ENS 45844
ENS Event | |
|---|---|
16:19 Apr 15, 2010 | |
| Title | High Pressure Coolant Injection Declared Inoperable Due to Voiding in Discharge Piping |
| Event Description | The Unit 2 HPCI [High Pressure Coolant Injection] system was declared inoperable due to failure to meet acceptance criteria for air voiding in the discharge piping. UT [Ultrasonic Testing] inspection identified an air void of approximately 0.515 cubic ft. HPCI remains available and on-line risk remains green.
The HPCI discharge piping has been vented. Preliminary post venting UT inspections indicate current void volume is less than acceptance criteria. Certified UT inspectors have been dispatched to validate preliminary UT results. The event is being reported under 10CFR50.72(b)(3)(v)(D). The NRC Senior Resident Inspector has been informed of the event. The acceptance criteria for voids is less than or equal to 0.052 cubic ft.
Following the void identification, an engineering evaluation was initiated to determine the impact of the non-condensable gas pocket identified in the HPCI piping. The evaluation was completed and the following results were obtained. The pocket of non-condensable gas in the HPCI discharge piping did not adversely affect the ability of the system to maintain peak cladding temperatures below required limits. The pressure that would have been experienced during an initiation of the system was determined to be within the design pressure of the system. Additionally, the potential force imbalances that would be experienced during a system initiation were determined to be within the piping design allowables. Based on the engineering evaluation, the pocket of non-condensable gas did not have a detrimental effect on HPCI system operation. The ability of the HPCI system to perform its intended safety function was maintained throughout this condition. Therefore, the above notification is being retracted. The NRC Resident Inspector has been notified. Notified R3DO(Pelke) |
| Where | |
|---|---|
Dresden  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+1.63 h0.0679 days <br />0.0097 weeks <br />0.00223 months <br />) | |
| Opened: | Brian Pigg 17:57 Apr 15, 2010 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Jun 2, 2010 |
| 45844 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |