05000387/LER-2015-001, Regarding Inoperability of the B Emergency Diesel Generator Due to Fuel Oil Leakage

Regarding Inoperability of the B Emergency Diesel Generator Due to Fuel Oil Leakage

ML15118A636
Person / Time
Site:	Susquehanna
Issue date:	04/28/2015
From:	Franke J Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7323 LER 15-001-00
Download: ML15118A636 (3)

LER-2015-001, Regarding Inoperability of the B Emergency Diesel Generator Due to Fuel Oil Leakage

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3872015001R00 - NRC Website

text

APR 2 8 2015

.Jon A. Franke Site Vice President U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 PPL Susquehanna, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.2904 Fax570.542.1504 jfranke@pplweb.com SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387(388)/2015-001-00 UNIT 1 LICENSE NO. NPF-14 UNIT 2 LICENSE NO. NPF -22 PLA-7323 10 CFR 50.73 Docket No 50-387 50-388 Attached is Licensee Event Report (LER) 50-387(388)/2015-001-00. The LER reports an event involving the inoperability of an emergency diesel generator due to fuel oil leakage.

This event was determined to be reportable under 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specifications.

There were no actual consequences to the health and safety of the public as a result of this event.

This letter contains no new regulatory commitments.

Attachment: LER 50-387(388)/2015-001-00 Copy:

NRC Region I Mr. J. E. Greives, NRC Sr. Resident Inspector Mr. J. A. Whited, NRC Project Manager Mr. L. J. Winker, PA DEP/BRP

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0113112017 (02*2014)

, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.

6. LER NUMBER

3. PAGE I

SEQUENTIAL I REVISION NUMBER NUMBER YEAR 2 of 2 2015

- 001

- 00 Besides the affected DG, there were no systems, structures, or components that were inoperable at the start of the event and contributed to the event.

EVENT DESCRIPTION

During a routine surveillance test run on March 2, 2015, the 'B' Emergency Diesel Generator (DG) [EllS System Identifier: EK] was declared inoperable due to fuel oil leakage from the fuel oil drain line crossover piping [EllS System/Component Identifier: DC/PSP].

The DG was declared inoperable because it was not known if the DG would have been able to meet its mission time due to the risk of fire from the leaking fuel oil. The leaking drain line piping was replaced and the 'B' DG was restored to operable on March 3, 2015.

On January 31, 2015, fuel oil drain line pipe fretting and fuel oil leakage was identified on the 'B' DG at a leak rate of approximately 12 drops per minute. A prompt operability determination (POD) was performed that concluded that there was no impact on the ability of the DG to perform its safety function with the existing leak. The DG was later declared inoperable on March 2, 2015 when the leak rate increased to approximately 24 drops per minute with some spraying action observed. Based on the initial identification of leakage on January 31, 2015, firm evidence is considered to exist to indicate that the condition existed prior to the time of discovery. Therefore, this condition is considered to be reportable under 10 CFR 50.73(a)(2)(i)(B) as a condition prohibited by Technical Specification 3.8.1.

CAUSE OF THE EVENT

The direct cause of the fuel oil leakage was determined to be fretting, due to normal engine vibration, from the fuel oil drain line crossover piping rubbing against a metal clamp used to support the piping. The underlying cause of the fretting was determined to be an inadequate design of the support clamp. The design did not take into account the engine vibration and the possibility of fretting-induced wear from metal-on-metal contact. Additional cause evaluation is in progress and a supplemental LER will be submitted based on the additional cause analysis, if necessary.

ANALYSIS/SAFETY SIGNIFICANCE

Given the location of the affected drain line piping and the design of the fuel oil system, the fuel oil leakage did not adversely impact the supply of fuel oil to the DG to perform its safety function for the required mission time. The DG was declared inoperable based on the condition not being bounded by the POD with respect to the risk of fire from the leaking fuel oil and the resulting potential impact of a fire on the DG's ability to meet its required mission time.

There were no actual consequences to the health and safety of the public as a result of this event.

CORRECTIVE ACTIONS

Immediate corrective action was taken to shut down the DG from its surveillance test, replace the affected piping, and complete the routine surveillance test run on the 'B' DG. The support clamp was then replaced with a clamp of a different design to account for engine vibration and fretting-induced wear. The extent of condition was evaluated and affected piping was replaced and clamps of a different design were installed on the 'A', 'C', and 'D' DGs.

PREVIOUS SIMILAR EVENTS

Although no fuel oil leakage was identified, fretting at this piping location was previously addressed in 2001 by replacing the affected piping.