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| {{#Wiki_filter:Slide 1 NEI 01-01 Need For NRC to Further Qualify or Modify its Endorsement of NEI 01-01 History Background LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)-Based Replacement Cards NRC Concerns with respect to NEI 01-01 NEI 01-01 Slide 2 NEI 01-01 History -102348 Revision 1, NEI 01-01: A revision of the EPRI TR-102348 to Reflect Later in 2002 NRC endorsed NEI 01-01 in Regulatory Issue Summary (RIS) 2002-22 As part of NEI 01-given as 1) the revision of 10 CFR 50.59 and 2) the availability of new regulatory guidance. Since NEI 01-01 was published many plants have included NEI 01-01 in their procedures for evaluating digital upgrades After the conclusion of the Digital I&C Project in 2011, the NRC and NEI identified a number of issues to continue to work on including the 10 CFR 50.59 process and the guidance in NEI 01-01 In December 2012 NRC again brought up the need to update/revisit NEI 01-01 Slide 3 NEI 01-01 Background Since the publication NEI 01-01 there has been a significant number of new regulatory guidance documents, and agency positions published (as a result of plant upgrades using digital systems). These include ISG-04, ISG-06, the software quality regulatory guides (Regulatory Guide 1.168. 1.169. 1.170, 1.171, 1.172, 1.173), Regulatory Guide 1.152, BTP-07-19. In addition to changes in regulatory guidance we also have operating experience experience (LaSalle 50.59 for Rod Control Management System and Harris 50.59 for implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards) that indicates the guidance in NEI 01-01 is not always being correctly interpreted. | | {{#Wiki_filter:NEI 01-01 Need For NRC to Further Qualify or Modify its Endorsement of NEI 01-01 |
| Slide 4 NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 In December 2009, NRC inspectors identified a concern regarding the replacement of an analog-based rod control management system (RCMS) with a computer-based system at LaSalle County Station, Unit 2. The RCMS is a nonsafety system; however, it is important to safety because it directly affects core reactivity. The inspectors determined that the licensee had not properly evaluated NEI 01-common-cause failure and the potential for spurious, uncontrolled simultaneous withdrawal of four control rods. During discussions with the inspectors, the licensee stated their belief that a software common-cause failure did not need to be considered in the 10 CFR 50.59 evaluation, based on the guidance in NEI 01-01, Section 4.4.6. | | * History |
| Slide 5 NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 The licensee interpreted NEI 01-01, Section 4.4.6. to allow changes if the likelihood of a software common-cause failure could be justified as sufficiently low because of the high quality of the software application The licensee incorrectly determined that the software quality was sufficiently high to provide reasonable assurance that the likelihood of software failure was not creditable and therefore the digital upgrade would not require prior NRC review on the basis of software common-cause failures The licensee implemented compensatory actions to mitigate the consequences of a software common-cause failure of the RCMS. IN 2010-01-01 to address the issues discussed in the IN Slide 6 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards Earlier this year, NRC inspectors identified a concern with the 10 CFR 50.59 evaluation associated with a modification that implemented Complex Programmable Logic Device (CPLD) based replacement cards for the Solid State Protection System (SSPS) at Harris. The SSPS circuit boards provide the coincidence logic to produce actuation signals for operation of the reactor trip and engineered safety features of the reactor protection system. Unlike the original SSPS boards, which use fixed logic devices, the replacements SSPS boards use CPLD technology. The CPLD-based SSPS boards (CPLD boards) require the use of software tools to develop an application-specific software (data file), which resides in function. NEI 01-01 Slide 7 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards evaluation. For instance the CPLD boards contained software, but the 50.59 did not address the quality of the software The licensee did not perform engineering evaluations addressed in Section 4.4.6 and described in Chapter 5 of NEI 01-01 to evaluate the quality and design processes to determine if there is reasonable assurance that the likelihood of failure due to software was sufficiently low These evaluations are necessary to assess whether failures due to software, including software CCF, need to be addressed further NEI 01-01 Slide 8 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards The