ML14182A267

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Refers to Enforcement Conference Held on 940726 W/Cp&L Re Apparent Violations Involving MSIV Design & Testing, Inability to Maintain Positive CR Pressure in Adjacent Areas in Accident Conditions & Sloppy Corrective Actions.W/Encls
ML14182A267
Person / Time
Site: Robinson Duke Energy icon.png
Issue date: 08/05/1994
From: Merschoff E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To: Hinnant C
CAROLINA POWER & LIGHT CO.
References
EA-94-119, NUDOCS 9408190058
Download: ML14182A267 (63)
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Text

(NUDOCS OFFSITE FACILITY)

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9408190058 DOC.DATE: 94/08/05 NOTARIZED: NO DOCKET #

ACIL:50-261 H.B. Robinson Plant, Unit 2, Carolina Power & Light C 05000261 AUTH.NAME AUTHOR AFFILIATION ERSCHOFF,E.W.

Region 2 (Post 820201)

RECIP.NAME RECIPIENT AFFILIATION HINNANT,C.S.

Carolina Power & Light Co.

P

SUBJECT:

Refers to enforcement conference held on 940726 w/CP&L re apparent violations involving MSIV design & testing, R

inability to maintain positive CR pressure in adjacent areas in accident conditions & sloppy corrective actions.W/encls.

DISTRIBUTION CODE: IE01D COPIES RECEIVED:LTR _

ENCL SIZE: ____

TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response 0

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T NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT 504-2083 ) TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 19 ENCL 19

0 AUG -5 9

Docket No.:

50-261 License No.:

DPR-23 EA 94-119 Carolina Power and Light Company ATTN: Mr. C. S. Hinnant Vice President H. B. Robinson Steam Electric Plant Unit 2 P. 0. Box 790 Hartsville, SC 29550-0790 Gentlemen:

SUBJECT:

ENFORCEMENT CONFERENCE

SUMMARY

(NRC INSPECTION REPORT NO. 50-261/94-16)

This letter refers to the Enforcement Conference held at our request on July 26, 1994. This meeting concerned activities authorized for your Robinson facility. The purpose of the conference was to discuss the apparent violations involving MSIV design and testing; the inability to maintain positive control room pressure with respect to adjacent areas during certain accident conditions; and inadequate corrective action pertaining to issues identified by a contractor. A list of attendees and a copy of your slides are enclosed. We are continuing our review of these issues to determine the appropriate enforcement action.

In accordance with Section 2.790 of the NRC's "Rules of Practice," Part 2, Title 10, Code of Federal Regulations, a copy of this letter and its enclosures will be placed in the NRC Public Document Room.

Should you have any questions concerning this letter, please contact us.

Sincerely, Original signed by:

Luis A. Reyes/for Ellis W. Merschoff, Director Division of Reactor Projects

Enclosures:

1. List of Attendees
2. Licensee Slides

.L jQI1) cc w/encls:

(See page 2) 9408190058 940805 PDR ADOCK 05000261 GI PDR

Carolina Power and Light Company 2

cc w/encls:

M. P. Pearson Plant Manager H. B. Robinson Steam Electric Plant P. 0. Box 790 Hartsville, SC 29550 H. W. Habermeyer, Jr.

Vice President Nuclear Services Department Carolina Power & Light Company P. 0. Box 1551 - Mail 0HS7 Raleigh, NC 27602 R. Krich, Manager Regulatory Compliance H. B. Robinson Steam Electric Plant P. 0. Box 790 Hartsville, SC 29550 Max Batavia, Chief Bureau of Radiological Health Dept. of Health and Environmental

.Control 2600 Bull Street Columbia, SC 29201 Dayne H. Brown, Director Division of Radiation Protection N. C. Department of Environmental Commerce & Natural Resources P. 0. Box 27687 Raleigh, NC 27611-7687 H. Ray Starling Manager - Legal Department Carolina Power and Light Co.

