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Category:Differing Professional Opinion Case File
MONTHYEARML21047A2412021-02-16016 February 2021
DPO-2019-001, Redacted Differing Professional Opinion (DPO) Case File (Public)
ML0711502362007-04-16016 April 2007
DPO-2006-002: DPO Followup Actions and Schedule
ML0711502382007-04-16016 April 2007
DPO-2006-003: DPO Followup Actions and Schedule
ML0712903082007-02-17017 February 2007
DPO Decision-Memo to M. Shannon, Rii, from J. Dyer, NRR, Subject: DPO Panel Response to DPO-2006-002-Final Report
ML0711502322007-02-17017 February 2007
DPO-2006-002: DPO Milestones and Timeliness Goals
ML0712903022007-02-12012 February 2007
DPO Panel Report Is Final-Memo to J. Dyer, NRR, from J. Grobe, Ades/Nrr, Subject: DPO Panel Response to DPO-2006-002 Final Report
ML0711502242007-01-31031 January 2007
E-Mail from R. Pedersen, Dpopm, to EDO Extension Request, Subject: Extension Request for DPO (Atts.- 10/30/2006 e-mail to J. Grobe, Ades/Nrr, from R. Pedersen, Dpopm, Subject: DPOs 2006-002 and -003 Extension Request and Resolution Schedule
ML0712902962007-01-29029 January 2007
Email from T. Liu, NRR, to R. Pedersen, Dpopm, Subject: Extension Request to DPO-2006-002
ML0711502232007-01-29029 January 2007
E-Mail from R. Pedersen, Dpopm, to M. Shannon, Rii, Subject: DPO-2006-003 Decision Memo
ML0712903192007-01-20020 January 2007
DPO Decision-Memo to M. Shannon, Rii, from J. Dyer, NRR, Subject: DPO Panel Response to DPO-2006-003
ML0711502212007-01-20020 January 2007
DPO-2006-003: DPO Milestones and Timeliness Goals
ML0711502202006-12-19019 December 2006
2 Part E-Mail Between R. Pedersen, Dpopm, and M. Shannon, Rii, Subject: Action: DPO-2006-002 Comments
ML0711502192006-12-18018 December 2006
Resolution Schedule for DPOs 2006-002 and 2006-003
ML0712902862006-12-0404 December 2006
Email from J. Dyer, NRR, to R. Pedersen, Dpopm, Subject: Office Director Comments on DPO-2006-003 Panel Report
ML0712903252006-11-22022 November 2006
Email from M. Shannon, R11, to R. Pedersen, Dpopm, Subject: Action: Review DPO-2006-003 Report
ML0711502182006-11-18018 November 2006
DPO-2006-002: DPO Milestones and Timeliness Goals
ML0712902832006-11-13013 November 2006
DPO Panel Report-Memo to J. Dyer, NRR, from J. Grobe, Ades/Nrr, Subject: DPO Panel Response to DPO-2006-002
ML0712902552006-11-0808 November 2006
Memo to R. Pedersen, Dpopm, from L. Reyes, EDO, Subject: Approved Extension Request for DPOs 2006-002 and 2006-003
ML0711502152006-11-0707 November 2006
Memo to L. Reyes, EDO, from R. Pedersen, Dpopm, Subject: Extension Request for DPOs 2006-002 and 2006-003, (Encl. 1-DPO-2006-002: DPO Milestones and Timeliness Goals, Encl. 2-DPO-2006-003: DPO Milestones and Timeliness Goals, Encl. 3..
ML0711502142006-10-31031 October 2006
3-Part E-Mail Between R. Pedersen, Dpopm, to M. Shannon, Rii, Subject: Action: Review DPO-2006-003 Report
ML0712902512006-10-26026 October 2006
DPO Panel Report-Memo to J. Dyer, NRR, from J. Grobe, Ades/Nrr, Subject: DPO Panel Response to DPO-2006-003
ML0711502012006-09-15015 September 2006
E-Mail from R. Pedersen, Dpopm, to M. Shannon, Rii, Subject: Fyi: Status on DPO-2006-002, DPO-2006-003
ML0712902472006-08-15015 August 2006
DPO Panel 2nd Meeting Agenda - August 15, 2006 DPO 2006-002 and DPO 2006-003
ML0711501992006-08-15015 August 2006
DPO-2006-002 Chronology and Status
ML0711501952006-07-20020 July 2006
DPO-2006-002 Chronology and Status
ML0712902452006-06-0202 June 2006
DPO Panel Memo-from J. Dyer, NRR, Subject: Ad Hoc Review Panel - DPO Involving Oconee ECCS Sump Screen and Use of Leak Before Break in ECCS
ML0711501942006-06-0202 June 2006
June 2006 Monthly Report for DPO-2006-002,-003
ML0711501932006-05-22022 May 2006
DPO Tasking Memo to J. Dyer, NRR, from R. Pedersen, Dpopm, Subject: DPO Involving Oconee Use of Leak Before Break in ECCS
ML0711501912006-05-22022 May 2006
DPO Tasking Memo to J. Dyer, NRR, from R. Pedersen, Dpopm, Subject: DPO Involving Oconee ECCS Sump Screens
ML0711501902006-05-12012 May 2006
E-Mail from R. Pedersen, Dpopm, to M. Shannon, Rii, Subject: Acceptance of DPOs
ML0711501862006-05-12012 May 2006
E-Mail from R. Pedersen, Dpopm, to L. Reyes, EDO, M. Virgilio, Dedmrs, W. Dean, Ao/Edo, Subject: Fyi: New DPO (2006-002) on Oconee ECCS Sump Screens
ML0711501882006-05-12012 May 2006
E-Mail from R. Pedersen, Dpopm, to L. Reyes, EDO, M. Virgilio, Dedmrs, W. Dean, Ao/Edo, Subject: Fyi: New DPO (2006-003) on Use of Leak Before Break in ECCS
ML0712902442006-05-0303 May 2006
DPO Submittal, DPO-2006-003 from M. Shannon, Rii
ML0712902332006-05-0303 May 2006
DPO Submittal, DPO-2006-002 from M. Shannon, Rii
ML0605405422005-09-0606 September 2005
DPO Decision
ML0524302592005-08-31031 August 2005
DPO-Extension Request
ML0607603252005-08-31031 August 2005
Approved Extension Request
ML0605405332005-08-17017 August 2005
DPO Report Is Final
ML0605800272005-08-10010 August 2005
DPO Extension Request Approval
ML0522401712005-08-10010 August 2005
DPO Extension Request
ML0606200372005-07-28028 July 2005
Submitter'S Additional Comments on DPO Panel Report
ML0605405102005-07-27027 July 2005
Submitter'S Additional Comments on DPO Panel Report
ML0605405042005-07-26026 July 2005
Region Ii'S Comments on DPO Panel Report
ML0605404982005-07-25025 July 2005
Submitter'S Comments on DPO Report
ML0605404352005-07-19019 July 2005
DPO Panel Report
ML0605404722005-03-11011 March 2005
DPO Panel Memo
ML0505500522005-02-25025 February 2005
DPO Tasking Memo
ML0605906512005-02-22022 February 2005
Acceptance of DPO
ML0605906532005-02-16016 February 2005
DPO Submittal
2021-02-16
[Table view]
Category:Memoranda
MONTHYEARML23118A2852023-05-0202 May 2023
Public Meeting Summary - 2022 Annual Assessment Meeting Regarding Catawba Nuclear Station, McGuire Nuclear and Oconee Nuclear Station
ML22299A0482023-01-11011 January 2023
Final Environmental Assessment and Finding of No Significant Impact for the Duke Energys Updated Decommissioning Funding Plans Submitted in Accordance with 10 CFR 72.30(C) for Oconee Nuclear Station Independent Spent Fuel Storage Installati
ML22349A1482022-12-19019 December 2022
Transmittal Letter for Oconee SE for SLRA Review
ML22193A2542022-08-0505 August 2022
SLRA - Audit Report
ML22111A3142022-05-0202 May 2022
Limited Aging Management Audit Plan Regarding the Subsequent License Renewal Application Review
ML22084A6142022-04-0404 April 2022
SLRA - Summary of March 16, 2022 (Closed Public Meeting)
ML22024A1392022-03-11011 March 2022
SLRA - Request for Withholding Information
ML21347A0102021-12-20020 December 2021
Proposed Alternative to Implement ASME Code Case OMN-26
ML21279A1542021-11-0808 November 2021
August 25, 2021, Oconee Nuclear Station, Units 1, 2, and 3 Subsequent License Renewal Application Public Environmental Scoping Meeting Summary Memo
