05000412/LER-2023-004, Condition Prohibited by Technical Specification and Loss of Safety Function Due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil: Difference between revisions

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{{#Wiki_filter:Beaver Valley Power Station energy P. O. Box4 Shippingport, PA 15077 harbor I
{{#Wiki_filter:energy harbor Barry N. Blair Site Vice President I
 
September 8, 2023 L-23-197 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001  
Barry N. Blair 724-682-5234 Site Vice President Fax : 724-643-8069
 
September 8, 2023 L-23-197 10 CFR 50.73
 
ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001


==SUBJECT:==
==SUBJECT:==
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2023-004-00
Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2023-004-00 10 CFR 50.73 Beaver Valley Power Station P.O. Box4 Shippingport, PA 15077 724-682-5234 Fax: 724-643-8069 Enclosed is Licensee Event Report (LER) 2023-004-00, "Condition Prohibited by Technical Specifications and Loss of Safety Function due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil." This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), 10 CFR 50.73(a)(2)(v)(A) and 10 CFR 50. 73(a)(2)(v)(D).
There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Ms. Julie Hartig, Manager (Acting), Regulatory Compliance and Emergency Response, at 724-682-4224.
Sincerely, W,r,..1;,kf\.
CoT,tOJ Barry N. Blair fuf.._
e1rcu-r
&.,A IL Enclosure: Beaver Valley Power Station, Unit No. 2 LER 2023-004-00 cc:
NRC Region I Administrator NRC Senior Resident Inspector NRC Project Manager INPO Records Center (via INPO Industry Reporting and Information System)
BRP/DEP


Enclosed is Licensee Event Report (LER) 2023-004-00, "Condition Prohibited by Technical Specifications and Loss of Safety Function due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil." This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), 10 CFR 50.73(a)(2)(v)(A) and 10 CFR 50. 73(a)(2)(v)(D).
Enclosure L-23-197 Beaver Valley Power Station, Unit No. 2 LER 2023-004-00  


There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Ms. Julie Hartig, Manager (Acting), Regulatory Compliance and Emergency Response, at 724-682-4224.
=Abstract=
 
Beaver Valley Power Station, Unit No. 2
Sincerely, W,r,..1;,kf\\. CoT,tOJ Barry N. Blair fuf.._ e1rcu-r &.,A IL


Enclosure: Beaver Valley Power Station, Unit No. 2 LER 2023-004-00
00412 4
Condition Prohibited by Technical Specification and Loss of Safety Function due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil 07 12 2023 2023 004 00 09 08 2023 1
100


cc: NRC Region I Administrator NRC Senior Resident Inspector NRC Project Manager INPO Records Center (via INPO Industry Reporting and Information System)
Julie Hartig, Manager (Acting), Regulatory Compliance and Emergency Response 724-682-4224
BRP/DEP Enclosure L-23-197


Beaver Valley Power Station, Unit No. 2 LER 2023-004-00
=Abstract=
At 1617 on July 12, 2023, with Beaver Valley Power Station, Unit No. 2 (BVPS-2) at 100 percent power in Mode 1, the 2-2 Emergency Diesel Generator (EDG) was declared Inoperable due to its Rocker Arm Lube Oil (LO) System viscosity degrading such that the required 30-day mission time would not be met. This was likely due to Fuel Oil System leakage into the Rocker Arm LO System from a loose fuel oil injection line packing nut. The effectiveness of torquing the packing nut was indeterminate during subsequent LO test results. Compensatory measures were implemented to monitor and maintain the LO viscosity within the required limit by a proceduralized drain and fill process that will be executed based on LO sample results and EDG run time. The 2-2 EDG was declared Operable at 0615 on July 15, 2023.
At 1617 on July 12, 2023, with Beaver Valley Power Station, Unit No. 2 (BVPS-2) at 100 percent power in Mode 1, the 2-2 Emergency Diesel Generator (EDG) was declared Inoperable due to its Rocker Arm Lube Oil (LO) System viscosity degrading such that the required 30-day mission time would not be met. This was likely due to Fuel Oil System leakage into the Rocker Arm LO System from a loose fuel oil injection line packing nut. The effectiveness of torquing the packing nut was indeterminate during subsequent LO test results. Compensatory measures were implemented to monitor and maintain the LO viscosity within the required limit by a proceduralized drain and fill process that will be executed based on LO sample results and EDG run time. The 2-2 EDG was declared Operable at 0615 on July 15, 2023.
This event is reportable as a Condition Prohibited by Technical Specifications per 10 CFR 50.73(a)(2)(i)(B) and as a Loss of Safety Function per 10 CFR 50.73(a)(2)(v)(A) and (D). The additional planned corrective action is to implement a permanent repair if fuel oil leakage increases during continued monitoring. Enhancements include revising the maintenance procedures to check the tightness of fuel oil packing nuts and to replace the high-pressure fuel oil line O-rings and packing on both EDGs.
This event is reportable as a Condition Prohibited by Technical Specifications per 10 CFR 50.73(a)(2)(i)(B) and as a Loss of Safety Function per 10 CFR 50.73(a)(2)(v)(A) and (D). The additional planned corrective action is to implement a permanent repair if fuel oil leakage increases during continued monitoring. Enhancements include revising the maintenance procedures to check the tightness of fuel oil packing nuts and to replace the high-pressure fuel oil line O-rings and packing on both EDGs.
 