P. 0. Box 1551 Raleigh, NC 27602 Karen E. Long Assistant Attorney General State of North Carolina P. 0. Box 629 Raleigh, NC 27602 (cc w/encls cont'd - See page 3)

Carolina Power and Light Company 3

U 5 W4 (cc w/encls cont'd)

Robert P. Gruber Executive Director Public Staff - NCUC P. 0. Box 29520 Raleigh, NC 27626-0520 Public Service Commission State of South Carolina P. 0. Box 11649 Columbia, SC 29211 Hartsville Memorial Library 147 W. College Hartsville, SC 29550 bcc w/encls:

H. Christensen, RH B. Mozafari, NRR B. Uryc, RH Document Control Desk NRC Resident Inspector

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Nuclear Regulatory Commission Route 5, Box 413 Hartsville, SC 29550 SEND

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ENCLOSURE 1 LIST OF ATTENDEES Nuclear Requlatory Commission:

S. D. Ebneter, Regional Administrator, Region II (RH)

E. W. Merschoff, Director, Division of Reactor Projects (DRP), RH B. S. Mallett, Acting Deputy Director, Division of Reactor Safety (DRS), RH R. V. Crlenjak, Acting Chief, Engineering Branch, DRS, RH H. 0. Christensen, Acting Chief, Reactor Projects Branch 1, DRP, RHI C. F. Evans, Regional Counsel, RH L. J. Watson, Enforcement Specialist, Enforcement and Investigation Coordination Staff, RH W. T. Orders, Senior Resident Inspector - Robinson, DRP, RH P. M. Byron, Resident Inspector - Brunswick, DRP, RH B. L. Mozafari, Project Manager, Office of Nuclear Reactor Regulation M. A. Satorius, Enforcement Specialist, Office of Enforcement Licensee Attendees:

W. Campbell, Vice President, Nuclear Engineering C. Hinnant, Vice President, Robinson G. Miller, Manager, Engineering, Robinson R. Krich, Manager, Regulatory Affairs R. Rogan, Manager, Nuclear Licensing, CP&L W. Dorman, Manager, Corrective Action Program

CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 NRC ENFORCEMENT CONFERENCE July 26, 1994 Atlanta, Georgia

Aglda Introduction......................

C.S.Hinnant Main Steam Isolation Valve Testing.

G. D. Miller And Design Issues Control Room Emergency Pressurization..

G. D. Miller ENERCON Study....................

C.

S.

Hinnant Summary and Conclusions C. S. Hinnant

Agida Introduction........................ C. S. Hinnant Main Steam Isolation Valve Testing........

G. D. Miller And Design Issues Control Room Emergency Pressurization..

G. D. Miller ENERCON Study....................

C.

S.

Hinnant Summary and Conclusions

... C. S. Hinnant

MSIV Testing Design Issues

  • Introduction
  • Background
  • Adequacy Of Testing
  • Adequacy Of Design To Keep Valve Closed
  • Conclusions

MSIV Testing A Design Issues Introduction Statement Of Apparent Violation Regarding Testing

MSIV Testing ii Design Issues Introduction Statement Of Apparent Violation Regarding Desg "The Licensee's Design Control Measures, As They Pertain To The Main Steam Isolation Valves, Were Inadequate, In That In January 1994, With The Reactor In Hot Shutdown Condition, The Licensee Determined That The Valves Were Incapable Of Closing In The Required Time And/Or Remaining Closed If Instrument Air, A Non-Safety Related System Was Isolated From The Valve Actuators."

MSIV Testing d Design Issues

Background

Design And Function

  • 26 Inch Swing Check Valve Operated By Air Piston Closure Is Resisted By Steam Pressure Exerted On Stem Of Valve In Open Position Closure Is Assisted By A Spring On The Valve Stem; MSIV Is Not A "Fail Safe" Valve Closure Is Accelerated By Pressure Differential Exerted On Disc Of Valve By Forward Steam Flow When Disc Is Inserted Into Flow Stream

MSIV Testing A Design Issues

Background

Design And Function Instrument Air Powered Actuation System Instrument Air Supplies An Air Accumulator At Each MSIV MSIVs Are Safety-Related; Instrument Air System Is Not Solenoid Valves Operate In Pairs To Direct Air To One Side Of The Piston In The Air Cylinder And Exhaust The Other Side Closing Solenoids Energize On Closure Signal Since 1986, MSIV Actuation Single-Failure Proof

MSIV Testing 1& Design Issues

Background

Design And Function

  • Main Steam Line Break (MSLB) Accident UFSAR Chapter 15 Safety Analysis Of Most Limiting MSLB Is Based Upon Full Closure Of MSIVs Within 7 Seconds Of Receipt Of Safety Injection Signal