inspectors found that the licensee did not perform defense-in-depth and diversity (D3) analysis and software CCF engineering evaluations These evaluations are required by 3.2.2 of NEI 01-01 and should have been preformed for the Human Systems Interface (HSI) functions. Section 3.2.2 states in part, that for digital modifications, the D3 aspects of the upgraded design are analyzed to assure that where there are potential vulnerabilities to software CCF, the plant has adequate capability to cope with them. Failure to address D3 and software CCF prevented the licensee from being able to demonstrate that the new CPLD boards did not create the possibility of a malfunction the SSPS with a different result from that analyzed in the UFSAR. NEI 01-01 NEI 01-01 NRC Concerns with Respect to NEI 01-01 NEI 01-01 Definitions Although current at the time, the change in technology, particularly associated software tools to support both software based systems and logic devices, has left some definitions in NEI 01-01 in need of revision These definitions include hardware, firmware, computer, computer program, diversity, defense-in-depth and software tools References to NRC Guidance and Discussion of the Guidance As a result of the NRC Digital Instrumentation and Control Project and routine guidance maintenance a significant number of NRC guidance documents referenced in NEI 01-01 have changed. These include Regulatory Guides 1.152, 1.168-1.173, ISG-02, ISG-4, ISG-6, BTP-07-19, etc. 19 Regulatory positions taken associated with the Wolf Creek FPGA implementation, SERs on software tools, etc. Slide 9 NEI 01-01 NRC Concerns with Respect to NEI 01-01 As a result of the experience from the LaSalle and Harris 10 CFR 50.59 inspections it is clear that some of the guidance in NEI 01-01 is not being interpreted in a way that leads to appropriate application of 10 CFR 50.59. A Diversity and Defense-in-Depth analysis must be preformed and appropriate design decisions and support 10 CFR 50.59 analyses criteria must be examined (Sections 3.2.2, 4.4.6 and Appendix A) It appears that licensees may be interpreting the NEI 01-01 to exclude from consideration software common-cause failure vulnerabilities based on a high-quality software design, implementation, and verification and validation program. Section 3.2.2 states in part, that for digital modifications, D3 is analyzed to assure that where there are vulnerabilities to software CCF, the plant has adequate capability to cope. However, it also contains language that can be interpreted as not requiring a D3 analysis for software deemed to have low likelihood of failure. Slide 10 NEI 01-01 NRC Concerns with Respect to NEI 01-01 There are a number of examples (such as Example 4-1) and text (section 4.3.2) that may provide misleading direction associated with screening out of systems with software Even though the example given is appropriate, the extension to all other systems may not be, and needs to be updated to more appropriately support current applications Slide 11 Slide 12 NEI 01-01 Discussion Because of ongoing challenges with the interpretation of NEI 01-01, changes in regulatory guidance since its endorsement, and the wide-spread use of new technology, NRC plans to further qualify or modify its endorsement of NEI 01-01 (RIS 2002-22) Several paths are being considered: Re-endorsing NEI 01-01 with additional regulatory positions to provide additional clarity to guidance associated with the difficulties that have been experienced Endorsement of an updated version of NEI 01-01 that addresses all changes to regulatory guidance, new technology, and lessons learned from LaSalle and Harris A combination of the above two options in which, the NRC, in the short term further qualifies it endorsement, while a new version is developed}} | | * Background |
| | * LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 |
| | * Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)-Based Replacement Cards |
| | * NRC Concerns with respect to NEI 01-01 |
| | * Discussion of Regarding the NRC staffs future endorsement of NEI 01-01 Slide 1 |
| | |
| | NEI 01-01 History |
| | * In 2002 Guideline on Licensing Digital Upgrades, TR-102348 Revision 1, NEI 01-01: A revision of the EPRI TR-102348 to Reflect Changes to the 10 CFR 50.59 Rule was published |
| | * Later in 2002 NRC endorsed NEI 01-01 in Regulatory Issue Summary (RIS) 2002-22 |
| | * As part of NEI 01-01s Summary the reasons for updating were given as 1) the revision of 10 CFR 50.59 and 2) the availability of new regulatory guidance. |
| | * Since NEI 01-01 was published many plants have included NEI 01-01 in their procedures for evaluating digital upgrades |
