05000482/FIN-2013008-07
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Failure to Account for Flow Measurement Uncertainty when Operating the Residual Heat Removal Pumps in the Low Flow Regime |
| Description | The team identified a Green, non-cited violation of 10 CFR 50, Appendix B, Criterion III, Design Control, which states, in part, Measures shall be established to assure that applicable regulatory requirements and the design basis are correctly translated into specifications, drawings, procedures, and instructions. The design control measures shall provide for verifying or checking the adequacy of design, such as by the performance of design reviews, by the use of alternate or simplified calculational methods, or by the performance of a suitable testing program. Specifically, on August 27, 2013, the team identified that the licensee had failed to account for flow measurement uncertainties of the Residual Heat Removal System. Technical Specifications require that when operating in Mode 6, the circulating residual heat removal flow is required to be greater than or equal to 1000 gpm for adequate heat removal and to prevent stratification, and Alarm Response Procedure ALR 00-049C, RHR LOOP 1 FLOW LOW, requires that when operating the residual heat removal pumps at low flows that the flow must be at or above 1700 gpm for pump protection. The failure to account for flow measurement uncertainties could allow flow to actually be below the required technical specification and alarm response limits, without the operators knowledge. The licensee has entered this issue into their corrective action program as Condition Reports CR-73071 and CR-73231. The team determined that the failure to account for flow measurement uncertainties when operating Residual Heat Removal pumps at low flows was a performance deficiency. This finding was more than minor because it was associated with the Procedure Quality attribute of the Reactor Safety, Mitigating Systems Cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, the failure to account for flow measurement uncertainties in the residual heat removal system could allow operation below technical specification and alarm response limits and potentially damage the residual heat removal pumps. In accordance with NRC Inspection Manual Chapter 0609, Appendix G, Shutdown Operations Significance Determination Process, the finding was determined to have very low safety significance (Green), because the finding did not require a quantitative assessment because adequate mitigating equipment remained available and the finding did not constitute a loss of control as defined in Appendix G. This finding did not have a cross-cutting aspect because the most significant contributor to the performance deficiency did not reflect current licensee performance. |
| Site: | Wolf Creek  |
|---|---|
| Report | IR 05000482/2013008 Section 1R21 |
| Date counted | Sep 30, 2013 (2013Q3) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.21 |
| Inspectors (proximate) | S Garchow B Correll A Sengupta H Leake R Kopriva T Farnholtz |
| Violation of: | Technical Specification - Procedures 10 CFR 50 Appendix B Criterion III, Design Control Technical Specification |
| INPO aspect | |
| ' | |
Finding - Wolf Creek - IR 05000482/2013008 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Wolf Creek) @ 2013Q3
Self-Identified List (Wolf Creek)
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||