ML062840672
| ML062840672 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 10/11/2006 |
| From: | Crouch W Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC8795 | |
| Download: ML062840672 (35) | |
Text
October 11, 2006 10 CFR 50.55a U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop: OWFN P1-35 Washington, D.C. 20555-0001 Gentlemen:
In the Matter of ) Docket No. 50-296 Tennessee Valley Authority )
BROWNS FERRY NUCLEAR PLANT (BFN) - UNIT 3 - AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) SECTION XI, INSERVICE INSPECTION PROGRAM FOR THE THIRD TEN-YEAR INSPECTION INTERVAL - REQUEST FOR RELIEF 3-ISI-21, RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI) (TAC NO. MC8795)
TVA submitted, by letter dated October 19, 2005, its Third Ten-Year Inservice Inspection (ISI) and System Pressure Test (SPT) Programs for Unit 3 of the Browns Ferry Nuclear Plant.
The Code of record for the Third Ten-Year Interval ISI and SPT Programs is the 2001 Edition, 2003 Addenda of the ASME Boiler and Pressure Vessel Code,Section XI. The Third Ten-Year Interval began on November 19, 2005.
During its review of the BFN Unit 3 Third Ten-Year Interval Inservice Inspection Interval Program, the NRC staff identified questions, by letter dated September 15, 2006, regarding BFN Unit 3 request for relief 3-ISI-21. Request for relief 3-ISI-21 addresses TVAs proposed risk informed inservice inspection (RI-ISI) program. As a result, TVA is providing responses to the NRC questions in Enclosure 1 to this letter.
U.S. Nuclear Regulatory Commission Page 2 October 11, 2006 contains lists the commitment contained in this submittal. If you have any questions, please contact me at (256) 729-2636.
Sincerely, Original signed by:
William D. Crouch Manager of Licensing and Industry Affairs Enclosure cc: See Page 3
U.S. Nuclear Regulatory Commission Page 3 October 11, 2006 Enclosures cc (Enclosures):
Mr. Malcolm T. Widmann, Branch Chief U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611-6970 Ms. Eva A. Brown, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North (MS 08G9) 11555 Rockville Pike Rockville, Maryland 20852-2739 Ms. Margaret Chernoff, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North (MS 08G9) 11555 Rockville Pike Rockville, Maryland 20852-2739
U.S. Nuclear Regulatory Commission Page 4 October 11, 2006 DTL:JWD:BAB Enclosures cc (Enclosures):
B. M. Aukland, POB 2C-BFN M. Bajestani, NAB, 1A-BFN A. S. Bhatnagar, LP 6A-C R. H. Bryan, BR 4X-C Samuel Flood, CMB 1B-BFN R. G. Jones, POB 2C-BFN G. V. Little, NAB 1D-BFN R. A. DeLong, SAB 1A-BFN B. J. OGrady, PAB 1E-BFN K. W. Singer, LP 6A-C P. D. Swafford, LP 6A-C E. J. Vigluicci, ET 11A-K NSRB Support, LP 5M-C (w/enclosures)
EDMS, WT CA-K (w/enclosures) s:\licensing\submit\subs\U3 ASME ISI 3rd Int 3-ISI-21 RAI Response.doc
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNIT 3 AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)
SECTION XI, INSERVICE INSPECTION (ISI) PROGRAM, THIRD TEN-YEAR INSPECTION INTERVAL REQUEST FOR RELIEF 3-ISI-21, RISK INFORMED INSERVICE INSPECTION (RI-ISI) PROGRAM RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
(SEE ATTACHED)
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNIT 3 AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)
SECTION XI, INSERVICE INSPECTION (ISI) PROGRAM, THIRD TEN-YEAR INSPECTION INTERVAL REQUEST FOR RELIEF 3-ISI-21, EXAMINATION AND TESTING OF SNUBBERS, RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
During its review of the BFN Unit 3 Third Interval Program, the NRC staff identified questions regarding request for relief 3-ISI-21. These questions were transmitted to TVA by NRC letter dated September 15, 2006. Listed below are the specific NRC requests and the corresponding TVA responses.
NRC Request 1 On page 31 and 32 of 193 of Relief Request (RR) 3-ISI-21 dated October 19, 2005, Section 7.0 Part (1) and (2) contains the following:
Note: Class 1 (Class 2) piping welds shall be in accordance with the RI-ISI [risk-informed inservice inspection] additional examination requirements of [American Society of Mechanical Engineers (ASME)] Code Case N-577, as outlined in Section 7.12 of this program.
Section 7.12.5.4.J. states: "An evaluation shall be performed to establish when those examinations are to be conducted." Use of an evaluation to determine when a second sample expansion is to be performed is inconsistent with regulations. If flaws or relevant conditions are identified, sample expansions are to occur during the current outage in accordance with IWB-2430(b).
The licensee needs to address the time frame in which sample expansions will be performed.
TVA Response to NRC Request 1 TVA will perform sample expansions during the current outage as required by IWB-2430(b). The BFN Unit 3 ISI Program (3-SI-4.6.G) will be revised to reflect this requirement.
E1-2
NRC Request 2 Of the items selected for RI-ISI listed in the table included in Attachment 1, state how many are socket welds. Provide a breakdown of the examination technique to be performed on the items selected for examination, include the frequency of examination.
TVA Response to NRC Request 2 None of the items selected for RI-ISI are socket welds; however, all socket welds receive, and will continue to receive, a VT-2 examination in conjunction with the system pressure test.
The examination technique on the items selected for examination, including the frequency of examination, is provided in Attachment A of this enclosure, Examination Technique and Frequency.
NRC Request 3 Page 61, Section 7.12.4, references Part 6 of Table R-A and 3-SI-4.6.G-A. These references are not provided. The licensee also lists ASME Code Case N-577 as part of the guidance used to develop its RI-ISI program. The staff has not endorsed the use of Code Case N-577. The licensee needs to provide the references or explain the licensees Risk-Informed Process.