| | * After the conclusion of the Digital I&C Project in 2011, the NRC and NEI identified a number of issues to continue to work on including the 10 CFR 50.59 process and the guidance in NEI 01-01 |
| | * In December 2012 NRC again brought up the need to update/revisit NEI 01-01 Slide 2 |
| | |
| | NEI 01-01 |
| | |
| | ===Background=== |
| | * Since the publication NEI 01-01 there has been a significant number of new regulatory guidance documents, and agency positions published (as a result of plant upgrades using digital systems). These include ISG-04, ISG-06, the software quality regulatory guides (Regulatory Guide 1.168. 1.169. 1.170, 1.171, 1.172, 1.173), Regulatory Guide 1.152, BTP-07-19. |
| | * In addition to changes in regulatory guidance we also have operating experience experience (LaSalle 50.59 for Rod Control Management System and Harris 50.59 for implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards) that indicates the guidance in NEI 01-01 is not always being correctly interpreted. |
| | Slide 3 |
| | |
| | NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 |
| | * In December 2009, NRC inspectors identified a concern regarding the replacement of an analog-based rod control management system (RCMS) with a computer-based system at LaSalle County Station, Unit 2. |
| | * The RCMS is a nonsafety system; however, it is important to safety because it directly affects core reactivity. |
| | * The inspectors determined that the licensee had not properly evaluated NEI 01-01, Appendix A, Supplemental Questions associated with software common-cause failure and the potential for spurious, uncontrolled simultaneous withdrawal of four control rods. |
| | * During discussions with the inspectors, the licensee stated their belief that a software common-cause failure did not need to be considered in the 10 CFR 50.59 evaluation, based on the guidance in NEI 01-01, Section 4.4.6. |
| | Slide 4 |
| | |
| | NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10 |
| | * The licensee interpreted NEI 01-01, Section 4.4.6. to allow changes if the likelihood of a software common-cause failure could be justified as sufficiently low because of the high quality of the software application |
| | * The licensee incorrectly determined that the software quality was sufficiently high to provide reasonable assurance that the likelihood of software failure was not creditable and therefore the digital upgrade would not require prior NRC review on the basis of software common-cause failures |
| | * The licensee implemented compensatory actions to mitigate the consequences of a software common-cause failure of the RCMS. |
| | * IN 2010-10 stated the staffs intent to further qualify the endorsement of NEI 01-01 to address the issues discussed in the IN Slide 5 |
| | |
| | NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) |
| | Based Replacement Cards |
| | * Earlier this year, NRC inspectors identified a concern with the 10 CFR 50.59 evaluation associated with a modification that implemented Complex Programmable Logic Device (CPLD) based replacement cards for the Solid State Protection System (SSPS) at Harris. |
| | * The SSPS circuit boards provide the coincidence logic to produce actuation signals for operation of the reactor trip and engineered safety features of the reactor protection system. Unlike the original SSPS boards, which use fixed logic devices, the replacements SSPS boards use CPLD technology. |
| | * The CPLD-based SSPS boards (CPLD boards) require the use of software tools to develop an application-specific software (data file), which resides in the memory of the CPLD, that program the boards logic to perform a desired function. |
| | Slide 6 |
| | |
| | NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) |
| | Based Replacement Cards |
| | * The inspectors identified concerns with the licensees the 50.59 evaluation. For instance the CPLD boards contained software, but the 50.59 did not address the quality of the software |
| | - The licensee did not perform engineering evaluations addressed in Section 4.4.6 and described in Chapter 5 of NEI 01-01 to evaluate the quality and design processes to determine if there is reasonable assurance that the likelihood of failure due to software was sufficiently low |
| | - These evaluations are necessary to assess whether failures due to software, including software CCF, need to be addressed further Slide 7 |
| | |
| | NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD) |
| | Based Replacement Cards |
| | * The inspectors found that the licensee did not perform defense-in-depth and diversity (D3) analysis and software CCF engineering evaluations |
| | - These evaluations are required by 3.2.2 of NEI 01-01 and should have been preformed for the Human Systems Interface (HSI) functions. |
