ENS 40785
ENS Event | |
|---|---|
18:37 May 30, 2004 | |
| Title | |
| Event Description | The High Pressure Core Spray (HPCS) system was declared inoperable due to the pump's failure to meet the flow requirement specified in TS Surveillance Requirement 3.5.1.4. This surveillance is normally performed on a quarterly basis in accordance with the plant's In-service Testing (IST) Program. The flow values measured during the performance of this surveillance were below both the normal and alert ranges. This test had also been run on 5/27/04 with results in the alert range; HPCS system instruments had been vented between the two tests to rule out the possibility that the results were due to measurement errors.
Upon declaring the HPCS pump inoperable, TS 3.5.1 Action B was entered. In accordance with Action B, the Reactor Core Isolation Cooling (RCIC) system was verified to be operable. With the RCIC system verified operable, Action B provides a 14-day completion time to restore HPCS to an operable status. All other Emergency Core Cooling Systems (ECCS) were operable during this event. This event is being reported as an event or condition that could have prevented the fulfillment of a safety function credited for mitigating the consequences of an accident. The HPCS system is a single train system at Columbia. The licensee notified the NRC Resident Inspector.
On May 30, 2004, Energy Northwest provided an 8-hour notification pursuant to 10 CFR50.72(b)(3)(v)(D). This notification reported the apparent failure of the High Pressure Core Spray (HPCS) system's pump to meet the flow requirements of Surveillance Requirement (SR) 3.5.1.4. Upon the apparent failure to satisfy this SR, Energy Northwest entered Action B of Technical Specification (TS) 3.5.1 (14 day completion time) and initiated actions to investigate the cause of this apparent failure. This investigation determined the cause of this apparent failure was due to an anomaly in the processing of the pressure and flow input signals and the instrumentation used for documenting the results of the surveillance. Additional testing using alternative instrumentation determined the HPCS pump was fully capable of providing flow within the existing acceptance criteria of the plant's In-service Testing (IST) Program and thus capable of satisfying the SR. This investigation determined that no actual degradation of the pump existed that would have caused a valid failure of the SR. This was an instrumentation issue only. The HPCS system would have been capable of performing its specified safety function in the as-found condition and was capable of fully satisfying the SR. Therefore, this condition would not have prevented the fulfillment of a safety function and is therefore not reportable under 10CFR50.72. The HPCS system was declared OPERABLE on June 03, 2004 at 22:59 PDT. The NRC Resident Inspector was notified. |
| Where | |
|---|---|
Columbia Generating Station  Washington (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+0.05 h0.00208 days <br />2.97619e-4 weeks <br />6.849e-5 months <br />) | |
| Opened: | Mike Brandon 18:40 May 30, 2004 |
| NRC Officer: | Mike Ripley |
| Last Updated: | Jun 15, 2004 |
| 40785 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (65 %) |
| After | Power Operation (65 %) |