The references or explanation needs to include how the program was developed, using what guidance, and explain any deviations from the referenced guidance.
TVA Response to NRC Request 3 The process used is the same as that outlined in TVAs original RI-ISI submittal transmitted by TVA letters dated April 23, October 25, and November 10, 1999, and January 18, 2000. TVAs RI-ISI program was approved by NRCs SER (TAC No. MA5355) transmitted by letter dated February 11, 2000. Attachment B of this enclosure provides an overview of the BFN Unit 3 RI-ISI process.
Code Case N-577 is listed in Regulatory Guide 1.193, ASME Code Cases Not Approved For Use, for the following reasons:
(1) The Code Case does not address inspection strategy for existing augmented and other inspection programs such as intergranular stress corrosion cracking (IGSCC),
E1-3
flow-assisted corrosion (FAC), microbiological corrosion (MIC), and pitting.
BFN Risk-Informed ISI Program: Each system is reviewed for degradation mechanisms. Items selected for examination with degradation mechanism under these augmented programs are examined in accordance with the program as stated in Code Case 577. The other examinations of these programs are not affected by the Risk-Informed ISI Program and are still performed in accordance with that augmented program with the exception of Category A IGSSC welds which are selected in accordance with the Risk-Informed ISI Program. BFN views Risk-Informed examinations selected in augmented programs as dual credit as they are satisfying two different programs.
(2) The Code Case does not provide system-level guidelines for change in risk evaluation to ensure that the risk from individual system failures will be kept small and dominant risk contributors will not be created.
The BFN Risk-Informed ISI Program, SPP-9.3, Plant Modifications and Engineering Change Control, requires design changes to be reviewed for Risk-Informed ISI effects and impacts during the design preparation phase.
In addition, BFN evaluates dominate contributors to risk through the sensitivity studies to ensure systems/segments are not masked by the large risk contributors.
As a result, the BFN Unit 3 Risk-Informed ISI Program addresses NRC concerns with regard to Code Case N-577 and utilizing it as stated as a guide is acceptable. The BFN Unit 3 third ten-year interval RI-ISI Program is consistent with the discussion noted in the NRC February 11, 2000, SER for the BFN Unit 3 RI-ISI program for the second ten-year interval.
NRC Request 4 Page 64 addresses the Corrective Action Program. The licensee states that "For Code Piping categorized as High Safety Significance (HSS) the corrective action shall be consistent with the provision of ASME Code Section XI." Describe what corrective action measures will be used for Low Safety Significant (LSS) Code piping.
E1-4
TVA Response to NRC Request 4 The corrective actions used for Low Safety Significance (LSS)
Code piping are consistent with the provisions of ASME Code Section XI, Subarticles IWB-3142, and IWC-3132.
NRC Request 5 Define the smallest diameter pipe included in the scope of the RI-ISI program for Class 1 and 2 piping. Specify whether the scope included all Class 1 and 2 piping or if there was a defined minimum diameter. Provide justification for the defined scope.
TVA Response to NRC Request 5 The BFN Unit 3 RI-ISI Program scope includes all Class 1 and 2 piping. There is no defined minimum pipe diameter.
NRC Request 6 to RR 3-ISI-1 indicates that the number of inspections was reduced from 100 in the second interval to 71 proposed for the third interval. Notable are reductions in examinations of Category A intergranular stress-corrosion cracking (IGSCC) susceptible piping associated with the reactor recirculation, reactor water cleanup, and core spray systems, as well as of Category C IGSCC-susceptible piping associated with the core spray system.
Tennessee Valley Authority (TVA) states on page 190 that deletions from the previous program are entirely attributable to lower failure rates due to the implementation of the hydrogen water chemistry/noble metal injection program, with the corresponding impact on IGSCC.
Provide a description of TVAs methodology and an explanation of how the estimated reduction in the failure rates propagated through the methodology result in the significant reduction in the number of inspections for the third 10-year interval. The explanation should address the following specific questions the staff has developed based on the information provided in the submittal.
A. Explain precisely how TVA was able to justify the deletion of each of the discontinued inspections in your proposed RI-ISI program for the third interval. For those welds in segments re-categorized from HSS to LSS, data for both the previous program and the proposed program, similar to that E1-5
provided in Enclosure 2 of TVAs response to Requests for Additional Information dated January 18, 2000, is suggested. For deleted welds in segments still considered HSS, data in the format of Table 3.8-1 of TVAs original submittal is suggested. Also, please add to this table the previous and proposed failure rate, core damage frequency (CDF), and risk reduction worth RRW data for each of these welds. If certain welds, with a previous quantified failure rate now have a zero failure rate, provide documentation to demonstrate that the traditional ASME Section XI criteria are being met.
B. It was observed that, despite the net reduction of proposed inspections, there were a few added inspections (e.g., two new intergranular stress-corrosion cracking Category C locations in the reactor recirculation system).
Explain the reason for these additions.
TVA Response to NRC Request 6 A. For the BFN RI-ISI Program revision, the entire process was repeated with the new failure rates resulting from the implementation of the hydrogen water chemistry/noble metal injection program, with a new total CDF and LERF due to piping failure calculated, and new risk reduction worth (RRW) values calculated for each segment.
In the original process, the BFN Expert Panel decided that, in addition to segments with RRW >1.005 being considered HSS, any segment with RRW > 1.001, and any segment whose failure could result in a large LOCA, would also be considered HSS. Due to this decision, the segments that were no longer HSS due to the decreased failure rates were still considered HSS due to the additional criteria. The new process also designated two additional segments HSS due to a higher LERF RRW when compared to the new lower total LERF. The results of the new analysis are compared to the results of the original analysis in the Attachment C of this enclosure Segment Significance Comparison.
The failure rates for each weld were then combined with the Conditional Core Damage Probability (CCDP) and Conditional Large Early Release Probability (CLERP) of their respective segments to calculate RRW for each weld.
Any weld with RRW > 1.001 was selected for examination.
This is presented in Attachment D of this enclosure Element Selection (Quantified RRW).
