05000387/FIN-2015001-01
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Finding | |
|---|---|
| Title | SBO Diesel Fuel Oil Cloud Point |
| Description | The inspectors identified a finding of very low safety significance (Green) for not establishing diesel fuel oil specifications to ensure diesel-driven equipment important to safety will function during expected low ambient temperatures. Specifically, PPL did not establish appropriate measures for diesel fuel oil cloud point and the station blackout diesel generator (Blue Max) was potentially rendered non-functional when ambient air temperatures fell below the cloud point temperature of the diesel fuel oil. PPL implemented compensatory actions to monitor diesel fuel oil temperatures in the Blue Max every shift and erected a temporary heated structure to restore and maintain functionality. Inspectors determined the performance deficiency was more than minor because it adversely affected the equipment performance attribute of the mitigating systems cornerstone to ensure the availability of systems that respond to initiating events to prevent undesirable consequences (i.e., core damage). Specifically, by not ensuring the cloud point of the diesel fuel oil was below the temperature of the surrounding ambient environment, the Blue Max was potentially non-functional during expected low temperature conditions. In accordance with NRC IMC 0609, Attachment 4, "Initial Characterization of Findings," Table 2, Cornerstones Affected by Degraded Condition or Programmatic Weakness, the issue was determined to affect the Mitigating Systems Cornerstone. Per IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings at Power, Exhibit 2, Mitigating Systems Screening Questions, the inspectors conservatively answered YES to question A.4, Does the finding represent an actual loss of function of one or more non-Tech Spec Trains of equipment designated as high safety-significant in accordance with the licensees maintenance rule program for > 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />? and determined that a detailed risk evaluation was needed to assess the safety significance of this finding. The inspectors used Systems Analysis Programs for Hands-On Evaluation (SAPHIRE) Revision 8.1.2, and the Standardized Plant Analysis Risk (SPAR) Model for Susquehanna Unit 1 and 2, Versions 8.23 and 8.21, respectively, to conduct an evaluation of the safety significance of this finding. In consultation with a regional Senior Reactor Analyst (SRA), a bounding analysis was conducted using conservative assumptions to approximate the worst case increased risk associated with the degraded condition of the Emergency Power Supply (EPS) Blue Max Diesel Generator. The calculated delta core damage frequency (CDF) for this condition was low E-8, or very low safety significance (Green). Inspectors noted that the most dominant core damage sequence was a loss of offsite power with coincident failure of all installed EDGs. In accordance with IMC 0609 Appendix A, since the change in core damage frequency was less than 1E-7, no further evaluation of external events or LERF was required. This finding was determined to be Green. The finding was determined to have a cross-cutting aspect in the area of Problem Identification and Resolution, Evaluation, in that, PPL did not thoroughly evaluate the effects of cold weather on the diesel fuel oil systems for diesel driven equipment to ensure that resolutions address the extent of conditions commensurate with their safety significance. Specifically, PPL did not thoroughly evaluate the effects of cold temperatures on the diesel fuel oil system when performing the functionality assessment for the Blue Max to ensure it maintained availability [P.2]. |
| Site: | Susquehanna  |
|---|---|
| Report | IR 05000387/2015001 Section 1R01 |
| Date counted | Mar 31, 2015 (2015Q1) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.01 |
| Inspectors (proximate) | A Turilin F Bower J Grieves N Graneto T Daun T O'Hara |
| CCA | P.2, Evaluation |
| INPO aspect | PI.2 |
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Finding - Susquehanna - IR 05000387/2015001 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Susquehanna) @ 2015Q1
Self-Identified List (Susquehanna)
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