ML20205K478
| ML20205K478 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/07/1999 |
| From: | De Agazio A NRC (Affiliation Not Assigned) |
| To: | NRC (Affiliation Not Assigned) |
| References | |
| TAC-MA3989, NUDOCS 9904130239 | |
| Download: ML20205K478 (9) | |
Text
o April 7, 1999
- '
- LICENSEE:
Tcnnissu V:lliy Authority FACILITY:
Browns Ferry, Unit 2
SUBJECT:
SUMMARY
OF MEETING WITH TENNESSEE VALLEY AUTHORITY -
MEETING OF FEBRUARY 4,1999 AND TELEPHONE DISCUSSION ON FEBRUARY 12,1999 (TAC NO. MA3989)
On February 4,1999, the U. S. Nuclear Regulatory Commission (NRC) saff met with the representatives of the Tennessee Valley Authority (TVA), the licensee for Browns Ferry
- Nuclear Plant, Units 1,2 and 3. The purpose of the meeting was to discuss TVA's submittal of the proposed risk-informed inservice inspection (RI-ISI) program for Browns Ferry Nuclear Plant, Unit 2 (BFN-2) piping and solicit NRC's preliminary comments on TVA's proposed program.- On February 12,1999, BFN Licensing Manager, Tim Abney, and the NRC staff (Syed Ali, Bob Hermann, Goutam Bagchi, Al DeAgazio, and Rich Barrett) had a follow-up telephone conversation to further. discuss the BFNP RI-ISI submittals This summary documents both the February 4,1999, meeting and the February 12,1999, telephone discussion.
~ provides a list of meeting attendees. Attachment 2 summarizes the discussion. is the licensee's handout.
original signed by:
Albert De Agazio, Senior Project Manager, Section 2 Project Directorate il Division of Licensing Project Management Office of Nuclear Reactor R6gulation Docket Nos. 50-260
Enclosures:
- 1. Attendance List
- 2. Meeting Summary,1/4/99
- 3. TVA Handouts
. m.tI hh3 N
4 cc: See next page.
DISTRIBUTION:
E-Mail Docket File:
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ADeAgazlo PFrederickson, Ril
' GBagchi BFN Reading WBateman TSullivan ACRS-MTschiltz (MDT)
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OGC BSheron SPeterson
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RBarrett LRaghavan l
MRubin To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure. "N" = No copy Docket Name: G:\\BFN\\MS990204.WPD OFFICE ' PDII 2/PM /]M//l E PDII 2/LA l
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DATE 04/ # /99 04/ I /99 04/ (0 /99 9904130239 990407 Nficial Record Copy PDR >ADOCK 05000260 P
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April 7, 1999 LICENSEE:
Tennessee Valley Authority FACILITY:
Browns Ferry, Unit 2
SUBJECT:
SUMMARY
OF MEETING WITH TENNESSEE VALLEY AUTHORITY -
MEETING OF FEBRUARY 4,1999 AND TE.a EPHONE DISCUSSION ON FEBRUARY 12,1999 (TAC NO. MA3989)
On February 4,1999, the U. S. Nuclear Regulatory Commission (NRC) staff met with the representatives of the Tennessee Valley Authority (TVA), the licensee for Browns Ferry Nuclear Plant, Units 1,2 and 3. The purpose of the meeting was to discuss TVA's submittal of the proposed risk informed inservice inspection (RI-ISI) program for Browns Ferry Nuclear Plant, Unit 2 (BFN-2) piping and solicit NRC's preliminary comments on TVA'a proposed program.
On February 12,1999, BFN Ucensing Manager, Tim Abney, and the NRC staff (Syed Ali, Bob Hermann, Goutam Bagchi, Al DeAgazio, and Rich Barrett) had a follow-up telephone conversation to further discuss the BFNP RI-ISI submittals.
This summary documents both the Februar,'4,1999, meeting and the February 12,1999, telephone discussion. provides a list of meeting attendees. Attachment 2 summarizes the discussion. is the licensee's handout.