E1-6
In most cases for segments influenced by the hydrogen water chemistry/noble metal injection program, the failure rates went to zero and the segments were no longer HSS based on RRW. These segments were however designated HSS based on the expanded criteria. The welds in these segments were subject to ASME Section XI criteria (i.e.,
25 percent of the total population, with no less than one examination per segment). These segments had a total population of 84 welds, and 21 were selected for examination. This is presented in Attachment E Element Selection (Zero Failure Rate). A portion of the decrease in weld examinations is due to the reduction in welds selected by RRW compared to those selected by this method.
Another portion resulted from reduced RRW for Category A welds in segments determined to be HSS based on RRW from other welds in the segment.
B. Two additional IGSCC Category C welds were selected for examination due to the RRW process. These Category C welds were not influenced by the hydrogen water chemistry/noble metal injection program, and retained their higher failure rates. As such, they had a higher RRW when compared to the revised total CDF. See segment 3-074-005 in Attachment D Element Selection (Quantified RRW).
NRC Request 7 A January 23-26, 2006 Nuclear Regulatory Commission (NRC) audit of the licensees probabilistic risk assessments (PRAs) noted significant changes to the PRA model that can impact CDF, large early release frequency (LERF), and, ultimately, risk reduction worth. Many of these changes are described in a report from ERIN Engineering and Research, Inc. (ERIN), August 2003 (provided to the staff during this audit) which covers Levels A and B Facts and Observations from the industry peer certification of the Browns Ferry Nuclear Plant, Unit 3 (BFN3)
PRA, as well as observations during a separate review by ERIN, identified as an evaluation of PER BFPER970822 R0.
Given the numerous changes to TVAs PRA, describe in more detail the process used to evaluate the impact of these changes on the current risk-ranking of the BFN3s pipe segments. As part of the description, indicate whether or not the conditional core damage probability (CCDPs) of the segments with the current PRA model were recalculated.
If TVA did perform a recalculation, provide the date, revision number, base CDF and LERF of the PRA model used for E1-7
redetermining CCDPs, CDFs, or conditional CDF of the pipe segments.
If TVA did not perform a recalculation, explain why the changes made to the PRA in connection with the Facts and Observations and PER item resolutions of August 2003, do not impact the risk-ranking of BFN3s pipe segments.
TVA Response to NRC Request 7 The current EPU based Unit 3 PRA model (U3060706) incorporated some of the significant changes similar to the Unit 1 Extended Power Uprate (EPU) model (U1060616), such as thermal-hydraulic analysis resulting in revised success criteria, elimination of CRD as a high pressure injection source, human reliability analysis resulting in revised human error probabilities, etc.
The Unit 3 EPU revision resulted in significant changes in the CDF and LERF values. The CDF changed from 1.91E-6 to 2.71E-6 and the LERF changed from 2.68E-7 to 3.78E-7. The current non-EPU calculation has not been revised for EPU conditions. However, the new model was reviewed for future impacts on the RI-ISI program. The conditional core damage probability (CCDPs) and RRWs were re-calculated. Preliminary results show minor changes in the High Safety Significance (HSS) segments. Several other segments changed from Low to Medium category. The changes in the segments significance due to EPU conditions will not be factored in the RI-ISI program until the implementation of EPU and subsequent inspection. This is consistent with NEI 04-05, Living Program Guidance to Maintain Risk-Informed Inservice Inspection Programs For Nuclear Plant Piping Systems, Section 4.2, Periodic Reviews, and BFNs implementing surveillance instruction 3-SI-4.6.G, Section 7.12.5, Living Program.
NRC Request 8 The above audit (Agencywide Documents Access and Management System Accession number ML060440588) assessed that the significant changes to the PRA model fit the definition of a PRA upgrade as defined in Section 2 of the ASME PRA standard.
The audit also identified a lack of peer review of this upgrade, which is contrary to the guidance in the ASME PRA standard. The audit also identified a lack of peer review of this upgrade, which is contrary to the guidance in the ASME PRA standard, Section 5.4, and reinforced by NRC Regulatory Guide 1.200 (page 1.200-49).
Since a peer review has not been conducted, provide the following information:
E1-8
A. A description of the review processes TVA employed in conjunction with the upgrades to the PRA models. Along with this, describe the level of expertise of the reviewers.
B. An evaluation of the impact of the non-EPU related modeling errors specifically noted in Section 3.8 of the audit report (also documented in the BFN3 Corrective Action Program as Problem Evaluation Report (PER) No.
96035) on the RI-ISI application. In other words, if these errors are corrected, what impact will this have on the relative importance of BFN3s pipe segments?
TVA Response to NRC Request 8 A. The audit in question was primarily intended for the Unit 1 EPU model. The Unit 1 model is currently being reviewed by industry and utility PRA experts using the ASME RA-S-2002 standard and other NEI and NRC guidance documents. Based on the peer review and their observations, appropriate changes will be made to the Unit 1 model. Any impacts on the Units 2 and 3 model will be addressed in accordance with the BFN corrective action program.
B. BFN PER 96035 documented an error that no Human Reliability Analysis (HRA) considerations were identified for Units 2 and 3 to reflect EPU conditions. Based on our review, significant aspects of the HRA in the Units 2 and 3 model were revised to address EPU conditions (e.g., operator timing of early actions, emergency depressurization, etc.).
As stated in TVAs response to NRC request number 7 above, the changes in segment significance due to EPU conditions will not be factored into the Unit 3 RI-ISI program until the implementation of EPU and subsequent inspections.
