ML030280481

Reactor Vessel Head Degradation Lessons-Learned Task Force - Public Meeting, November 20, 2002 (Presentation Slides)

ML030280481
Person / Time
Site:	Davis Besse
Issue date:	11/20/2002
From:	Office of Nuclear Reactor Regulation
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pj- F O 1- . -1O United States Nuclear Regulatory Commission Davis-Besse Reactor Vessel Head Degradation Lessons-Learned Task Force Public Meeting November 20, 2002 I

Meeting Agenda

"*Introduction and Opening Remarks Art Howell

"*Overview Ed Hackett

"*Results Ed Hackett

"*Recommendations Ed Hackett

"*Future Activities Art Howell

"*Discussion/Questions All

"*Closing Remarks Art Howell 2

Overview

Background

• NRC has taken the initiative to conduct lessons-learned reviews for significant issues

, Self-critical

, Improvements made Examples:

"*Indian Point 2 steam generator tube failure (2000)

"* NRC inspections at the South Texas Project (1995) 3

Overview Objectives and Scope

"*Perform independent evaluation

"*Review:

, Reactor oversight process

, Regulatory processes

, Research activities International practices

, Generic Issues program

"*Identify and recommend improvements 4

Overview Composition and Attributes

"*Multi-disciplined, experienced team

"*No previous significant involvement in Davis-Besse Nuclear Power Station (DBNPS) oversight

"*Observation by State of Ohio

"*Stakeholder input to task force review activities o Solicited input at two public meetings 5

Overview Review Methods

"* Comprised of two groups

"* Performed document reviews and conducted interviews

"* Conducted fact finding at DBNPS site

"* Conducted reviews at NRC Regional and Headquarters Offices 6

Overview Report

"*The report is available on ADAMS (the NRC electronic document management system)

• Accession number: ML022760414

"*The report is also available on the NRC's public website http://www.nrc.gov/reactors/operating/ops experience/vessel-head-degradation/news, html

"*The report issuance was coordinated with other NRC offices because of ongoing NRC reviews DBNPS plant-specific issues were provided to the NRC's 0350 Oversight Panel for follow up, as appropriate 7

Results Overall Conclusions

"*NRC and industry recognized potential for this type of event nearly 10 years ago

"*Initial conclusion was that vessel head penetration nozzle cracking was not an immediate safety concern

"*NRC and DBNPS failed to learn key lessons from past boric acid-induced degradation events S

Results Overall Conclusions (continued)

The leaking nozzle and vessel head degradation event was not prevented

• The NRC, DBNPS, and the nuclear industry failed to adequately review, assess, and follow up on relevant operating experience

• DBNPS failed to assure that plant safety issues would receive appropriate attention

• The NRC failed to integrate known or available information into its assessments of DBNPS's safety performance 9

Results Overall Conclusions (continued)

• Other contributing factors Guidance and requirements Staffing and resources

• DBNPS communications Licensing processes and implementation 10

Results NRC and Industry Review, Assessment, and Follow up of Operating Experience

"*Significant operating experience involving boric acid leakage and corrosion

"*Generic Communication Program implementation

"*Generic Issues Program implementation

"*Operating experience involving foreign nuclear power plants

"*Assessment and verification of industry technical information

"*NRC operating experience review and assessment capability 11

Results DBNPS Assurance of Plant Safety

• Reactor coolant system leakage symptoms and indications

• Boric acid corrosion control program and implementation

• Owners group and industry guidance

• Internal and external operating experience awareness

• Oversight of safety related activities 12

Results NRC Assessment of DBNPS Safety Performance

"* Reactor coolant system leakage assessment

"* Inspection program implementation

"* Integration and assessment of performance data

"* Guidance and requirements

"* Staffing and resources

"* Davis-Besse Nuclear Power Station communications

"* Licensing process guidance and implementation 13

Recommendations Recommendation Areas

"*Inspection guidance

"*Operating experience assessment

"*Code inspection requirements

"*NRC programs and capabilities (including training and experience)

"*Leakage monitoring requirements and methods

"*Technical information and guidance

"*NRC licensing processes

"*Previous NRC lessons-learned reviews 14

Future Activities Senior Management Review Team

"*The Senior Management Review Team is reviewing the report's recommendations

"*Plans are being established for addressing the recommendations

"*Actions are already underway to implement some of the recommendations 15

Closing Remarks Summary

• The NRC conducted a comprehensive, self-critical assessment of its regulatory processes as a result of the DBNPS degraded reactor vessel head.

• The NRC identified a number of areas for improvement and has initiated actions to address these areas.

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