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| {{#Wiki_filter:1NRR-DMPSPEm ResourceFrom:Chawla, MaheshSent:Wednesday, March 28, 2018 5:12 PMTo:Davis, J.Michael (J.Michael.Davis@nexteraenergy.com)Cc:'laura.swenzinski@nexteraenergy.com'; Catron, Steve (Steve.Catron@fpl.com); Kilby, Gary; Murrell, Bob (Bob.Murrell@nexteraenergy.com); Probst, Jim; Weaver, Tracy | | {{#Wiki_filter:1NRR-DMPSPEm Resource From:Chawla, Mahesh Sent:Wednesday, March 28, 2018 5:12 PM To:Davis, J.Michael (J.Micha el.Davis@nexteraenergy.com) |
| | Cc:'laura.swenzinski@nexteraenergy.com'; Catron |
| | , Steve (Steve.Catron@fpl.com); Kilby, Gary; Murrell, Bob (Bob.Murrell@nexterae nergy.com); Probst, Jim; Weaver, Tracy |
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| ==Subject:== | | ==Subject:== |
| Final RAI for Duane Arnold (DAEC) Re: 5th-10 year ISI (RR-05) (EPID L-2017-LLR-0140)Attachments:EPID L-2017-LLR-0140 - Final RAIs - RR05.docx | | Final RAI for Duane Arnold (DAEC) Re: 5t h-10 year ISI (RR-05) (EPID L-2017-LLR-0140) |
| | Attachments: |
| | EPID L-2017-LLR-0140 - Final RAIs - RR05.docx |
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| ==Dear Mr. Davis:== | | ==Dear Mr. Davis:== |
| By letter dated November 16, 2017, (ADAMS Accession No. ML17325B215) NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR) as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). The RR, designated as RR-05, is being requested in order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current ASME Code Section XI requirements.
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| On March 13, 2018, the U.S. Nuclear Regulatory Commission (NRC) staff sent you a draft request for additional information identifying the additional information needed to complete its review. On March 28, 2018, a teleconference was held between the NRC staff and your representatives to providing any clarification needed for the request for additional information (RAI). During the teleconference, your representatives acknowledged a clear understanding of the requested information. Attached, please find the final RAI. Please provide your written response on the docket prior to 30 days from the receipt of this email, as agreed upon by your representative.
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| Thank you for your attention. | | By letter dated November 16, 2017, (ADAMS Accession No. ML17325B215) NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR) as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). The RR, designated as RR-05, is being requested in |
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| | order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current ASME Code Section XI requirements. |
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| | On March 13, 2018, the U.S. Nuclear Regulatory Commission (NRC) staff sent you a draft request for additional information identifying the additional information needed to complete its review. On March 28, 2018, a teleconference was held between the NRC staff and your representatives to providing any clarification needed for the request for additional information (RAI). During the teleconference, your representatives acknowledged a clear understanding of the requested information. |
| | Attached, please find the final RAI. Please provide your written response on the docket prior to 30 days from the receipt of this email, as agreed upon by your representative. |
| | |
| | Thank you for your attention. |
| | |
| Mahesh (Mac) Chawla United States Nuclear Regulatory Commission (NRC) | | Mahesh (Mac) Chawla United States Nuclear Regulatory Commission (NRC) |
| Licensing Project Manager - NRR/DORL/LPL3 Mahesh.chawla@nrc.gov (301) 415-8371 Hearing Identifier: NRR_DMPS Email Number: 265 Mail Envelope Properties (Mahesh.Chawla@nrc.gov20180328171100) | | Licensing Project Manager - NRR/DORL/LPL3 Mahesh.chawla@nrc.gov (301) 415-8371 |
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| | Hearing Identifier: NRR_DMPS Email Number: 265 Mail Envelope Properties (Mahesh.Chawla@nrc.gov20180328171100) |
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| ==Subject:== | | ==Subject:== |
| Final RAI for Duane Arnold (DAEC) Re: 5th-10 year ISI (RR-05) (EPID L-2017-LLR-0140) Sent Date: 3/28/2018 5:11:40 PM Received Date: 3/28/2018 5:11:00 PM From: Chawla, Mahesh Created By: Mahesh.Chawla@nrc.gov Recipients: "'laura.swenzinski@nexteraenergy.com'" <laura.swenzinski@nexteraenergy.com> Tracking Status: None "Catron, Steve (Steve.Catron@fpl.com)" <Steve.Catron@fpl.com> Tracking Status: None "Kilby, Gary" <Gary.Kilby@fpl.com> | | Final RAI for Duane Arnold (DAEC) Re: 5th-10 year ISI (RR-05) (EPID L-2017-LLR-0140) Sent Date: 3/28/2018 5:11:40 PM Received Date: 3/28/2018 5:11:00 PM From: Chawla, Mahesh Created By: Mahesh.Chawla@nrc.gov Recipients: "'laura.swenzinski@nexteraenergy.com'" <laura.swenzinski@nexteraenergy.com> Tracking Status: None "Catron, Steve (Steve.Catron@fpl.com)" <Steve.Catron@fpl.com> Tracking Status: None "Kilby, Gary" <Gary.Kilby@fpl.com> |
| Tracking Status: None "Murrell, Bob (Bob.Murrell@nexteraenergy.com)" <Bob.Murrell@nexteraenergy.com> Tracking Status: None "Probst, Jim" <Jim.Probst@nexteraenergy.com> Tracking Status: None "Weaver, Tracy" <Tracy.Weaver@nexteraenergy.com> Tracking Status: None "Davis, J.Michael (J.Michael.Davis@nexteraenergy.com)" <J.Michael.Davis@nexteraenergy.com> Tracking Status: None | | Tracking Status: None "Murrell, Bob (Bob.Murrell@nexteraenergy.com)" <Bob.Murrell@nexteraenergy.com> Tracking Status: None "Probst, Jim" <Jim.Probst@nexteraenergy.com> Tracking Status: None "Weaver, Tracy" <Tracy.Weaver@nexteraenergy.com> Tracking Status: None "Davis, J.Michael (J.Michael.Davis@nexteraenergy.com)" <J.Michael.Davis@nexteraenergy.com> Tracking Status: None |
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| Post Office: Files Size Date & Time MESSAGE 1424 3/28/2018 5:11:00 PM EPID L-2017-LLR-0140 - Final RAIs - RR05.docx 31271 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received: | | Post Office: Files Size Date & Time MESSAGE 1424 3/28/2018 5:11:00 PM EPID L-2017-LLR-0140 - Final RAIs - RR05.docx 31271 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received: |