| | - Section 3.2.2 states in part, that for digital modifications, the D3 aspects of the upgraded design are analyzed to assure that where there are potential vulnerabilities to software CCF, the plant has adequate capability to cope with them. |
| | * Failure to address D3 and software CCF prevented the licensee from being able to demonstrate that the new CPLD boards did not create the possibility of a malfunction the SSPS with a different result from that analyzed in the UFSAR. |
| | Slide 8 |
| | |
| | NEI 01-01 NRC Concerns with Respect to NEI 01-01 |
| | * NEI 01-01 Definitions |
| | - Although current at the time, the change in technology, particularly associated with more extensive use of CPLDs and FPGAs, and the more extensive use of software tools to support both software based systems and logic devices, has left some definitions in NEI 01-01 in need of revision |
| | - These definitions include hardware, firmware, computer, computer program, diversity, defense-in-depth and software tools |
| | * References to NRC Guidance and Discussion of the Guidance |
| | - As a result of the NRC Digital Instrumentation and Control Project and routine guidance maintenance a significant number of NRC guidance documents referenced in NEI 01-01 have changed. These include Regulatory Guides 1.152, 1.168-1.173, ISG-02, ISG-4, ISG-6, BTP-07-19, etc. |
| | - Of particular concern is the interpretation of simple devices in BTP-07-19 |
| | - Regulatory positions taken associated with the Wolf Creek FPGA implementation, SERs on software tools, etc. |
| | Slide 9 |
| | |
| | NEI 01-01 NRC Concerns with Respect to NEI 01-01 |
| | * As a result of the experience from the LaSalle and Harris 10 CFR 50.59 inspections it is clear that some of the guidance in NEI 01-01 is not being interpreted in a way that leads to appropriate application of 10 CFR 50.59. |
| | - A Diversity and Defense-in-Depth analysis must be preformed and appropriate design decisions and support 10 CFR 50.59 analyses criteria must be examined (Sections 3.2.2, 4.4.6 and Appendix A) |
| | - It appears that licensees may be interpreting the NEI 01-01 to exclude from consideration software common-cause failure vulnerabilities based on a high-quality software design, implementation, and verification and validation program. |
| | * Section 3.2.2 states in part, that for digital modifications, D3 is analyzed to assure that where there are vulnerabilities to software CCF, the plant has adequate capability to cope. However, it also contains language that can be interpreted as not requiring a D3 analysis for software deemed to have low likelihood of failure. |
| | Slide 10 |
| | |
| | NEI 01-01 NRC Concerns with Respect to NEI 01-01 |
| | * There are a number of examples (such as Example 4-1) and text (section 4.3.2) that may provide misleading direction associated with screening out of systems with software |
| | - In such a case, even when it affects redundant systems, the digital upgrade would screen out. |
| | * Even though the example given is appropriate, the extension to all other systems may not be, and needs to be updated to more appropriately support current applications Slide 11 |
| | |
| | NEI 01-01 Discussion |
| | * Because of ongoing challenges with the interpretation of NEI 01-01, changes in regulatory guidance since its endorsement, and the wide-spread use of new technology, NRC plans to further qualify or modify its endorsement of NEI 01-01 (RIS 2002-22) |
| | * Several paths are being considered: |
| | - Re-endorsing NEI 01-01 with additional regulatory positions to provide additional clarity to guidance associated with the difficulties that have been experienced |
| | - Endorsement of an updated version of NEI 01-01 that addresses all changes to regulatory guidance, new technology, and lessons learned from LaSalle and Harris |
| | - A combination of the above two options in which, the NRC, in the short term further qualifies it endorsement, while a new version is developed Slide 12}} |
|
|---|
Category:Meeting Briefing Package/Handouts
MONTHYEARML24100A7672024-04-11011 April 2024
Meeting Slides - Preapplication with Constellation on Planned Fleet Alternative Request to Adopt OMN-2
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Slides - Constellation - Pre-Application Regarding Hooded Masks 4/9/2024 Meeting Slides (L-2024-LLM-0041)
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Duke Energy Sites Annual Assessment Meeting Presentation Slides April 23, 2024
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Constellation Pre-Application January 30, 2024, Meeting Slides - Proposed Alternative to Utilize Code Case N-932, Alternative Requirements for Acceptance of Containment Base Metal Corrosion or Erosion
ML23341A1522023-12-0707 December 2023
December 11, 2023 Public Meeting - RIPE Exemption Request - Licensee Slides