E1-9
ATTACHMENT A BFN UNIT 3 RISK INFORMED ISI PROGRAM REQUEST FOR RELIEF 3-ISI-21, RAI RESPONSE EXAMINATION TECHNIQUE AND FREQUENCY E1-10
BFN Unit 3, RI-ISI Program Examination Technique And Frequency Examinations Segment Plant ID Deg Mode Item # Exam Freq 3-001-002 DSAS-3-03 Stress R1.11 XI Vol Interval 3-001-036 FAC locations FAC R1.18 Note 1 Note 2 3-001-037 FAC locations FAC R1.18 Note 1 Note 2 3-001-038 FAC locations FAC R1.18 Note 1 Note 2 3-001-039 FAC locations FAC R1.18 Note 1 Note 2 3-001-046 DSMS-3-15 Stress R1.11 XI Vol Interval 3-003-006 FAC locations FAC R1.18 Note 1 Note 2 3-003-007 FAC locations FAC R1.18 Note 1 Note 2 3-003-008 GFW-3-02 Thermal R1.11 XI Vol Interval 3-003-009 GFW-3-19 Thermal R1.11 XI Vol Interval 3-003-009 FAC locations FAC R1.18 Note 1 Note 2 3-003-036 FAC locations FAC R1.18 Note 1 Note 2 3-003-037 FAC locations FAC R1.18 Note 1 Note 2 3-003-038 FAC locations FAC R1.18 Note 1 Note 2 3-003-039 FAC locations FAC R1.18 Note 1 Note 2 3-003-040 FAC locations FAC R1.18 Note 1 Note 2 3-003-041 FAC locations FAC R1.18 Note 1 Note 2 3-003-042 FAC locations FAC R1.18 Note 1 Note 2 3-003-043 FAC locations FAC R1.18 Note 1 Note 2 3-068-001 GR-3-53(OL) IGSCC-E R1.16 IGSCC Vol Interval 3-068-002 KR-3-02 IGSCC-C R1.16 IGSCC Vol Interval GR-3-03(OL) IGSCC-E R1.16 IGSCC Vol Interval 3-068-003 RWR-3-001-G019 IGSCC-A R1.16 IGSCC Vol Interval 3-068-004 RWR-3-001-G016 IGSCC-A R1.16 IGSCC Vol Interval 3-068-005 RWR-3-001-G006 IGSCC-A R1.16 IGSCC Vol Interval 3-068-006 RWR-3-001-G007 IGSCC-A R1.16 IGSCC Vol Interval 3-068-007 RWR-3-001-G012 IGSCC-A R1.16 IGSCC Vol Interval 3-068-008 RWR-3-001-G015 IGSCC-A R1.16 IGSCC Vol Interval 3-068-009 RWR-3-002-G023 IGSCC-A R1.16 IGSCC Vol Interval 3-068-010 RWR-3-002-G022 IGSCC-A R1.16 IGSCC Vol Interval 3-068-011 RWR-3-002-G007 IGSCC-A R1.16 IGSCC Vol Interval 3-068-012 RWR-3-002-G018 IGSCC-A R1.16 IGSCC Vol Interval 3-068-013 RWR-3-002-G003 IGSCC-A R1.16 IGSCC Vol Interval 3-068-014 KR-3-24 IGSCC-C R1.16 IGSCC Vol Interval GR-3-27(OL) IGSCC-E R1.16 IGSCC Vol Interval 3-068-015 RWR-3-002-G019 IGSCC-A R1.16 IGSCC Vol Interval E1-11
Segment Plant ID Deg Mode Item # Exam Freq 3-068-016 GR-3-63 IGSCC-E R1.16 IGSCC Vol 6 year GR-3-59(OL) IGSCC-E R1.16 IGSCC Vol Interval GR-3-60(OL) IGSCC-E R1.16 IGSCC Vol Interval GR-3-64(OL) IGSCC-E R1.16 IGSCC Vol Interval 3-069-001 RWCU-3-001-G026 IGSCC-A R1.16 IGSCC Vol Interval 3-069-003 RWCU-3-007-G004 Thermal R1.11 XI Vol Interval 3-071-011 TRCIC-3-061 Stress R1.11 XI Vol Interval 3-073-001 THPCI-3-073A Stress R1.11 XI Vol Interval 3-073-002 THPCI-3-107 Stress R1.11 XI Vol Interval THPCI-3-109 Stress R1.11 XI Vol Interval 3-074-005 DRHR-3-03B IGSCC-G R1.16 VT-2 Cycle DSRHR-3-01 IGSCC-C R1.16 IGSCC Vol Interval DRHR-3-04 IGSCC-C R1.16 IGSCC Vol Interval RHR-3-002-G003 Thermal R1.11 XI Vol Interval 3-074-007 DRHR-3-19 Thermal R1.11 XI Vol Interval DRHR-3-21 IGSCC-C R1.16 IGSCC Vol Interval DSRHR-3-08 IGSCC-C R1.16 IGSCC Vol Interval DSRHR-3-10 IGSCC-C R1.16 IGSCC Vol Interval DSRHR-3-11(OL) IGSCC-E R1.16 IGSCC Vol Alt cycle TRHR-3-191 IGSCC-C R1.16 IGSCC Vol Interval 3-074-009 TRHR-3-293 Stress R1.11 XI Vol Interval 3-074-010 DRHR-3-12 IGSCC-D R1.16 IGSCC Vol 6 year 3-074-013 DRHR-3-13B IGSCC-G R1.16 VT-2 Cycle DRHR-3-13 IGSCC-C R1.16 IGSCC Vol Interval DSRHR-3-05A IGSCC-C R1.16 IGSCC Vol Interval RHR-3-002-G001 Thermal R1.11 XI Vol Interval 3-074-027 TRHR-3-246 Stress R1.11 XI Vol Interval 3-074-029 TRHR-3-222 Stress R1.11 XI Vol Interval 3-074-031 TRHR-3-281 Stress R1.11 XI Vol Interval 3-075-001 DSCS-3-07 IGSCC-C R1.16 IGSCC Vol Interval DSCS-3-08 IGSCC-C R1.16 IGSCC Vol Interval DSCS-3-09 Thermal R1.11 XI Vol Interval 3-075-002 DCS-3-04 IGSCC-C R1.16 IGSCC Vol Interval DSCS-3-01 IGSCC-C R1.16 IGSCC Vol Interval DSCS-3-02 IGSCC-C R1.16 IGSCC Vol Interval Notes:
Note 1 Examination to be performed per FAC program.