| 1 Request for Additional Information Re: Duane Arnold Energy Center Fifth-10 Year Inservice Inspection Interval Program Plan Relief Request No. RR-05 Docket No. 50-331 By letter dated November 16, 2017 (ADAMS Accession No. ML17325B215), NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR), as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). RR-05 is being requested in order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current requirements of Class 1 and 2 examination Categories B-F, B-J, C-F-1, and C-F-2 as specified in Table IWB 2500-1, and Table IWC 2500-1 of the 2007 Edition with 2008 Addenda of ASME Code Section XI. The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your proposed request and has identified an area where additional information is needed to complete its review. The following requests for additional information (RAIs) require licensee responses: APLA-RAI-01 In DAEC RR-05 submittal, page 5, "Risk Impact Analysis," the licensee states, in part: The revised program continues to be less than the EPRI criterion with a total change in plant risk of 4.34E-09 in regards to CDF and 4.3E-09 in regards to LERF. NRC Staff Request: a. Regarding the statement above, since LERF is typically at least an order of magnitude lower than CDF, explain why the total changes in CDF and LERF are essentially equal. b. Explain why the 03RWCU System parameter (exhibited in the Risk Impact Results matrix), on page 5, has a change in LERF exceeding that of CDF. The NRC staff is requesting clarification in the data set since CDF values would typically be greater than LERF values. APLA-RAI-02 According to Regulatory Issue Summary 2007-06, the NRC would expect licensees to fully address all scope elements consistent with Revision 2 of Regulatory Guide (RG) 1.200 by the end of 2009 (i.e., one year implementation period). Revision 2 of RG 1.200 endorses, with exceptions and clarifications, the combined American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) PRA standard (ASME/ANS RA-Sa-2009). In Attachment 2, "DAEC PRA Model Quality Summary," page 2 (of the submittal), the licensee states, in part: | | 1 Request for Additional Information Re: Duane Arnold Energy Center Fifth-10 Year Inservice Inspection Interval Program Plan Relief Request No. RR-05 Docket No. 50-331 By letter dated November 16, 2017 (ADAMS Accession No. ML17325B215), NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR), as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). RR-05 is being requested in order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current requirements of Class 1 and 2 examination Categories B-F, B-J, C-F-1, and C-F-2 as specified in Table IWB 2500-1, and Table IWC 2500-1 of the 2007 Edition with 2008 Addenda of ASME Code Section XI. |
| 2 The focused scope peer review conducted in March 2011 -utilized version RA-Sa-2009 of the ASME Standard as endorsed and clarified by the NRC in Regulatory Guide 1.200, Revision 2. NRC Staff Request: The NRC staff is requesting the licensee to confirm that all technical elements in Part 2 of the Standard, including internal flooding, were included in this March 2011 review. If not, please identify any gaps between the peer review and the requirements in RG 1.200, Revision 2, particularly focusing on those technical elements for which the most current peer review remains from 2007 against Rev. 1 of RG 1.200. APLA-RAI-03 The NRC staff identified during its review the need for the licensee to further address several previously identified gaps that were incorporated into the DAEC PRA. Specifically, more information is requested re: DAEC Focused Peer Review Findings (Table C-1) which include: a. Findings & Observations (F&O) DA-D4-01A, which the licensee states, in part: To address this associated finding, the reasonableness of the prior and posterior distributions was reviewed; it was concluded no model changes were required. This implies that the mean of the likelihood (3/544 = 0.0055) was significantly higher (a factor of 60) than that for the prior (9E-5). The NRC staff determined this may suggest a Bayesian approach may not be appropriate if plant-specific behavior is significantly different (worse) than generic. NRC Staff Request: Did these values change subsequently such that the focused scope review had different values where the prior and likelihood were more aligned? Provide the results of the final Bayesian analysis and the conclusion by the peer review team that this Supporting Requirement (SR) is now MET. b. F&O IE-B3-01A, which the licensee states, in part: Several findings and suggestions under HLR-A and HLR-B have been dispositioned / resolved, but the subsuming (IE-B3) and screening (IE-C4 (C6)) | | The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your proposed request and has identified an area where additional information is needed to complete its review. The following requests for additional information (RAIs) require licensee responses: |
| of initiating events does not meet the standard. In particular, the Finding cited, (1) RBCCW is subsumed by TT, but not failed given TT; (2) GSW is subsumed by TC, but not failed given TC; (3) 1A1/1A2 bus failures and partial loss of feedwater are binned to TT, but their impact not modeled given TT; and (4) 1A3/1A4 bus failures are subsumed with TT, but unavailability of emergency power given failure of the bus. Additionally, the licensee stated that the CDF is 3.5E-09/yr. | | APLA-RAI-01 In DAEC RR-05 submittal, page 5, "Risk Impact Analysis," the licensee states, in part: |
| 3 NRC Staff Request: Provide the NRC staff with information regarding these deficiencies due to subsuming, specifically are they rectified? Additionally, the information provided in the disposition cites conservatisms with respect to piping leg breaks not yet incorporated into the model. It is not clear to the NRC staff if any sequences initiated by or subsequently involving these breaks could be affected by the application such that failure to incorporate these into the PRA could underestimate the change in CDF or LERF. If so, provide information (e.g., a sensitivity evaluation) that includes these into the applicable risk metrics and determine any effect. c. F&O HR-A1-01A and F&O HR-A2-01A, which the licensee states, in part: The approach used in the DAEC PRA was different than currently prescribed in the standard, but is considered capable of accurately identifying pre-initiators. As such this variance from the standard has no impact on this application. NRC Staff Request: Provide the NRC staff with information regarding why the use of this "different approach", as stated above, accurately identifies pre-initiators such that it is equivalent to the approach required by the Standard (ASME/ANS RA-Sa-2009). d. F&O HR-C1-01A, which the licensee states, in part: In other cases, the [Human Failure Events] HFE is at the train level, but no corresponding system level dependent HFE is included. NRC Staff Request: The F&O disposition cites addition of train-level pre-initiating HFEs to the model. However, it is not clear to the NRC staff if this deficiency regarding "corresponding system-level dependent HFEs" has been corrected as well. If not, provide the NRC staff with information (e.g., performance of a sensitivity evaluation) incorporating these dependencies and assess any effect on the risk metrics. APLA-RAI-04 The NRC staff identified during its review of the licensee's source material regarding the RI-ISI consequence evaluation (Table C-2), that several items exhibited in the matrix required additional information, including: a. For Item No. 49, the licensee states, in part: Given that Level 2 results are often the determining parameter for assignment of consequence category in the RI-ISI evaluation, this item is judged to have little influence on its results. | | The revised program continues to be less than the EPRI criterion with a total change in plant risk of 4.34E-09 in regards to CDF and 4.3E-09 in regards to LERF. NRC Staff Request: |