ML23317A0712023-11-14014 November 2023
NRC Pre-Submittal Meeting on November 14th, 2023 - TSTF-591 and Selected 50.69 License Condition Updates (EPID L-2023-LLM-0098) (Slides)
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Pool Swell License - Amendment Request
ML22251A2352022-09-14014 September 2022
Presentation Slides for September 14, 2022, Observation Public Meeting
ML22153A3842022-06-0606 June 2022
Duke Energy Presentation Material for June 6, 2022 Public Meeting on GSI-191 Closeout
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Bru Har Combined 2021 Assessment Meeting Slides
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Slides for Presubmittial Meeting for Proposed Alternative to Adopt ASME Code Case N-921 to Extend the Inservice Inspection Interval
ML21194A1582021-07-13013 July 2021
and Lasalle Nuclear Generating Stations 2020 Annual Assessment Meeting Slides
ML21141A0102021-05-21021 May 2021
La Salle County Station, Units 1 and 2, May 27, 2021 Pre Submission Public Meeting Slides (EPID-L-2021-LRM-0052)
ML20261G7322020-09-16016 September 2020
Pre-Submittal Slides Extend 120-month Isi/Ist Interval Under 50.55a
ML20238B8662020-08-25025 August 2020
Hq Online EOC Slides
ML20178A4202020-06-30030 June 2020
NEI Slides for June 30, 2020, Public Meeting on COVID-19 Response
ML20170B0212020-06-23023 June 2020
NRC Pre-Submittal Meeting Byron Unit 2 One-Time Deferral of Reactor Pressure Vessel Head Penetration Nozzle (Rpvhpn) Inspections
ML20169A5592020-06-16016 June 2020
Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections (Rev 1)
ML20163A6552020-06-16016 June 2020
6-16-20 Byron Unit 2 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections
ML20100G6342020-04-0909 April 2020
Revised- Bru 2019 Annual Assessment Meeting Slides
ML19318F9512019-11-20020 November 2019
Presentation Slides for November 20, 2019, Pre-Application Meeting - Request for Revision to Quality Assurance Program Internal Audit Frequency
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Duke Energy Presentation for the Pre-submittal Meeting on November 18, 2019, Regarding the RPV Stud Examination Relief Request
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Presentation: Duke Energy Presubmittal Meeting - August 7, 2019
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BWR Fleet Msv/Srv - Testing Frequency Relief Request NRC Pre-Application Meeting June 4, 2019
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BWR Fleet Mssv/Srv Testing Frequency Relief Request NRC Pre-Application Meeting June 4, 2019
ML19077A3672019-03-14014 March 2019
March 14, 2019 Pre-submittal Meeting TS DNBR Safety Limit Change LAR Meeting Slides
ML19022A2002019-01-23023 January 2019
Request for Use of ASME Code Case N-879 for Exelon Nuclear Power Plants
ML18351A1342018-12-20020 December 2018
December 20, 2018 Pre-submittal Meeting Slides for Escw Risk-Informed LAR
ML18347B3142018-12-19019 December 2018
Bwrvip/Asme Relief Request Discussion December 19, 2018
ML18334A2162018-11-30030 November 2018
Presentation Slides: Exelon BWR MSIV (Boiling-Water Reactor - Main Steam Isolation Valve) Leakage Optimization for NRC Pre-Submittal Meeting of December 6, 2018
ML18319A1272018-11-19019 November 2018
Slides for 11/19/18 Public Meeting - Exelon Fleet LAR for Common Language for TS 5.7 High Radiation Areas
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Pre-Submittal Meeting - November 8, 2018 - License Amendment Request for Shearon Harris Nuclear Power Plant Emergency Plan Revision
ML18054B3592018-02-27027 February 2018
Slide: NRC Pre-Submittal Meeting for Exelon Fleet LAR to Relocate TS Unit Staff Qualification ANSI Requirements to the QATR, February 27, 2018, Profile Info: Submitted by Frank Mascitelli
ML17331A6272017-11-29029 November 2017
Duke Energy Pre-Submittal Meeting Presentation, Brunswick, Harris, and Robinson License Amendment Requests Regarding 10 CFR 50.69
ML17250B2382017-08-30030 August 2017
TMRE Presubmittal NRC
ML17142A2382017-05-25025 May 2017
OEDO-17-00280 - Briefing Package for Drop-In Visit on June 9, 2017, by Senior Management of Exelon Generation Company, LLC with Chairman Svinicki, Commissioner Baran, and Commissioner Burns
ML17044A0892017-03-0202 March 2017
EDG SR Presubmittal Meeting March 2, 2017
ML16267A0292016-09-29029 September 2016
SFP Pre-Submittal Meeting Slides - BWR Storage Rack Inserts, Updated NCS Analysis at Harris Nuclear Plant
ML16194A0062016-07-12012 July 2016
Pre-Application Meeting Presentation Regarding LaSalle County Station License Amendment Request for Revision of Suppression Pool Swell Design Analysis
ML16112A2932016-05-0202 May 2016
05/02/2016 Presentation for Closed Pre-Submittal Meeting with Duke Energy Progress, Inc., to Discuss Fuel Reload Design Methodology Reports and Proposed LAR Re. H. B. Robinson And Shearon Harris Plants (CAC Nos. MF7443 And MF7444)