Albert De Agazio, Senior Project Manager, Section 2 Project Directorate 11 Division of Licensing Project Managment Office of Nuclear Reactor Regulation Docket Nos. 50-260
Enclosures:
- 1. Attendance List
- 2. Meeting Summary,1/4/99
- 3. TVA Handouts cc w/encis: See next page I
r TG:nn:ss 3 Vcliey Authority CROWNS FERRY NUCLEAR PLANT
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cc:
Mr. J. A. Scalice Mr. Mark J. Burzynski, Managar Chief Nuclear Officer and Nuclear Licensing Executive Vice President Tennessee Valley Authority Tennessee Valley Authority 4X Blue Ridge 6A Lookout Place 1101 Market Street 1101 Market Street Chattar soga, TN 37402-2801 Chattanooga, Tennessee 37402-2801 Mr. Timothy E. Abney, Manager Senior Vice Pres! dent Licensing and Industry Affairs Nuclear Operations Browns Ferry Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000 1101 Market Street Decatur, AL 35609 Chattanooga, TN 37402-2801 Senior Resident inspector Mr. Jack A. Bailey, Vice President U.S. Nuclear Regulatory Commission Engineering & Technica! Services Browns Ferry Nuclear Plant Tennessee Valley Authority 10833 Shaw Road 6A Lookout Place Athens, AL 35611 1101 Market Street Chattanooga, TN 37402-2801 State Health Officer Alabama Dept. of Public Health Mr. Karl W. Singer, Site Vice President 434 Monroe Street Browns Ferry Nuclear Plant Montgomery, AL 36130-1701 Tennessee Valley Authority P.O. Box 2000 Chairman Decatur, AL 35609 Limestone County Commission 310 West Washington Street General Counsel Athens, AL 35611 Tennessee Valley Authority ET 10H 400 West Summit Hill Drive Knoxville, TN 37902 Mr. Raul R. Baron, General Manager Nuclear Assurance Tennessee Valley Authority
- SM Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 Mr. Robert G. Jones, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 l
I LIST OF ATTENDEES i
.t MEETING WITH REPRESENTATIVES OF TENNESSEE VALLEY AUTHORITY ROCKVILLE. MARYLAND Februarv 4.1999 Name Oraanization L. Raghavan NRR Mark Rubin NRR 1
Dick Wessman NRR Rich Barrett NRR Stephen Dinsmore NRR Bill Bateman NRR Goutam Bagchi NRR Ted Sullivan NRR Bob Hermann NRR Syed Ali NRR George Georgiev NRR Patrick O'Regan EPRI David O. Harris Enertech Robin Graybeal Enertech L.J. Victory, Jr.
Enertech J.D. White Curtis-wright Henry Jones TVA John Lee Sparks TVA Tim Abney TVA
q FEBRUARY 4.1999. MEETING DISCUSSION Tennessee Valley Authority (TVA) introduced the proposed Browns Ferry Nuclear Plant (BFN-2) risk-informed inservice inspection (RI-ISI) program and presented an overview cf the submittal contents, methodology, key elements, and results summary. The foilowing is e summary of the discussions:
1.
The M*tC staff stated that parts of the (TVA) submittal do not comply with the Westinghouse Owners Group Topical Report, WCAP-14572, (here-in-after referred to as the WCAP) methodology. The submittalidentifies several differences, but does net systematically identify all the major differences and provide discussions explaining why the difference should be acceptable. Two major differences in the supporting probabilistic risk analysis (PRA) not discussed in the submittal are: (1) the lack of large early release frequency (LERF) based safety significance classification (WCAP, page 104), and (2) the lack of system and plant level change in core damage frequency and LEFsF estimates that form the basis for the results evaluation criterion in the WCAP methodology (WCAP, page 207). Also, due to the timing of the BFN 2 submittal, TVA has not addressed changes to be incorporated into the next revision of the WCAP and the staff's safety evaluation report (SER) on the WCAP methodology issued in December 1998. For example, as stated in the WCAP SER, the staff found that the uncertainty analysis presented as a generic sensitivity study in the WCAP, Revision 1 (WCAP, page 123) should be routinely applied as part of the methodology.
2.
The U. S. Nuclear Regulatory Commission (NRC) staff commented that the RI ISI work on the development of Regulatory Guides, Standard Review Plan, and pilot plants has been proceeding with the understanding that augmented programs are outside the scope of RI-ISI. The BFN-2 proposed RI-ISI program affects the current American Society of Mechanical Engineers (ASME) Code Section XI as well as the augmented ISI program for intergrannular stress corrosion cracking (IGSCC). The iicensee stated that the BFN-2 proposed RI-ISI program is based on the WCAP, Revision 1. The staff noted that the WCAP states that the augmented ISI programs for IGSCC will not be impacted under the WCAP methodology, The staff's SER for WCAP, Revision 1, also states that the augmented ISI programs, such as those for IGSCC, will not be changed under the RI-ISI programs.
3.
The staff stated that traditional engineering evaluations should play a major role in establishing the regulatory position in the risk informed approach to change the augmented inspection programs for active degradation mechanisms, such as IGSCC.
4.
The ctaff informed TVA of its recent initiatives with the boiling water reactor owners group vesselintegrity program (BWR-VIP) regarding developing an approach to reduce the scope of the Generic Letter (GL) 88-01 IGSCC augmented inspections. The staff suggested that TVA may wish to consider changing its IGSCC inspection program in conjunction with the BWR Owners Group initiatives :ather than under the RI-ISI program changes.
5.
The staff stated that the pc-PRAISE Code has been exclusively used for the piping segment failure probabilities in the BFN-2 RI-ISI analysis. Validation and verification of the pc-PRAISE Code, including a clear understanding of the use of the failure criteria would be necessary before these estimates can be used for risk asststo ent.
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- 6.
TVA stated that they are planning an RI !Si submittal for BFN-3 in a few months.
The differences between the BFN-2 methodology (both the PRA analysis and the inclusion of IGSCC and the methodology approved during the Surry pilot and WCAP topical reviews are substantial. Although some variation between specific applications is expected, the analyses discussed in item 4 above were the result of much staff and industry interaction during the WCAP and Surry reviews, and determined by the staff to be necessary. BFN-2 should include these evaluations in its process. BFN 2 should also carefully review the Surry and WCAP SERs and be prepared to provide discussion if other parts of the acceptable mediodology are not part of BFN-2's analysis.