MSIV Testing A* Design Issues

Background

Applicable Technical Specifications (TS) Requirements

Requires That The MSIVs Be Operable And Capable Of Closing In Five Seconds Or Less Before The Reactor Is Heated Above 350 Degrees F

Requires Safety-Related Components Be Tested In Accordance With Section XI Of The ASME Code 10

MSIV Testing Design Issues

Background

Applicable Technical Specifications (TS) Requirements

Requires That The MSIVs Be Tested At Each Refueling Interval To Show That Closure Time Is Five Seconds Or Less Under No Flow, No Load Conditions

  • The TS Surveillance Requirements Are Not Explicit Either With Regard To The Temperature At Which Tests Are To Be Performed Or With Regard To Whether Instrument Air Can Be Used

MSIV Testing A* Design Issues

Background

Surveillance Test Considerations

Used To Meet TS 3.4.1 And TS 4.7.1 Performed With Instrument Air Connected Usually Performed "Hot"

MSIV Testing A Design Issues

Background

Surveillance Test Considerations

  • OST-702: Operations Surveillance Test Procedure For "ISI Secondary Side Valve Test (Cold Shutdown Greater Than 48 Hours Unless Previously Completed Within Ninety Days)"

Used To Meet TS 4.0.1.a Performed With And Without Instrument Air Connected Usually Performed "Cold"

MSIV Testing A Design Issues

Background

Surveillance Test Considerations

  • Impractical To Test Equipment Under Conditions Identical To Actual Design Basis Conditions
  • Artificialities In Testing Methods -- Both Conservative And Non-Conservative
  • Achievement Of Reasonable Assurance Of Operability Based On Surveillance Test Results Does Not Require Testing Methods With Minimum Artificiality
  • Objective Is To Reduce Artificiality In Testing Methods To The Maximum Extent Practical 14

MSIV Testing A Design Issues

Background

Chronology 1977 ASME Section XI Testing Program Began/ OST 702 Testing Commenced 12/84 NRC Inspection 84-44 Leading To Notice Of Violation (NOV) 84-44-02 (2/85) 1/85 Testing Of MSIVs Identified Single-Failure Susceptibility And Resulted In Temporary Modification 3/85 Response To NOV 84-44-02 10/85 NRC Information Notice 85-84, "Inadequate In Service Testing Of MSIVs" 15

MSIV Testing h& Design Issues

Background

Chronology 3/86 Second Vent Valve Installed 7/86 NRC Inspection Report 86-15 Closes Out NOV 84-44-02 1/94 MSIV Testing Failures 16

MSIV Testing )& Design Issues Adequacy of Testing Testing Methods

  • Testing With Instrument Air Connected Is A Non Conservative Artificiality
  • Testing Under "Cold" Rather Than "Hot" Conditions Is A Non-Conservative Artificiality
  • Testing Under "No Load, No Flow" Rather Than "With Steam Flow" Conditions Is A Highly Conservative Artificiality
  • Closest Practical Emulation Of Actual Design Conditions Would Be To Test "Hot" Without Instrument Air 17

MSIV Testing Ald Design Issues Adequacy of Testing Historical Test Data

  • Data Is Available For Tests Performed "Cold" Both With And Without Instrument Air
  • Data Is Available For Tests Performed With Instrument Air Under Both "Hot" and "Cold" Conditions
  • Analysis Of This Data Provides Insight On The Relative Importance Of Testing Conditions On MSIV Closure Times 18

MSIV Testing 4 Design Issues Adequacy of Testing Test Data Analysis Results

  • MSIV Closure Time Is Approximately 1.3 Seconds Slower Under "Hot" Conditions Than Under "Cold" Conditions
  • MSIV Closure Time Is Not Significantly Affected By The Availability Of Instrument Air -- Approximately 0.3 Seconds Slower Without Air
  • . MSIV Closure Time Test Results Under "Hot" Conditions Averaged 4.5 Seconds

MSIV Testing 4*

Design Issues Adequacy Of Testing Conclusions

  • Historical Testing Results Demonstrate That Surveillance Testing Of The MSIVs Provided Reasonable Assurance That:

