ENS 47515
ENS Event | |
|---|---|
23:35 Dec 9, 2011 | |
| Title | Part 21 Issue with Seismic Clips on Rcic System Controllers Results in System Inoperability |
| Event Description | On December 7, 2011, a 10 CFR 21 report (reference NRC EN 47498) was received from a vendor for a defect with NUS Controllers. The defect involves spring clips that form part of the seismic restraints for the controllers. The controllers referenced in the report are installed for the Reactor Core Isolation Cooling (RCIC) system in the control room and remote shutdown panel. Based on initial information provided by the vendor, it was determined that the RCIC system remained operable. On December 9, 2011, additional information provided by the vendor did not support the immediate operability determination and the RCIC system was declared inoperable for Technical Specification (TS) Limiting Condition for Operation (LCO) 3.5.3 Condition A at 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br /> [EST]. At 1932 hours0.0224 days <br />0.537 hours <br />0.00319 weeks <br />7.35126e-4 months <br /> [EST], the High Pressure Core Spray system was verified operable per TS LCO 3.5.3 Required Action A.1. TS LCO 3.5.3 Required Action A2 requires restoration of the RCIC system to operable status within 14 days. Qualified spring clips have been obtained and will be installed on the controllers. This condition is being reported in accordance with 10 CFR 50.72(b)(3)(v)(B) as a condition that at the time of discovery could have prevented the fulfillment of the safety function of a system needed to remove residual heat.
The NRC Resident Inspector has been notified.
As a follow-up to the condition reported above, we have replaced the affected seismic clips on the controllers and the Reactor Core Isolation Cooling system is now operable as of 0734 on December 10, 2011. The NRC Resident Inspector has been notified." R3DO (Skokowski) notified.
The vendor provided a seismic report to the station. This report showed that the seismic clips holding the Reactor Core Isolation Cooling (RCIC) controller meet the Operating Basis Earthquake (OBE) test requirements and design requirements for a Safe Shutdown Earthquake (SSE) for Perry. Based on this review, it was determined that the spring clips would function properly during and OBE and SSE. Because the condition reported in Event Number 47515 would not have prevented the fulfillment of the safety function of a system needed to remove residual heat, the condition is not reportable, and this notification is being retracted. The evaluation for this condition is documented in condition report 2011-06531. The NRC Resident Inspector has been informed." Notified R3DO (Giessner) and Part 21 Group via email. |
| Where | |
|---|---|
Perry  Ohio (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat | |
| Time - Person (Reporting Time:+-0.9 h-0.0375 days <br />-0.00536 weeks <br />-0.00123 months <br />) | |
| Opened: | James Pry 22:41 Dec 9, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | Feb 6, 2012 |
| 47515 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |