05000440/FIN-2007010-02: Difference between revisions
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{{finding | {{finding | ||
| title = | | title = RCIC Operability Between January 2006 and December 2007 | ||
| docket = 05000440 | | docket = 05000440 | ||
| inspection report = IR 05000440/2007010 | | inspection report = IR 05000440/2007010 | ||
| Line 12: | Line 12: | ||
| identified by = NRC | | identified by = NRC | ||
| Inspection procedure = IP 71153 | | Inspection procedure = IP 71153 | ||
| Inspector = M Wilk, A Dahbur, G Wright, M Franke, J Cameronm, | | Inspector = M Wilk, A Dahbur, G Wright, M Franke, J Cameronm, Wilks Sheldon, C Brown, G Wright | ||
| CCA = N/A for ROP | | CCA = N/A for ROP | ||
| INPO aspect = | | INPO aspect = | ||
| description = Based on document reviews, activity observations, and discussions with the licensee, the Team concluded that as of December 4, 2007, the licensees response to the RCIC systems performance during the November 28, 2007, event was not consistent with the safety significance of the issue. Further, the scope and depth of the licensees evaluation of the RCIC systems performance was inadequate. Based on its inspection activities, the Team concluded that the licensee focused initial troubleshooting activities on RCIC performance issues that were thought to be caused by entrained air (gas) in process flow measuring instrument lines. Further, the licensee maintained focus on air entrainment as the primary cause of the RCIC system failure in spite of available information that would bring into question the performance of the control system. The NRC initially questioned the RCIC flow controller settings on November 29, 2007. The Team questioned the as-found settings for gain, reset, and rate after reviewing the system response data traces for the two RCIC trip events. The Team had specifically asked why the system response traces showed an immediate and opposite reaction from the flow controller to any changes in the flow rate (indicative of an excessive rate setting). Further, the Team questioned whether the licensee had noted the similarity of the traces to the Bailey Meter Technical Manual example of an excessive rate setting. The licensees investigative team replied that the controller settings were as recommended by the users group and that the rate setting was not used. The statement that the rate setting was not used was later found to be inaccurate when the flow control module was inspected. The licensees response was that RCIC system performance was caused by air entrainment in the instrument lines and that General Electric (GE) was consulted to confirm the licensees evaluation. The first indication by the licensee that they were investigating the RCIC flow controller as a potential cause of failure of the RCIC system was contained in a draft of the Immediate Investigation provided to the Team and the licensees Plant Oversight Review Committee (PORC) on December 2, 2007. This document provided controller settings (gain, reset, and rate) that had been applied to the RCIC flow controller since January 2006. The Teams review of the flow controller settings (Gain - 0.1, Reset - 40.0, Rate - 9.25) on December 2, 2007, identified that they were not consistent with the controller manufacturer recommendations. Specifically, the Bailey instruction manual for the controller stated that the product of the rate and reset settings should be less than or equal to (<) 1. The technical manual adjustment procedure was also specific in the order of adjustments (gain, reset, then rate) and stated that if the rate setting was used, the gain and reset would most likely have to be re-adjusted to ensure that the product of the reset and rate was < 1. The Perry RCIC flow controller rate and reset product was 370. The Team noted that the disparity between the as found product of 370 and the vendor recommendation that the product be < 1 was neither discussed nor identified in the Immediate Investigation, indicating to the Team that the licensee did not recognize the significance of the discrepancy. The Team also noted that the licensees procedure for tuning the flow controller, ICI-C-E51-3, RCIC Control System Tuning, Revision 5 dated 2005, did not address the reset and rate product nor did it reference the Bailey technical manual. 10 Enclosure At the final briefing on December 4, 2007, the Team left Perry management with the following items: 1. The licensees investigation team composition for the RCIC system was not consistent with the safety significance and complexity of the issue. 2. As of December 4, 2007, the team indicated to the licensee that there was not reasonable assurance that RCIC was operable. 3. RCIC operability from January 2006 to November 28, 2007, was an Unresolved Item (05000440/2007010-02). | | description = Based on document reviews, activity observations, and discussions with the licensee, the Team concluded that as of December 4, 2007, the licensees response to the RCIC systems performance during the November 28, 2007, event was not consistent with the safety significance of the issue. Further, the scope and depth of the licensees evaluation of the RCIC systems performance was inadequate. Based on its inspection activities, the Team concluded that the licensee focused initial troubleshooting activities on RCIC performance issues that were thought to be caused by entrained air (gas) in process flow measuring instrument lines. Further, the licensee maintained focus on air entrainment as the primary cause of the RCIC system failure in spite of available information that would bring into question the performance of the control system. The NRC initially questioned the RCIC flow controller settings on November 29, 2007. The Team questioned the as-found settings for gain, reset, and rate after reviewing the system response data traces for the two RCIC trip events. The Team had specifically asked why the system response traces showed an immediate and opposite reaction from the flow controller to any changes in the flow rate (indicative of an excessive rate setting). Further, the Team questioned whether the licensee had noted the similarity of the traces to the Bailey Meter Technical Manual example of an excessive rate setting. The licensees investigative team replied that the controller settings were as recommended by the users group and that the rate setting was not used. The statement that the rate setting was not used was later found to be inaccurate when the flow control module was inspected. The licensees response was that RCIC system performance was caused by air entrainment in the instrument lines and that General Electric (GE) was consulted to confirm the licensees evaluation. The first indication by the licensee that they were investigating the RCIC flow controller as a potential cause of failure of the RCIC system was contained in a draft of the Immediate Investigation provided to the Team and the licensees Plant Oversight Review Committee (PORC) on December 2, 2007. This document provided controller settings (gain, reset, and rate) that had been applied to the RCIC flow controller since January 2006. The Teams review of the flow controller settings (Gain - 0.1, Reset - 40.0, Rate - 9.25) on December 2, 2007, identified that they were not consistent with the controller manufacturer recommendations. Specifically, the Bailey instruction manual for the controller stated that the product of the rate and reset settings should be less than or equal to (<) 1. The technical manual adjustment procedure was also specific in the order of adjustments (gain, reset, then rate) and stated that if the rate setting was used, the gain and reset would most likely have to be re-adjusted to ensure that the product of the reset and rate was < 1. The Perry RCIC flow controller rate and reset product was 370. The Team noted that the disparity between the as found product of 370 and the vendor recommendation that the product be < 1 was neither discussed nor identified in the Immediate Investigation, indicating to the Team that the licensee did not recognize the significance of the discrepancy. The Team also noted that the licensees procedure for tuning the flow controller, ICI-C-E51-3, RCIC Control System Tuning, Revision 5 dated 2005, did not address the reset and rate product nor did it reference the Bailey technical manual. 10 Enclosure At the final briefing on December 4, 2007, the Team left Perry management with the following items: 1. The licensees investigation team composition for the RCIC system was not consistent with the safety significance and complexity of the issue. 2. As of December 4, 2007, the team indicated to the licensee that there was not reasonable assurance that RCIC was operable. 3. RCIC operability from January 2006 to November 28, 2007, was an Unresolved Item (05000440/2007010-02). | ||
}} | }} | ||
Latest revision as of 20:32, 20 February 2018
| Site: | Perry  |
|---|---|
| Report | IR 05000440/2007010 Section 4OA3 |
| Date counted | Dec 31, 2007 (2007Q4) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | M Wilk A Dahbur G Wright M Franke J Cameronm Wilks Sheldon C Brown G Wright |
| INPO aspect | |
| ' | |