ML021630270
| ML021630270 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/11/2002 |
| From: | Woods H Office of Nuclear Regulatory Research |
| To: | |
| References | |
| Download: ML021630270 (17) | |
Text
June 11, 2002 LICENSEE: FirstEnergy Nuclear Operating Company (FENOC)
FACILITY: Beaver Valley Power Station (BVPS), Unit 1
SUBJECT:
SUMMARY
OF MAY 14, 2002, PUBLIC MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY (FENOC) AND THEIR CONSULTANTS REGARDING ON-GOING PRESSURIZED THERMAL SHOCK (PTS)
RULEMAKING EFFORT
Background
The Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research (NRC Research), staff is currently conducting an analysis of the risk due to PTS at U.S. Pressurized Water Reactors (PWRs).
The results will be used as part of the bases for a subsequent evaluation (and possible change) of the PTS rule, Title 10 of the Code of Federal Regulations, Section 50.61. BVPS Unit 1 is one of four PWRs that have volunteered to be evaluated as part of the analysis.
Discussion On May 14, 2002, members of the NRC Research staff met in a public meeting at the BVPS in Shippingport, Pennsylvania, with representatives of FENOC, Westinghouse Electric Co. (W),
Sandia National Laboratories (SNL), Science Applications International Corp. (SAIC), and Information Systems Laboratory (ISL), to discuss preliminary results of the NRC Research staffs analysis of the risk at BVPS Unit 1 due to hypothetical PTS events. Enclosure 1 is the agenda and Enclosure 2 is the list of attendees.
The meeting started with an NRC Research staff presentation of the overall organization of the joint NRC Research & Industry PTS risk analysis effort, showing how the Probabilistic Risk Analysis (PRA), Human Reliability Analysis (HRA), Thermal Hydraulic (TH), and Probabilistic Fracture Mechanics portions of the analysis will be utilized, along with their associated uncertainty analyses, to produce the final PTS-related risk for each of the four plants included in the study (Oconee, Beaver Valley, Palisades, and Calvert Cliffs).
The NRC Research staff presentation also discussed the major objectives of the meeting, which were to present draft results of the preliminary BVPS Unit 1 PRA, HRA, and TH analyses, and obtain the FENOC staffs comments and suggestions. The presentation indicated that the preliminary analyses were performed in a somewhat conservative way, which would CONTACT: H. Woods, RES 301-415-6622
FirstEnergy Nuclear Operating Company nevertheless be able to identify the PTS-risk-significant areas and thus allow subsequent efforts to concentrate on making the PRA analysis of those areas more realistic. This process saves the expenditure of scarce resources in areas that do not contribute significantly to PTS risk. is the NRCs and NRC contractors slides used during this discussion.
Next, the principal PRA/HRA contractors (from SNL and SAIC) discussed the preliminary results, stressing areas identified by the analyses that contribute significant PTS risk, and inviting comments from the FENOC and W staffs, particularly about ways those parts of the analyses might be made more complete and realistic.
In discussions that followed, the FENOC staff expressed general agreement with the models and techniques used by the staff and their contractors in the analyses. However, in keeping with the primary purpose of the meeting (i.e., to discuss ways the analysis results might be made more complete and realistic) the FENOC staff offered the following preliminary comments:
- 1) During feed and bleed, only two high-head safety injection (HHSI) pumps can operate. A third (standby) pump cannot be loaded to a bus with an operating HHSI pump. TH calculations should be examined to ensure that only two pumps are operating.
- 2) The following scenario should be considered: the steam dump valve down stream of the main steam isolation valves (MSIVs) opens resulting in cool down and depressurization of the primary reactor coolant system. HHSI starts. MSIVs close, but HHSI continues to run resulting in repressurization. Repressurization causes a pressurizer safety relief valve (SRV) to open.
The SRV sticks open.
- 3) For loss of feedwater sequences, both the dedicated auxiliary feedwater (AFW) pump and the condensate booster pumps should be included in the model. Procedures applicable to each sequence (e.g., RT1-2 sequence #9) should be used to determine which pump should be used first.