ML16077A1562016-03-22022 March 2016
Fleet: Pre-application Teleconference with Exelon to Discuss a Potential License Amendment Request Regarding Operating Training Standards
ML16077A3492016-03-17017 March 2016
NRC Briefing Slides for LaSalle Dseis Public Meeting March 22, 2016
ML16075A3292016-03-16016 March 2016
OEDO-16-00165 - Briefing Package for Drop-In Visit on March 23, 2016, by Senior Management of Exelon Generation Company, LLC with the NRC Executive Director for Operations
RA-15-0041, Attachment 1, Affidavit and Attachment 3, Pre-Submittal Meeting Presentation Materials on DPC-NF-2010-A and DPC-NE-2011-P Methodologies (Redacted)2015-09-18018 September 2015
Attachment 1, Affidavit and Attachment 3, Pre-Submittal Meeting Presentation Materials on DPC-NF-2010-A and DPC-NE-2011-P Methodologies (Redacted)
ML15062A3642015-03-0303 March 2015
Environmental Scoping Briefing for March 10th Meetings
ML15058A6322015-02-27027 February 2015
LSCS Scoping Briefing Prepared 2-27-15 for March 10th Meeting
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Summary of Category 1 Public Meeting - Annual Assessment of Shearon Harris Nuclear Plant
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Summary of Public Meeting with Duke Energy Carolinas, LLC, to Provide Opportunities to Discuss the Planned Fukushima-Related Modifications
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2024-04-09
[Table view]
Category:Slides and Viewgraphs
MONTHYEARML24100A7672024-04-11011 April 2024
Meeting Slides - Preapplication with Constellation on Planned Fleet Alternative Request to Adopt OMN-2
ML24089A2612024-04-0909 April 2024
Slides - Constellation - Pre-Application Regarding Hooded Masks 4/9/2024 Meeting Slides (L-2024-LLM-0041)
ML24100A8062024-04-0909 April 2024
Duke Energy Sites Annual Assessment Meeting Presentation Slides April 23, 2024
ML24029A1742024-01-30030 January 2024
Constellation Pre-Application January 30, 2024, Meeting Slides - Proposed Alternative to Utilize Code Case N-932, Alternative Requirements for Acceptance of Containment Base Metal Corrosion or Erosion
ML23341A1522023-12-0707 December 2023
December 11, 2023 Public Meeting - RIPE Exemption Request - Licensee Slides
ML23317A0712023-11-14014 November 2023
NRC Pre-Submittal Meeting on November 14th, 2023 - TSTF-591 and Selected 50.69 License Condition Updates (EPID L-2023-LLM-0098) (Slides)
ML23255A1042023-08-11011 August 2023
Slides - Constellation - Pre-Application EP 9/18/2023 Draft CEG Presubmittal SG Performance Monitoring Plan Meeting Handout
ML23114A0672023-04-26026 April 2023
April 26 2023 Public Meeting - RIPE LAR - Licensee Slides
NEI 99-01, Slides - Constellation - Pre-Application EP 2/23/2023 Meeting Slides2023-02-21021 February 2023
Slides - Constellation - Pre-Application EP 2/23/2023 Meeting Slides
ML22311A5112022-11-0707 November 2022
Pool Swell License - Amendment Request
ML22251A2352022-09-14014 September 2022
Presentation Slides for September 14, 2022, Observation Public Meeting
ML22153A3842022-06-0606 June 2022
Duke Energy Presentation Material for June 6, 2022 Public Meeting on GSI-191 Closeout
ML22109A2122022-04-20020 April 2022
Duke Energy Pre-Submittal Public April 20, 2022, Meeting Presentation
ML22091A1332022-04-0101 April 2022
Bru Har Combined 2021 Assessment Meeting Slides
ML21322A3262021-11-29029 November 2021
Duke Energy November 29, 2021 Pre-Submittal Public Meeting Slides for EOF Relocation Licensing Amendment Request
ML21314A4472021-11-10010 November 2021
Slides for Presubmittial Meeting for Proposed Alternative to Adopt ASME Code Case N-921 to Extend the Inservice Inspection Interval
ML21194A1582021-07-13013 July 2021
and Lasalle Nuclear Generating Stations 2020 Annual Assessment Meeting Slides
ML21162A3322021-06-11011 June 2021
BWR Fleet Relief Request Associated with RPV Instrument Nozzle Repairs
ML21141A0102021-05-21021 May 2021
La Salle County Station, Units 1 and 2, May 27, 2021 Pre Submission Public Meeting Slides (EPID-L-2021-LRM-0052)
ML20261G7322020-09-16016 September 2020
Pre-Submittal Slides Extend 120-month Isi/Ist Interval Under 50.55a
ML20238B8662020-08-25025 August 2020
Hq Online EOC Slides
ML20178A4202020-06-30030 June 2020
NEI Slides for June 30, 2020, Public Meeting on COVID-19 Response
ML20170B0212020-06-23023 June 2020
NRC Pre-Submittal Meeting Byron Unit 2 One-Time Deferral of Reactor Pressure Vessel Head Penetration Nozzle (Rpvhpn) Inspections
ML20169A5592020-06-16016 June 2020
Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections (Rev 1)
ML20163A6552020-06-16016 June 2020
6-16-20 Byron Unit 2 Steam Generator License Amendment Request Pre-Submittal Meeting (NRC) - Byron Unit 2 LAR for One-Time Deferral of Steam Generator Inspections