ML21064A3502021-07-26026 July 2021
OEDO-21-00048 - Oconee Nuclear Station, Units 1, 2, and 3 - Response Memorandum
ML21195A2692021-07-14014 July 2021
Meeting Summary: Pre-Submittal Meeting for the Oconee Subsequent License Renewal Application (EPID Number: L-2020-RNW-0028) (Docket Numbers: 50 269, 50-270, and 50-287) - Memo
ML21055A8672021-04-22022 April 2021
Memo to File: Final Ea/Fonsi of Independent Spent Fuel Storage Facilities Decommissioning Funding Plans Related to Oconee
ML21099A0932021-04-0909 April 2021
Public Meeting Summary - 2020 Annual Assessment Meeting Regarding Catawba, McGuire, and Oconee Nuclear Stations
ML20357B1332020-12-30030 December 2020
Transmittal Memo - Delivery of Partial Deliverable Associated with the Trace Code Maintenance, Plant Model Maintenance, and Plant Model Development to Support Licensing Actions and Emergent Technical Issues User Need
ML20141L4172020-05-20020 May 2020
EOC Public Meeting Summary
ML20036E3902020-02-11011 February 2020
Regulatory Audit in Support of Review of License Amendment Request to Revise the Licensing Basis for High Energy Line Breaks Outside of the Containment Building
ML19102A3352019-04-12012 April 2019
Public Meeting Summary - Oconee Nuclear Station Docket Nos. 50-269, 50-270, and 50-287
ML19037A0052019-02-0808 February 2019
Regulatory Audit in Support of Review of License Amendment Request No. 2018-02
ML18226A2152019-01-22022 January 2019
Response to Task Interface Agreement 2014-04, Adequacy of the Oconee Nuclear Station Design and Licensing Bases for Degraded Voltage Protection (TAC Nos. MF4622, MF4623, and MF4624; EPID L-2014-LRA-0003)
ML18082A0582018-03-23023 March 2018
Summary of Meeting with Oconee Nuclear Station to Discuss Annual Assessment of Oconee for the Period of January 01, 2017 - December 31, 2017
ML18032A4612018-03-0505 March 2018
Regulatory Audit in Support of Review of License Amendment Request No. 2017-03
ML18004A0122018-01-0404 January 2018
Regulatory Audit in Support of Review of Proposed Alternative (CAC Nos. MF7365, MF7366 and MF7367; EPID No. L-2016-LLR-001)
ML17264A0312017-09-29029 September 2017
Draft Response to Task Interface Agreement 2014-05 to Licensee Oconee Design Analysis for Single Failure/Integration of Class 1E Direct Current Control Cabling in Raceways with High Energy Power Cabling
ML17202U7312017-07-25025 July 2017
Regulatory Audit in Support of License Amendment Request No. 2015-03
ML17103A0292017-04-13013 April 2017
Summary of Meeting to Provide Opportunities to Discuss Annual Assessment of Oconee Nuclear Station Units 1, 2 and 3
ML16088A2042016-03-28028 March 2016
Memo T Bowers from s Ruffin, Technical Assistance Requests - Review 2015 Tri-Annual Decommissioning Funding Plans for Multiple Independent Spent Fuel Storage Installations W/ Encl 2 (Template)
ML16088A2052016-03-28028 March 2016
Enclosure 1 - (72.30 DFP Reviews to Be Completed 2015) - Memo T Bowers from s Ruffin, Technial Assistance Requests - Review 2015 Tri-Annual Decommissioning Funding Plans for Multiple Independent Spent Fuel Storage Installations
ML16061A5652016-03-0909 March 2016
Request for Additional Information for Relief Request 14-ON-001, Letdown Cooler Nozzle Welds
ML16056A5832016-02-26026 February 2016
and 3, Draft Request for Additional Information License Amendment Request to Adopt Emergency Action Level Scheme Based on NEI 99-01 Rev.6
ML16021A3452016-01-29029 January 2016
Draft Request for Additional Information License Amendment to Add High Flux Trip for 3 Reactor Coolant Pump Operation
ML15364A3802016-01-0808 January 2016
Draft Request for Additional Information Relief Request ON-GRR-01
ML15363A2962015-12-29029 December 2015
Special Inspection Charter to Evaluate the Power Cable Failures/Degradations on the Oconee Units 1 and 3 Startup Transformers
ML15345A3982015-12-15015 December 2015
Draft Request for Additional Information License Amendment Request to Adopt Emergency Action Level Scheme Based on NEI 99-01 Rev. 6
ML15265A1272015-09-17017 September 2015