- 4) On loss of red or white 120 VAC bus, only one HHSI pump is available. Determine if this is modeled correctly in the PRA and TH calculations (the same issue applies to loss of 125 VDC buses).
- 5) Determine whether the loss of a 4 kV/480 VAC bus initiator should be added to the model.
If so, only one HHSI pump would be left.
- 6) For AFW, on loss of blue or yellow 120 VAC bus, only partial flow is available to steam generators. Determine if effects of this need to be included in the models.
These comments will be considered by the NRC staff and their contractors, along with any additional comments received from the FENOC or W staffs after their further review.
Summary, Action Items, and Agreements The FENOC staff volunteered to provide additional, more detailed comments in writing to the NRC Research staff during June 2002, providing justifications for any modifications they might
FirstEnergy Nuclear Operating Company request to the analysis. The NRC Research staff and its contractors will review any requested changes, and will modify their analyses to reflect any changes they find to be acceptable.
This meeting was not an inspection. Instead, it was an information exchange meeting with a licensee who has volunteered to cooperate with NRC Researchs PTS evaluation effort. As such, no open items were identified that require future actions or NRC approvals. No requests or agreements resulting from the meeting are required to be met, nor are they enforceable in any way.
The NRC Research staff appreciates the cooperation and suggestions that were made by the FENOC staff. NRC Research understands that it is very much dependent upon such voluntary cooperation to obtain the information and feedback needed to reach the joint NRC and nuclear industry goal of achieving a PTS analysis of BVPS as it is actually built and operated. We look forward to continued interactions with FENOC so that we can achieve that mutually desired goal.
Hugh W. Woods, Senior Task Manager Probabilistic Risk Analysis Branch Division of Risk Analysis and Applications Office of Nuclear Regulatory Research Docket No. 50-334
Enclosures:
- 1. Agenda
- 2. List of Attendees
- 3. NRC's and NRC contractors' slides used at the meeting cc w/encls: See next page HWoods SNewberry DBessette MCunningham TBergman, EDO RI ACRS SRichards RLaufer DCollins MOBrien JRogge, RI RConte, RI DScrenci, OPA RI DKern, RI DMcCain NSiu, RES BPlatchek, RI PUBLIC PDI-1 RF OGC JZwolinski/TMarsh DOCUMENT NAME:g:\pts\2ndMtgMins.wpd OAR in ADAMS? (Y or N) Y ADAMS ACCESSION NO.: TEMPLATE NO. RES-Publicly Available? (Y or N) Y DATE OF RELEASE TO PUBLIC SENSITIVE? N To receive a copy of this document, indicate in the box: "C" = Copy without enclosures "E" = Copy with enclosures "N" = No copy OFFICE DRAA/PRAB DRAA/PRAB DRAA NRR/PM/ NRR/SC/
PDI-1 PDI-1 NAME H. Woods* M. Cunningham* S. Newberry* D. Collins* R. Laufer*
DATE 05/22/02 05/23/02 05/27/02 06/11/02 06/11/02 (RES File Code) RES -2C-1A2
- See previous concurrence
Mary OReilly, Attorney Bureau of Radiation Protection FirstEnergy Nuclear Operating Company ATTN: Larry Ryan FirstEnergy Corporation P O Box 2063 76 South Main Street Harrisburg, PA 17120 Akron, OH 44308 Mayor of the Borough of FirstEnergy Nuclear Operating Company Shippingport Regulatory Affairs/Corrective Action Section P O Box 3 Larry R. Freeland, Manager Shippingport, PA 15077 Beaver Valley Power Station Post Office Box 4, BV-A Regional Administrator, Region I Shippingport, PA 15077 U.S. Nuclear Regulatory Commission 475 Allendale Road Commissioner James R. Lewis King of Prussia, PA 19406 West Virginia Division of Labor 749-B, Building No. 6 Resident Inspector Capitol Complex U.S. Nuclear Regulatory Commission Charleston, WV 25305 Post Office Box 298 Shippingport, PA 15077 Director, Utilities Department Public Utilities Commission FirstEnergy Nuclear Operating Company 180 East Broad Street Beaver Valley Power Station Columbus, OH 43266-0573 ATTN: M. P. Pearson, Director Services and Projects (BV-IPAB)
Director, Pennsylvania Emergency Post Office Box 4 Management Agency Shippingport, PA 15077 2605 Interstate Dr.
