RBG-45124, Suppl to 990907 Response to Violations Noted in Insp Rept 50-458/99-07.Info to Address Specific Requests in 990920 Conference Call Re DG Assessment Completion Dates for Corrective Actions & DG Maint Rule (a)(1) Status,Encl

Suppl to 990907 Response to Violations Noted in Insp Rept 50-458/99-07.Info to Address Specific Requests in 990920 Conference Call Re DG Assessment Completion Dates for Corrective Actions & DG Maint Rule (a)(1) Status,Encl

ML20212F722
Person / Time
Site:	River Bend
Issue date:	09/24/1999
From:	King R ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
50-458-99-07, EA-99-158, RBF1-99-0284, RBG-45124, NUDOCS 9909280338
Download: ML20212F722 (7)

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Ent:rgy oper ti:ns, Inc.

/ River Bend Station 5485 U S. Highway 61

.! "bas) P O. Box 220 h St. Francisvilie. LA 70775 Tel 225 336 6225 Fax 225 635 5068 Rick J. King D m1or iJuclear Safety Assurance September 24,1999 -

U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Subject:

Supplemental Response to Apparent Violations in IR 50-458/99-07 l EA 99-158 '

River Bend Station Docket No. 50-458 License No. NPF-47 File No.: G9.5, G15.4.1 RBG-45124 RBF1-99-0284 Ladies and Gentlemen, This letter supplements the River Bend Station response dated September 7,1999, to apparent violations contained in Inspection Report 50-458/99-07. A conference call was held on September 20,1999, with Messrs. William Johnson, Dale Powers, and Gary Sanborn of the NRC staff to discuss additionat information. Attached is the information to address ine specific requests in the conference call regarding the diesel generator assessment, completion dates for corrective actions, and diesel generator maintenance rule (a)(1) status.

Should you have any further questions regarding our response to the Inspection Report, '

please contact Mr. . toe Leavines at (225)381-4642. i Sincerely, RJK/dhw T '

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Supplemental Response to Apparent Violations in IR 50-458/99-07

' River Bend Station .

RBF1-99-0284 RBG-45124 {

September 24,1999 i page 2 of 2 l i l-cc: U.- S. Nuclear Regulatory Commission l

Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 L

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NRC Sr. Resident inspector ,

P. O. Box 1050

,., St. Francisville. LA 70775 ,

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i lI NRR Project Manager, Robert Fretz l U.S. Nuclear Regulatory Commission M/S OWFN 04DO3 Washington, D.C. 20555

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L Director, Of.ce of Enforcement i

. U. S. Nuclear Regulatory Commission 1

Washington, D. C. 20555-0001 I

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4 Attachment 1 Summary of Diesel Generator Reliability Self-Assessment in March 1999, a Diesel Dependability Team was formed and tasked with assessing the 3 adverse trend identified in performance of the Division I and 11 diesel generators (DG). l The DGs had been listed as (a)(1) systems in accordance with the Maintenance Rule due to identified functional failures. Historical performance was reviewed and the effectiveness of corrective actions were assessed by the team. Additionally, the process for reporting and resolving problems was also evaluated.

The broad categories of contributing factors to DG unavailability were examined: (1) materials and design, (2) human performance, and (3) programmatic deficiencies.

Operating logs and Condition Reports related to the DGs were reviewed for the period of 1994 to present. Training programs for operators and maintenance technicians were reviewed, as were the pertinent operating procedures, interviews with other TDI diesel owners and engine contractors were conducted. Implementing processes for preventive maintenance activity, as well as vendor recommended maintenance, were examined.

Formal root cause analysis techniques were applied to the information gathered. The results of previous assessments and improvement initiatives were reviewed to determine the status of previously developed action plans.

The initial results of the team's assessment grouped the root causes of continuing l challenges to DG reliability into three categories:

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. Coordination problems between departments l l l

• Inadequate execution oi .txisting procedures l

• Allowing periods of improved performance to lower the priority of long-term improvement plans.

Recent organizational changes in the RBS engin.eering department have included the formation of a multi-disciplined team assigned to support improvements in DG performance. Projects for the improvement of the design and materiel condition of the DGs and supporting systems have recently been completed, and others are in development .

The specific results of the DG team improvements and future plans to address DG reliability will be discussed during a meeting this fall to be scheduled with members of the NRC Region IV staff.

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Attachment 2 Scheduled Completion Dates for Corrective Actions to Prevent Recurrence Listed in Response to IR 50-458/99-07 l

The action items and scheduled due dates are as follows:

i 1. Training on taper pin staking techniques will be incorporated into the l

continuing maintenance training module.

Due date: Complete

2. An evaluation of past work on Division I and 11 diesel generators will be conducted to assess compliance with the Service Information Memoranda.

