05000306/FIN-2013011-02
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Finding | |
|---|---|
| Title | Outside Lift System (OlS) Girder Failure to Meet American Institute of Steel Construction (AISC) Requirements |
| Description | The inspectors identified a finding of very low safety significance (Green) involving the licensees failure to meet the requirements of the American Institute of Steel Construction (AISC) specification. Specifically, the licensee did not use the specified minimum yield strength of the outside lift system (OLS) girder material to establish an appropriate factor of safety to qualify the allowable loads that can be safely handled by the OLS girder. The AISC factor of safety to failure ensured the OLS girder would maintain structural integrity (no permanent deformation or structural failure) when subjected to the applied loads (lifted load, wind load, design basis earthquake load). This issue was entered into the licensees Corrective Action Program (CAP) as CAP 1404203, OLS calculation used actual material strength rather than ASTM. The licensee performed a functionality assessment to demonstrate that there was reasonable assurance the OLS girder remained capable of performing its intended design functions. The inspectors determined the finding to be more than minor because the finding was associated with the Initiating Events Cornerstone objective to limit the likelihood of events that upset plant stability and challenge critical safety functions during shutdown. Specifically, the load handling reliability of the OLS girder inherently decreased when the AISC requirements were not met. The inspectors determined the finding could be evaluated using the SDP in accordance with Inspection Manual Chapter 0609, Significance Determination Process, Attachment 0609.04, Phase 1 -- Initial Screening and Characterization of Findings, Table 3. Since the finding was associated with shutdown (defueled) conditions, the inspectors used IMC 0609, Appendix G, Shutdown Operations Significance Determination Process. The inspectors determined that none of the conditions constituting a loss of control were met as described in Appendix G, Attachment 1, Phase I Operational Checklists for Both PWRS and BWRS, for this finding and no Phase II or Phase III analysis was required. Therefore, the inspectors determined that this finding was of very low safety significance. No violation of regulatory requirements is associated with this finding. The inspectors identified that there was a Human Performance, Design Margin (H.6) cross-cutting aspect associated with this finding for the licensee failure to ensure the OLS girder reflected the intended design margins (Section 4OA5.2). |
| Site: | Prairie Island  |
|---|---|
| Report | IR 05000306/2013011 Section 4OA5 |
| Date counted | Mar 31, 2014 (2014Q1) |
| Type: | Finding: Green |
| cornerstone | Initiating Events |
| Identified by: | NRC identified |
| Inspection Procedure: | |
| Inspectors (proximate) | A Shaikh D Hills E Sanchez J Bozga K Stoedter M Phalen |
| CCA | H.6, Design Margins |
| INPO aspect | WP.2 |
| Finding closed by | |
| IR 05000282/2013011 (27 February 2014) | |
| ' | |
Finding - Prairie Island - IR 05000306/2013011 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Prairie Island) @ 2014Q1
Self-Identified List (Prairie Island)
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