05000461/LER-2003-001
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4612003001R00 - NRC Website | |
PLANT CONDITIONS PRIOR TO THE EVENT:
Unit: 1; Event Date: 02/19/03; Event Time: 0615 Central Standard Time MODE: 1 (POWER OPERATION); Reactor Power: 091.1 percent Reactor Coolant System Temperature: 522 degrees Fahrenheit Reactor Coolant System Pressure: 1016 pounds per square inch gage
DESCRIPTION OF EVENT
On February 19, 2003, at about 0215 hours0.00249 days <br />0.0597 hours <br />3.554894e-4 weeks <br />8.18075e-5 months <br />, Primary Containment Isolation Valve (PCIV)[ISV] 1E12-F004B, Residual Heat Removal (RHR) System [BO] Train B Suppression Pool Suction Valve, was de-energized in the open position. The valve was de-energized in accordance with clearance number 02-01 RH-J09A to support work on several other valves [V] during a RHR Train B maintenance outage; no work was planned in the outage for this specific valve. The valve is a normally open motor [MO]-operated PCIV with remote operation capability from the Main Control Room (MCR) in the event operator action is required to close the valve during design basis accident conditions. This valve does not have an automatic isolation function. De-energizing this valve in the open position made the valve inoperable and incapable of performing its function to isolate the penetration on demand from the MCR. Making this valve inoperable requires entry into Technical Specification (TS) 3.6.1.3, Action A.1 which requires the affected penetration [PEN] to be isolated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> with a closed, deactivated automatic isolation valve, or by a closed manual isolation valve.
The capability for isolating Primary Containment Penetration 1MC-12 includes PCIV 1E12-F004B, and manual isolation valve 1E12-F304B that was in the open position.
At about 1430 on February 20, during shift turnover, the Control Room Supervisor (CRS) stated that manual isolation valve 1E12-F304B was in the closed position. A Reactor Operator (RO) challenged the CRS on the position of the manual isolation valve, noting that the clearance for the work did not require closure of the manual isolation valve. An investigation was immediately conducted by the oncoming CRS, validating at 1440 hours0.0167 days <br />0.4 hours <br />0.00238 weeks <br />5.4792e-4 months <br /> that the manual isolation valve was not in the closed position. At 1611 hours0.0186 days <br />0.448 hours <br />0.00266 weeks <br />6.129855e-4 months <br /> manual isolation valve 1E12-F304B was shut to satisfy the requirements of TS 3.6.1.3, Action A.1.
The Shift Manager ordered a Prompt Investigation to begin under the Corrective Action Program, and Condition Report 145537 was initiated to track the investigation and corrective action for this event.
No automatic or manually initiated safety system actuations were necessary to place the plant in a safe and stable condition. No other inoperable equipment or components directly affected this event.
CAUSE OF EVENT
Investigation of the cause of this event identified two root causes. The first root cause is the clearance writer (licensed operator) failed to exercise adequate self-checking during development of the clearance. The clearance writer omitted from the clearance a tag to address closure of PCIV 1E12-F004B. Contributing to this cause was the lack of written guidance on isolating Primary Containment penetrations.
The second root cause is the personnel involved in implementing the clearance did not apply sufficient rigor and attention to detail to meet TS requirements. The review of the clearance failed to identify that PCIV 1E12-F004B was de-energized incorrectly in the open position. The Reactor Operators (licensed) involved in review of the clearance did not tag the PCIV to isolate the penetration. The CRS (licensed) review of controls needed for compliance with the TS was not independent as required. Prior to review of the clearance, the CRS had extensive discussion about the clearance and administrative controls with the Work Control Supervisor (licensed). The Work Control Supervisor was the tagging authority.
A contributing factor was the Reactor Operators were not clear on the application of TS 3.6.1.3 Action A.1 in the case of a non-automatic PCIV.
SAFETY ANALYSIS
This event is reportable under the provisions of 10CFR50.73(a)(2)(i)(B) due to the failure to isolate Primary Containment Penetration 1MC-12 within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> after de- energizing PCIV 1E12-F004B in the open position.
PCIV 1E12-F004B was inoperable for 37 hours4.282407e-4 days <br />0.0103 hours <br />6.117725e-5 weeks <br />1.40785e-5 months <br /> and 56 minutes without isolating Primary Containment Penetration 1MC-12, 33 hours3.819444e-4 days <br />0.00917 hours <br />5.456349e-5 weeks <br />1.25565e-5 months <br /> and 56 minutes longer that permitted by TS 3.6.1.3, Action A.1.
There was no work planned in the RHR outage for PCIV 1E12-F004B, no work to breach the Emergency Core Cooling System piping (Closed Loop Outside Containment (CLOC)), and the CLOC was not drained, therefore, there was no open pathway in the physical integrity of the reactor containment or actual reduction in the atmospheric control function of the reactor containment due to this event.
Further, in the event of a design basis accident, the Primary Containment penetration isolation function could have been maintained. PCIV 1E12-F004B could have been closed from the MCR after sending a non-licensed operator to re-energize the valve at its breaker on Elevation 781 Auxiliary Building. There would be no radiation concerns in this area until well after an event exceeded the design basis event. The Updated Safety Analysis Report Section 6.3.2.8 identifies the design basis for closing manually activated PCIV 1E12-F004B, indicating that necessary operator response times for this manual action are approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 30 minutes. This time bounds the time necessary for energizing the breaker and closing PCIV 1E12-F004B.
No safety system functional failures occurred during this event.
CORRECTIVE ACTION
An Operations Policy Statement will be issued to implement a method for completing clearance development sheets. (ATI 145537-24) A dynamic learning activity (DLA) will be implemented to challenge licensed operator proficiency on Operations Fundamentals, including rigor and attention to detail. � (ATI 145537-25) The personnel involved in this event were coached / counseled on their errors.
Procedure OP-CL-109-101, Clearance and Tagging, will be revised to include guidance on isolating Primary Containment penetrations. (ATI 145537-34)
PREVIOUS OCCURRENCES
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COMPONENT FAILURE DATA
Manufacturer � Nomenclature � Model Number � Manufacturer Part Number None