ENS 44994
ENS Event | |
|---|---|
23:28 Apr 16, 2009 | |
| Title | Reactor Shutdown Required By Technical Specifications |
| Event Description | At 1828 [CDT] on 4/16/09, it was discovered that the procedure for calibrating Low Steam Line Pressure Safety Injection Lead/Lag units may not ensure that the Tech Spec setpoint requirements were met. Calibration methodology used a ratio of lead over lag time constants to determine acceptance criteria. KPS [Kewaunee Power Station] Tech Specs Table 3.5-1 item 4 requires that the lead and lag time constants have individual ESF initiation instrument setting limits. When the error was discovered, data was reviewed from the most recent calibrations of the pressure channels. While the ratios met acceptance criteria per the calibration procedure, the individual lag time constants did not meet acceptance criteria per Tech Specs. Per TS Table 3.5-3 item 1c, all channels of the Low Steam Pressure/Line Safety Injection signal were declared inoperable. Per KPS Tech Spec 3.5.c., the plant must be placed in Hot Shutdown, as soon as practicable.
Negative reactivity insertion began at 2004 [CDT] on 4/16/09. Therefore, this is reportable under 10 CFR 50.72(b)(2)(i) 'Initiation of a shutdown required by Tech Specs.' Since both trains of Steam Line Low Pressure SI channels are affected this is also reportable under 10 CFR 50.72(b)(3)(ii)(B) 'any event or condition that results in the nuclear plant being in an unanalyzed condition that significantly degrades plant safety' and 10 CFR 50.72(b)(3)(v)(D) 'any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.' At 2140 CDT, the reactor was at 56% power and hot shutdown is expected to be achieved at 2330 CDT. The licensee notified the NRC Resident Inspector. |
| Where | |
|---|---|
Kewaunee  Wisconsin (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+-0.92 h-0.0383 days <br />-0.00548 weeks <br />-0.00126 months <br />) | |
| Opened: | Brad Gauger 22:33 Apr 16, 2009 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Apr 16, 2009 |
| 44994 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (56 %) |