Monday, March 13, 2017

Junk Outage Maintenance At Susquehanna: Two Oil Leaks Upon First Startup

It sounds like a coverup as they didn't save the leaking gasket...

Susquehanna Steam Electric Station 05000-387
Unit 1

EVENT DESCRIPTION

On April 22, 2016 at approximately 11:25, Unit 1 entered Mode 1.

On April 22, 2016 at approximately 12:09, Technical Specification (TS) 3.5.3 was entered and the RCIC [EllS System Identifier: BN] Quarterly Flow Surveillance was performed with reactor pressure vessel (RPV) pressure at approximately 930 psig.

On April 22, 2016 at approximately 14:00, a two to three drops per second leak on the 1 F212B, RCIC Turbine Lube Oil Filter [EllS Component Identifier: FL T], was identified.

On April 22, 2016 at approximately 16:01, the main turbine [EllS System Identifier: TA] was tripped due to a seal oil leak on the collector end of the generator [EllS System Identifier: TB].

On April 22, 2016 at approximately 20:57, the reactor entered Mode 2.

On April 23, 2016 at approximately 00:46, the reactor entered Mode 3. RPV Pressure was below 150 psig at approximately 03:00.

On April 23, 2016 at approximately 03:55, an operability review concluded that RCIC was inoperable since there was no guarantee that RCIC would meet its mission time with the identified leak. 
On April 23, 2016 at approximately 06:54, the reactor entered Mode 4.

On April 30, 2016, both filter elements and all gaskets were replaced. These actions corrected the leak and RCIC was subsequently declared operable.

The leakage identified on April 22, 2016 was considered sufficient to require declaring RCIC inoperable.

RCIC was also considered to have been inoperable prior to the transition to Mode 1. As a result, the condition was considered a violation of Technical Specification (TS) 3.0.4 and reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

CAUSE OF EVENT

The two items replaced to correct the leak were the gaskets and the filters. The filters would not cause an oil leak in the system and no deficiencies within the filters were identified. The gaskets were disposed of prior to the evaluation, and were the only difference that could have potentially resulted in the oil leak. Based on this available information, the direct cause of the leak was determined to be an unidentified gasket issue. A manufacturing defect or poor seating caused by pressurization are two of the potential gasket issues that could have caused the leak; however, a definitive apparent cause could not be determined.

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