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Revised- Bru 2019 Annual Assessment Meeting Slides
ML20099C9992020-04-0808 April 2020
Har 2019 Mtg Slides
ML20099D1282020-04-0808 April 2020
Bru 2019 Mtg Slides
ML19318F2912019-11-18018 November 2019
Duke Energy Presentation for the Pre-submittal Meeting on November 18, 2019, Regarding the RPV Stud Examination Relief Request
ML19233A0462019-08-21021 August 2019
Presentation: Harris/Nrc Pre-submittal Meeting: Risk-Informed Completion Times, August 22, 2019
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2024-04-09
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NEI 01-01 Need For NRC to Further Qualify or Modify its Endorsement of NEI 01-01
- Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)-Based Replacement Cards
- Discussion of Regarding the NRC staffs future endorsement of NEI 01-01 Slide 1
NEI 01-01 History
- In 2002 Guideline on Licensing Digital Upgrades, TR-102348 Revision 1, NEI 01-01: A revision of the EPRI TR-102348 to Reflect Changes to the 10 CFR 50.59 Rule was published
- Later in 2002 NRC endorsed NEI 01-01 in Regulatory Issue Summary (RIS) 2002-22
- As part of NEI 01-01s Summary the reasons for updating were given as 1) the revision of 10 CFR 50.59 and 2) the availability of new regulatory guidance.
- Since NEI 01-01 was published many plants have included NEI 01-01 in their procedures for evaluating digital upgrades
- After the conclusion of the Digital I&C Project in 2011, the NRC and NEI identified a number of issues to continue to work on including the 10 CFR 50.59 process and the guidance in NEI 01-01
- In December 2012 NRC again brought up the need to update/revisit NEI 01-01 Slide 2
NEI 01-01
Background
- Since the publication NEI 01-01 there has been a significant number of new regulatory guidance documents, and agency positions published (as a result of plant upgrades using digital systems). These include ISG-04, ISG-06, the software quality regulatory guides (Regulatory Guide 1.168. 1.169. 1.170, 1.171, 1.172, 1.173), Regulatory Guide 1.152, BTP-07-19.
- In addition to changes in regulatory guidance we also have operating experience experience (LaSalle 50.59 for Rod Control Management System and Harris 50.59 for implementation of Complex Programmable Logic Device (CPLD) Based Replacement Cards) that indicates the guidance in NEI 01-01 is not always being correctly interpreted.
Slide 3
NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10
- In December 2009, NRC inspectors identified a concern regarding the replacement of an analog-based rod control management system (RCMS) with a computer-based system at LaSalle County Station, Unit 2.
- The RCMS is a nonsafety system; however, it is important to safety because it directly affects core reactivity.
- The inspectors determined that the licensee had not properly evaluated NEI 01-01, Appendix A, Supplemental Questions associated with software common-cause failure and the potential for spurious, uncontrolled simultaneous withdrawal of four control rods.
- During discussions with the inspectors, the licensee stated their belief that a software common-cause failure did not need to be considered in the 10 CFR 50.59 evaluation, based on the guidance in NEI 01-01, Section 4.4.6.
Slide 4
NEI 01-01 LaSalle 10 CFR 50.59 for Rod Control Management System and IN 2010-10
- The licensee interpreted NEI 01-01, Section 4.4.6. to allow changes if the likelihood of a software common-cause failure could be justified as sufficiently low because of the high quality of the software application
- The licensee incorrectly determined that the software quality was sufficiently high to provide reasonable assurance that the likelihood of software failure was not creditable and therefore the digital upgrade would not require prior NRC review on the basis of software common-cause failures
- The licensee implemented compensatory actions to mitigate the consequences of a software common-cause failure of the RCMS.
- IN 2010-10 stated the staffs intent to further qualify the endorsement of NEI 01-01 to address the issues discussed in the IN Slide 5
NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)
Based Replacement Cards
- Earlier this year, NRC inspectors identified a concern with the 10 CFR 50.59 evaluation associated with a modification that implemented Complex Programmable Logic Device (CPLD) based replacement cards for the Solid State Protection System (SSPS) at Harris.
- The SSPS circuit boards provide the coincidence logic to produce actuation signals for operation of the reactor trip and engineered safety features of the reactor protection system. Unlike the original SSPS boards, which use fixed logic devices, the replacements SSPS boards use CPLD technology.