The staff requested TVA to reassess its approach to develop an acceptable RI-ISI program, _
e.g., a separate ASME Code Section XI dedicated submittal or a restructured, combined Section XI and augmented program pilot activity endorsed by tne BWR Owners Group. The staff will hold its further review of the submittal pending TVA's response.
FEBRUARY 12.1999 TELEPHONE DISCUSSION On February 12,1999, TVA licensing representative Tim Abney and NRC staff (Syed Ali, Bob Hermann, Goutam Bagchi, Al DeAgazio, Rich Barrett) had a follow-up telephone conversation to further discuss the BFNP RI-ISI submittals for Units 1 and 2 piping.
TVA indicated that it intends to re submit BFN-2 RI-ISI proposed program along witt 3FN-3 program in about 4 to 6 weeks. In these submittals. TVA will subdivide the RI-ISI program into two parts:
g.
GL 88-01 Category A welds and ASME XI welds h.
GL 88-01 Category B to G welds TVA indicated that it would request the NRC to complete its review of the part (a) program above by the end of the year 1999.
TVA also stated that it has contacted BWR Owners Group in order to pursue spor.sorship of a TVA Pilot / Topical Report on ISI programs that addresses risk-informed augmented inspection that is done typically for IGSCC. TVA requested that the NRC staff consider the pilot status categorization for the BFN Rl-ISI program.
The NRC staff sta'.ed that it will issue the February 4,1999 meeting summary summarizing the results of the staff acceptance review for the BFN-2 RI-ISI submittal.
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l! 1 BROWNS FERRY l
RISK INFORMED INSERVICE PROGRAM l
(Submittal Discussion)
TOPICS Browns Ferry submittal contents.
Methodology of preparation Key Elements Results Summary SUBMITTAL CONTENTS Addresses thefour Principal Elements ofRegulatory Guide 1.174 Submits the proposed risk informed program, addresses the regulations, describes the content of the submittal, and requests NRC approval.
Defines the actual proposal, including summary, applicability (unit and compon+nts),
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requirements from which reliefis requested, basis for relief, alternative examinatic>ns, and justification for the granting of relief. Includes a discussion of PSA Quality Defense-in-Depth Safety Margins Change in Risk Performance Monitoring 7
Includes the proposed program,2-SI-4.6.G, with the proposed changes highlighted.
Appendix A contains a description of the analysis methodology, analysis results, and l
provides the data for each individual system.
Contains the Regulatcry Guide 1.178 documentation summary table cross-referenced to submittallocation.
' Centains a summary of the proposed changes to the current BFN ISI program l
lhelosure 3 9
s METHODOLOGY Probabilistic and deterministic engineering analysis performed and integrated through the use of an Expert Fanel.
Reviewed NRC guidance concerning use ofrisk informed methodology and piping failure probabilities. Regulatory Guide 1.174,1.178. Reviewed Westinghouse Owners riroup Topical Report, WCAP-14572.
Defined piping system scope to include ASME Section XI Class 1,2 or 3, systems modeled in the PSA, safety significant systems defined by Maintenance Rule, 10CFR50.65.
Analysis performed in accordance with ASME Code Case N-577 Weld Failure rates calculated using PRAISE computer code.
Consequences quantified through the plant PRA.
Expert Panel included operational interface review.
- Simulator used to verify plant response to piping failure.
Expert Panel added segments for defense-in-depth including all segments with Risk Reduction Worth greater than 1.000 and large break LOCA segments.
Welds were selected for inspection based on the actual calculated risk for each individual weld. All welds with RRW greater than 1.000 were selected.
Specifically defined examination methods to address applicable degradation mechanisms such as IGSCC.
Defined inspection competency requirements for IGSCC in accordance with NUREG.,
0313.
Constructed a revision to existing Surveillance Instruction 2-SI-4.6.G in accordance with Position 3 of Regulatory Guide 1.178.
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t KEY ELEMENTS Relief requested for AShE Section XI in accordance with 10CFR50.55a.
1 Alternate IGSCC Program subtritted as allowed by GL 88-01. Other augmented programs are unaffected.
Different than the Surry submittal in the following ways:
- Failure rates were calculated for each weld in a segment Failure rate was calculated with PRAISE vs SRRA
- Welds were selected fer inspection based on calculated risk for each weld. No statistical sampling was used.
Utilized the latest version of PRAISE in program development.
Researched maintenance and corrective action program databases for failure history.
Researched inspection history and used actual Browns Ferry data including existing flaw sizes as PRAISE input.
PSA has been evaluated by BWROG Peer Review Process and determined adequate to support a risk-ranking application.
RESULTS
SUMMARY
Improves safety with targeted inspections and selective inspection techniques.
l Reduces cost and exposure. Estimates are $2.7 million and 84 REM for one unit per 10 year interval.
Meets the intent of Risk Informed Regulation.
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