Note 2 Examinations to be scheduled per the FAC program. This schedule is a function of previous exam results and predicted wear rate.
IGSCC Vol Volumetric examination per NUREG-0313 capable of detecting IGSCC. Competency requirements of NUREG-0313 are applicable.
XI Vol Volumetric examination per Section XI of the Boiler and Pressure Vessel Code as implemented by 2-SI-4.6.G.
Interval Examined once per ten-year interval per the requirements of Section XI and the requirements of VIP-075 for IGSCC Category A , C, and E overlay welds.
6 year Examined every six year per the requirements of VIP-075 for IGSCC Category D and E stress improved welds.
Cycle Examined every cycle per the requirements of VIP-075 for IGSCC Category G welds.
Examinations shall be scheduled such that the requirements of IWB-2412 of Section XI are satisfied.
E1-12
ATTACHMENT B BFN UNIT 3 RISK INFORMED ISI PROGRAM REQUEST FOR RELIEF 3-ISI-21, RAI RESPONSE Unit 3 RISK-INFORMED ISI PROCESS E1-13
BFN UNIT 3 RISK-INFORMED ISI PROCESS The processes used to develop the RI-ISI program are consistent with the methodology described in ASME Section XI, Code Case N-577 and WCAP-14572, Revision 1, as modified by the September 30, 1998, letter to the NRC from the Westinghouse Owners Group, with the deviations listed below. TVA addresses the NRC objections to Code Case N-577 in its response to NRC request number three in this enclosure.
The process that is being applied, involves the following steps:
- Scope Definition
- Segment Definition
- Consequence Evaluation
- Failure Assessment
- Risk Evaluation
- Expert Panel Categorization
- Element/NDE Selection
- Implement Program
- Feedback Loop Deviations from the process described in WCAP-14572 are as follows:
Calculation of Failure Rate WCAP-14572 uses the Westinghouse Structural Reliability and Risk Assessment Model (SRRA) to calculate failure rates. TVA uses WinPRAISE, a Microsoft Windows based version of the PRAISE code used as the benchmark for SRRA in WCAP-14572 Supplement 1.
Determination of Failure Rate for a Segment In the WCAP process, one or more points deemed most susceptible to a postulated failure mechanism were selected for each segment, and a failure rate calculated for that point or points. If more than one point was calculated, the worst result was used to determine segment risk. At TVA, failure rates were quantified for the individual elements in a segment, and the highest individual failure rate was used to determine segment risk.
Uncertainty Analysis In paragraph 3.6.1 of the WCAP reference is made to uncertainty analyses to address uncertainty in failure probabilities and consequence. As modified by the WOG letter of September 30, 1998, E1-14
it states that a simplified uncertainty analysis should also be performed to ensure that no low safety significant segments could move into the high safety significance category when reasonable variations are considered. As a practice, the TVA Expert Panel considered all segments in this significance range (1.005 > Risk Reduction Worth (RRW) > 1.001) to be High Safety Significant, in lieu of performing the sensitivity study.
Structural Element Selection In WCAP-14572, selection of elements in Region 2 of the Structural Element Selection Matrix shown in Figure 3.7-1 of the WCAP is determined by a statistical evaluation process.
According to paragraph 3.7.2 of the WCAP, this statistical model is used to ensure that an acceptable level of reliability is achieved. At TVA, two methods were used to select elements in Region 2. For those elements with a quantified failure rate, that failure rate was used to select the elements. For some elements, the calculated failure rate was zero. As stated in 3.7.5 of the WCAP (as modified by the WOG letter of September 30, 1998) additional rationale must be developed when a statistical model cannot be applied to determine the minimum number of examination locations for a given segment. Since a calculated failure probability is a necessary input to a statistical evaluation, an alternative which would provide assurance of an acceptable level of reliability was used. The existing examination requirements of Section XI have provided such an acceptable level; therefore, the existing Section XI criteria were used; i.e., 25% for Class 1 and 7.5% for Class 2.
E1-15
ATTACHMENT C BFN UNIT 3 RISK INFORMED ISI PROGRAM REQUEST FOR RELIEF 3-ISI-21, RAI RESPONSE SEGMENT SIGNIFICANCE COMPARISON E1-16
Segment Significance Comparison Segment Safety Significance Original Interval 3 Revision Segment CDF Segment LERF Safety Segment CDF Segment LERF Safety Segment Reason Reason CDF RRW LERF RRW Significance CDF RRW LERF RRW Significance 3-001- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
036 1.005 1.005 3-001- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
037 1.005 1.005 3-001- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
038 1.005 1.005 3-001- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
039 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
006 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
007 1.005 1.005 3-003- 1.02E-08 1.000 2.86E-09 1.000 LSS n/a 3.28E-09 1.001 1.92E-10 1.008 HSS LERF RRW >
009 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
036 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
037 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
038 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
039 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
040 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
041 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
042 1.005 1.005 3-003- 5.65E-08 1.005 1.58E-08 1.000 HSS CDF RRW > 2.95E-08 1.013 0.00E+00 1.000 HSS CDF RRW >