- The CPLD-based SSPS boards (CPLD boards) require the use of software tools to develop an application-specific software (data file), which resides in the memory of the CPLD, that program the boards logic to perform a desired function.
Slide 6
NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)
Based Replacement Cards
- The inspectors identified concerns with the licensees the 50.59 evaluation. For instance the CPLD boards contained software, but the 50.59 did not address the quality of the software
- The licensee did not perform engineering evaluations addressed in Section 4.4.6 and described in Chapter 5 of NEI 01-01 to evaluate the quality and design processes to determine if there is reasonable assurance that the likelihood of failure due to software was sufficiently low
- These evaluations are necessary to assess whether failures due to software, including software CCF, need to be addressed further Slide 7
NEI 01-01 Harris 10 CFR 50.59 for Implementation of Complex Programmable Logic Device (CPLD)
Based Replacement Cards
- The inspectors found that the licensee did not perform defense-in-depth and diversity (D3) analysis and software CCF engineering evaluations
- These evaluations are required by 3.2.2 of NEI 01-01 and should have been preformed for the Human Systems Interface (HSI) functions.
- Section 3.2.2 states in part, that for digital modifications, the D3 aspects of the upgraded design are analyzed to assure that where there are potential vulnerabilities to software CCF, the plant has adequate capability to cope with them.
- Failure to address D3 and software CCF prevented the licensee from being able to demonstrate that the new CPLD boards did not create the possibility of a malfunction the SSPS with a different result from that analyzed in the UFSAR.
Slide 8
NEI 01-01 NRC Concerns with Respect to NEI 01-01
- Although current at the time, the change in technology, particularly associated with more extensive use of CPLDs and FPGAs, and the more extensive use of software tools to support both software based systems and logic devices, has left some definitions in NEI 01-01 in need of revision
- These definitions include hardware, firmware, computer, computer program, diversity, defense-in-depth and software tools
- References to NRC Guidance and Discussion of the Guidance
- As a result of the NRC Digital Instrumentation and Control Project and routine guidance maintenance a significant number of NRC guidance documents referenced in NEI 01-01 have changed. These include Regulatory Guides 1.152, 1.168-1.173, ISG-02, ISG-4, ISG-6, BTP-07-19, etc.
- Of particular concern is the interpretation of simple devices in BTP-07-19
- Regulatory positions taken associated with the Wolf Creek FPGA implementation, SERs on software tools, etc.
Slide 9
NEI 01-01 NRC Concerns with Respect to NEI 01-01
- As a result of the experience from the LaSalle and Harris 10 CFR 50.59 inspections it is clear that some of the guidance in NEI 01-01 is not being interpreted in a way that leads to appropriate application of 10 CFR 50.59.
- A Diversity and Defense-in-Depth analysis must be preformed and appropriate design decisions and support 10 CFR 50.59 analyses criteria must be examined (Sections 3.2.2, 4.4.6 and Appendix A)
- It appears that licensees may be interpreting the NEI 01-01 to exclude from consideration software common-cause failure vulnerabilities based on a high-quality software design, implementation, and verification and validation program.
- Section 3.2.2 states in part, that for digital modifications, D3 is analyzed to assure that where there are vulnerabilities to software CCF, the plant has adequate capability to cope. However, it also contains language that can be interpreted as not requiring a D3 analysis for software deemed to have low likelihood of failure.
Slide 10
NEI 01-01 NRC Concerns with Respect to NEI 01-01
- There are a number of examples (such as Example 4-1) and text (section 4.3.2) that may provide misleading direction associated with screening out of systems with software
- In such a case, even when it affects redundant systems, the digital upgrade would screen out.
- Even though the example given is appropriate, the extension to all other systems may not be, and needs to be updated to more appropriately support current applications Slide 11
NEI 01-01 Discussion
- Because of ongoing challenges with the interpretation of NEI 01-01, changes in regulatory guidance since its endorsement, and the wide-spread use of new technology, NRC plans to further qualify or modify its endorsement of NEI 01-01 (RIS 2002-22)
- Several paths are being considered:
- Re-endorsing NEI 01-01 with additional regulatory positions to provide additional clarity to guidance associated with the difficulties that have been experienced
- Endorsement of an updated version of NEI 01-01 that addresses all changes to regulatory guidance, new technology, and lessons learned from LaSalle and Harris
- A combination of the above two options in which, the NRC, in the short term further qualifies it endorsement, while a new version is developed Slide 12
