05000305/LER-2011-003
| Kewaunee Power Station | |
| Event date: | 03-24-2011 |
|---|---|
| Report date: | 05-23-2011 |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3052011003R00 - NRC Website | |
Event Description
At 1125 on March 24, 2011, it was identified that the electrical breaker [BKR] for motor operated valve SI- 11A [20], Safety Injection to Loop A Cold Leg, was in the ON position with the valve open instead of the required valve open with the breaker in the LOCKED OFF position as needed to meet Technical Specification (TS) 3.5.2, Emergency Core Cooling Systems (ECCS) — Operating, MODES 1, 2, and 3 Surveillance Requirements.
The Plant was in the process of exiting a refueling outage. While in MODE 4, procedure SP-33-297A, Safety Injection to Loop A Cold Leg Check Valve Leakage Measurement, and procedure SP-33-297B, Safety Injection to Loop B Cold Leg Check Valve Leakage Measurement, were being performed. The procedures positioned various motor operated valves closed that are normally open with their breakers LOCKED OFF per an approved checklist to provide the flow path from the emergency core cooling system (ECCS) pumps to the reactor coolant system (RCS) [AB].
The check valve testing per the procedures was performed the evening of March 23rd and into the morning of March 24th. After this and other testing was completed, the plant transitioned to MODE 3 at 0258 on March 24th.
The procedures, as written, did not provide direction for realignment of certain valves or to verify proper system alignment for the operating MODE. This was the case specifically in SP-33-297A for valve SI-11A, Safety Injection to Loop A Cold Leg, in which the valve was returned to the open position but the breaker was left ON. In the case during performance of SP-33-297B, valve SI-11B [20], Safety Injection to Loop B Cold Leg, was returned to the open position and its breaker was positioned to LOCKED OFF.
When it was identified that the breaker for SI-11A was in the ON position in MODE 3, it was also recognized that the requirements of LCO 3.0.4, for entering a Mode of Applicability when an LCO is not met, were not completed prior to entering MODE 3.
LCO 3.0.4 states:
When an LCO is not met, entry into a MODE or other specified condition in the Applicability shall only be made:
a. When the associated ACTIONS to be entered permit continued operation in the MODE or other specified condition in the Applicability for an unlimited period of time; b. After performance of a risk assessment addressing inoperable systems and components, consideration of the results, determination of the acceptability of entering the MODE or other specified condition in the Applicability, and establishment of risk management actions, if appropriate; exceptions to this Specification are stated in the individual specifications; or c. When an allowance is stated in the individual value, parameter, or other specification.
This Specification shall not prevent entry into MODES or other specified conditions in the Applicability that are required to comply with ACTIONS or that are part of a shutdown of the unit.
U.S. NUCLEAR REGULATORY COMMISSION NRC FORM 366A (10-2010) LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
Therefore, since the MODES 1, 2, and 3 Surveillance Requirement SR 3.5.2.1 was not met prior to leaving Mode 4 and entering Mode 3, Technical Specifications were violated.
Thus, this event is being reported pursuant to 10 CFR 50.73(a)(2)(i)(B) for "Any operation or condition prohibited by the plant's Technical Specifications.
Event and Safety Consequence Analysis As a part of TS 3.5.2, Emergency Core Cooling Systems (ECCS) — Operating, Surveillance Requirement, SR 3.5.2.1, is required for MODES 1, 2, and 3.
SR 3.5.2.1 is performed to verify the following valves are in the listed position with motive power to the valve operator removed: SI-9A [20], Safety Injection to RCS Cold Legs; SI-11A, Safety Injection to Loop A Cold Leg; SI-11B, Safety Injection to Loop B Cold Leg; and SI-4A [20] or SI-4B [20], Refueling Water Storage Tank to Safety Injection Pumps. The Surveillance is applicable in Modes 1, 2, and 3 and the Frequency for the Surveillance is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The purpose of SR 3.5.2.1 is to provide for verification of proper valve position to ensure that the flow path from the emergency core cooling system (ECCS) pumps to the RCS is maintained. Misalignment of these valves could render both ECCS trains inoperable. Securing these valves in position with their respective power breaker locked out ensures that they cannot change position as a result of an active failure or be inadvertently misaligned. These valves are of the type described in IE Information Notice 87-01, RHR VALVE MISALIGNMENT CAUSES DEGRADATION OF ECCS IN PWRS, that can disable the function of both ECCS trains and invalidate the accident analyses.
Mode 3 was entered from Mode 4 at 0258 on March 24, 2011. The breaker for SI-11A was turned Off and LOCKED at 1130 on March 24, 2011. The breaker was in the ON position instead of the required position of LOCKED OFF for a period of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and 32 minutes.
Additionally, a prompt extent of condition evaluation was performed with no other Safety Injection [BQ] valves and their breakers being identified in the wrong position.
Since SI-11A was in its appropriate open position to provide the ECCS flowpath and the breaker for the valve was in the ON position for only a short time, there was a very low safety significance associated with this event.
Cause
This event was due to inadequate guidance in procedure SP-33-297A, Safety Injection to Loop A Cold Leg Check Valve Leakage Measurement. Procedure SP-33-297A did not provide direction for performing valve breaker manipulations and did not include steps to verify valve SI-11A was in the open position (nor did it specify the final position of other valve breakers and valves).
U.S. NUCLEAR REGULATORY COMMISSION NRC FORM 366A (10-2010) LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
Corrective Actions
The following immediate corrective actions were taken:
- SI-11A was verified open and its breaker was turned OFF and LOCKED.
- A prompt extent of condition evaluation for Safety Injection valves and their associated breaker positions was performed with no incorrect positioning identified.
Additional corrective actions were taken to:
- Place the SP-33-297A and SP-33-297B procedures on administrative hold and initiate a procedure change request to revise the procedures to include specific breaker positioning and valve alignment during the testing and upon completion of the testing.
Similar Events A review of Licensee Event Reports covering the last three years did not identify any similar events.
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