| 4 NRC Staff Request: Provide the NRC staff with information regarding the stated term "little influence" and justify why any such influence would not affect the risk metrics appropriate for this application in any detrimental way. b. For Item No. 58, there is no information provided in either the Status or Estimated RI-ISI Impact columns of the matrix. NRC Staff Request: Provide this information for Item No. 58, or justify to the NRC staff why there is no information. c. For Item No. 59, the licensee states, in part: The subject gate [RCIC-07-01] is a very low contributor to RCIC system failure. Therefore this item has essentially no influence on the RI-ISI application. NRC Staff Request: Provide the NRC staff with information regarding any effect from the retention of gate RCIC 01 that could lead to an underestimate of any of the applicable risk metrics for this application. d. For Item No. 63, the licensee states, in part: Modeling of water hammer is very low contributor to HPCI and RCIC system failure. NRC Staff Request: Provide the NRC staff with information regarding the basis for the statement above (e.g., what are the failure likelihoods for HPCI and RCIC currently modeled and how do they compare with the likely value for water hammer). e. For Item No. 64, the licensee states, in part: The current treatment of human actions to manage water level following plant trips, including ATWS, is believed to be overly conservative and would benefit from refinement. The current model is conservative for the RI-ISI application with respect to this time. NRC Staff Request: Provide the NRC staff with information regarding any potential dependencies among these separate events, such that the current combined failure probability may be under-estimated if these dependencies are not modeled. If so, provide a quantitative evaluation (e.g., a sensitivity evaluation) addressing any potential dependencies. | | : a. Regarding the statement above, since LERF is typically at least an order of magnitude lower than CDF, explain why the total changes in CDF and LERF are essentially equal. |
| 5 APLA-RAI-05 The NRC staff's review of the licensee's source material regarding plant modifications assessed as potentially having a PRA impact (Table C-3), that EC No. 156110, "Installation of Well Water Isolation Valve V44-0509," requires additional information: For EC No. 156110, the licensee states, in part: This is acceptable based on low safety significance of well water system isolation valves. NRC Staff Request: Provide the NRC staff with information regarding if the use of the above stated term "low safety significance" includes "low risk importance" such that the exclusion remains justified for this application.}} | | : b. Explain why the 03RWCU System parameter (exhibited in the Risk Impact Results matrix), |
| | on page 5, has a change in LERF exceeding that of CDF. The NRC staff is requesting clarification in the data set since CDF values would typically be greater than LERF values. |
| | APLA-RAI-02 According to Regulatory Issue Summary 2007-06, the NRC would expect licensees to fully address all scope elements consistent with Revision 2 of Regulatory Guide (RG) 1.200 by the end of 2009 (i.e., one year implementation period). Revision 2 of RG 1.200 endorses, with exceptions and clarifications, the combined American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) PRA standard (ASME/ANS RA-Sa-2009). |
| | In Attachment 2, "DAEC PRA Model Quality Summary," page 2 (of the submittal), the licensee states, in part: |
| | 2 The focused scope peer review conducted in March 2011 -utilized version RA-Sa-2009 of the ASME Standard as endorsed and clarified by the NRC in Regulatory Guide 1.200, Revision 2. |
| | NRC Staff Request: |
| | The NRC staff is requesting the licensee to confirm t hat all technical elements in Part 2 of the Standard, including internal flooding, were included in this March 2011 review. If not, please identify any gaps between the peer review and the requirements in RG 1.200, Revision 2, particularly focusing on those technical elements for which the most current peer review remains from 2007 against Rev. 1 of RG 1.200. |
| | APLA-RAI-03 The NRC staff identified during its review the need for the licensee to further address several previously identified gaps that were incorporated into the DAEC PRA. Specifically, more information is requested re: DAEC Focused Peer Review Findings (Table C-1) which include: |
| | : a. Findings & Observations (F&O) DA-D4-01A, which the licensee states, in part: |
| | To address this associated finding, the reasonableness of the prior and posterior distributions was reviewed; it was concluded no model changes were required. |
| | This implies that the mean of the likelihood (3/544 = 0.0055) was significantly higher (a factor of |
| | : 60) than that for the prior (9E-5). The NRC staff determined this may suggest a Bayesian approach may not be appropriate if plant-specific behavior is significantly different (worse) than generic. |
| | NRC Staff Request: |
| | Did these values change subsequently such that the focused scope review had different values where the prior and likelihood were more aligned? Provide the results of the final Bayesian analysis and the conclusion by the peer review team that this Supporting Requirement (SR) is now MET. |
| | : b. F&O IE-B3-01A, which the licensee states, in part: |
| | Several findings and suggestions under HLR-A and HLR-B have been dispositioned / resolved, but the subsuming (IE-B3) and screening (IE-C4 (C6)) |
| | of initiating events does not meet the standard. |
| | In particular, the Finding cited, (1) RBCCW is subsumed by TT, but not failed given TT; (2) GSW is subsumed by TC, but not failed given TC; (3) 1A1/1A2 bus failures and partial loss of feedwater are binned to TT, but their impact not modeled given TT; and (4) 1A3/1A4 bus failures are subsumed with TT, but unavailability of emergency power given failure of the bus. Additionally, the licensee stated that the CDF is 3.5E-09/yr. |