The MSIVs Would Have Performed Their Intended Design Function Under The Most Limiting, Postulated MSLB Accident Conditions Analyzed Testing Would Have Revealed Degraded Performance 20

MSIV Testing A Design Issues Adequacy Of Testing Actions Taken Since January 1994

  • OST-501 Was Revised To Test MSIV Closure Under "Hot, No Load, No Flow" Conditions With The Instrument Air System Isolated
  • Revised OST-501 Test Was Successfully Performed On The MSIVs Prior To Return To Power Operations

MSIV Testing ASI Design Issues Adequacy Of Design To Keep Valves Closed

Background

  • Historical MSIV Surveillance Testing Confirmed Adequacy Of Design To Assure MSIV Closure
  • MSIV Drifted Off Seat In January, 1994 Under "Hot, No Differential Pressure" Conditions With Instrument Air System Isolated For Approximately 24 Hours
  • Cause Determined To Be Insufficient Leak Tightness Of MSIV Air Operating System
  • No Apparent Duration Criteria In Licensing Basis With Respect To Maintaining The MSIVs Closed 22

MSIV Testing Y& Design Issues Adequacy Of Design To Keep Valves Closed

  • Safety Significance For Conditions In Which There Is A Need To Keep The MSIVs Closed, There Will Be Sufficient Differential Pressure Across The Valve To Ensure That It Remains Closed For A MSIV To Drift Open, There Would Have To Be Sufficient Pressure Inside The Valve Body, In Addition To Little Or No Differential Pressure Across The Valve 23

MSIV Testing zd Design Issues Adequacy Of Design To Keep Valves Closed Corrective Actions Taken Since January 1994

  • Installation Of Additional Accumulators In February 1994 Increased MSIV Accumulator Air Volume Capacity -- Providing Additional Margin To Decrease Closure Time And To Keep Valves Closed
  • Tested Actuator Air Lines, Hoses, And Connections For Leak Tightness 24

MSIV Testing A Design Issues Adequacy Of Design To Keep Valves Closed Additional Corrective Actions

  • Evaluate Adequacy Of The Periodic Testing To Verify Leak Tightness That Is Currently In Place
  • Evaluate The Need For Additional Post-Accident Controls To Ensure MSIVs Remain Closed 25

MSIV Testing h& Design Issues Conclusions Surveillance Testing

  • The MSIV Test Conditions Used Prior To February 1994 Included Certain Artificialities When Compared To The Actual Conditions Under Which The MSIVs Would Be Required To Perform Their Intended Safety Function
  • The "Conservative" Artificialities In Those MSIV Test Conditions Compensated For The "Non-Conservative" Artificialities 26

MSIV Testing A Design Issues Conclusions Surveillance Testing

  • Historical MSIV Test Results Provide Reasonable Assurance That The MSIVs Would Have Performed Their Intended Safety Function Under Postulated Design Basis Accident Conditions
  • Testing Would Have Revealed Degraded Performance
  • Subsequent To The February 1994 Modification Of The Air Supply System To The MSIVs, The Conditions Under Which MSIVs Are Tested Has Been Enhanced By Removal Of The "Non-Conservative" Testing Artificiality 27

MSIV Testing A1 Design Issues Conclusions Design

  • The Design Of The MSIVs As Of January 1994 Was Adequate To Ensure That The Valves Were Capable Of Closing In The Required Time
  • The Modification To The MSIV Air Actuating System In February 1994 Provided Additional Design Margin Both For Closing The MSIVs And For Keeping The MSIVs Closed
  • Additional Evaluation Will Be Performed Related To Maintaining MSIV Air Actuation System Leak Tightness
  • Licensee Event Report Will Be Revised 28

Ag da Introduction.................

... C.S. Hinnant Main Steam Isolation Valve Testing.

G. D. Miller And Design Issues Control Room Emergency Pressurization..

G. D. Miller ENERCON Study C.

S.