Due date: October 22,1999

3. An evaluation of the Division lli diesel generator will be performed to confirm the adequacy of vendor documentation.

Due date: December 31,1999

4. A sampling of vendor documents on other systems and equipment has been initiated to determine whether this type of condition exists elsewhere.

Due date: December 31,1999

5. An effectiveness review of the corrective actions taken to address the condition of the Division I and 11 diesel generators, as well as training related to this event, will be performed.

Due date: March 31, 2000 i

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r Attachment 3 Diesel Generator Maintenance Rule (a)(1) Status

1. When were the Division I and 11 diesel generators placed into Maintenance i Rule category (a)(1)? l The diesel generator system (system no. 309) was ide rified by the Maintenance Rule ,

expert panel as (a)(1) status for review by the system ingineer during the December 2, '

1998, meeting. System 309 was placed in (a)(1) statas under the Maintenance Rule on March 2,1999. The problems with each diesel generator were as follows:

1. The Division i diesel generator had two Maintenance Preventable Functional Failures (MPFF) in the last 18 months (a governor booster servo oil leak and a revet failure on the K1 excitation shutdown relay) and one Repetitive MPFF in tre last 36 months (a reset failure on the K1 relay).

2. The Division li diesel generator had one MPFF in the last 18 months (a reset failure of the K1 relay), and one Repetitive MPFF in the last 36 months (a reset failure on K1 relay).

3. The Division lli diesel generator had two MPFF's in the last 18 months (a loss of generator load indication and mis-operation of the K15 engine lockout relay).

l Maintenance Rule performance criteria for diesel generator functional failures are: (1) no more than one MPFF every 18 months per division, and (2) no Repetitive MPFFs in a 36 month period per division.

2. What were the monitoring and performance goals when the diesel generators were placed in (a)(1) status?

The Maintenance Rule performance criteria for the diesel generator system are: (1) no more than one MPFF every 18 months per division, (2) no Repetitive MPFFs in a 36 month period per division, and (3) availability of each division no less than 97.5%.

Specific actions to address the functional failures detailed above and return the diesel generator system to (a)(2) Maintenance Rule status are:

1. Revise surveillance procedures for the Division lil diesel generator to preclude simultaneous operation of synchronization scope switches at the local control panel and in the main control room, eliminated a potential cause for loss of generator load indication. This action is complete.

2. Revise operating procedures for the Division 111 diesel generator to provide instructions on how to reset the engine lockout K15 relay. This action is complete.

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3. Revise preventative maintenance procedures for the Division I and ll diesel generators to replace the governor booster servo every 10 years. This action is complete.

4. Implement a design change on the Division I and 11 dieselGenerators to eliminate simultaneous application of latch and reset signals to the excitation shutdown K1 relay from the electro-pneumatic control system. Completion of this action is being tracked in the station's corrective action program, and is scheduled for completion by March 1,2000.

An additional MPFF has occurred on the Division I diesel generator. On March 24, 1999, the main fuel pump coupling failed due to improper assembly during maintenance activities in February 1999. An additional goal for the diesel generator system has been established to address this condition:

5. No MPFFs of the Division I or ll diesel generators will be caused by the fuel system from March 24,1999, to September 24,2000

3. What performance measures were not met as a result of the fuel oil booster pump coupling / Loctite issue?

There are no performance measures for the fuel oil booster pump. The failure of the pump resulted in the loss of a Maintenance Rule function to provide adequate fuel to the diesel for it to run. The specific performance measures for the diesel generator system are discussed Question No. 2 above.

The malfunction of the fuel oil booster pump caused the failure of the DG to operate while under a normal start signal. The DG is equipped with a electrically driven fuel oil booster pump powered from the station's non-safety 125 volt DC system. Based on a 1 design review, the DC pump will start on an emergency DG start signal, and will run to  !

support engine operation as long as power is available. The non-safety station batteries are designed for a two-hour capacity following isolation of the battery charger from the i DC bus by a loss of coolant accident signal.

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4. What is the history of EOl's experience with the measures in Question No.

3 above?

l A review of the functional failures in the diesel generator system for the previous four l years was conducted. No similar events associated with fuel oil pump failures at RBS were identified.

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! 5. Does the performance history of the Division I,11, and lli diesel generators require that they remain in (a)(1) status?

The Division I and ll diesel generators will remain in (a)(1) status until implementation of

! the design change to eliminate simultaneous application of latch and reset signals to the excitation shutdown relay. Additionally, the Division I and ll diesel generators will remain in (a)(1) status until September 24,2000, provided no additional MPFFs are caused by fuel system failures.

The Division lli diesel generator is of a different manufacturer, Electro-Motive Division, than the Division I and 11 diesel generators. Sixteen months have elapsed since the MPFFs occurred on the Division lli diesel generator. It will remain in (a)(1) status until the expert panel determines that the implemented corrective actions have been effective. {

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