| | 3 NRC Staff Request: |
| | Provide the NRC staff with information regarding these deficiencies due to subsuming, specifically are they rectified? Additionally, the information provided in the disposition cites conservatisms with respect to piping leg breaks not yet incorporated into the model. It is not clear to the NRC staff if any sequences initiated by or subsequently involving these breaks could be affected by the application such that failure to incorporate these into the PRA could underestimate the change in CDF or LERF. If so, provide information (e.g., a sensitivity evaluation) that includes these into the applicable risk metrics and determine any effect. |
| | : c. F&O HR-A1-01A and F&O HR-A2-01A, which the licensee states, in part: |
| | The approach used in the DAEC PRA was different than currently prescribed in the standard, but is considered capable of accurately identifying pre-initiators. As such this variance from the standard has no impact on this application. |
| | NRC Staff Request: |
| | Provide the NRC staff with information regarding why the use of this "different approach", as stated above, accurately identifies pre-initiators such that it is equivalent to the approach required by the Standard (ASME/ANS RA-Sa-2009). |
| | : d. F&O HR-C1-01A, which the licensee states, in part: |
| | In other cases, the [Human Failure Events] HFE is at the train level, but no corresponding system level dependent HFE is included. |
| | NRC Staff Request: |
| | The F&O disposition cites addition of train-level pre-initiating HFEs to the model. However, it is not clear to the NRC staff if this deficiency r egarding "corresponding system-level dependent HFEs" has been corrected as well. If not, provide the NRC staff with information (e.g., performance of a sensitivity evaluation) incorporating these dependencies and assess any effect on the risk metrics. |
| | APLA-RAI-04 The NRC staff identified during its review of the licensee's source material regarding the RI-ISI |
| | |
| | consequence evaluation (Table C-2), that severa l items exhibited in the matrix required additional information, including: |
| | : a. For Item No. 49, the licensee states, in part: |
| | Given that Level 2 results are often the determining parameter for assignment of consequence category in the RI-ISI evaluation, this item is judged to have little influence on its results. |
| | 4 NRC Staff Request: |
| | Provide the NRC staff with information regarding the stated term "little influence" and justify why any such influence would not affect the risk metrics appropriate for this application in any detrimental way. |
| | : b. For Item No. 58, there is no information provided in either the Status or Estimated RI-ISI Impact columns of the matrix. |
| | NRC Staff Request: |
| | Provide this information for Item No. 58, or justify to the NRC staff why there is no information. |
| | : c. For Item No. 59, the licensee states, in part: |
| | The subject gate [RCIC-07-01] is a very low contributor to RCIC system failure. Therefore this item has essentially no influence on the RI-ISI application. |
| | NRC Staff Request: |
| | Provide the NRC staff with information regarding any effect from the retention of gate RCIC 01 that could lead to an underestimate of any of the applicable risk metrics for this application. |
| | : d. For Item No. 63, the licensee states, in part: |
| | Modeling of water hammer is very low contributor to HPCI and RCIC system failure. |
| | NRC Staff Request: |
| | Provide the NRC staff with information regarding the basis for the statement above (e.g., what are the failure likelihoods for HPCI and RCIC currently modeled and how do they compare with the likely value for water hammer). |
| | : e. For Item No. 64, the licensee states, in part: |
| | The current treatment of human actions to manage water level following plant |
| | |
| | trips, including ATWS, is believed to be overly conservative and would benefit from refinement. The current model is conservative for the RI-ISI application with respect to this time. |
| | NRC Staff Request: |
| | Provide the NRC staff with information regarding any potential dependencies among these separate events, such that the current combined failure probability may be under-estimated if these dependencies are not modeled. If so, provide a quantitative evaluation (e.g., a sensitivity evaluation) addressing any potential dependencies. |
| | 5 APLA-RAI-05 The NRC staff's review of the licensee's source material regarding plant modifications assessed as potentially having a PRA impact (Table C-3), that EC No. 156110, "Installation of Well Water Isolation Valve V44-0509," requires additional information: |
| | For EC No. 156110, the licensee states, in part: |
| | This is acceptable based on low safety significance of well water system isolation valves. NRC Staff Request: |
| | Provide the NRC staff with information regarding if the use of the above stated term "low safety significance" includes "low risk importance" such that the exclusion remains justified for this application.}} |
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EPID:L-2017-LLR-0140, Fifth Inservice Inspection Interval Program Plan Relief Request No. RR-05 (Open) |
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Category:E-Mail
MONTHYEARML24122C6922024-05-0101 May 2024 NextEra Fleet EP Amendment - Demonstration Drill ML23109A1862023-04-19019 April 2023 and Turkey Point Acceptance of Requested Licensing Action Proposed Alternative to Asme Section XI Authorizing Implementation of Asme Code Case N-752-1 ML22067A0922022-03-0303 March 2022 State Consultation - Duane Arnold ISFSI-Only EP License Amendment ML22040A1162022-02-0808 February 2022 Email to G. Van Noordennen Zion and La Crosse Review Schedule Changes ML22027A3582022-01-26026 January 2022 DAEC: CY2022 Inspection Plan, Docket No: 05000331, License No: DPR-49 ML22007A3102022-01-0505 January 2022 State Consultation - Draft No Significant Hazards Determination Regarding a LAR for NextEra Energy Duane Arnold, LLC, Duane Arnold Energy Center ISFSI in Palo, Iowa ML22005A0992022-01-0404 January 2022 Email from a Snyder to a Leek Re State Consultation - Draft No Significant Hazards Determination - License Amend. Req. for NextEra Energy, LLC, DAEC ISFSI in Palo, Iowa ML22005A0862022-01-0404 January 2022 1-4-2022 Email Communication to Duane Arnold Regarding Its ISFSI Related Exemption Request on Supplemental Information Needed ML22005A1012022-01-0404 January 2022 Email from a Leek to a Snyder Re State Consultation - Draft No Significant Hazards Determination - License Amend. Req. for NextEra Energy, LLC, DAEC