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BACKGROUND
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: 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
Beaver Valley Power Station, Unit No. 2 (BVPS-2) has a Train A and a Train B Emergency Diesel Generator (EDG) [EK]
052 050
to power their respective emergency buses and associated Engineered Safety Feature (ESF) Systems. The redundant trains ensure the minimum safety functions will be performed with either EDG Operable.
 
The EDG Lube Oil (LO) System [LA] provides lubrication to the main bearings, crank pins, camshaft bearing, and other oil-lubricated wearing parts within the EDG. The EDG LO System also includes a Rocker Arm LO System that provides lubrication for the rocker arms and valve gear while the EDG is operating. The Rocker Arm LO reservoir level is maintained by the EDG LO System through a level control valve.
 
Leakage from the Fuel Oil System [DC] injectors or fuel oil line connections may cause fuel oil to contaminate the Rocker Arm LO System. Fuel oil contamination above 6.17 percent into the Rocker Arm LO System degrades the required viscosity for the LO to perform its function.
 
Technical Specification LCO 3.8.1, AC Sources - Operating, requires two EDGs in Modes 1-4. If one required EDG is Inoperable, the required action per the Technical Specification Bases is to restore the EDG within 72 hours or shutdown the unit to Mode 3 within 6 hours and Mode 5 within 36 hours.
 
Technical Specification LCO 3.8.2, AC Sources - Shutdown, requires one EDG in Modes 5 and 6. If the required EDG is Inoperable, the required action is to suspend core alterations and positive reactivity additions, and to restore the EDG immediately.
 
==DESCRIPTION OF EVENT==
On July 12, 2023, with BVPS-2 at 100 percent power in Mode 1, an increased amount of fuel oil at a concentration of 3.7 percent was discovered during lube oil analysis of the 2-2 EDG Rocker Arm LO reservoir. This LO sample had been obtained on June 28, 2023, and was a step change from the 1.9 percent concentration identified in a previous sample obtained on April 19, 2023. With a calculated leak rate of 0.082 percent / hour, the 2-2 EDG would have been capable of operating for approximately 3.13 days until the maximum calculated dilution of 6.17 percent was met. The 2-2 EDG would not have been able to meet its mission time of 30 days; therefore, the 2-2 EDG was declared Inoperable at 1617 on July 12, 2023.
 
No observable leakage was found during troubleshooting to identify the source of leakage. However, the fuel injection line packing nut on cylinder No. 11 was found loose and tightened two revolutions.
 
LO samples were taken during the subsequent nine-hour 2-2 EDG maintenance run completed on July 14, 2023. Based on the LO sample test results, it is indeterminate if the leak had been repaired or if residual fuel oil remained present in the LO system during the EDG run.
 
DESCRIPTION OF EVENT (Continued)
 
Compensatory measures were established to restore and maintain Operability of the Rocker Arm LO System, and the 2-2 EDG was declared Operable at 0615 on July 15, 2023. The fuel oil concentration in the LO system will be monitored and the viscosity will be maintained within the required limits by using a proceduralized drain and fill process as directed by sample results and EDG run time.
 
It is believed that the fuel oil leakage into the Rocker Arm LO System was the result of fuel oil injector maintenance that occurred during the BVPS-2 23rd refueling outage (2R23) in which the EDG maintenance window began on April 10, 2023; therefore, the 2-2 EDG was Inoperable from that time until compensatory measures were established on July 15, 2023.
 
The Past Operability Review identifies that during Mode 6, when at least one EDG is required to be Operable per LCO 3.8.2, the 2-1 EDG was simultaneously Inoperable from April 24, 2023 to May 4, 2023.
 
Additionally, the 2-1 EDG was Inoperable other times to support minor maintenance and testing following 2R23 while BVPS-2 was in Mode 1. However, the Inoperable time in each case was less than the 3.13 days that the 2-2 EDG was capable of performing its safety function.
 
==CAUSE OF EVENT==
The most likely direct cause of the event is the loose packing nut on the fuel injection line to the No. 11 cylinder. The contributing cause is there are no preventative maintenance instructions for the injector high pressure fuel oil lines that would identify an unrecognized loose packing nut.
 
==ANALYSIS OF EVENT==
This event is reportable as a Condition Prohibited by Technical Specifications per 10 CFR 50.73(a)(2)(i)(B) as the 2-2 EDG was Inoperable for approximately three months. This is also reportable as a Condition that Could Have Prevented Fulfillment of a Safety Function per 10 CFR 50.73(a)(2)(v)(A) and (D) for the period of Inoperability in Mode 6 during 2R23 in which the 2-1 EDG was also Inoperable.
 
The plant risk associated with the 2-2 EDG fuel oil dilution of the Rocker Arm LO event is considered to be very low safety significance. This is based on the fact that the EDG was determined to have remained capable of satisfying its PRA mission time of 24 hours over the entire period in which the identified condition existed.


==CORRECTIVE ACTIONS==
==CORRECTIVE ACTIONS==
==Completed Corrective Actions==
==Completed Corrective Actions==
: 1) The packing nut associated with the fuel injection line to the No. 11 cylinder has been tightened.
: 1) The packing nut associated with the fuel injection line to the No. 11 cylinder has been tightened.
: 2) Compensatory measures have been implemented to ensure the Rocker Arm LO System required viscosity is maintained.
: 2) Compensatory measures have been implemented to ensure the Rocker Arm LO System required viscosity is maintained.  


==Planned Corrective Actions==
==Planned Corrective Actions==
: 1) Perform a permanent repair if there is evidence of increased leakage that dilutes the LO greater than 0.11 percent/hour.
: 1) Perform a permanent repair if there is evidence of increased leakage that dilutes the LO greater than 0.11 percent/hour.
Planned Enhancements:
Planned Enhancements:
: 1) Revise maintenance procedures to check the tightness of the fuel oil packing nuts.
: 1) Revise maintenance procedures to check the tightness of the fuel oil packing nuts.
: 2) As these are likely original equipment, replace the high-pressure fuel oil line O-rings and packing on the 2-1 and 2-2 EDGs.
: 2) As these are likely original equipment, replace the high-pressure fuel oil line O-rings and packing on the 2-1 and 2-2 EDGs.  


==PREVIOUS SIMILAR EVENTS==
==PREVIOUS SIMILAR EVENTS==
A review for similar events was performed. The 2-2 EDG LO had degraded viscosity due to fuel oil intrusion because of an air bound gravity drain line from the fuel oil injection pumps to the underground storage tank. This prevented excess fuel oil from the fuel oil injection pumps from draining and allowed intrusion into the LO. The 2-2 EDG was declared Inoperable, and a Condition Prohibited by Technical Specifications and a Loss of Safety Function was reported in LER 2022-001-00 on September 8, 2022. Although the events were similar in nature, the cause was unrelated to this issue.
A review for similar events was performed. The 2-2 EDG LO had degraded viscosity due to fuel oil intrusion because of an air bound gravity drain line from the fuel oil injection pumps to the underground storage tank. This prevented excess fuel oil from the fuel oil injection pumps from draining and allowed intrusion into the LO. The 2-2 EDG was declared Inoperable, and a Condition Prohibited by Technical Specifications and a Loss of Safety Function was reported in LER 2022-001-00 on September 8, 2022. Although the events were similar in nature, the cause was unrelated to this issue.
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Latest revision as of 05:44, 21 February 2026

Condition Prohibited by Technical Specification and Loss of Safety Function Due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil
ML23251A141
Person / Time
Site: Beaver Valley
Issue date: 09/08/2023
From: Blair B
Energy Harbor Nuclear Corp
To:
Document Control Desk
References
L-23-197 LER 2023-004-00
Download: ML23251A141 (1)
v • d • e


LER-2023-004, Condition Prohibited by Technical Specification and Loss of Safety Function Due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor
4122023004R00 - NRC Website
v • d • e

text

energy harbor Barry N. Blair Site Vice President I

September 8, 2023 L-23-197 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, License No. NPF-73 LER 2023-004-00 10 CFR 50.73 Beaver Valley Power Station P.O. Box4 Shippingport, PA 15077 724-682-5234 Fax: 724-643-8069 Enclosed is Licensee Event Report (LER) 2023-004-00, "Condition Prohibited by Technical Specifications and Loss of Safety Function due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil." This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), 10 CFR 50.73(a)(2)(v)(A) and 10 CFR 50. 73(a)(2)(v)(D).

There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Ms. Julie Hartig, Manager (Acting), Regulatory Compliance and Emergency Response, at 724-682-4224.

Sincerely, W,r,..1;,kf\.

CoT,tOJ Barry N. Blair fuf.._

e1rcu-r

&.,A IL Enclosure: Beaver Valley Power Station, Unit No. 2 LER 2023-004-00 cc:

NRC Region I Administrator NRC Senior Resident Inspector NRC Project Manager INPO Records Center (via INPO Industry Reporting and Information System)

BRP/DEP

Enclosure L-23-197 Beaver Valley Power Station, Unit No. 2 LER 2023-004-00

Abstract

Beaver Valley Power Station, Unit No. 2

00412 4

Condition Prohibited by Technical Specification and Loss of Safety Function due to Emergency Diesel Generator Lube Oil Contamination by Fuel Oil 07 12 2023 2023 004 00 09 08 2023 1

100

Julie Hartig, Manager (Acting), Regulatory Compliance and Emergency Response 724-682-4224

At 1617 on July 12, 2023, with Beaver Valley Power Station, Unit No. 2 (BVPS-2) at 100 percent power in Mode 1, the 2-2 Emergency Diesel Generator (EDG) was declared Inoperable due to its Rocker Arm Lube Oil (LO) System viscosity degrading such that the required 30-day mission time would not be met. This was likely due to Fuel Oil System leakage into the Rocker Arm LO System from a loose fuel oil injection line packing nut. The effectiveness of torquing the packing nut was indeterminate during subsequent LO test results. Compensatory measures were implemented to monitor and maintain the LO viscosity within the required limit by a proceduralized drain and fill process that will be executed based on LO sample results and EDG run time. The 2-2 EDG was declared Operable at 0615 on July 15, 2023.

This event is reportable as a Condition Prohibited by Technical Specifications per 10 CFR 50.73(a)(2)(i)(B) and as a Loss of Safety Function per 10 CFR 50.73(a)(2)(v)(A) and (D). The additional planned corrective action is to implement a permanent repair if fuel oil leakage increases during continued monitoring. Enhancements include revising the maintenance procedures to check the tightness of fuel oil packing nuts and to replace the high-pressure fuel oil line O-rings and packing on both EDGs.

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3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.

052 050

CORRECTIVE ACTIONS

Completed Corrective Actions

1) The packing nut associated with the fuel injection line to the No. 11 cylinder has been tightened.
2) Compensatory measures have been implemented to ensure the Rocker Arm LO System required viscosity is maintained.

Planned Corrective Actions

1) Perform a permanent repair if there is evidence of increased leakage that dilutes the LO greater than 0.11 percent/hour.

Planned Enhancements:

1) Revise maintenance procedures to check the tightness of the fuel oil packing nuts.
2) As these are likely original equipment, replace the high-pressure fuel oil line O-rings and packing on the 2-1 and 2-2 EDGs.

PREVIOUS SIMILAR EVENTS

A review for similar events was performed. The 2-2 EDG LO had degraded viscosity due to fuel oil intrusion because of an air bound gravity drain line from the fuel oil injection pumps to the underground storage tank. This prevented excess fuel oil from the fuel oil injection pumps from draining and allowed intrusion into the LO. The 2-2 EDG was declared Inoperable, and a Condition Prohibited by Technical Specifications and a Loss of Safety Function was reported in LER 2022-001-00 on September 8, 2022. Although the events were similar in nature, the cause was unrelated to this issue.

4 4

Beaver Valley Power Station, Unit No. 2 00412 2023 004 00

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