043 1.005 1.005 3-068- 2.80E-07 1.025 0.00E+00 1.000 HSS CDF RRW > 4.15E-09 1.002 0.00E+00 1.000 HSS Defense in Depth 001 1.005 CDF RRW >
1.001 3-068- 2.68E-08 1.002 3.08E-09 1.000 HSS Defense in 1.11E-10 1.000 7.42E-13 1.000 HSS Defense in Depth 002 Depth Large LOCA CDF RRW >
1.001 3-068- 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 003 Depth Large LOCA Large LOCA 3-068- 1.52E-08 1.001 4.25E-09 1.001 HSS Defense in 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 004 Depth Large LOCA CDF RRW >
1.001 E1-17
Original Interval 3 Revision Segment CDF Segment LERF Safety Segment CDF Segment LERF Safety Segment Reason Reason CDF RRW LERF RRW Significance CDF RRW LERF RRW Significance 3-068- 1.82E-07 1.016 5.09E-08 1.014 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 005 1.005 Large LOCA 3-068- 6.57E-07 1.060 1.84E-07 1.052 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 006 1.005 Large LOCA 3-068- 3.86E-07 1.034 1.08E-07 1.030 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 007 1.005 Large LOCA 3-068- 1.66E-07 1.015 4.64E-08 1.013 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 008 1.005 Large LOCA 3-068- 7.48E-09 1.000 2.09E-09 1.000 HSS Defense in 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 009 Depth Large LOCA Large LOCA 3-068- 1.54E-07 1.013 4.31E-08 1.012 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 010 1.005 Large LOCA 3-068- 5.66E-07 1.051 1.59E-07 1.044 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 011 1.005 Large LOCA 3-068- 4.59E-07 1.041 1.29E-07 1.036 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 012 1.005 Large LOCA 3-068- 4.03E-07 1.036 1.13E-07 1.031 HSS CDF RRW > 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 013 1.005 Large LOCA 3-068- 3.20E-09 1.000 8.95w-10 1.000 HSS Defense in 1.12E-10 1.000 7.58E-13 1.000 HSS Defense in Depth 014 Depth Large LOCA Large LOCA 3-068- 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in 0.00E+00 1.000 0.00E+00 1.000 HSS Defense in Depth 015 Depth Large LOCA Large LOCA 3-068- 2.83E-08 1.002 0.00E+00 1.000 HSS Defense in 1.44E-10 1.000 0.00E+00 1.000 HSS Defense in Depth 016 Depth CDF RRW >
CDF RRW > 1.001 1.001 3-069- 1.52E-06 1.151 4.25E-07 1.000 HSS CDF RRW > 2.34E-09 1.001 0.00E+00 1.000 HSS Defense in Depth 001 1.005 CDF RRW >
1.001 3-073- 2.82E-09 1.000 8.84E-12 1.000 HSS Defense in 7.56E-11 1.000 0.00E+00 1.000 HSS Defense in Depth 001 Depth Large LOCA Large LOCA E1-18
Original Interval 3 Revision Segment CDF Segment LERF Safety Segment CDF Segment LERF Safety Segment Reason Reason CDF RRW LERF RRW Significance CDF RRW LERF RRW Significance 3-074- 6.13E-08 1.005 1.72E-08 1.005 HSS CDF RRW > 1.14E-07 1.051 7.73E-10 1.032 HSS CDF RRW >
005 1.005 1.005 3-074- 1.17E-06 1.112 1.63E-07 1.046 HSS CDF RRW > 3.61E-07 1.182 0.00E+00 1.000 HSS CDF RRW >
007 1.005 1.005 3-074- 8.48E-09 1.000 2.37E-09 1.000 LSS n/a 5.75E-10 1.000 7.53E-11 1.003 HSS Defense in Depth 010 LERF RRW >
1.001 3-074- 5.17E-07 1.047 1.45E-07 1.040 HSS CDF RRW > 4.33E-07 1.226 2.89E-09 1.1314 HSS CDF RRW >
013 1.005 1.005 3-075- 1.55E-06 1.154 4.34E-07 1.132 HSS CDF RRW > 9.18E-08 1.041 2.70E-09 1.122 HSS CDF RRW >
001 1.005 1.005 3-075- 2.39E-06 1.260 6.70E-07 1.219 HSS CDF RRW > 9.17E-07 1.641 1.77E-08 3.492 HSS CDF RRW >
002 1.005 1.005 E1-19
ATTACHMENT D BFN UNIT 3 RISK INFORMED ISI PROGRAM REQUEST FOR RELIEF 3-ISI-21, RAI RESPONSE ELEMENT SELECTION (QUANTIFIED RRW)
E1-20
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-001-036 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-001-037 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-001-038 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-001-039 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-006 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-007 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-009 FAC areas per program 5.81E-05 5.64E-05 3.30E-06 3.28E-09 1.92E-10 1.001 1.007 1.007 Selected 4 8 8 3-003-036 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-037 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-038 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-039 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-040 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-041 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-042 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-003-043 FAC areas per program 5.81E-05 5.07E-04 0.00E+00 2.95E-08 0.00E+00 1.012 1.000 1.012 Selected 7 0 7 3-068-001 KR-3-49 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-57(OL) 6.15E-08 4.69E-04 0.00E+00 2.88E-11 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-58 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 E1-21
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-068-001 KR-3-47 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 KR-3-48 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-56 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 KR-3-46 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-54(OL) 2.31E-07 4.69E-04 0.00E+00 1.08E-10 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-55 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 KR-3-45 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 N1A-SE 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-001 GR-3-53(OL) 8.85E-06 4.69E-04 0.00E+00 4.15E-09 0.00E+00 1.001 1.000 1.001 Selected 8 0 8 3-068-002 GR-3-04 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 GR-3-07 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 GR-3-01 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 GR-3-02 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 KR-3-01 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 GR-3-03(OL) 1.92E-07 5.80E-04 3.86E-06 1.11E-10 7.41E-13 1.000 1.000 1.000 --