ISFSI in Palo Iowa ML22004A0122022-01-0303 January 2022 E-mail from M. Davis, NextEra, to A. Snyder, NRC, - Duane Arnold Energy Center - Supplement Information to Technical Specification Amendment Application ML21354A6722021-12-17017 December 2021 Email to State of Iowa - Draft EA on Duane Arnold Exemption ML21214A0502021-08-0101 August 2021 Acceptance of License Amendment Request to Adopt an ISFSI-Only Physical Security Plan ML21214A0482021-08-0101 August 2021 Acceptance of License Amendment Request to Adopt an ISFSI-Only Emergency Plan ML21165A1212021-06-10010 June 2021 E-mail from M. Davis, Duane Arnold, to M. Doell and R. Edwards, NRC - Duane Arnold Defueled Emergency Plan Implementation Confirmation ML21117A2752021-04-26026 April 2021 Acceptance of Updated Spent Fuel Management Plan ML21089A2092021-03-19019 March 2021 Spent Fuel Pattern Procedure ML21068A3352021-03-0707 March 2021 Acceptance of License Amendment Request to Adopt ISFSI-Only Technical Specifications ML21056A2172021-02-17017 February 2021 Acceptance of License Amendment Request to Revise the Physical Security Plan Requirements ML21032A1852021-02-0101 February 2021 Daec_ CY2021 Inspection Plan ML21006A4052021-01-0606 January 2021 NRR E-mail Capture - Final RAI - Duane Arnold - Post-Shutdown Decommissioning Activities Report ML20338A0032020-12-0101 December 2020 Letter from EPRI to Mr. Scott Wall, BWRVIP 2020-100, 288 Surveillance Capsule Test Results Report ML20316A0212020-11-10010 November 2020 NRR E-mail Capture - Final RAI - Duane Arnold - Duane Arnold Amendment for Proposed Defueled EP and EAL Scheme ML20289A3522020-10-14014 October 2020 NRR E-mail Capture - Duane Arnold Energy Center -Acceptance of Requested Licensing Action, One-Time Exemption from 10 CFR 50, Appendix E, Biennial Emergency Preparedness Exercise Requirements Due to COVID-19 Pandemic (EPID No. L-2020-LLE-01 ML20153A3772020-05-28028 May 2020 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center Quality Assurance Topical Report (FPL-3) - EPID L-2020-LLQ-0002) ML20154K6202020-05-27027 May 2020 COVID-19 Preparedness Assessments for FEMA Region VII Duane Arnold Energy Center (DAEC) and Quad Cities Generating Station (Qcgs) ML20141L8132020-05-19019 May 2020 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center (DAEC) - Exemption Request for Security Training Requirements Due to COVID-19 Pandemic - EPID L-2020-LLE-0042 to 45, L-2020-LLE-0051 ML20129J8282020-05-0606 May 2020 NRR E-mail Capture - LIC-109 Acceptance Review of Duane Arnold Request for Exemption from Portions of 10 CFR 50.47 and Appendix E - EPID L-2020-LLE-0023 ML20127H8662020-05-0505 May 2020 NRR E-mail Capture - Duane Arnold Energy Center (DAEC) - Request for Additional Information (RAI) - Request for Exemptions from 10 CFR 50.82(a)(8)(i)(A) and 1O CFR 50.75(h)(1)(iv) - EPID L-2020-LLE-0011 ML20122A1152020-04-30030 April 2020 NRR E-mail Capture - Duane Arnold Energy Center -Acceptance of Post-Shutdown Decommissioning Activities Report ML20087F2872020-03-26026 March 2020 NRR E-mail Capture - LIC-109 Acceptance Review of Duane Arnold Request for Exemption from 10 CFR 50.82(a)(8)(i)(A) and 1O CFR 50.75(h)(1)(iv) - EPID L-2020-LLE-0011 ML20129J8322020-03-19019 March 2020 NRR E-mail Capture - (External_Sender) Teleconference with Nextra Energy - Duane Arnold Physical Security Plan LIC-109 Review Status ML20022A3602020-01-22022 January 2020 NRR E-mail Capture - Duane Arnold Energy Center - Acceptance of Requested Licensing Action, Proposed Partial Exemption from Record Retention Requirements ML19352G6872019-12-11011 December 2019 12-11-19 Email to FEMA: Response to FEMA Questions on Proposed DAEC Emergency Plan ML19302G9732019-10-29029 October 2019 NRR E-mail Capture - LIC-109 Acceptance of Duane Arnold Energy Center (DAEC) - License Amendment Request (TSCR- 186): Removal of License Condition 2.C.(3), Fire Protection Program - EPID L-2019-LLA-0211 ML19302G3212019-10-29029 October 2019 LIC-109 Acceptance of Duane Arnold Energy Center (DAEC) - License Amendment Request (TSCR- 186) - Removal of License Condition 2.C.(3), Fire Protection Program - EPID L-2019-LLA-0211 ML19280A0352019-10-0404 October 2019 NRR E-mail Capture - Final - RAI Related to License Amendment Request (TSCR-182) for Proposed Changes to the Emergency Plan for Permanently Defueled Conditions at Duane Arnold Energy Center (DAEC) - L-2019-LLA-0075 ML19206A2182019-07-25025 July 2019 NRR E-mail Capture - LIC-109 Acceptance of Duane Arnold Energy Center (DAEC) - License Amendment Request (TSCR-183) - Application to Revise Operating License and TS for Permanently Defueled Condition - EPID L-2019-LLA-0130 ML19183A0172019-06-26026 June 2019 NRR E-mail Capture - LIC-109 Acceptance of Request for Change in the BWRVIP Integrated Surveillance Program Test Schedule to Accommodate Early Closure of the Duane Arnold Energy Center - EPID L-2019-LRO-0042 ML19122A4882019-04-29029 April 2019 NRR E-mail Capture - LIC-109 Acceptance of License Amendment Request (TSCR-182) for Duane Arnold Energy Center (DAEC) - Proposed Changes to the Emergency Plan for Permanently Defueled Condition - EPID L-2019-LLA-0075 ML19086A3502019-03-27027 March 2019 NRR E-mail Capture - LIC-109 Acceptance of the Request for Exemption from 10 CFR 73.55(p)(1)(I) and 10 CFR 73.55(p)(1)(ii) for Duane Arnold Energy Center - EPID L-2019-LLE-0003 ML19064A2032019-03-0404 March 2019 NRR E-mail Capture - Results of LIC-109 Acceptance Review - Duane Arnold Energy Center - Request for Approval of Certified Fuel Handler Training Program, EPID L-2019-LLL-0003 ML18283B0522018-10-0909 October 2018 NRR E-mail Capture - Final Second Round - Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18255A2922018-09-11011 September 2018 NRR E-mail Capture - Draft Second Round - Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18166A2982018-06-15015 June 2018 NRR E-mail Capture - Draft Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18108A3102018-04-12012 April 2018 NRR E-mail Capture - Audit at NextEra Headquarters, Juno Beach, Florida - April 24, 2018 Through April 26, 2018 - 50.69 LARs for Duane Arnold Energy Center (Daec), and Point Beach Nuclear Plant (Pbnp), Units 1 and 2 - EPIDs L-2017-LLA-0283/ ML18088A0102018-03-28028 March 2018 NRR E-mail Capture - Final RAI for Duane Arnold (DAEC) 5th-10 Year ISI (RR-05) ML18037B0032018-02-0606 February 2018 NRR E-mail Capture - Draft Request for Additional Information - Duane Arnold Energy Center (DAEC) - License Amendment Request (TSCR-170), Revision to Technical Specification 3.5.1, ECCS-Operating - EPID L-2017-LLA-0288 ML18025A2362018-01-24024 January 2018 NRR E-mail Capture - Resent - LIC-109 Acceptance - Duane Arnold LAR (TSCR-166) - Adoption of Emergency Action Level (EAL) Scheme Pursuant to NEI 99-01, Revision 6, Development of EALs for Non-Passive Reactors ML18023A0752018-01-22022 January 2018 NRR E-mail Capture - LIC-109 Acceptance - Duane Arnold License Amendment Request (LAR) (TSCR-179) - Application to Add Technical Specification 3.2.3, Linear Heat Generation Rate - EPID: L-2017-LLA-0436 ML18019A0732018-01-18018 January 2018 NRR E-mail Capture - LIC-109 Acceptance - Duane Arnold License Amend Request (LAR)(TSCR-178) - Application to Reduce the Required Number of Operable Suppression Chamber-to-Drywell Vacuum Breakers 2024-05-01