Hinnant Summary and Conclusions C. S. Hinnant 29

Control Room Emeqncy Pressurization Outline

  • Introduction
  • Overview
  • Background
  • Causes
  • Safety Significance
  • Corrective Actions
  • Conclusions 30

Control Room Eme ency Pressurization Introduction Statement of Apparent Violation

  • "The test program established by the licensee to demonstrate that the control room air ventilation system would perform its intended safety function was inadequate in that it did not ensure that the system could produce and maintain a positive pressure in the control room with respect to areas adjacent to the control room and the outdoors."
  • Additionally, Concerns With Respect To Meeting UFSAR Commitments Were Identified During An NRC Inspection In May, 1994 31

Control Room Emefncy Pressurization Overview

  • The Design And Post Modification Test Of The 1991 Modification To The Control Room Ventilation System (CRVS) To Add An Emergency Pressurization Mode Did Not Account For A Previously Unanalyzed Scenario In Which Operator Action Would Have Been Required
  • Surveillance Test Procedures Did Not Adequately Specify Proper Initial Conditions Nor Required Testing With Respect To Adjacent Rooms
  • Probability Of The Unanalyzed Scenario Having Occurred Was Low
  • Operators Would Have Had At Least One Hour To Diagnose And Take Action To Mitigate The Conditions Prior To Exceeding GDC-19 Dose Limits 32

Control Room Eme~ncy Pressurization Overview

  • Corrective Actions Were Promptly Implemented
  • UFSAR Commitment Concerns Addressed In Response To NRC Identified Deviation

Control Room Emegncy Pressurization

Background

  • Original CRVS Design Single Train; No Pressurization Mode
  • 1991 Modification To CRVS Was Designed In Response To NUREG-0737, Item III.D.3.4 Redundant Trains; Emergency Pressurization Mode

Control Room Eme ncy Pressurization

Background

  • Modification Design Based On Assumption Of Coincident LOCA-LOOP Design Did Not Take Into Account The Impact Of A Post Accident Configuration Of The Ventilation System Serving Adjacent Rooms On The CRVS Emergency Pressurization Mode Of Operation Design Should Have Considered LOCA With Off-Site Power And The Failure Of A Specific Non-Safety Related Ventilation Fan (HVE-7)

Control Room Eme ncy Pressurization Causes

  • The Modification Design And Post Modification Test Failed To Consider The Impact Of Potential Ventilation Configurations On The Safety Function Of The CRVS Emergency Pressurization Mode
  • Inadequate Understanding Of Testing Requirements And Commitments 36

Control Room Eme ncy Pressurization Safety Significance

  • Probability Of The Unanalyzed Scenario Having Occurred Was Low
  • Operators Would Have Had At Least One Hour To Diagnose And Take Actions To Mitigate The Condition Prior To Exceeding GDC-19 Dose Limits 3-7

Control Room Emeoncy Pressurization Corrective Actions

  • Specific Design Issue Operating Procedures Revised To Delineate Required Actions
  • Testing Issues Specific Initial Conditions And Acceptance Criterion Added To Refueling Frequency Surveillance Test

- No Future Periodic Testing Of Adjacent Areas Will Be Needed To Verify System Performance 38

Control Room Eme ncy Pressurization Corrective Actions

  • Generic Implications A Representative Sample Of Other NUREG 0737 Modifications Will Be Evaluated For Adequacy Of:
  • Initial Conditions
  • Possible Interactions With Other Systems
  • The Associated Surveillance Tests 39

Control Room Eme ncy Pressurization Conclusions

  • The Design Of The 1991 CRVS Emergency Pressurization Mode Modification Did Not Account For All Possible RAB Ventilation System Configurations There Was A Previously Unanalyzed, Low Probability Scenario In Which Operator Action Would Have Been Required
  • Corrective Actions To Specific Concern Were Promptly Taken
  • Surveillance Testing Requirements And Commitments Were Not Appropriately Translated Into Procedures
  • Appropriate Changes Will Be Made To Surveillance Test Procedures 40

Control Room Eme ency Pressurization Conclusions

  • Safety Consequences Were Not Significant Low Probability Event Time Would Have Been Available For Operator Diagnosis And Mitigation
  • Actions To Address Generic Concern Are Being Implemented
  • Licensee Event Report Will Be Revised
  • Internal SSFI In Progress 41

Ag da Introduction........................ C. S. Hinnant Main Steam Isolation Valve Testing.