Harrisburg, PA 17110-9364 FirstEnergy Nuclear Operating Company Beaver Valley Power Station Ohio EPA-DERR Mr. B. F. Sepelak ATTN: Zack A. Clayton Post Office Box 4, BV-A Post Office Box 1049 Shippingport, PA 15077 Columbus, OH 43266-0149 Mr. Mark B. Bezilla Dr. Judith Johnsrud Senior Vice President National Energy Committee FirstEnergy Nuclear Operating Company Sierra Club Beaver Valley Power Station 433 Orlando Avenue Post Office Box 4 State College, PA 16803 Shippingport, PA 15077 L. W. Pearce, Plant Manager (BV-IPAB)
FirstEnergy Nuclear Operating Company Beaver Valley Power Station Post Office Box 4 Shippingport, PA 15077
AGENDA MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY (FENOC)
AND THEIR CONSULTANTS REGARDING ON-GOING PRESSURIZED THERMAL SHOCK (PTS) RULEMAKING EFFORT May 14, 2002 - 9:00 - 4:00 PM 9:00-9:30 Introduction/Overview H. (Roy) Woods (NRC)
Introduction of Attendees (NRC and FENOC)
Purpose/Goals of Meeting Status/Schedule of PTS Program 9:30-11:00 Presentation of Probabilistic Risk Donnie Whitehead (SNL)
Analysis Approach and Preliminary Results Alan Kolaczkowski (SAIC) 11:00-12:00 Discussion All (NRC and FENOC) 12:00-1:00 Lunch 1:00-3:30 Continuation of Discussion All (NRC and FENOC) 3:30-4:00 Summary (Action Items, Commitments) All (NRC and FENOC)
Enclosure 1
LIST OF ATTENDEES MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY (FENOC)
AND THEIR CONSULTANTS REGARDING ON-GOING PRESSURIZED THERMAL SHOCK (PTS) RULEMAKING EFFORT MAY 14, 2002 NAME ORGANIZATION David Bessette NRC/RESEARCH Hugh (Roy) Woods NRC/RESEARCH Alan Kolaczkowski Science Applications International Corp. (SAIC)
Donnie Whitehead Sandia National Laboratories Robert Beaton Information Systems Laboratory Dennis Weakland FENOC Chris Hynes FENOC Ken Frederick FENOC Bill Etzel FENOC Bruce Bishop Westinghouse Electric Corp.
Eric Frantz Westinghouse Electric Corp.
Barry Sloane Westinghouse Electric Corp.
Enclosure 2
SLIDES USED AT THE MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY (FENOC) AND THEIR CONSULTANTS REGARDING ON-GOING PRESSURIZED THERMAL SHOCK (PTS) RULEMAKING EFFORT Enclosure 3
PRA/HRA & TH for PTS Rule Revision Roy Woods Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Presented to FirstEnergy Nuclear Operating Co. (FENOC) at Beaver Valley Power Station (BVPS)
May 14, 2002
Development of Technical Basis to Revise PTS Rule 10 CFR 50.61 FirstEnergy Nuclear Operating Company Use Public Meetings to Identify Use Public Meetings to Identify Areas in 10CFR 50.61 that need Open Technical Questions in:
Re-assessment (RG 1.99 Rev.) --Identify and Bin PTS Events (PRA)
--Embrittlement Correlations --Thermal Hydraulics
--Margin Terms, etc. --Probabilistic Fracture Mechanics
--Overall Uncertainty Analysis Staff Develops Proposed Changes Collect Information, Develop Methods, To 50.61 Areas. Potentially Use Do Specific Analyses, Involve Public, to
--Fully Participatory Rule Making with --Resolve Open Questions Public Involvement --Involve PRA in All Aspects Identify & Bin Events (PRA) Thermal Hydraulics Probabilistic Fracture Mechanics Re-assess PTS Risk Acceptance
--Use IPTS 3-plant study --Use expert panel and --Revise Flaw Distributions Criterion
--Update plant-specific PRAs, --Limited TH analyses to estimate --Revise Embrittlement Correlations --Base on Risk Informed Guidance if available (1) Effect of TH improvements --Revise Fracture Toughness Models --Consider LERF, Effect on Containment
--Update Events Frequencies (2) Uncertainty bounds in TH results --Material Property Variability --Develop Commission Papers (INPO, plant info, etc.) --Develop Up-to-date Fluence Maps, etc.