[Table view] Category:Request for Additional Information (RAI)
MONTHYEARML24193A2432024-07-12012 July 2024 – Interim Audit Summary Report in Support of Review of License Amendment Requests Regarding Fleet Emergency Plan ML22005A0862022-01-0404 January 2022 1-4-2022 Email Communication to Duane Arnold Regarding Its ISFSI Related Exemption Request on Supplemental Information Needed ML21335A0712021-12-0101 December 2021 Request for Additional Information - Duane Arnold Energy Center ISFSI Only Emergency Plan ML21335A0702021-12-0101 December 2021 Cover Letter to B. Coffey from K. Conway - Duane Arnold Energy Center RAI Re License Amendment Request for ISFSI Only Emergency Plan ML21250A3002021-09-0808 September 2021 Defueled Physical Security Plan RAI Cover Letter ML21006A4052021-01-0606 January 2021 NRR E-mail Capture - Final RAI - Duane Arnold - Post-Shutdown Decommissioning Activities Report ML20316A0212020-11-10010 November 2020 NRR E-mail Capture - Final RAI - Duane Arnold - Duane Arnold Amendment for Proposed Defueled EP and EAL Scheme ML20153A3772020-05-28028 May 2020 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center Quality Assurance Topical Report (FPL-3) - EPID L-2020-LLQ-0002) ML20141L8132020-05-19019 May 2020 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center (DAEC) - Exemption Request for Security Training Requirements Due to COVID-19 Pandemic - EPID L-2020-LLE-0042 to 45, L-2020-LLE-0051 ML20133K0482020-05-14014 May 2020 Information Request to Support the NRC Annual Baseline Emergency Action Level and Emergency Plan Changes Inspection ML20127H8662020-05-0505 May 2020 NRR E-mail Capture - Duane Arnold Energy Center (DAEC) - Request for Additional Information (RAI) - Request for Exemptions from 10 CFR 50.82(a)(8)(i)(A) and 1O CFR 50.75(h)(1)(iv) - EPID L-2020-LLE-0011 ML19280A0352019-10-0404 October 2019 NRR E-mail Capture - Final - RAI Related to License Amendment Request (TSCR-182) for Proposed Changes to the Emergency Plan for Permanently Defueled Conditions at Duane Arnold Energy Center (DAEC) - L-2019-LLA-0075 ML18283B0522018-10-0909 October 2018 NRR E-mail Capture - Final Second Round - Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18255A2922018-09-11011 September 2018 NRR E-mail Capture - Draft Second Round - Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18247A2002018-08-21021 August 2018 E-Mailed Request for Information for Duane Arnold, Dated 08/21/18 (DRS-M.Holmberg) ML18166A2982018-06-15015 June 2018 NRR E-mail Capture - Draft Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - LAR TSCR-166, Adoption of EAL Scheme Pursuant to NEI 99-01 - EPID L-2017-LLA-0420 ML18088A0102018-03-28028 March 2018 NRR E-mail Capture - Final RAI for Duane Arnold (DAEC) 5th-10 Year ISI (RR-05) ML18058A0522018-02-27027 February 2018 Enclosurequest for Additional Information (Letter: RAI Regarding Florida Power and Light/Nextera Decommissioning Funding Plan Updates for St. Lucie, Units 1 & 2; Seabrook Station; Duane Arnold Energy Center; and Point Beach, Units 1 and 2) ML18037B0032018-02-0606 February 2018 NRR E-mail Capture - Draft Request for Additional Information - Duane Arnold Energy Center (DAEC) - License Amendment Request (TSCR-170), Revision to Technical Specification 3.5.1, ECCS-Operating - EPID L-2017-LLA-0288 ML17347A8752017-12-12012 December 2017 NRR E-mail Capture - Second Round of Request for Additional Information - Duane Arnold Energy Center (DAEC) - LAR to Adopt TST-542, Revision 2, Reactor Pressure Vessel Water Inventory Control - CAC No. MF9829 ML17277A3652017-10-0404 October 2017 NRR E-mail Capture - Final Request for Additional Information - Duane Arnold - Application to Revise Technical Specifications to Adopt TSTF-542, Revision 2, Reactor Pressure Vessel Water Inventory Control - CAC No. MF9829 ML17240A0082017-08-25025 August 2017 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center (DAEC) - Fifth Ten Year Service Inspection Interval - Relief Request No. RR-04, Rev. 0 - Proposed Alternative for Seal Weld Procedure Qualification - MF937 ML17220A3332017-08-0808 August 2017 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center - Relief Request No. RR-03 - Alternative Requirements for Nozzle Inner Radius and Nozzle-To-Shell Welds - CAC No. MF9374 ML17159A7962017-06-0707 June 2017 17 Duane Arnold Energy Center - Information Request to Support the NRC Annual Baseline Emergency Action Level and Emergency Plan Changes Inspection (Mxg) ML17068A0632017-03-0808 March 2017 NRR E-mail Capture - Final - Request for Additional Information (RAI) - Duane Arnold Energy Center (DAEC) - Revision to Staff Augmentation Times in the Duane Arnold Energy Center (DAEC) Emergency Plan (Eplan) - MF8390 ML16333A4622016-11-28028 November 2016 NRR E-mail Capture - Final Request for Additional Information - Duane Arnold Energy Center - LAR - SFP Criticality - MF7486 ML16326A0092016-11-18018 November 2016 NRR E-mail Capture - Request for Additional Information Re. Nextera/Fpl LAR to Adopt TSTF-545 - CACs MF8203, MF8204, MF8208, and MF8209 ML16313A0742016-11-0808 November 2016 NextEra Audit Plan Nov 2016 (DAEC SFP Criticality LAR) ML16075A0032016-03-14014 March 2016 NRR E-mail Capture - Request for Additional Information - Duane Arnold Energy Center - LAR to Reduce the Reactor Steam Dome Pressure Specified in the Technical Specifications 2.1.1, Reactor Core Safety Limits - MF6618 ML16074A3142016-03-14014 March 2016 NRR E-mail Capture - Second Round RAIs - Duane Arnold Energy Center - LAR (TSCR-143) to Extend Containment Leakage Test Frequency - MF6619 ML16021A0122016-01-21021 January 2016 Request for Additional Information by the Containment & Ventilation Branch and PRA Licensing Branch License Amendment Request - Extension of the 10 CFR 50 Appendix J Containment Type a & Type C Test Intervals ML16022A0092016-01-21021 January 2016 NRR E-mail Capture - Request for Additional Information - LAR to Revise and Relocate Pressure and Temperature Limit Curves to a Pressure and Temperature Limits Report - MF6617 ML16014A6962016-01-0707 January 2016 E-Mail: Duane Arnold, MOD/50.59 Inspection Request for Information (Jsp) ML16005A6082015-12-24024 December 2015 E-Mail: Duane Arnold