0 0 0 3-068-002 RWR-3-001-G025 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 KR-3-02 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-002 KR-3-04 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 E1-22
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-068-002 SW-TPR-3-19 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 GR-3-30 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 GR-3-33 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 GR-3-28 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 RWR-3-02-G025 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 GR-3-27(OL) 1.92E-07 5.83E-04 3.95E-06 1.12E-10 7.58E-13 1.000 1.000 1.000 --
0 0 0 3-068-014 KR-3-26 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 KR-3-24 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 GR-3-29 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 KR-3-23 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-014 SW-TPR-3-21 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-63A 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-61 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-59(OL) 2.31E-09 4.69E-04 0.00E+00 1.08E-12 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 N1B-SE 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-62 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-63 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 KR-3-51 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 E1-23
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-068-016 GR-3-60(OL) 3.08E-07 4.69E-04 0.00E+00 1.44E-10 0.00E+00 1.000 1.000 1.000 --
1 0 1 3-068-016 KR-3-50 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 KR-3-52 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-64(OL) 2.42E-07 4.69E-04 0.00E+00 1.13E-10 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 GR-3-63B 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-068-016 KR-3-53 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-043 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G020 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G014 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G015 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-066 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G016 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G017 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G018 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G019 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-044 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G024 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-069-001 RWCU-3-001-G025 0.00E+00 5.08E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 E1-24
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-069-001 RWCU-3-001-G026 4.62E-06 5.08E-04 0.00E+00 2.35E-09 0.00E+00 1.001 1.000 1.001 Selected 0 0 0 3-074-005 DRHR-3-05 3.13E-07 5.83E-04 3.95E-06 1.82E-10 1.24E-12 1.000 1.000 1.000 --
1 0 1 3-074-005 DRHR-3-06 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 DRHR-3-07 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 DSRHR-3-02 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 DSRHR-3-03 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 DRHR-3-03B 1.96E-04 5.83E-04 3.95E-06 1.14E-07 7.74E-10 1.051 1.032 1.051 Selected 2 3 2 3-074-005 DSRHR-3-01 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 DRHR-3-04 5.11E-05 5.83E-04 3.95E-06 2.98E-08 2.02E-10 1.012 1.008 1.012 Selected 9 2 9 3-074-005 DSRHR-3-04A 6.03E-07 5.83E-04 3.95E-06 3.52E-10 2.38E-12 1.000 1.000 1.000 --
1 1 1 3-074-005 DSRHR-3-04 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 RHR-3-002-G004 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-005 RHR-3-002-G003 0.00E+00 5.83E-04 3.95E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 DRHR-3-22 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 DRHR-3-23 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 DRHR-3-19 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 DSRHR-3-09 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 DSRHR-3-08 7.96E-05 4.69E-04 0.00E+00 3.73E-08 0.00E+00 1.016 1.000 1.016 Selected 2 0 2 E1-25
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-074-007 DRHR-3-21 1.38E-04 4.69E-04 0.00E+00 6.47E-08 0.00E+00 1.028 1.000 1.028 Selected 4 0 4 3-074-007 DSRHR-3-10 7.69E-04 4.69E-04 0.00E+00 3.61E-07 0.00E+00 1.181 1.000 1.181 Selected 7 0 7 3-074-007 DSRHR-3-11(OL) 1.97E-04 4.69E-04 0.00E+00 9.24E-08 0.00E+00 1.041 1.000 1.041 Selected 0 0 0 3-074-007 TRHR-3-191 3.00E-04 4.69E-04 0.00E+00 1.41E-07 0.00E+00 1.063 1.000 1.063 Selected 8 0 8 3-074-007 TRHR-3-193 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-007 TRHR-3-192 0.00E+00 4.69E-04 0.00E+00 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-010 DRHR-3-12 4.87E-05 1.18E-05 1.55E-06 5.75E-10 7.55E-11 1.000 1.003 1.003 Selected 2 1 1 3-074-013 DRHR-3-15 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-013 DRHR-3-16 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-013 DSRHR-3-06 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-013 DRHR-3-14 6.25E-07 5.80E-04 3.86E-06 3.63E-10 2.41E-12 1.000 1.000 1.000 --
2 1 2 3-074-013 DSRHR-3-05A 2.50E-06 5.80E-04 3.86E-06 1.45E-09 9.65E-12 1.000 1.000 1.000 --
6 4 6 3-074-013 DRHR-3-13 1.23E-04 5.80E-04 3.86E-06 7.13E-08 4.75E-10 1.031 1.019 1.031 Selected 4 5 4 3-074-013 DRHR-3-13B 7.47E-04 5.80E-04 3.86E-06 4.33E-07 2.88E-09 1.226 1.131 1.226 Selected 5 8 5 3-074-013 DSRHR-3-05A 3.65E-04 5.80E-04 3.86E-06 2.12E-07 1.41E-09 1.099 1.060 1.099 Selected 2 3 2 3-074-013 DSRHR-3-07 6.65E-07 5.80E-04 3.86E-06 3.86E-10 2.57E-12 1.000 1.000 1.000 --