G. D. Miller And Design Issues Control Room Emergency Pressurization.

G. D. Miller ENERCONStudy C.S.Hinnant Summary and Conclusions

. C. S. Hinnant 42

ENERCM4 Study Outline

  • Background
  • Cause
  • Contributing Factor
  • Safety Significance
  • Corrective Actions
  • Additional Actions 43

ENERC4 Study Statement Of Apparent Violation

  • Failure To Take Adequate Corrective Action In A Timely Fashion To Potential Technical Specification Deficiencies Identified By ENERCON In June, 1992

ENERC 4 Study

Background

  • Previous Reportable Occurrences Of Surveillance Test (ST) Procedures Not Covering All Technical Specifications (TS) Surveillance Requirements (SRs)
  • NRC Issued Violation In 1990 For Repeat Occurrences Of Inadequate ST Procedures
  • Plant Nuclear Safety Committee (PNSC) Initiated Evaluation Of Issue In 1990 - Corporate Nuclear Safety (CNS) Organization To Perform Independent Review 45

ENERC04 Study

Background

  • CNS Reports That A More Detailed Evaluation Is Needed To Assess Adequacy Of ST Procedures
  • ENERCON Contracted And Study Initiated In April, 1991
  • Study Completed And Report Issued In June, 1992 Enhancements Identified 18 Review Deficiencies Identified 46

ENERC04 Study

Background

  • Initial Evaluation And Recommended Disposition Of 13 Items Completed In January, 1993; No Operability Or Reportable Concerns Identified
  • Some Items Entered Into Corrective Action System Follow Through Incomplete 47

ENERC04 Study

Background

  • As Part Of January, 1994 Restart Effort, PNSC Reviewed 18 Items And Assessed Adequacy Of ST Procedure Program PNSC Concluded That Program Is Adequate PNSC Concluded That None Of The 18 Items Precluded Plant Start Up Action Item To Evaluate Reportability Of 18 Items Established

ENERC4 Study

Background

  • Reportability Evaluation Completed On February 4, 1994 Two Of The 18 Items Determined To Have Resulted In Reportable Conditions; SRs Not Satisfied Licensee Event Report Submitted 49

ENERC~4 Study Cause

  • Lack Of Management Oversight And Involvement Methods And Schedules For Confirming And Dispositioning Deficient Items Not Established Corrective Action Process Not Effectively Used
  • Study Was Performed For A "Committee" Rather Than An Organizational Unit Leading To Unclear Accountability 50

ENERC*4 Study Safety Significance

  • Proper Testing Of Circuits Associated With The Identified Inadequate ST Procedures Successfully Performed; Circuits Would Have Performed As Required When Called Upon During An Accident

ENERC 4 Study Corrective Actions

  • Specific Reported Deficiencies Affected ST Procedures Revised Testing Conducted 52

ENERC0 Study Corrective Actions

  • Management Oversight And Involvement Increased Standards And Expectations For Management Strengthened Corrective Action Process And Management Oversight Of Corrective Action Program Implementation PNSC Action Items Assigned To Organizational Units And Tracked To Completion 53

ENERC04 Study Additional Actions

  • Implementing ST Procedure Program Improvements Centralizing ST Scheduling And Tracking Establishing Setpoint Bases Evaluation Of Enercon Recommended Testing Practices Complete
  • Sample Of Other TS Circuit Surveillance Requirements 54

ENERC0 Study Conclusions

  • Substantial Effort Expended On Review Of TS Table Containing Majority Of Instrumentation Circuits
  • Only Three Tests Identified As Not Meeting TS Requirements
  • No Safety Significant Concerns 55

Ag da Introduction........................ C. S. Hinnant Main Steam Isolation Valve Testing.

G. D. Miller And Design Issues i

Control Room Emergency Pressurization.

G. D. Miller ENERCON Study C.

S. Hinnant Summary and Conclusions C. S. Hinnant 56

Summary ADConclusions

  • Although Issues Occurred In The Past, We Have A Thorough Understanding Of The Causes
  • Each Issue Represents A Serious Concern; However, None Are Safety Significant
  • Based On The Causes Of Each Of The Issues, Confidence In Testing Program Remains Adequate
  • Improvements In Corrective Action Program Effectiveness Are In Progress 57

Summary A Conclusions

  • Need For Increased Involvement By Engineering And Improvements In Engineering Evaluations Is Recognized And Is In Progress
  • Recognize That While Specific Deficiencies Similar To Those Discussed May Recur, Corrective Actions Are Being Taken To Address The Broader Issues 59
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