05000247/LER-2012-007
| Indian Point 2 | |
| Event date: | 06-21-2012 |
|---|---|
| Report date: | 08-20-2012 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 2472012007R00 - NRC Website | |
Note: The Energy Industry Identification System Codes are identified within the brackets {}.
DESCRIPTION OF EVENT
On June 21, 2012, the results of a diesel fuel oil (FO) {DC} sample from the Diesel Generator (DG) Reserve FO Storage Tank {DE} were received from an offsite vendor that showed the total particulates (10.8 mg/L) were not within the allowable value per Technical Specification (TS) 5.5.11 (Diesel Fuel Oil Testing Program) (10.0 mg/L) for Unit 2 and TS 5.5.12 for Unit 3. The sample was obtained on May 25, 2012, per TS Surveillance Requirement 3.8.3.4 to verify that FO properties of new and stored FO are within the limits specified in the Diesel FO Testing Program. TS 3.8.3 (Diesel Fuel Oil and Starting Air) Condition D was entered for both units (Units 2 & 3) upon review of the results on June 21, 2012, with a required action to restore stored FO total particulates to within limits in 30 days. The condition was recorded in the Indian Point Energy Center (IPEC) Corrective Action Program (CAP) as Condition Report CR-IP2- 2012-04132 for Unit 2 and CR-IP3-2012-01914 for Unit 3. On June 21, 2012, confirmatory FO samples (#1 and #2) were obtained and shipped to two separate FO analysis vendors [sample #1 to River Bend Station (RBS) and sample #2 to Herguth]. Confirmatory sample # 1 did not yield a valid result because of uncertainty over the exact standard used. FO sample #2 received on June 27, 2012 yielded a result of 12.9 mg/L. On June 25, 2012, confirmatory samples #3 and #4 were obtained and shipped to RBS and Herguth respectively. On June 26, 2012, results of confirmatory sample #3 analyzed by RBS was received yielding a result of 9.5 mg/L. On June 28, 2012, results of confirmatory sample #4 analyzed by Herguth was received yielding a result of 9.94 mg/L. Although confirmatory samples #3 and #4 were within TS limits, Chemistry conservatively concluded the sample was out of spec based on the results of the multiple samples analyzed and the high particulate results recorded. On July 5, 2012, actions were completed to provide the required total usable FO in temporary FO onsite trailers that met TS SR 3.8.3.4 and TS 3.8.3 Condition D was exited. On July 24, 2012, the DG FO reserve storage tank was declared operable after actions were completed to restore the DG FO reserve storage tank FO properties to the requirements of the Diesel Fuel Oil Testing Program.
Investigations revealed that some previous FO samples were not within the TS allowable value and in some cases no credible documentation was available to verify operability during past operation. An increasing trend in FO particulates was evident since June 17, 2010. On June 17, 2010, the FO Reserve Storage Tank particulate level showed a step increase from approximately 1 mg/L to 8 mg/L. This increase coincided with a change in FO sample vendor (Martel to Herguth) in April 2010. FO particulate continued to indicate a generally increasing trend from the June 17, 2010 value (8 mg/L) to the present. During the period between June 17, 2011 to May 25, 2012, FO particulate level had been vendor analyzed as exceeding the TS allowable value (10.0 mg/L) on five occasions.
- FO sample particulate results analyzed by Herguth for a June 17, 2011 sample (13.4 mg/L). No Condition Report (CR) initiated and the conduct of follow-up sampling and testing could not be substantiated.
- FO sample particulate results analyzed by Herguth for a December 1, 2011 sample (13.2 mg/L). No Condition Report (CR) initiated and the conduct of follow-up sampling and testing could not be substantiated.
- FO sample particulate results analyzed by Herguth for a February 28, 2012 sample (12 mg/L). Sample results received on March 14, 2012. CR-IP2-2012-01831 and CR-IP3- 2012-00805 recorded condition. In-house analysis of FO sample for particulates on March 15, 2012, yielded a result of 1.22 mg/L. Operability of FO Reserve Storage Tank was based on the In-House sample results. The In-House FO sample result of 1.22 mg/L was entered into the Indian Point Energy Center (IPEC) Chemistry Data Management System (CDMS).
The Cause of Event The apparent cause was a lack of trending and the failure to use the IPEC corrective action program (CAP). The increasing trend in FO particulate level was not properly recorded in the CAP. The step change increase in FO particulate that occurred in 2010 coinciding with the change in FO sample vendor was not documented in the CAP. Had the condition been properly recorded and trended, early remedial action would have been initiated. The FO monitoring program failed to identify the trend because the program had degraded. Quarterly FO sample results were being entered in the IPEC data tracking system but were not being entered into the CAP when out of spec nor were quarterly FO sample results being trended for approximately 10 months in 2011. This was due to the retirement of the individual responsible for these tasks which was not managed to ensure his duties were re-assigned.
Corrective Actions
The following corrective actions have been or will be performed under the Corrective Action Program (CAP) to address the cause of this event.
- Implement a process for formal trending of safety related chemistry analysis results.
- Updating the duty matrix to ensure responsibilities for trending are assigned and documented.
- A stand down of the chemistry department will be performed to review the CR process and sampling protocol and training will be performed on the event and lessons learned.
- An assessment will be performed to determine the cause of the step increase in FO particulate after the change in sample vendor.
