ML020990054
| ML020990054 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/10/2002 |
| From: | Steven Bloom NRC/NRR/DE/EMCB |
| To: | Stephanie Coffin NRC/NRR/DE/EMCB |
| References | |
| IEB-02-001 | |
| Download: ML020990054 (7) | |
Text
April 10, 2002 MEMORANDUM TO: Stephanie M. Coffin, Section Chief Structural Integrity and Metallurgy Section Materials and Chemical Engineering Branch FROM: Steven D. Bloom, Lead Project Manager for Bulletin 2002-01(RA by SB)
Structural Integrity and Metallurgy Section Materials and Chemical Engineering Branch
SUBJECT:
SUMMARY
OF MEETING HELD ON MARCH 19, 2002, WITH NUCLEAR ENERGY INSTITUTE AND ELECTRIC POWER RESEARCH INSTITUTE - MATERIAL RELIABILITY PROGRAM TO DISCUSS THE GENERIC IMPLICATIONS OF THE DAVIS-BESSE REACTOR VESSEL HEAD DEGRADATION On March 19, 2002, representatives of Nuclear Energy Institute (NEI) and Electric Power Research Institute - Material Reliability Program (EPRI-MRP) met to discuss the generic implications of the Davis-Besse reactor vessel head degradation. This was a Type 2 public meeting. Copies of the slides used during the meeting are available under ADAMS accession number ML020920666 and ML020920585 the NRC web site at http://www.nrc.gov/reactors/operating/ops-experience/vessel-head-degradation.html.
The meeting started with a description of the purpose of the meeting, and the NRC public meeting policy. The meeting continued with some brief comments by Brian Sheron, Associated Director, ADPT who gave a brief overview of the issue at Davis-Besse and then by Alex Marion of NEI, who stated that he believed that the bulletin was appropriate. The meeting attendance is attachment 1.
Mike Short, Chairman of the Issues and Integration Group (IIG), of EPRI-MRP, started his presentation with a review of the March 11, 2002, letter from Brian Sheron to Alex Marion. He reviewed the three questions asked in the letter and some brief responses to them. Mike Short stated that work being performed on the probabilistic fracture mechanics (PFM) which was supposed to be completed in May 2002, will be impacted pending the root cause of the Davis Besse degradation. He described three potential root causes: (1) leakage from sources above the head, (2) leakage of reactor coolant through flaws in penetration nozzles, and (3) previous stable accumulation of boric acid deposits wetted by leakage through flaws in penetration nozzles. He stated that they are not ruling out any potential root causes, but are leaning toward 2 and 3. He stated that if the nozzle at Davis-Besse had not fallen over, they would have repaired the nozzle, and then gone back and cleaned the head and would have performed further inspection which would have found the cavity.
Mike Short stated that MRP had sent the licensees four questions and then established acceptance criteria for the responses. The questions were grouped in two areas, most recent inspections and future inspections and spring outages. The acceptance criteria grouped the plants in categories 1 through 4 and an other category. He stated that their assessment was
in progress and that they would be supplying the responses and their assessment to the NRC.
He stated that category 1 plants performed both qualified and effective visual inspections per Bulletin 2001-01. He stated that following the root cause evaluation, MRP would review previous work performed in 1990s in this area and if not enough information, would consider additional testing. The EPRI would be reviewing the Boric Acid Corrosion Guidebook if additional revision was necessary.
Mike Short went over the various categories from the recent survey and combined that with the susceptibility rankings from Bulletin 2001-01.
- 1. All 11 plants in the < 5 Effective Full Power Year (EFPY) susceptibility group (except Davis-Besse) have already performed 100% bare-head inspections. These plants found no significant boric acid deposits on their vessel heads.
- 2. The nine plants in the 5-10 EFPY group have either performed 100% bare-head inspection or will be during their upcoming spring 2002 outages. The six plants which have already performed their inspections found no significant boric acid deposits.
- 3. There are 11 plants in the 10-15 EFPY susceptibility group, two of which have performed 100% bare-head inspections with no boric acid deposits. Three of these plants have had limited visual head inspections with no above-head events, and 2 of them will have spring 2002 outages. There were five plants which had limited visual head inspections with some previous leakage, one plant performed a supplemental inspection in response to the Davis-Besse concern. The remaining four plants will be performing inspections during their spring 2002 outages. There was one plant in the other category because it had identified boric acid and evaluated minor wastage on the head.
- 4. The remaining plants were in the > 15 EFPY grouping, with eight in the 15-20 EFPY Group, five in the 20-30 EFPY group, and 25 in the > 30 EFPY group. Within each of these groupings, there were numerous plants with outages during the spring 2002 outages and others with outages in the future. There was one plant in the other category in the 15-20 EFPY group and four plants in the other group from the >30 EFPY group.
The MRP will be working on a response plan to the Davis-Besse degradation, by reviewing the root cause analysis and reviewing it for generic implications, using the November 2001 Boric Acid Corrosion Guidebook. Mike Short stated that the nozzle repair at Oconee was different than that at Davis-Besse. At Oconee they had greater than 20 nozzles where they used a manual process and where as at Davis-Besse it was by machine. At Oconee, the post repair, pre-weld NDE verified material outside the nozzle. The MRP stated that if the repair had been completed at Davis-Besse, the post repair pre-weld NDE would have discovered the cavity.
Based on Davis-Besse, no plants were moving up their outages, however, Vogtle was modifying its inspections to perform an under insulation inspection.
Ken Karwoski described Bulletin 2002-01 by detailing the information required for the 15-day, 30-day and 60-day responses. The 15-day response is requiring information about the licensees reactor pressure vessel head inspections and any history of leakage of boric acid in the life of the plant, and the ability to identify degradation on the head. The 30-day response requires information 30 days following the next outage during which the licensee performs a
vessel head inspection. The 60-day response requires information about the effectiveness of the boric acid inspection program maintaining reactor coolant pressure boundary integrity.
Project No. 0689
Attachment:
As stated CONTACT Steven D. Bloom, NRR/EMCB 415-1313
MEETING WITH NUCLEAR ENERGY INSTITUTE (NEI) AND ELECTRIC POWER RESEARCH INSTITUTE - MATERIAL RELIABILITY PROGRAM (EPRI-MRP)
MEETING ATTENDEES GENERIC IMPLICATIONS OF THE DAVIS-BESSE REACTOR VESSEL HEAD DEGRADATION MARCH 19, 2002 NAME AFFILIATION B. Sheron NRC J. Strosnider NRC J. Grobe NRC W. Bateman NRC K. Karwoski NRC S. Bloom NRC A. Mendiola NRC S. Long NRC A. Lee NRC B. Wetzel NRC M. Switzer NRC W. Cullen NRC M. Weston NRC T. Koshy NRC J. Starefos NRC J. Chung NRC L. Gerke NRC T. Bilik NRC J. Medoff NRC P. Kuo NRC H. Nieh NRC J. Colaccino NRC A. Hiser NRC E. Hackett NRC G. Longo NRC V. Dricks NRC F. Jaxheimer NRC J. Dozier NRC B. McCabe NRC M. McConnell NRC A. Passarelli NRC R. Taylor NRC J. Beall NRC W. Beckner NRC J. Calvo NRC I. Jung NRC J. Uhle NRC K. Wichman NRC ATTACHMENT M. Short SCE & MRP
L. Hartz Dominion Engineering & MRP A. Marion NEI J. Woodard SNC G. Vine EPRI L. Mathews SNC D. Lochbaum UCS G. Tesfaye CCNPPI D. Wight FERC F. Madden STARS J. Widay RG&E B. Flynn RG&E D. Mauldin APS B. Beasley SNC L. Bohn NMC E. Weinkam NMC D. Pace Entergy D. Horner McGraw-Hill J. Wood FENOC B. Miller Entergy B. Wendland ANI P. Rush MPR D. Raleigh Scientech R. Huston Licensing Support Services C. Brinkman Westinghouse Electric Co.
S. Mori Kansai Electric B. Bishop Westinghouse Electric Co.
S. Lurie Westinghouse Electric Co.
H. Fontecilla Dominion Engineering D. Gortcheus TVA M. Murphy PABRP C. Welty EPRI V. Wagoner CP&L M. Fleming Dominion Engineering T. Alley Duke Energy M. Robinson Duke Energy D. Lounsbury PSEG M. Bezilla PSEG J. Meister Exelon R. Brown TVA S. Traiforos SAT Consultants, Inc.
D. Schlader Framatome - ANP K. Moore Framatome - ANP E. Schoonover SCE R. Cohen Sitcap L. Connor Consultant F. Ammirato EPRI A. Wyche SERCH Licensing/Bechtel T. Satyansharma AEP D. Moody SAB P. Bryant NEI P. Campbell Winston & Strawn
G. Orrill Lehman Brothers D. Mattson Structural Integrity Associates (By phone)
A. Goyen Duke Energy (By phone)
J. Bostelman ITSC (By phone)
K. Scherich MRP (By phone)
M. Lashley STPNOC (By phone)
M. Wilken American Electric Power (By phone)
R. Schonenberg Dominion Connecticut (By phone)
Ken Karwoski described Bulletin 2002-01 by detailing the information required for the 15-day, 30-day and 60-day responses. The 15-day response is requiring information about the licensees reactor pressure vessel head inspections and any history of leakage of boric acid in the life of the plant, and the ability to identify degradation on the head. The 30-day response
requires information 30 days following the next outage during which the licensee performs a vessel head inspection. The 60-day response requires information about the effectiveness of the boric acid inspection program maintaining reactor coolant pressure boundary integrity.
Project No. 0689
Attachment:
As stated CONTACT Steven D. Bloom, NRR/EMCB 415-1313 DISTRIBUTION EMCB R/F WHBateman ADAMS/ACCESSION No.: ML020990054 OFFICE EMCB:DE:NRR SC:EMCB:DE:NRR NAME SDBloom SMCoffin DATE 04/10/02 04/10/02 OFFICIAL RECORD COPY