05000244/LER-2015-001
| R. E. Ginna Nuclear Power Plant | |
| Event date: | 06-30-2015 |
|---|---|
| Report date: | 09-24-2015 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 2442015001R01 - NRC Website | |
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DESCRIPTION OF EVENT
A. PLANT OPERATING CONDITIONS BEFORE THE EVENT
Mode: 1 Reactor Power: 100 Percent Event Date: 06/30/2015 Event Time: 0800
B. DESCRIPTION OF EVENT
On July 6, 2014, a rod dropped indication was received for L06. A troubleshooting plan was initiated to install an Astromed digital chart recorder to power cabinet 1AC to monitor L06 gripper coil control power.
On June 28, 2015, the control rod data recorder for L06 indicated an event trigger. Instrument Maintenance responded to this event and determined that the recorder had captured a signal noise spike of 0.5VDC that was not related to CRDM coil operation. To investigate the noise spike, an I&C technician manipulated recorder files to read the signal traces.
On June 30, 2015, during rod movement testing, the recorder for L06 failed to trigger when L06 stationary coil changed state. It was then realized that TS LCO 3.1.7.A.3.2 had been violated for not reviewing the parameters of the rod control system for indications of rod movement for the rod with an inoperable position indicator (control rod L06) within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This was an administrative error since the PPCS indication of control rod L06 was available for the duration of the installed data recorder unavailability.
C. CAUSE OF EVENT
Analysis of the as found condition determined that the cause of the event was a technician inadvertently manipulating the trigger settings while reviewing data in capture mode.
This event was entered into the site corrective action program (IR-02521934).
D. SAFETY CONSEQUENCES
Since PPCS computer indication was available and functional during the period of time that the installed data recorder was unavailable, there was not a period of time where control rod L06 was not being monitored. The rod position indication was administratively removed from service due to the previous hardware malfunction and had not yet been declared operable. However, the PPCS indication of rod position for control rod L06 was actually available during the time period the installed data recorder was not receiving a trigger signal to indicate rod movement.
TS LCO 3.1.7.A.3.2 was violated administratively in that the parameters of the rod control system could not be reviewed every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> from the time maintenance activities were performed on June 28, 2015 to when it was noted that there was no trigger signal received during rod motion testing on June 30, 2015.
This event is reportable in accordance with 10 CFR50.73, Licensee Events Report System under item 10CFR50.73(a)(2)(i)(B), based on operation or condition which was prohibited by Technical Specifications due to Ginna not reviewing the parameters of the rod control system for indications of rod movement for the rod with an inoperable position indicator for the L06 position indication and thus not performing required actions in accordance with TS LCO 3.1.7.A.3.2.
E. CORRECTIVE ACTIONS:
1. Eliminated the reliance of a trigger to start data capture. Data is now stored continually on stored files, which are downloaded to a thumb drive for viewing. This eliminates inadvertent file manipulations and/or possible corruption during mode transfer.
2. Increased monitoring frequency of the data.
3. Revised work documents with appropriate guidance and controls.
F. PREVIOUS SIMILAR OCCURRENCES
None.
G. COMPONENT FAILURE DATA
Not applicable, no components failed during this event.