05000254/LER-2004-002

LER-2004-002, Quad Cities Nuclear Power Station Unit 1 05000254 1 of 4

Docket Number
Event date:	07-30-2004
Report date:	09-28-2004
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
2542004002R00 - NRC Website

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6 PAGE (3) Quad Cities Nuclear Power Station Unit 1 05000254 NUMBER NUMBER (If more space is required, use additional copies of NRC Form 366A)(17)

PLANT AND SYSTEM IDENTIFICATION

General Electric - Boiling Water Reactor, 2957 Megawatts Thermal Rated Core Power Energy Industry Identification System (EIIS) codes are identified in the text as [XX].

EVENT IDENTIFICATION

Technical Specification Allowable Value Exceeded for Low Pressure Coolant Injection Loop Select Reactor Low Pressure Switches A.C CONDITION PRIOR TO EVENT Unit: 1MEvent Date: July 30, 2004 Event Time: 2125 hours0.0246 days <br />0.59 hours <br />0.00351 weeks <br />8.085625e-4 months <br /> Reactor Mode: 1 Mode Name: Power Operation Power Level: 085% Power Operation (1) - Mode switch in the RUN position with average reactor coolant temperature at any temperature.

B. DESCRIPTION OF EVENT

On July 30, 2004, during performance of the Residual Heat Removal (RHR)/ Low Pressure Coolant Injection (LPCI) [BO] reactor low pressure calibration and functional test on the Unit 1 A loop, two switches [PS] were found outside of the technical specification allowable values. Each switch was adjusted to within the appropriate setting tolerances at the time of discovery.

These switches provide a permissive signal on low reactor pressure during single recirculation loop operation or operation with no recirculation loops. This permissive signal allows the process of selecting a recirculation loop for injection to proceed.

C. CAUSE OF EVENT

The root cause of this event was determined to be an unapproved/undocumented historic modification to remove one of the two internal micro-switches in the pressure switch some time prior to 1996. This created an imbalance between the internal Bourdon tube actuating plate and the micro-switch actuating plunger. This led to instrument drift, which, combined with a change to the calibration frequency from quarterly to biannually in 2001, resulted in the switches being found outside of the technical specification allowable value.

Because the unapproved/undocumented modification occurred prior to 1996, it is impractical to determine the cause of the modification. Also, because the root cause of this event was historical in nature and many improvements have been implemented in recent years in the configuration control program, corrective actions addressing configuration control, beyond the briefing material described below, are not necessary.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6 PAGE (3) Quad Cities Nuclear Power Station Unit 1 05000254 NUMBER� NUMBER (II more space is required, use additional copies of NRC Form 366A)(17) A search of other applications of Barksdale pressure switches at Quad Cities Nuclear Power Station was performed to ensure there were no other examples of the undocumented removal of spare micro-switches.

D. SAFETY ANALYSIS

The safety significance of this event was minimal. Although the switches had drifted outside of the technical specification allowable value (Technical Specification Table 3.3.5.1-1, Function 2.d, Reactor Steam Dome Pressure Low [break detection]), they retained the capability of performing the safety function. There is a margin included in the setpoint calculation. The switches had not drifted beyond the analytical limits, and did not exceed the technical specification allowable value by more than the margin included in the calculation. Therefore, it is reasonable to assume that the switches would have performed the safety function.

This event does not constitute a Safety System Functional Failure.

The Unit 2 switches were inspected and it was determined that this problem did not switches.

E. CORRECTIVE ACTIONS

Immediate Actions

The switches were calibrated to the appropriate setting tolerance.

Corrective Actions to be Completed:

The Unit 1 Barksdale LPCI Loop Select Reactor Low Pressure pressure switches will be calibrated on a 3-month frequency until the switches are replaced.

The Unit 1 Barksdale LPCI Loop Select Reactor Low Pressure pressure switches will be replaced with a similar dual micro-switch model or with a single micro-switch model.

Material will be prepared discussing the importance of configuration control, using this event as the topic of information. The material will be distributed to Maintenance, Operations and Engineering for use in department discussions.

F. PREVIOUS OCCURRENCES

There have been no reportable instances of instrument drift on these instruments.

However, there have been instances of instrument drift on the Main Steam Line High Flow instruments:

Flow Switches due to Inadequate Drift Allowance used in Setpoint Calculation," dated September 15, 2003.

Flow Switches due to Inadequate Drift Allowance used in Setpoint Calculation," FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6 PAGE (3) Quad Cities Nuclear Power Station Unit 1 05000254 NUMBER NUMBER (If more space is required, use additional copies of NRC Form 366A)(17) .

dated September 13, 2004.

These instances of instrument drift were attributed to inadequate drift allowance, and did not involve configuration control.

There have been three reportable instances of configuration control since 2002:

Discharge Instrument Volume Input to the Reactor Protection System," dated September 30, 2002.

Detached Wire,' dated November 29, 2002.

Inoperable due to Misposition of Instrument Valve,' dated August 18, 2003.

These instances of configuration control involved recent instances of design error (2-02-004), care during installation and maintenance (2-02-005) or valve misposition (2-03-003). The corrective actions addressed the specific instances and the general issue of configuration control during design, installation, maintenance and operation. They would not have precluded the historical configuration control issue in this LER.

G.CCOMPONENT FAILURE DATA The switches are Barksdale pressure switches, model number B2T-Al2SS.