Memoranda to C. Bladey Notice of Availability of Exemption for Duke Energy Carolinas, LLC, Oconee Nuclear Station Independent Spent Fuel Storage Installation
ML15231A1922015-08-19019 August 2015
NRC June 9 2009 Memo Revision
ML15233A4952015-08-14014 August 2015
Memo to C Bladey, Notice of Environmental Assessment and Finding of No Significant Impact - Duke Ene4rgy Carolinas LLC, Oconee Nuclear Station ISFSI - Admin EA Memo
ML15181A4332015-07-0707 July 2015
Closure of Licensee Responses to External Flooding Letters
ML15099A5612015-05-11011 May 2015
Safety Evaluation for Duke Submittal on Electronic Records (Nirma)
ML15089A1642015-04-27027 April 2015
Summary of February 25, 2015, Partially Closed Meeting with Industry Stakeholders Regarding the Babcock and Wilcox Loss of Coolant Accident Evaluation Model Analysis
ML15113A6262015-04-23023 April 2015
April 14, 2015 Summary of Public Meeting on Oconee Nuclear Station, Units 1, 2 and 3 to Discuss the Annual Assessment
ML14356A0052014-12-31031 December 2014
Summary of December 3, 2014, Category 1 Public Meeting with Duke Energy Carolinas, LLC to Discuss NTTF Recommendation 2.1, Flooding Response for Oconee Nuclear Station, Units 1, 2, and 3
ML14311A8622014-11-0707 November 2014
Request for Technical Assistance Regarding the Adequacy of the Oconee Station Design and Licensing Bases for the Degraded Voltage Relay Protection Design (TIA 2014-04) (Final)
ML14147A3652014-05-27027 May 2014
Annual Assessment Public Meeting Summary Memo
ML14058A0162014-02-0404 February 2014
Draft Memo from M. Cunningham, NRR Et Al to E. Leeds, NRR on Oconee Flood Protection and the Jocassee Dam Hazard Basis for NRC Allowing Continued Operation
ML14058A0182014-02-0404 February 2014
Draft Memo from M. Cunningham, NRR Et Al to E. Leeds, NRR on Oconee Flood Protection and the Jocassee Dam Hazard Basis for NRC Allowing Continued Operation
ML14058A0172014-02-0404 February 2014
Draft Memo from M. Cunningham, NRR Et Al to E. Leeds, NRR on Oconee Flood Protection and the Jocassee Dam Hazard Basis for NRC Allowing Continued Operation
ML14055A4742014-02-0404 February 2014
Draft Memorandum from G. Cunningham, NRR to E. Leeds, NRR on Oconee Flood Protection and the Jocassee Dam Hazard Basis for Continued Operation
ML13351A3172013-12-24024 December 2013
Safety Evaluation Input Regarding Temporary Technical Specification Change Request to Extend the Completion Time for an Inoperable Keowee Hydro Unit
ML13303B8282013-11-0101 November 2013
Notice of Meeting with Duke Energy to Discuss Proposed License Amendment Request Regarding Temporary Technical Specification Change for One Keowee Hydro Unit Inoperable - Oconee Nuclear Station, Units 1, 2, and 3
ML13295A3062013-10-22022 October 2013
Meeting Notice with Duke Energy Carolinas, LLC Discuss the Planned Modifications Related to the Fukushima Flood Hazard Reevaluations for the Sites Operated by Duke Energy Carolinas, LLC
2023-05-02
[Table view] |
Text
February 17, 2007 MEMORANDUM TO: Melvin C. Shannon, Senior Resident Inspector Branch 1 Division of Reactor Projects Region II FROM: J. E. Dyer, Director/RA/
Office of Nuclear Reactor Regulation
SUBJECT:
DIFFERING PROFESSIONAL OPINION DECISION REGARDING USE OF LEAK-BEFORE-BREAK TECHNOLOGY INVOLVING RECIRCULATION SUMP STRAINERS AT OCONEE, UNITS 1 AND 2 (DPO-2006-002)
The purpose of this memorandum is to provide the management decision for the Differing Professional Opinion (DPO) regarding the use of leak-before-break (LBB) technology in the design of a facility modification involving installation of new emergency core cooling system (ECCS) recirculation sump strainers at Oconee, Units 1 and 2, that you submitted on May 3, 2006. In accordance with Management Directive 10.159, "The Differing Professional Opinions Program," I appointed an Ad Hoc Review Panel on June 2, 2006 to conduct an independent review of your concerns. The panel met with you on July 20, 2006 to obtain clarification on certain details of your concerns and you confirmed the panel's summary of the issues.