Request for Information; December 24, 2015 (AAS) ML15175A0652015-06-23023 June 2015 Ltr. 06/23/15 Duane Arnold Energy Center - Notification of an NRC Triennial Heat Sink Performance Inspection and Request for Information Inspection Report 05000331/2015003 (Axd) ML14057A7562014-02-25025 February 2014 14 Duane Arnold CDBI Request for Information ML14031A1462014-01-29029 January 2014 Update to NextEra Energy Duane Arnold, Llc'S Response to NRC Request for Additional Information Associated with Near-Term Task Force Recommendations ML13323B4432013-11-26026 November 2013 Interim Staff Evaluation and Request for Additional Information Regarding the Overall Integrated Plan for Implementation of Order EA-12-051, Reliable Spent Fuel Pool Instrumentation ML13255A1982013-09-16016 September 2013 Request for Additional Information Regarding Overall Integrated Plan for Reliable Spent Fuel Pool Instrumentation (Order Number EA-12-051) ML13175A3932013-06-27027 June 2013 Request for Additional Information for Review Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 ML13154A5112013-06-0404 June 2013 Rai'S Following Ifib Analysis of NextEra Energy'S 2013 Decommissioning Funding Status Reports for Duane Arnold Energy Center and Point Beach Units 1 and 2 ML12107A0592012-04-11011 April 2012 NRR E-mail Capture - ME7246 - DAEC - Request for Additional Information (RAI) Relief Requests NDR-R003, R010, R011, R014, R015 ML12056A0502012-03-12012 March 2012 Enclosure 4 - Recommendation 2.3: Flooding ML12056A0482012-03-12012 March 2012 Enclosure 2 - Recommendation 2.1: Flooding ML12056A0512012-03-12012 March 2012 Enclosure 5 - Recommendation 9.3: Emergency Preparedness ML12056A0492012-03-12012 March 2012 Enclosure 3 - Recommendation 2.3: Seismic ML12056A0472012-03-12012 March 2012 Enclosure 1 - Recommendation 2.1: Seismic ML1201203182012-01-17017 January 2012 Request for Additional Information Amendment to Change Emergency Action Levels ML12011A0602012-01-0404 January 2012 NRR E-mail Capture - ME6508 - DAEC - Emergency Action Level (EAL) Changes ML1132105812011-11-28028 November 2011 Request for Additional Information Regarding 60-Day Response to Bulletin 2011-01, Mitigating Strategies. 2024-07-12
[Table view] |
Text
1NRR-DMPSPEm Resource From:Chawla, Mahesh Sent:Wednesday, March 28, 2018 5:12 PM To:Davis, J.Michael (J.Micha el.Davis@nexteraenergy.com)
Cc:'laura.swenzinski@nexteraenergy.com'; Catron
, Steve (Steve.Catron@fpl.com); Kilby, Gary; Murrell, Bob (Bob.Murrell@nexterae nergy.com); Probst, Jim; Weaver, Tracy
Subject:
Final RAI for Duane Arnold (DAEC) Re: 5t h-10 year ISI (RR-05) (EPID L-2017-LLR-0140)
Attachments:
EPID L-2017-LLR-0140 - Final RAIs - RR05.docx
Dear Mr. Davis:
By letter dated November 16, 2017, (ADAMS Accession No. ML17325B215) NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR) as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). The RR, designated as RR-05, is being requested in
order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current ASME Code Section XI requirements.
On March 13, 2018, the U.S. Nuclear Regulatory Commission (NRC) staff sent you a draft request for additional information identifying the additional information needed to complete its review. On March 28, 2018, a teleconference was held between the NRC staff and your representatives to providing any clarification needed for the request for additional information (RAI). During the teleconference, your representatives acknowledged a clear understanding of the requested information.
Attached, please find the final RAI. Please provide your written response on the docket prior to 30 days from the receipt of this email, as agreed upon by your representative.
Thank you for your attention.
Mahesh (Mac) Chawla United States Nuclear Regulatory Commission (NRC)
Licensing Project Manager - NRR/DORL/LPL3 Mahesh.chawla@nrc.gov (301) 415-8371
Hearing Identifier: NRR_DMPS Email Number: 265 Mail Envelope Properties (Mahesh.Chawla@nrc.gov20180328171100)
Subject:
Final RAI for Duane Arnold (DAEC) Re: 5th-10 year ISI (RR-05) (EPID L-2017-LLR-0140) Sent Date: 3/28/2018 5:11:40 PM Received Date: 3/28/2018 5:11:00 PM From: Chawla, Mahesh Created By: Mahesh.Chawla@nrc.gov Recipients: "'laura.swenzinski@nexteraenergy.com'" <laura.swenzinski@nexteraenergy.com> Tracking Status: None "Catron, Steve (Steve.Catron@fpl.com)" <Steve.Catron@fpl.com> Tracking Status: None "Kilby, Gary" <Gary.Kilby@fpl.com>
Tracking Status: None "Murrell, Bob (Bob.Murrell@nexteraenergy.com)" <Bob.Murrell@nexteraenergy.com> Tracking Status: None "Probst, Jim" <Jim.Probst@nexteraenergy.com> Tracking Status: None "Weaver, Tracy" <Tracy.Weaver@nexteraenergy.com> Tracking Status: None "Davis, J.Michael (J.Michael.Davis@nexteraenergy.com)" <J.Michael.Davis@nexteraenergy.com> Tracking Status: None
Post Office: Files Size Date & Time MESSAGE 1424 3/28/2018 5:11:00 PM EPID L-2017-LLR-0140 - Final RAIs - RR05.docx 31271 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:
1 Request for Additional Information Re: Duane Arnold Energy Center Fifth-10 Year Inservice Inspection Interval Program Plan Relief Request No. RR-05 Docket No. 50-331 By letter dated November 16, 2017 (ADAMS Accession No. ML17325B215), NextEra Energy Duane Arnold, LLC (the licensee) submitted a relief request (RR), as part of the Fifth-10 year Inservice Inspection Interval Program Plan for Duane Arnold Energy Center (DAEC). RR-05 is being requested in order for DAEC to continue the implementation of the previously approved Risk-Informed lnservice Inspection Program (RI-ISI), as an alternative to the current requirements of Class 1 and 2 examination Categories B-F, B-J, C-F-1, and C-F-2 as specified in Table IWB 2500-1, and Table IWC 2500-1 of the 2007 Edition with 2008 Addenda of ASME Code Section XI.
The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your proposed request and has identified an area where additional information is needed to complete its review. The following requests for additional information (RAIs) require licensee responses:
APLA-RAI-01 In DAEC RR-05 submittal, page 5, "Risk Impact Analysis," the licensee states, in part:
The revised program continues to be less than the EPRI criterion with a total change in plant risk of 4.34E-09 in regards to CDF and 4.3E-09 in regards to LERF. NRC Staff Request:
- a. Regarding the statement above, since LERF is typically at least an order of magnitude lower than CDF, explain why the total changes in CDF and LERF are essentially equal.
- b. Explain why the 03RWCU System parameter (exhibited in the Risk Impact Results matrix),
on page 5, has a change in LERF exceeding that of CDF. The NRC staff is requesting clarification in the data set since CDF values would typically be greater than LERF values.
