ML033220255

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Slides for 11/17/03 Meeting with Congressman Kucinich
ML033220255
Person / Time
Site: Davis Besse Cleveland Electric icon.png
Issue date: 11/11/2003
From: Gerke L, Grobe J, Mary Johnson, Sheron B
Office of Nuclear Reactor Regulation, Division of Systems Safety and Analysis, Office of Congressional Affairs
To:
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ML032940151 List:
References
Download: ML033220255 (18)


Text

Briefing for Representative Kucinich's Staff on Activities at Davis-Besse Brian Sheron, Associate Director for Project Licensing and Technical Analysis, Office of Nuclear Reactor Regulation Michael Johnson, Deputy Director Division of Systems Safety and Analysis, Office of Nuclear Reactor Regulation Jack Grobe, Chairman, Davis-Besse Oversight Panel Laura Gerke, Office of Congressional Affairs November 11, 2003 1

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.! , 1 Concerns Expressed by Representative Kucinich

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Topics of Discussion

  • Overview of the Reactor Oversight Process (ROP)
  • Evaluation of the Davis-Besse Degraded Reactor Head
  • Discussion of NRC Oversight of Davis-Besse 3

NRC Reactor Oversight Process

  • Reactor Oversight Process framework is structured and focuses on safety
  • Action matrix integrates safety insights from SDPs and performance indicators resulting in consistent and predictable regulatory action 4

NRC Reactor Oversight

-I Process Framework REGULATORY FRAMEWORK Ccriersi

- HUMAN ---------- SAFETY CONSCIOUS WORIK--------------- 1'ROBLEM ---------

PERFORMANCE ENVIRONMENT IDENTIFICATION AND RESOLUTION 5

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,..Reactor Oversight Process

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~4' LEVEL OF SIGNIFICANCE ASSOCIATED I-

< 0 WITH INSPECTION FINDINGS

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  • Green - very low risk ,;;.mre~lh~aniF,00N0;!ears>ofp, significance ' W~~~~~~~~
  • White - low to moderate One Core Damage Event per 1,000,000 Years of Operation risk significance White
  • Yellow - substantive risk  :;One'.Core.Damage, Event per, significance -100,000 Years :of Operation:

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  • Red - high risk significance 7

& 0:Reactor Safety Significance Determination Process SI)P - Used to evaluate the safety significance of individual inspection findings for input to the action matrix.

- Uses Pre-established tools

- Findings must represent a deficiency in licensee performance

- SDP's for the Initiating Event, Mitigating Systems, and Barrier Integrity cornerstones are quantitative in nature, based on use of Probabilistic Risk Assessment techniques

- Other cornerstones are qualitative in nature 8

Reactor Safety Significance Determination Process Three Phases:

  • Phase 1 -Screens issues to quickly identify those of very low safety significance (Green)
  • Phase 2 - Simplified PRA tool to allow inspectors to evaluate findings. This tool tends to produce a conservative estimate of the risk.
  • Phase 3 - Full analysis by a risk analyst utilizing refined modeling assumptions. It uses best available methods to establish the risk significance.

9

Reactor Safety Significance I

Determination Process Review process

  • A Significance and Enforcement Review Panel is convened to review each evaluation that is greater than very low safety significance (Green). The panel is comprised of managers from headquarters and the regions.
  • A "preliminary determination" is transmitted to the licensee and the licensee is offered an opportunity to meet in public with the NRC or provide a written response
  • Final Determination is issued 10

NRC Action Matrix Am

  • Receives input from NRC inspections and plant performance indicators to determine appropriate NRC response
  • NRC response is structured and provides a graded approach to agency actions depending on level of licensee performance during the 12 month assessment window
  • NRC regulatory responses range from continued baseline inspections to regulatory orders to modify, suspend, or revoke operating license
  • Results are shared with licensee and public on the NRC web page and at annual public meetings in the vicinity of the plant 11

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0 NRCReactor Oversight Process i Reactor Oversight Process framework is structured and focuses on safety

  • Action matrix integrates safety insights from performance deficiencies and performance indicators resulting in consistent and predictable regulatory action 12
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NRC Oversight at Davis-Besse

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  • NRC implementing special oversight at Davis-Besse due to significant performance deficiencies
  • Significance Determination of reactor head wastage followed NRC Policies and Procedures e NRC Providing effective oversight of Davis-Besse 13

NRC Oversight at Davis-Besse

  • NRC Davis-Besse Oversight Panel chartered April 2002
  • Oversight Panel coordinates NRC activities and provides NRC oversight utilizing existing regulatory tools
  • SDP utilized to evaluate significance of performance deficiencies at Davis-Besse 14

"Red" Significance Determination at Davis-Besse

  • Performance deficiency involved the failure to effectively implement the corrective action program and boric acid corrosion management program
  • The performance deficiency resulted in Reactor Head Wastage which was a challenge to Barrier Integrity

Significance Determination of W-0Head Wastage

  • Phase 1 SDP revealed finding was greater than "Green"
  • Phase 2 SDP evaluation resulted in a "Red" finding
  • Phase 3 analysis uniquely challenging and evolved over time

- Preliminary Phase 3 analysis assuming plate stainless steel behavior revealed "Green" risk significance

- Cladding was not plate stainless steel

  • Flaws
  • Material Variations
  • Distortion and Cracks

- Corrosion mechanism and rate not well understood

  • Because Phase 3 analysis contained significant uncertainties, the Phase 2 analysis was utilized to determine the significance. This is consistent with SDP procedures.
  • Evaluation continues into cladding behavior and corrosion mechanisms 16

tN" REI,34 Current Status of NRC Oversight at Davis-Besse

  • NRC approval needed for plant restart
  • NRC Restart Checklist established-22 of 31 items completed
  • Extensive NRC assessment of Safety-Significant Systems and Programs, and Management and Human Performance
  • Approximately 70 public meetings conducted
  • Davis-Besse will not be permitted to restart until the NRC is convinced it can be safely operated
  • Oversight Panel will continue after restart 17

Conclusions

  • ROP provides a predictable and consistent safety focused regulatory response to licensee performance
  • Significance assessment of the Davis-Besse head degradation was performed in accordance with NRC policies and procedures
  • NRC instituted special oversight processes at Davis-Besse. The Facility will not be permitted to restart unless NRC is convinced it can be operated safely 18