NRC-93-0059, Responds to NRC Ltr Re Violations Noted in Insp Rept 50-341/93-07 on 930621.Corrective Actions:Established Quality of Corrective Action Measure & Monitored Deviation Event Rept

Responds to NRC Ltr Re Violations Noted in Insp Rept 50-341/93-07 on 930621.Corrective Actions:Established Quality of Corrective Action Measure & Monitored Deviation Event Rept

ML20046A420
Person / Time
Site:	Fermi
Issue date:	07/21/1993
From:	Gipson D DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CON-NRC-93-0059, CON-NRC-93-59 NUDOCS 9307280068
Download: ML20046A420 (6)

Text

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Douglas R. Gipson Sen or Vice Prendent Nuc ear Gr ne< anon Detroit re-6400 North D>ne Highway Ec ison

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July 21, 1993 NRC-93-0059 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C.

20555

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) NRC Inspection Report No. 50-341/93007, dated June 21. 1993 i

Subject:

Reply to Notice of Violation 93007-01a Enclosed is Detroit Edison's response to the Notice of Violation contained in Reference 2.

This violation was for failure to promptly identify and correct the cause of a High Pressure Coolant Injection 1

system water hammer which occurred on or before February 13, 1992.

Should you have any questions regarding this response, please contact j

Hr. Joseph H. Pendergast, Compliance Engineer at (313) 586-1682.

Sincerely, cc:

T. G. Colburn W. J. Kropp J. B. Martin H. P. Phillips Region III f

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9307280068 930721

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f Enclosure to NRC-93-0059 Page 1 Statement of Lhe Violation:

10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, in part, that measures shall be established to assure that cond1 Lions adverse to quality and nonconformances are promptly identified and corrected. The identification of the significant condition adverse to quality, the cause of the condition, and the corrective action taken shall be documented.

Contrary to the above:

a.

The licensee failed to promptly identify and correct the cause of a significant condition adverse to quality regarding a water hammer event which occurred on or before February 13, 1992, in the liigh Pressure Coolant Injection (HPCI) system. A piping failure analysis was not conducted until May 1993, approximately 15 months after the initial restraint deformation.

The Reason For The Violation:

The Reason For The Violation Associated With The Corrective Action Program:

Deviation Event Report (DER) 92-0063 was issued February 13, 1992 when three axial pipe restraints E41-3167-co2, c10 and c12 for the High Pressure Coolant Injection (HPCI) discharge piping were found with some loose wedge anchor bolts. The cause of the HPCI discharge piping restraint damage was determined to be a flow into void type water-hammer. Two surveillance tests were performed during the DER 92-0063 evaluation and water hammer was not observed as discussed below, DER 92-0063 was closed December 29, 1992 based on the fact that no excessive pipe movement was observed. The DER was closed based on the belief that the hanger damage observed occurred some time in the past and that the procedures in place were sufficient to prevent future water hammer. DER 92-0063 was closed without identification of the transient event and confirmation that the root cause was found.

The Reason For lhe Violation Due to the llPCI System Water llammer:

The method by which the water hammer occurred (i.e., void collapse) was recognized in 1992. Extensive investigations were conducted over a ten month period in 1992, however, these attempts to identify the specific cause of the void formation were unsuccessful.

l

t Enclosure to NRC-93-0059 Page 2 During this period field observations were made by engineering personnel during the performance of venting operations and pump startups. These observations included monitoring system carameters and stationing personnel in the HPCI pump room and_ torus room to monitor the discharge piping during surveillance tests for signs of water hammer. As stated above, however, these efforts were unsuccessful in identifying the rsot cause and because the water hammer transient had not been re-created, it was concluded that the damage had occurred sometime in the past.

Additional investigations performed during the evaluation of DER 93-0237 concluded that the void formation was most likely the result of an unusual set of c.

umstances where a very leak Light containment isolation valve E4150-Fe06, was apparently leaking more than the discharge line swing check valve and the Condensate Storage Tank (CST) return line gate and globe valves. The E4150-F006 leakage that was present apparently had pressurized and heated the water adjacent to the containment isolation valve.

Prior to the evaluation of DER 93-0237, the surveillance tests were run by opening the return path to the CST which depressurized the discharge line and caused the hot water near E4150-F006 to flash to steam.

This steam void. collapses upon system test initiation, causing.

the water hammer. The sporadic occurrence of the problem,- which is a function of when the last system vent occurred and of valve leakage, contributed to the failure to promptly identify the cause of the voiding in DER 92-0063 It should be noted that valve E4150-F006 is considered to be a tight valve. Leakage tests performed during the last two refueling outages measured the leakage past this valve to be.02 gpm and.06 gpm. The applicable Technical Specification for this valve is 1.0 gpm and therefore, no actions are planned or considered necessary to attempt to further reduce this leakage.

The Inspection Report stated that a piping failure analysis was not conducted until Hay 1993, approximately 15 months after the initial restraint deformation. An operability assessment completed on February 13, 1992 concluded that the system, although degraded by several loose anchor bolts, remained operable. This assessment was based on engineering judgement following system walkdown.

Because of the limited da. age to the pipe supports a piping failure analysis was not deemed necessary at that time. The damage discovered on April 27, 1993 was worse and the system was conservatively considered inoperable.

