ENS 44503
ENS Event | |
|---|---|
22:48 Sep 18, 2008 | |
| Title | Hpci Inoperable Due to Missing Insulation |
| Event Description | At 1848 on 09/18/2008, the control room was notified by system engineering that insulation was missing from the bottom of the HPCI turbine that could result in nearby electronic components being subjected to higher than design temperatures. This could challenge the ability of the HPCI system to perform its design function for the prescribed mission times. The condition does not prevent the high pressure coolant injection system from automatically starting and injecting during an accident. The longer term ability of the system to continue to inject is challenged by the existing condition.
The HPCI system was immediately declared inoperable while engineering continues to evaluate the condition to determine if an actual loss of design function has occurred. This is being reported as an event or condition that could have prevented fulfillment of a safety function required to mitigate the consequences of an accident in accordance with 10CFR50.72(b)(3)(v)(D). The licensee notified the NRC Resident Inspector.
On September 18, 2008, PPL Susquehanna LLC reported a potential loss of the HPCI safety function under the provisions of 10CFR50.72(b)(3)(v)(D). The report was made when it was discovered that insulation was missing from the bottom of the Unit 2 HPCI turbine. This situation raised concerns that increased area temperatures could adversely affect nearby electronic equipment needed to support long-term HPCI operation. A subsequent investigation has determined that all potentially affected components were rated for operation at temperatures greater than those anticipated during HPCI operation with the missing insulation. An additional physical inspection confirmed that there was no abnormal discoloration or visible signs of accelerated thermal aging on the components and wires in question. It has therefore been concluded that HPCI operability had not been impacted by the missing insulation. Accordingly, the loss of safety function reported on September 18th under ENS # 44503 is being retracted. The insulation has since been restored to the HPCI turbine. The licensee notified the NRC Resident Inspector. Notified the R1DO (Trapp). |
| Where | |
|---|---|
Susquehanna  Pennsylvania (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:+-1.62 h-0.0675 days <br />-0.00964 weeks <br />-0.00222 months <br />) | |
| Opened: | Dave Borger 21:11 Sep 18, 2008 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Nov 12, 2008 |
| 44503 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |