05000373/FIN-2011003-02
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Finding | |
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| Title | Potential Failure to Follow Work Instructions and Maintenance Process Associated with Activities Affecting the Stand-by Liquid Control (SBLC) System |
| Description | The inspectors identified a URI associated with the potential failure to follow work instructions and maintenance process associated with activities affecting quality. Specifically, following work on the Unit 1 SBLC system, the inspectors found several programmatic inconsistencies with the methods to return the system to an operable status and processes to perform post-maintenance testing (PMT) of the system. This item remains unresolved pending further review by the NRC staff. On June 22, 2011, following planned maintenance and diagnostic valve testing of the Unit 1 A SBLC storage tank outlet valve (1C41-F001A), operations and maintenance personnel were in the process of performing PMT on the SBLC system. Following the diagnostic valve testing on 1C41-F001A the valve is cycled open and closed to verify the position indications are working properly. The solution tank, which contains water with sodium pentaborate in solution, is normally isolated from the rest of the SBLC system by this valve. Opening 1C41-F001A creates the potential for transferring clean water to the solution tank and diluting the concentration of sodium pentaborate in it. This in turn could potentially place the solution tank concentration outside the TS-specified value. To account for instances like this one, TS SR 3.1.7.5 requires that the tank be sampled every time water is added to the tank. After performing diagnostic valve testing on 1C41-F001A and cycling the valve to test the position switch, the maintenance package work instructions, as part of the PMT to restore SBLC to operable status, included a final step to notify the chemistry department to sample the solution tank. This sample would ensure that the concentration in the tank was maintained within TS-specified value. Instead of notifying chemistry, operations personnel measured the level in the solution tank before and after cycling 1C41-F001A. Because there was no change in level, operations personnel eliminated the step requiring the notification of chemistry to take the sample and recorded in the control room logs that there was no level change. Following a successful run of the A train of SBLC, the system was returned to service that same day. On June 28, 2011, the inspectors raised the question of the appropriateness of this decision to not sample the concentration of the tank following work on 1C41-F001A and if it was in accordance with their process. The licensee subsequently sampled the concentration of the solution tank and the results were satisfactory. When the inspectors looked further into the licensees process for returning SBLC to service following diagnostic valve testing on this valve, they found several inconsistencies with the process. The inspectors compiled the maintenance history for these valves for both units going back 3 testing cycles for each. These valves are diagnostic-tested every 6 years. The inspectors found that the method for performing PMT and returning SBLC to an operable status was inconsistent throughout the years. For example, the last time 1C41-F001A was tested in September 2005, the SBLC head tank was isolated as part of the maintenance work. Since the head tank is considered the driver that would push clean water into the solution tank when 1C41-F001A is open, the work instructions did not even include a step to notify chemistry to sample the tank. The isolation of the tank as part of the clearance order was deemed enough for operations personnel to conclude that clean water wasnt going to change the concentration of the solution tank. In a separate instance in March 2002, following diagnostic valve testing, chemistry was notified as specified in the work instructions but the sample was taken greater than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the test. In addition, the inspectors noted that if a maintenance package is going to be changed (as in the case where instead of notifying chemistry, the lack of difference in level was taken as acceptable), procedure MA-AA-716-010, Maintenance Planning specifies that for work package revisions, a screening of the change should be performed and documented. The inspectors could not find verification that this screening was performed or documented in accordance with the maintenance planning procedure. The inspectors will review this issue to determine if the several inconsistencies identified with the PMT process of SBLC following diagnostic valve testing of 1C41-F001A constituted a performance deficiency. The inspectors also will engage plant personnel to ensure that the licensee is implementing the Maintenance Planning guidelines and PMT methods consistently for this system. A URI is opened pending further review by the NRC staff. |
| Site: | LaSalle  |
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| Report | IR 05000373/2011003 Section 1R15 |
| Date counted | Jun 30, 2011 (2011Q2) |
| Type: | URI: |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | R Jickling R Ruiz R Winter F Ramirez A Dahbur K Riemer J Yesinowski R Walton M Munirn Shahr Ruiz F Ramirez K Riemer S Sheldon M Mitchell B Kemker D Jones J Yesinowski P Smagacz J Corujo-Sandin P Cardona-Morales |
| INPO aspect | |
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Finding - LaSalle - IR 05000373/2011003 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (LaSalle) @ 2011Q2
Self-Identified List (LaSalle)
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