APLA-RAI-02 According to Regulatory Issue Summary 2007-06, the NRC would expect licensees to fully address all scope elements consistent with Revision 2 of Regulatory Guide (RG) 1.200 by the end of 2009 (i.e., one year implementation period). Revision 2 of RG 1.200 endorses, with exceptions and clarifications, the combined American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) PRA standard (ASME/ANS RA-Sa-2009).
In Attachment 2, "DAEC PRA Model Quality Summary," page 2 (of the submittal), the licensee states, in part:
2 The focused scope peer review conducted in March 2011 -utilized version RA-Sa-2009 of the ASME Standard as endorsed and clarified by the NRC in Regulatory Guide 1.200, Revision 2.
NRC Staff Request:
The NRC staff is requesting the licensee to confirm t hat all technical elements in Part 2 of the Standard, including internal flooding, were included in this March 2011 review. If not, please identify any gaps between the peer review and the requirements in RG 1.200, Revision 2, particularly focusing on those technical elements for which the most current peer review remains from 2007 against Rev. 1 of RG 1.200.
APLA-RAI-03 The NRC staff identified during its review the need for the licensee to further address several previously identified gaps that were incorporated into the DAEC PRA. Specifically, more information is requested re: DAEC Focused Peer Review Findings (Table C-1) which include:
- a. Findings & Observations (F&O) DA-D4-01A, which the licensee states, in part:
To address this associated finding, the reasonableness of the prior and posterior distributions was reviewed; it was concluded no model changes were required.
This implies that the mean of the likelihood (3/544 = 0.0055) was significantly higher (a factor of
- 60) than that for the prior (9E-5). The NRC staff determined this may suggest a Bayesian approach may not be appropriate if plant-specific behavior is significantly different (worse) than generic.
NRC Staff Request:
Did these values change subsequently such that the focused scope review had different values where the prior and likelihood were more aligned? Provide the results of the final Bayesian analysis and the conclusion by the peer review team that this Supporting Requirement (SR) is now MET.
- b. F&O IE-B3-01A, which the licensee states, in part:
Several findings and suggestions under HLR-A and HLR-B have been dispositioned / resolved, but the subsuming (IE-B3) and screening (IE-C4 (C6))
of initiating events does not meet the standard.
In particular, the Finding cited, (1) RBCCW is subsumed by TT, but not failed given TT; (2) GSW is subsumed by TC, but not failed given TC; (3) 1A1/1A2 bus failures and partial loss of feedwater are binned to TT, but their impact not modeled given TT; and (4) 1A3/1A4 bus failures are subsumed with TT, but unavailability of emergency power given failure of the bus. Additionally, the licensee stated that the CDF is 3.5E-09/yr.
3 NRC Staff Request:
Provide the NRC staff with information regarding these deficiencies due to subsuming, specifically are they rectified? Additionally, the information provided in the disposition cites conservatisms with respect to piping leg breaks not yet incorporated into the model. It is not clear to the NRC staff if any sequences initiated by or subsequently involving these breaks could be affected by the application such that failure to incorporate these into the PRA could underestimate the change in CDF or LERF. If so, provide information (e.g., a sensitivity evaluation) that includes these into the applicable risk metrics and determine any effect.
- c. F&O HR-A1-01A and F&O HR-A2-01A, which the licensee states, in part:
The approach used in the DAEC PRA was different than currently prescribed in the standard, but is considered capable of accurately identifying pre-initiators. As such this variance from the standard has no impact on this application.
NRC Staff Request:
Provide the NRC staff with information regarding why the use of this "different approach", as stated above, accurately identifies pre-initiators such that it is equivalent to the approach required by the Standard (ASME/ANS RA-Sa-2009).
- d. F&O HR-C1-01A, which the licensee states, in part:
In other cases, the [Human Failure Events] HFE is at the train level, but no corresponding system level dependent HFE is included.
NRC Staff Request:
The F&O disposition cites addition of train-level pre-initiating HFEs to the model. However, it is not clear to the NRC staff if this deficiency r egarding "corresponding system-level dependent HFEs" has been corrected as well. If not, provide the NRC staff with information (e.g., performance of a sensitivity evaluation) incorporating these dependencies and assess any effect on the risk metrics.
APLA-RAI-04 The NRC staff identified during its review of the licensee's source material regarding the RI-ISI
consequence evaluation (Table C-2), that severa l items exhibited in the matrix required additional information, including:
- a. For Item No. 49, the licensee states, in part:
Given that Level 2 results are often the determining parameter for assignment of consequence category in the RI-ISI evaluation, this item is judged to have little influence on its results.
4 NRC Staff Request:
Provide the NRC staff with information regarding the stated term "little influence" and justify why any such influence would not affect the risk metrics appropriate for this application in any detrimental way.
- b. For Item No. 58, there is no information provided in either the Status or Estimated RI-ISI Impact columns of the matrix.
NRC Staff Request:
Provide this information for Item No. 58, or justify to the NRC staff why there is no information.
- c. For Item No. 59, the licensee states, in part:
The subject gate [RCIC-07-01] is a very low contributor to RCIC system failure. Therefore this item has essentially no influence on the RI-ISI application.
NRC Staff Request:
Provide the NRC staff with information regarding any effect from the retention of gate RCIC 01 that could lead to an underestimate of any of the applicable risk metrics for this application.
- d. For Item No. 63, the licensee states, in part:
Modeling of water hammer is very low contributor to HPCI and RCIC system failure.
NRC Staff Request:
Provide the NRC staff with information regarding the basis for the statement above (e.g., what are the failure likelihoods for HPCI and RCIC currently modeled and how do they compare with the likely value for water hammer).
- e. For Item No. 64, the licensee states, in part:
The current treatment of human actions to manage water level following plant
trips, including ATWS, is believed to be overly conservative and would benefit from refinement. The current model is conservative for the RI-ISI application with respect to this time.
NRC Staff Request:
Provide the NRC staff with information regarding any potential dependencies among these separate events, such that the current combined failure probability may be under-estimated if these dependencies are not modeled. If so, provide a quantitative evaluation (e.g., a sensitivity evaluation) addressing any potential dependencies.
5 APLA-RAI-05 The NRC staff's review of the licensee's source material regarding plant modifications assessed as potentially having a PRA impact (Table C-3), that EC No. 156110, "Installation of Well Water Isolation Valve V44-0509," requires additional information:
For EC No. 156110, the licensee states, in part:
This is acceptable based on low safety significance of well water system isolation valves. NRC Staff Request:
Provide the NRC staff with information regarding if the use of the above stated term "low safety significance" includes "low risk importance" such that the exclusion remains justified for this application.