performed an immediate operability determination and concluded that the diesel and its support systems were operable based on no severe weather in the area. While evaluating permanent corrective actions, the licensee installed a temporary repair to the vent pipes using a rubber wrap and installed a small concrete berm to minimize the potential amount of water in the immediate area. This finding was entered in to the licensees corrective action program as CR-WF3-2014-05413. The team determined that the failure to identify and correct through-wall corrosion on the emergency diesel generator A and B day tank vents was a performance deficiency. This performance deficiency was more than minor because it was associated with the design control and equipment performance attributes of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to events to prevent undesirable consequences. Specifically, the licensee failed to identify, evaluate, and correct through-wall corrosion on the emergency diesel generator A and B day tank vents. In accordance with Inspection Manual Chapter 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power, dated June 19, 2012, Exhibit 2, Mitigating Systems Screening Questions, the issue screened to Exhibit 4, External Events Screening Questions, because it was potentially risk-significant due to seismic, flooding, or severe weather. Per Exhibit 4 this finding screened to a Detailed Risk Evaluation because if the safety function were assumed completely failed it would degrade two trains of a multi-train system and it would degrade one or more trains of a system that supports a risk-significant system. A Region IV senior reactor analyst performed a detailed risk evaluation. The finding was preliminarily determined to be of greater than very low safety significance (greater than Green). The risk-important sequences included heavy-rain-induced losses of off-site power with the consequential failure of both emergency diesel generators. The ability to restore off-site power within four hours was important to avoid core damage. The finding was not significant to the large early release frequency. See Attachment 2, Detailed Risk Evaluation, for a detailed review of qualitative criteria also considered. This finding had a cross-cutting aspect in the area of human performance associated with procedure adherence because the licensee failed to ensure that individuals follow process, procedures, and work instructions (H.8). |
| Site: | Waterford  |
|---|---|
| Report | IR 05000382/2014007 Section 1R21 |
| Date counted | Mar 31, 2015 (2015Q1) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | C Speer F Ramirez G Replogle J Dixon J O'Donnell L Carson N Greene P Hernandez R Lantzb Larsone Ruesch G Gardner G Ottenberg P Wagner S Makor |
| Violation of: | 10 CFR 50 Appendix B Criterion XVI |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
| ' | |
Finding - Waterford - IR 05000382/2014007 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Waterford) @ 2015Q1
Self-Identified List (Waterford)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||