Public Meetings to Resolve Public Meetings to Gain Understanding on Outstanding Issues Developed Methods and Input Parameters PROPOSE TECHNICAL BASIS FOR Calculate Vessel Fracture Frequency Re-evaluate PTS Screening
--Mean Value and Variance Criterion REVISION TO 10 CFR 50.61 --Sensitivity & Uncertainty Analyses --Use Vessel Fracture Frequency
--Specific Regulatory Approach --Evaluate IPTS and Other Plants --PTS Risk Acceptance Criterion
--Risk Informed --Evaluate SECY 82-465 Analyses --Generic Sensitivity Analyses Results
--Can it be Performance Based? --Evaluate Effect on Containment PRA/HRA Objective Support development of technical basis for revised rule
Ensure overall process is coherent, risk-informed 6 Appropriate integration of T/H, PFM, and PRA/HRA 6 Consistent treatment of uncertainties 6
Support development of screening criteria 6 Derivation of embrittlement criteria from risk figures of merit 6 Criteria for risk figures of merit 6
Update old PTS/PRA studies 6 Reflect changes to study plants 6 Reflect changes to PRA state of the art, knowledge base 6 Update HRA 6 Address other plants Expectation: PFM provides most of the margin Overall Analysis Framework Overall PTS/PRA/HRA Analysis Approach
Estimate PTS-induced through-wall crack frequencies (TWCFs) for 4 plants, including uncertainties 6 Develop PTS/PRA/HRA models for Oconee and Beaver Valley 6 Review PTS/PRA/HRAs for Calvert Cliffs and Palisades 6 Resolve inconsistencies, generalize results to population
Develop TWCF vs. RTPTS relationship, e.g.,
PTS/PRA/HRA Analysis Status
Oconee
Kickoff meeting: March, 2000
Initial PRA/HRA & TH results: December, 2000
Review meeting at Duke Energy: January, 2001
Model revised, preliminary TWCF: Dec., 2001
Final TWCF: late May, 2002
Beaver Valley
Kickoff meeting: July, 2000
Initial PRA/HRA & TH results: April, 2002
Review meeting at FENOC: May 14, 2002
TWCF results: June, 2002
Palisades
Kickoff meeting: March, 2001
HRA Quant. meeting Nov., 2001
Initial PRA/HRA & TH results: April, 2002
TWCF results: June or July, 2002
Calvert Cliffs
Early meeting August, 2001
Kickoff meeting June 5-7, 2002
Initial results: TBD
TWCF: TBD Meeting Objectives
Present draft results of PTS PRA/HRA and TH analysis for Oconee
Obtain feedback on analysis results Include in the package so they are an official part of these Public Meeting Minutes the slides in the two .pdf files as follows (they're on the G drive).
2ndMtgSldsRB.pdf 2ndMtgSldsAK&DW.pdf Hardcopies of these two files follow. However, I do not want the hardcopies to be scanned - I want the .pdf files to be part of the package that's available on ADAMS with the preceeding file.
PLEASE DELETE THIS PAGE FROM THE PACKAGE - ITS A NOTE TO PATTY OR DANIELLE