05000335/LER-2009-001
| Docket Number Sequential Revmonth Day Year Year Month Day Yearnumber No. | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown |
| 3352009001R00 - NRC Website | |
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 2009 - 001
Description of the Event
EDG operability was called into question regarding verbatim compliance with the TS requirements. The Unit 1 TS surveillance (SR) 4.8.1.1.2a.3 verifies the fuel oil transfer pump (FOTP)[EIIS:DE] can be started and transfer fuel from the storage system [EIIS:DC]to the engine-mounted tank. Since the existing system design would not normally require a transfer pump to automatically start during the monthly surveillance run of the EDG, the procedure was revised to credit a gravity feed flow path verification and a separate manual start of the transfer pump on recirculation.
Compliance with the TS SR was accomplished in two steps as a form of overlap testing. One step validated the FOTP can be manually started and that the pump develops adequate discharge head while re-circulating fuel oil back to the storage tank. Another step validated there is a clear flow path for fuel oil from the storage tank, through the FOTP and to the engine-mounted day tank. The combination of these two steps ensured that the FOTP can be started, can provide flow, and that the flow path to the day tank is clear.
Thus, the TS SR was satisfied.
Cause of the Event
Since the existing system design would not normally require a transfer pump to automatically start during the monthly surveillance run of the EDG, the procedure was revised in 1993 to credit a gravity feed flow path verification and a separate manual start of the transfer pump on recirculation.
An evaluation determined the cause of the event to be a legacy process issue due to interpretation of technical specifications regarding the acceptability of overlap testing. Additionally, the design of the system in which the Unit 1 diesel oil transfer pump does not automatically start during normal operations and the day tanks are gravity fed, is not conducive to verbatim compliance in accordance with TS 4.8.1.1.2a.3 and is considered a contributing cause.
Analysis of the Event
Although compliance with the TS SR was accomplished in two steps as a form of overlap testing, the surveillance was not completed verbatim in accordance with the TS and is considered to be an operation of the facility in a condition prohibited by TS; and reportable in accordance with 10 CFR 50.73(a)(2)(i)(A).
Both Unit 1 EDGs are operable and within the surveillance requirement based on the PMT of the day tank level switches. This testing verified start of the transfer pump on lo-lo level, opening of the solenoid valves and the transfer of fuel to the engine mounted tanks. This did not affect the Unit 2 EDGs.
The Unit 2 fuel oil transfer system is a different design.
FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 2009 - 001 Analysis of Safety Significance Both Unit 1 EDGs are operable and within their surveillance requirement; the potential safety consequences of the event are low and there would have been no significant impact on the health and safety of the public.
Corrective Actions
The corrective actions and supporting actions were entered into the site corrective action program. Any changes to the proposed actions will be managed under the corrective action program.
1. Industry/Technical Specification Task Force (TSTF), TSTF-434-A, "Clarifying SR 3.0.1 Bases to state that Surveillance can be performed in steps" will be adopted for St. Lucie Technical Specifications, which will clarify the SR 4.0.1 Bases to state that surveillances can be performed in steps.
2. Revised Unit 1 procedure 1-OSP-59.01 A, "lA Emergency Diesel Generator Monthly Surveillance," to perform steps 6.1.3 and step 6.1.35.A.
without overlap testing.
3. Revised Unit 1 procedure 1-OSP-59.O1B "lB Emergency Diesel Generator Monthly Surveillance," to perform steps 7.1.3 and step 7.1.35.A.
without overlap testing.
4. Both unit procedures 1(2)-0SP-01.02, "Reactor Coolant Gas Vent System Flow Path Verification" [or appropriate Operations Fill and Vent Procedure] will be revised to verify flow through the Reactor Coolant System vent paths during venting. If TSTF-434-A is incorporated prior to the associated unit's outage, then this action will not be required to be completed.
5. Both unit procedures 1(2)-OSP-69.13A/B, "ESF - 18 Month Surveillance for SIAS/CIS/CSAS - Train A/B," will be revised for each safety injection tank to demonstrate operability by verifying that each safety injection tank isolation valve opens automatically.
If TSTF-434-A is incorporated prior to the associated unit's outage, then this action will not be required to be completed.
Similar Events An extent of condition evaluation was performed to identify if similar overlap testing was being performed when TS specified a direct test. Two additional TS SRs on each unit were found where St. Lucie tests were performed by overlapping, contrary to TS wording.
A TS SR for the reactor coolant gas system vent path was tested as described in the TS up until 1997 for Unit 2. The Unit 1 procedures were changed to match the Unit 2 procedures in 2001. The 50.59 screening did not identify FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) 2009 - 001 this as being a change to the intent of the TS requirement and therefore no changes to the TS were identified as required.
A TS SR for the safety injection tank (SIT) valves were verified to open on a safety injection signal as described in the TS SR until it was changed in 1999. The 50.59 screening for both Units did not identify this as being a change to the intent of the TS requirement, and therefore, no changes to the TS were determined to be required. The procedures and schedules will be changed to test these components in future outages, unless TSTF-434-A is incorporated into St. Lucie's TS basis prior to the associated unit's outage.