Event Analysis
The event is reportable under 10CFR50.73(a)(2)(i)(B). The licensee shall report any operation or condition which was prohibited by the plant's TS. This condition meets the reporting criteria because FO samples showed total particulates were not within the allowable value per TS 5.5.11 for Unit 2 and TS 5.5.12 for Unit 3. TS 3.8.3 (Diesel Fuel Oil and Starting Air) Condition D has a required action to restore stored FO total particulates to within limits within 30 days. Required action for TS Condition G (Required action and associated completion time not met) is to declare the EDGs inoperable. Failure to perform the TS required actions is a TS prohibited condition.
Review of past FO particulate conditions showed some previous FO sample results since June 17, 2011, were not within the TS allowable value and in some instances credible documentation was not available to verify operability during past operation. CR-IP2- 2012-04164 and CR-IP3-2012-01939 recorded the results of a review of the issues identified in CR-IP2-2012-00901 that there was no credible evidence that re-samples of the FO reserve tank were performed on June 29, 2011 and December 9, 2011. A past operability assessment concluded that the analyzed FO particulate level was found to be above the minimum TS limit for the second quarter 2011 per the June 2011 sample and fourth quarter per the December 2011 sample, and the TS 3.8.3 required actions not performed. The third quarter was within spec based on the September 2011 sample. An analysis concluded the FO Reserve Storage Tank particulate is actually high, at or just above the TS allowable value of 10.0 mg/L. Normalizing a best fit line of sampling data indicates that the FO particulate level can be as high as 12 mg/L. Four of the sample results known to have utilized the enhanced sampling techniques yielded an average of 10.1 mg/L which is below the best fit line, and is likely most representative of the FO Reserve Storage Tank particulate level.
The time of inoperability was estimated to have begun in June 2011 based on the July 2011 sample results. The out of spec FO conditions for the sample results received in July and December were not adequately addressed in 30 days and the required TS actions not taken nor were actions taken for the vendor analysis on March 15, 2012 and April 18, 2012, which is a TS prohibited condition reportable under 10CFR50.73(a)(2)(i)(B). This condition of FO not within specification for particulates is not reportable under 10CFR50.73(a)(2)(v) as a safety system functional failure. The Unit 2 TS 5.5.11 limit and the Unit 3 TS 5.5.12 limit is 10 mg/L. However, this limit is the supply limit to the Emergency Diesel Generators (EDG) (EK) FO filters (FLT} to ensure that particulates do not reach a limit of 20-25 mg/L which EPRI Standards considers the maximum acceptable limit for FO particulates. The actual FO particulate content was slightly above the TS limit of 10.0 mg/L. Additionally, the IPEC EDGs utilize two sets of Duplex filters on the inlet and outlet side of the EDG FO booster pump. These filters alarm on high differential pressure requiring actions by operators to swap filters without interruption to EDG operation. The out of service filter would then be changed out and returned to standby service. The particulate buildup on the filters would be a relatively slow process therefore sufficient time would be available to perform a filter change out and continue EDG operation. In accordance with reporting guidance in NUREG-1022, an additional random single failure need not be assumed in that system during the condition.
Past Similar Events
A review was performed of the past three years of Licensee Event Reports (LERs) for events reporting a TS violation due to inadequate sampling surveillances did not identify any LERs
Safety Significance
This event had no significant effect on the health and safety of the public. There were no actual safety consequences for the event because there were no accidents or transients requiring the use of the FO Reserve Storage Tank.
There were no significant potential safety consequences of this event. The UFSAR Design Basis Accident (DBA) and transient analysis assume Engineered Safety Features (ESF) are operable. The onsite EDGs are designed to provide sufficient capacity, capability, redundancy, and reliability to ensure the availability of necessary power to ESF systems.
The EDG FO system supports the operability of the EDGs. FO for the three EDGs is stored in three EDG FO storage tanks and a common EDG FO reserve tank. If the EDGs require FO from the FO reserve tank, the FO will be transported by truck to the EDG FO storage tanks.
Commercial FO supplies and trucking facilities are also available in the vicinity of the plant. For proper operation of the EDGs, it is necessary to ensure the proper quality of the FO. Regulatory Guide 1.137 addresses the recommended FO practices as supplemented by ANSI N195. The requirements for EDG FO testing methodology, frequency, and acceptance criteria are maintained in the program required by TS 5.5.11 for Unit 2 and TS 5.5.12 for Unit 3. Normally, trending of FO particulate levels allow sufficient time to correct high particulate levels prior to reaching the limit of acceptability. The presence of particulates does not mean failure of the FO to burn properly in the diesel engine. The TS 5.5.11 for Unit 2 and TS 5.5.12 for Unit 3 limit for FO particulate is 10 mg/L.
However, this limit is the supply limit to the Emergency Diesel Generators FO filters to ensure that particulates do not reach a limit of 20-25 mg/L which EPRI Standards considers the maximum acceptable limit for FO particulates. The actual FO particulate content was slightly above the TS limit of 10.0 mg/L. Additionally, the IPEC EDGs utilize two sets of Duplex filters on the inlet and outlet side of the EDG FO booster pump. These filters alarm on high differential pressure requiring actions by operators to swap filters without interruption to EDG operation. The out of service filter would then be changed out and returned to standby service. The particulate buildup on the filters would be a relatively slow process therefore sufficient time would be available to perform a filter change out and continue EDG operation.