2 1 2 3-074-013 RHR-3-002-G002 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-074-013 RHR-3-002-G001 0.00E+00 5.80E-04 3.86E-06 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 E1-26
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-075-001 01cs13hf 9.07E-08 2.26E-03 6.66E-05 2.05E-10 6.04E-12 1.000 1.000 1.000 --
1 2 2 3-075-001 TCS-3-401 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 TSCS-3-402 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 TCS-3-403 4.08E-13 2.26E-03 6.66E-05 9.22E-16 2.72E-17 1.000 1.000 1.000 --
0 0 0 3-075-001 TSCS-3-404 2.56E-13 2.26E-03 6.66E-05 5.79E-16 1.70E-17 1.000 1.000 1.000 --
0 0 0 3-075-001 DCS-3-14 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 DCS-3-13 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 TCS-3-410 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 TCS-3-406 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 DSCS-3-07 3.57E-05 2.26E-03 6.66E-05 8.07E-08 2.38E-09 1.035 1.106 1.106 Selected 6 2 2 3-075-001 DSCS-3-09 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 DSCS-3-08 4.06E-05 2.26E-03 6.66E-05 9.18E-08 2.70E-09 1.040 1.122 1.122 Selected 7 6 6 3-075-001 DCS-3-12 7.50E-16 2.26E-03 6.66E-05 1.70E-18 5.00E-20 1.000 1.000 1.000 --
0 0 0 3-075-001 DSCS-3-16B 7.50E-16 2.26E-03 6.66E-05 1.70E-18 5.00E-20 1.000 1.000 1.000 --
0 0 0 3-075-001 TCS-3-405 0.00E+00 2.26E-03 6.66E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-001 TSCS-3-409 1.04E-15 2.26E-03 6.66E-05 2.35E-18 6.93E-20 1.000 1.000 1.000 --
0 0 0 3-075-001 TSCS-3-408 3.63E-15 2.26E-03 6.66E-05 8.20E-18 2.42E-19 1.000 1.000 1.000 --
0 0 0 3-075-001 TSCS-3-407 5.70E-15 2.26E-03 6.66E-05 1.29E-17 3.80E-19 1.000 1.000 1.000 --
0 0 0 E1-27
ELEMENT SELECTION (QUANTIFIED RRW)
Segment Element P(f) CCDP CLERP CDF LERF RRW RRW MAX Status CDF LERF RRW 3-075-002 01cs13hf 9.07E-08 1.55E-03 3.00E-05 1.41E-10 2.72E-12 1.000 1.000 1.000 --
1 1 1 3-075-002 TCS-3-417 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 TSCS-3-418 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 TCS-3-419 6.36E-13 1.55E-03 3.00E-05 9.86E-16 1.91E-17 1.000 1.000 1.000 --
0 0 0 3-075-002 TSCS-3-420 9.78E-13 1.55E-03 3.00E-05 1.52E-15 2.93E-17 1.000 1.000 1.000 --
0 0 0 3-075-002 DCS-3-05 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 DCS-3-04 4.08E-06 1.55E-03 3.00E-05 6.32E-09 1.22E-10 1.002 1.005 1.005 Selected 7 0 0 3-075-002 TCS-3-426 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 TCS-3-422 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 DSCS-3-02 1.44E-04 1.55E-03 3.00E-05 2.23E-07 4.32E-09 1.105 1.211 1.211 Selected 1 3 3 3-075-002 DSCS-3-01 5.90E-04 1.55E-03 3.00E-05 9.15E-07 1.77E-08 1.638 3.505 3.505 Selected 9 7 7 3-075-002 TCS-3-421 0.00E+00 1.55E-03 3.00E-05 0.00E+00 0.00E+00 1.000 1.000 1.000 --
0 0 0 3-075-002 DSCS-3-16A 7.05E-15 1.55E-03 3.00E-05 1.09E-17 2.12E-19 1.000 1.000 1.000 --
0 0 0 3-075-002 DCS-3-03 7.05E-15 1.55E-03 3.00E-05 1.09E-17 2.12E-19 1.000 1.000 1.000 --
0 0 0 3-075-002 TSCS-3-425X 1.27E-15 1.55E-03 3.00E-05 1.97E-18 3.81E-20 1.000 1.000 1.000 --
0 0 0 3-075-002 TSCS-3-423 4.57E-15 1.55E-03 3.00E-05 7.08E-18 1.37E-19 1.000 1.000 1.000 --
0 0 0 3-075-002 TSCS-3-424 8.31E-15 1.55E-03 3.00E-05 1.29E-17 2.49E-19 1.000 1.000 1.000 --
0 0 0 E1-28
ATTACHMENT E BFN UNIT 3 RISK INFORMED ISI PROGRAM REQUEST FOR RELIEF 3-ISI-21, RAI RESPONSE ELEMENT SELECTION (ZERO FAILURE RATE)
E1-29
ELEMENT SELECTION (ZERO FAILURE RATE)
Segment Boundary Description Segment Selected Selected Population Element(s) Population 3-068-002 28" discharge line from Recirculation pump "A" to Recirc 10 GR-3-03(OL) 2 ring header KR-3-02 3-068-003 22" line Recirc ring header "A" 2 RWR-3-001-G019 1 3-068-004 12" discharge line from Recirc ring header "A" to 4 RWR-3-001-G016 1 Reactor (N2F) 3-068-005 12" discharge line from Recirc ring header "A" to 3 RWR-3-001-G006 1 Reactor (N2G) 3-068-006 12" discharge line from Recirc ring header "A" to 3 RWR-3-001-G007 1 Reactor (N2H) 3-068-007 12" discharge line from Recirc ring header "A" to 3 RWR-3-001-G012 1 Reactor (N2J) 3-068-008 12" discharge line from Recirc ring header "A" to 4 RWR-3-001-G013 1 Reactor (N2K) 3-068-009 12" discharge line from Recirc ring header "B" to 4 RWR-3-001-G023 1 Reactor (N2E) 3-068-010 12" discharge line from Recirc ring header "B" to 3 RWR-3-001-G022 1 Reactor (N2D) 3-068-011 12" discharge line from Recirc ring header "B" to 3 RWR-3-001-G007 1 Reactor (N2C) 3-068-012 12" discharge line from Recirc ring header "B" to 3 RWR-3-001-G018 1 Reactor (N2B) 3-068-013 12" discharge line from Recirc ring header "B" to 4 RWR-3-001-G003 1 Reactor (N2A) 3-068-014 28" discharge line from Recirculation pump "B" to Recirc 10 GR-3-27(OL) 2 ring header KR-3-24 3-068-015 22" line Recirc ring header "B" 2 RWR-3-001-G019 1 3-068-016 28" suction line from Reactor (N1B) to Recirculation 13 GR-3-60 (OL) 4 pump "B" GR-3-63, GR-3-64(OL),
GR-3-59(OL) 3-073-001 10" supply line from 26" MS line "B" to penetration X-11 13 THPCI-3-073A 1 Total 84 21 (25%)
E1-30
ENCLOSURE 2 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNIT 3 AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)
SECTION XI, INSERVICE INSPECTION (ISI) PROGRAM, THIRD TEN-YEAR INSPECTION INTERVAL REQUEST FOR RELIEF 3-ISI-21, RISK INFORMED INSERVICE INSPECTION (RI-ISI) PROGRAM RESPONSE TO NRC REQUEST FOR ADDITIONAL INFORMATION (RAI)
COMMITMENT LIST TVA will perform sample expansions during the current outage as required by IWB-2430(b). The BFN Unit 3 ISI Program (3-SI-4.6.G) will be revised to reflect this requirement.