A subsequent piping failure analysis was completed and-determined that the HPCI system was operable with the damaged hangers.

Enclosure to NRC-93-0059 Page 3 1he Corrective Steps That Ilave Been Taken And The Results Achieved:

Additional investigations were initiated as a result of the April 1993 event to determine the cause of the HPCI water hammer. These investigations included the installation of temporary pressure and temperature instrumentation to analyze the ilPCI pump start up.

The investigation confirmed that there was void formation in the !!PCI discharge piping created when the piping was depressurized by aligning the system to the CST for the surveillance test. To correct the problem system surveillance procedure 24.202.01, "HPCI Pump Time Response And Operability Test At 1025 PSI" was changed through the Temporary Change Notice (TCN) process. E4150-F008 was opened after the HPCI turbine was running instead of before the ifPCI turbine was started to keep the discharge header pressurized to eliminate the water hammer in the discharge piping. The surveillance was run on May 7, 1993 The surveillance was witnessed and no problems were identified.

The Reactor Core Isolation Cooling system is a similar system.

A walkdown of the HCIC pump discharge piping was conducted and no problems were identified. The system was also monitored during surveillance test and no problems were identified.

1he Correct.ive Steps That Will Be Taken To Avoid Further Violations:

The Corrective Steps That Will Be Taken To Avoid Further Violations For The Corrective Action Program:

A multi-disciplinary team, in conjunction with the Safety Engineering organization, identified the need for improvement in four areas of the Corrective Action program. Actions planned in these areas are:

1.

Incorporate " lessons learned" into " Problem Solving" (i.e.,

Root Cause Analysis) training including sensitivity for the need to establish the correct extent of problems and self checking of problem /cause/ corrective action by DER evaluators, reviewers and approvers. The Lessons Learned will be incorporated into Root Cause Analysis training by August 30, 1993 2.

A " Quality of Corrective Action" measure (s) is being established, and DERs will be monitored by the Safety Engineering organization for quality of root cause evaluations. Timely feedback (positive and negative) will be provided to DER evaluators and/or evaluating

Enclosure to NRC-93-0059 Page 4 p

organization management, for coaching to correct weaknesses and build on strengths. The " Quality of Corrective Action" effort is expected to be in place by August 30, 1993 3

Some of the DERs discussed in the inspection report were not classified as "Significant Conditions Adverse to Quality" and, as-o result did not require root cause analysis and corrective action to prevent recurrence.

Procedure, FIP-CA1-01 " Deviation and Corrective Action Reporting" will be revised to provide guidance to DER initiators / evaluators / reviewers to aid in determining when a formal root cause analysis.is required and develop corrective action to prevent recurrence. FIP-CA1-01 will be revised by August 30, 1993 4.

Identify and integrate key information sources into an integrated trend program (i.e., DER, corrective maintenance history, PDC, etc.) to the extent necessary to effectively identify declining trends and repeat problems.

This action involves the following elements:

a)

Identification of key sources of " trend" information, b)

Development of criteria for recognition of declining trends or repeat problems.

c)

Pilot implementation of the Integrated Trending

program, d)

Benchmark organizations with effective trend programs / capability.

e)

Evaluation of results of the pilot program.

f)

Program refinement based on opportunities for improvement identified in the pilot and benchmarking effort.

g)

Transfer of Integrated trending guidance and responsibility to appropriate Nuclear Generation Organizations, h)

Assure that integrated Trend Program needs are effectively addressed by Fermi 2 Information Systems short, medium and long range improvement plans.

m

Enclosure to NRC-93-0059 Page 5 The nature of this action is such that. implementation will be completed in phases, and will occur over a period of several years. Elements a through f are expected to be completed in the 4th quarter of 1993 Element g should be phased in by the 3rd quarter of 1994. Element h is associated with ec::puter systems and electronic data base improvements with a planning range beyond 1994. Some improvement in the ability to identify declining trends and repeat problems is expected as early as January, 1994.

The Corrective Steps That Will Be Taken To Avoid Further Violations For The HPCI System Water Hammer:

Permanent changes will be made to the llPCI system operating procedure 23.202 and surveillance test procedures 24.202.02, "HPCI Flow Rate Test at 165 PSIG Reactor Steam Pressure" and 24.202.01, "liPCI Pump Time Response and Operability Test at 1025 PSI" to incorporate the i

Temporary Changes discussed above. The system operating procedure and surveillance procedure revisions will be completed by August 16, 1993 A Fluid Transient Analysis to investigate the potential for water hammer during test, injection and system trips and to confirm root J

cause and corrective actions is in progress. This analysis will be completed by August 16.

Several llPCI system improvements are currently being evaluated.

Design Change EDP 13977, which is scheduled for the fourth refueling I

outage, will extend the vent line for the llPCI discharge piping to make system venting easier to perform. The EDP will also add pressure j

gauges so that the discharge pipe can be monitored. Consideration will also be given to removing some of the insulation from the !!PCI i

pump discharge piping in the steam tunnel to reduce heating of the water in the llPCI discharge line pipe. The need for similar modifications to the RCIC system will also be considered.

The Date When Full Compilance Will Be Achieved:

]

Detroit Edison is in full compliance. The llPCI system discharge piping water hammer present during past surveillance tests has been eliminated.

,