ENS 40925
ENS Event | |
|---|---|
03:24 Aug 5, 2004 | |
| Title | Low Refueling Water Storage Tank Level |
| Event Description | Following calibration of the refueling water storage tank (RWST) level indication, the as-left Control Room level instrument indicated 35.3 feet in the RWST. Tech Spec required level is 35.4 feet. Alternate indication including the local level indicator and the absence of a low RWST level alarm indicated adequate RWST level. A one hour Tech Spec AOT [Allowed Outage Time] was entered at 2324 EDT on 8/04/2004. Indicated level was restored to 35.4 feet at 0013 EDT on 08/05/04 and the AOT exited.
This event is being reported under 10 CFR.50.72(b)(3)(v)(D) as the indicated level of 35.3 feet could potentially constitute an event or condition which at the time of discovery could have prevented the fulfillment of the safety function of systems required to mitigate the consequences of an accident. Indicated level was restored to 35.4 feet by adding water to the RWST. Licensee is investigating the initial calibration on the level indicator. Licensee notified the NRC Resident Inspector.
Indian Point Unit 3 is withdrawing the 8-hour non-emergency notification made on August 5, 2004, at 0658 hours0.00762 days <br />0.183 hours <br />0.00109 weeks <br />2.50369e-4 months <br /> (EN Log No. 40925). The notification on August 5, reported an event or condition that could have prevented fulfillment of a safety function [10CFR50.72(b)(3)(v)(D)]. After calibration of the Refueling Water Storage Tank (RWST) level indication (LT-920), on August 4, 2004, the Control Room As-Left level instrument indicated 35.3 feet in the RWST. The Technical Specification (SR 3.5.4.2) required level is 35.4 feet. Alternate level indication including a local level indicator and the absence of a low RWST level alarm provided indication of adequate RWST level. The one-hour Allowed Outage Time (AOT) of TS 3.5.4.C was entered at 2324 hours0.0269 days <br />0.646 hours <br />0.00384 weeks <br />8.84282e-4 months <br />, on August 4, 2004. Water was added to the RWST and indicated RWST level in the Control Room was restored to 35.4 feet at 0013 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />, on August 5, 2004, and the TS AOT exited. Subsequently, a calibration check of the level instrument was performed on August 5, 2004, and the instrument failed the calibration. The instrument was declared inoperable and the 7-day AOT of TS 3.5.4.13 was entered at 1231 hours0.0142 days <br />0.342 hours <br />0.00204 weeks <br />4.683955e-4 months <br />. The notification is being retracted based on the engineering conclusion that the out of spec level indication was due to a failed level instrument. The RWST level was within spec as indicated by alternate level Indication including a local level indicator and absence of a low level alarm. These alternate level indication instruments are operable and within calibration. Therefore, Operations concluded the condition did not represent a RWST level below minimum TS level and the safety function of systems required to mitigate the consequences of an accident was met. Notified R1DO (Shanbaky) and NRR (Imbro). |
| Where | |
|---|---|
Indian Point  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+3.57 h0.149 days <br />0.0212 weeks <br />0.00489 months <br />) | |
| Opened: | T. R. Jones 06:58 Aug 5, 2004 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Aug 5, 2004 |
| 40925 - NRC Website | |
Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |