ML020990215

March 20, 2002 Meeting Handouts to Discuss Current Knowledge Relating to the Recently Identified Degradation of the Reactor Vessel Heat at the Davis-Besse Nuclear Power Station

ML020990215
Person / Time
Site:	Davis Besse
Issue date:	03/20/2002
From:	Sands S NRC/NRR/DLPM/LPD3
To:
References
Download: ML020990215 (14)

Text

U.S. NUCLEAR REGULATORY COMMISSION (9-9 "UNITED STATES 0 NUCLEAR REGULATORY COMMISSION Z WASHINGTON, D.C. 20555-0001 TRANSMITTAL OF MEETING HANDOUT MATERIALS FOR "IMMEDIATEPLACEMENT IN THE PUBLIC DOMAIN This form is to be filled out (typed or hand-printed)by the person who announced the meeting (i.e., the person who issued the meeting notice). The completed form, and the attachedcopy of meeting handout materials, will be sent to the Document ControlDesk on the same day of the meeting; under no circumstances will this be done later than the working day after the meeting.

Do not include proprietarymaterials.

DATE OF MEETING The attached document(s), which was/were handed out in this meeting, is/are to be placed 03/20/2002 in the public domain as soon as possible. The minutes of the meeting will be issued in the near future. Following are administrative details regarding this meeting:

Docket Number(s) 05000346 Plant/Facility Name Davis-Besse Nuclear Power Station TAC Number(s) (if available) NA Reference Meeting Notice March 14,2002 Purpose of Meeting (copy from meeting notice) To discuss current knowledge relating to the recently identified degradation of the reactor vessel head at the Davis-Besse Nuclear Power Station NAME OF PERSON WHO ISSUED MEETING NOTICE TITLE Stephen Sands Project Manager, NRR/DLPM/LPD3 OFFICE NRR DIVISION Division of Licensing Project Management BRANCH Project Directorate III Distribution of this form and attachments:

Docket File/Central File PUBLIC NRC FORM 658 (9-1999) PRINTED ON RECYCLED PAPER This form was designed using InForms

cREo March 20, 2002 Public Meeting on Reactor Pressure Vessel Head Degradation

MARCH 20. 2002 PUBLIC MEETING on REACTOR PRESSURE VESSEL HEAD DEGRADATION PURPOSE: To exchange information with stakeholders and respond to questions regarding degradation of the reactor pressure vessel head found at the Davis Besse Nuclear Power plant and NRC's actions to address the issue.

SUCCESS: Participants leave the meeting with clear understanding of the issue, stakeholder perspectives and concerns, and NRC's actions to address the issue and protect public health and safety.

AGENDA I. INTRODUCTIONS Tony Mendiola, Section Chief DLPM, NRR U.S. NRC II. OVERVIEW OF ISSUE (25 minutes) Jack Strosnider, Director Division of Engineering, NRR U.S. NRC III. QUESTION AND DISCUSSION PERIOD IV. ADJOURNMENT Page 1 of 12

OVERVIEW OF ISSUE I. Basic Plant and Reactor Pressure Vessel Overview II. Description of Degradation found at Davis Besse I1. Safety Implications IV. Industry/ licensee actions V. NRC Actions Page 2 of 12

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Reactor Pressure Vessel Head Degradation Location Reactor Pressure Vessel Head Reactor Pressure Reactor Pressure Vessel Head Nozzle (Alloy 600)

Area of Davis Besse Reactor Pressure Vessel Head Degradation FIG 2: REACTOR PRESSURE VESSEL HEAD Page 4 of 12

DESCRIPTION OF DEGRADATION FOUND AT DAVIS BESSE

• INSPECTIONS WERE BEING PERFORMED IN RESPONSE TO NRC BULLETIN 2001-01 REGARDING CRACKING OF CRDM NOZZLE PENETRATION TUBE

• NOZZLES INSPECTED WITH ULTRASONIC TESTING

- nozzles 1, 2, and 3 had through-wall cracks that leaked

- nozzles 5 and 47 had cracks that were not through-wall PROBLEMS ENCOUNTERED DURING REPAIR OF NOZZLE 3 NOZZLE 3 REMOVED FROM REACTOR VESSEL HEAD AND BORIC ACID DEPOSITS REMOVED

° IDENTIFIED DEGRADED AREAS ADJACENT TO NOZZLES 1, 2, AND 3 Page 5 of 12

FIG 3: TOP VIEW OF REACTOR VESSEL HEAD Page 6 of 12

2ZZ3 FIG 4: CROSS-SECTIONAL SKETCH OF DEGRADED AREA ADJACENT TO NOZZLE 3 Page 7 of 12

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SAFETY IMPLICATIONS

• VERY SERIOUS DEGRADATION

- Structural Margins Were Significantly Degraded

- Potential for Loss of Reactor Coolant Accident

• PLANT IS DESIGNED TO DEAL WITH A LOSS OF COOLANT ACCIDENT

- Emergency Core Cooling Systems, Control of Nuclear Reaction, Containment

- Unwanted Challenge to Systems and Operators PROMPT ACTION REQUIRED TO CONFIRM THAT SIMILAR PROBLEMS DON'T EXIST AT OTHER PLANTS Page 9 of 12

LICENSEE I INDUSTRY ACTIONS LICENSEE ACTIONS

- Plant is in safe, shutdown condition

- Licensee investigating extent and cause of degradation

- Licensee evaluating repair or replacement options

° INDUSTRY ACTION

- Industry survey to collect information on status of all pressurized water reactor plants

- Information presented at March 19 public meeting Page 10 of 12

NRC Actions

• INFORMATION NOTICE 2002-11 ISSUED MARCH 12, 2002

• NRC AUGMENTED INSPECTION TEAM (AIT) SENT TO SITE

• CONFIRMATORY ACTION LETTER ISSUED TO LICENSEE BULLETIN 2002-01 ISSUED ON MARCH 18, 2002 Page 11 of 12

BULLETIN REQUIRED INFORMATION WITHIN 15 DAYS:

SUMMARY

OF RPV HAD INSPECTION & MAINTENANCE PROGRAMS EVALUATION OF ABILITY OF INSPECTION AND MAINTENANCE PROGRAMS TO IDENTIFY DEGRADATION

• DESCRIPTION OF CONDITIONS THAT COULD LEAD TO DEGRADATION AND CORRECTIVE ACTIONS TAKEN TO ADDRESS SUCH CONDITIONS

• PLANS, BASIS AND SCHEDULE FOR FUTURE INSPECTIONS OF THE REACTOR VESSEL HEAD AND VESSEL HEAD PENETRATION NOZZLES BASIS FOR CONTINUED OPERATION UNTIL THE INSPECTIONS ARE PERFORMED WITHIN 30 DAYS:

RESULTS OF INSPECTIONS WITHIN 60 DAYS:

• BASIS FOR CONCLUDING BORIC ACID INSPECTION PROGRAM IS EFFECTIVELY MAINTAINING REACTOR COOLANT PRESSURE BOUNDARY INTEGRITY Page 12 of 12