I understand the background associated with this issue is as follows:
On August 18, 2005 and supplemented on September 15, 2005, Duke Energy Corporation ("the licensee") submitted a request to modify Oconee Nuclear Station, Units 1 and 2 Technical Specifications (TS) 3.5.2.6 and 3.5.3.6. The requested changes to TS 3.5.2.6 and 3.5.3.6 were related to replacement of the reactor building emergency sump suction inlet trash racks and screens with new sump strainers. The licensee planned to install the new ECCS sump strainers to address issues raised in Generic Safety Issue-191 (GSI-191), "Assessment of Debris Accumulation on Pressurized Water Reactor Sump Pump Performance," and requests made in Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors." In response to GL 2004-02, the licensee provided an engineering evaluation by Stone and Webster (Calculation S-003) to assess the impact of pipe rupture and jet impingement on the design function of the new sump strainers and determine if additional protection, i.e. jet impingement shields, were necessary. Calculation S-003 concluded that the design function of the sump strainers would not be compromised by jet impingement or pipe whip from any lines in the vicinity of the emergency sump. For the reactor coolant CONTACT: Tilda Y. Liu, NRR 415-1315
(-1/
'i system (RCS) cold leg, this conclusion was based .on crediting LBB technology. In a safety evaluation dated November 1, 2005, the NRC concurred with the conclusions of the licensee's engineering evaluation and issued Amendments 348 and 350 to modify the technical specifications necessitated by installation the of ECCS sump strainers in Oconee Nuclear Stations, Units 1 and 2.
The panel reviewed and described your concerns as follows:
The fundamental contention is that the ECCS sump strainer modification should not have been approved by the NRC nor implemented by the licensee. The submitter indicated that the new ECCS sump strainers at Oconee Units 1 and 2 can be adversely impacted by the dynamic effects of jet impingement from a potential RCS cold leg loss of coolant accident (LOCA) in a way that could disable the ECCS re-circulation function.
In approving the installation, the staff allowed dynamic effects to be excluded from the design bases for the strainers based on LBB technology. The submitter expressed that LBB technology should not have been credited by staff because the licensee has not submitted the information required to justify the application of LBB technology for NRC review and approval. The submitter also indicated that even if the required information is submitted, the staff should not permit the application of LBB technology because the NRC does not allow the use LBB technology to exclude dynamic effects such as jet impingement when those effects adversely impact the ECCS or containment.
The DPO resulted in part from the interpretation of Commission policy that LBB technology cannot be used if the dynamic effects of the pipe rupture adversely affect ECCS and containment. In support of this position, this DPO cited sections from the final rule that modified GDC-4 to permit exclusion of dynamic effects of high energy pipe ruptures from the design basis of systems, structures and components (SSC) based on LBB technology (52 FR 41288, October 27, 1987). Since then, the NRC has accepted the concept of LBB for certain large diameter high-quality piping systems such as the RCS cold leg line, thereby, permitting the removal, or non-installation, of various pipe-whip restraint devices and jet-impingement shields originally designed to mitigate the dynamic effects of a postulated instantaneous pipe rupture.
During the review, the panel noted that the central issue raised in this DPO had not been effectively resolved through normal interactions between the two division management teams in the Regional Office and NRR, or via an established NRR process for resolving questions on the application of Commission's regulations, such as the Task Interface Agreement (TIA) process.
The panel provided the results of its review in a report dated November 13, 2006 which you were provided a copy. The panel reached the following overall conclusions:
The concern regarding inappropriate application of LBB technology in the ECCS recirculation sump strainer modification at Oconee, Units 1 and 2, was based on an incorrect understanding of the Commission's regulations and policy on the use of LBB technology in the design of the ECCS. The regulations and policy support the staffs decision to authorize the application of LBB technology to this modification.
The staff reviewed and documented the approval of the application of LBB technology for reactor coolant system cold leg breaks that could affect the ECCS recirculation sump strainer for Oconee, Units 1 and 2, pursuant to the draft Standard Review Plan 3.6.3, "Leak-Before-Break Evaluation."
In reaching my decision, I reviewed the panel's report and discussed the report with the panel chair. I understand that you did not have any comments with regards to the panel's report issued on November 13, 2006. Based on these reviews, I agree with the conclusions of the panel. The panel provided one recommendation. My decision regarding its recommendation, and the rationale for the decision, is provided below.
RECOMMENDATION: The staff should develop a knowledge management document describing the NRC's policy and practice on the application of LBB.
Decision: Agree with the recommendation. The staff will review its existing documents and enhance the understanding on the application of LBB by developing a knowledge management document as appropriate.
Rationale: This DPO issue demonstrated that the application of LBB technology involves many regulatory developments over time and may not be apparent and easily understood. A knowledge management document that would clearly restate and present all the background and developments to the application LBB technology would enhance the effectiveness and efficiency on the part of the staff and the inspectors as they perform technical reviews and inspections related to the LBB issues.
I would like to express my appreciation to you for having first brought your concerns up through your first and second line supervisors. I commend your willingness to subsequently use the DPO Program in raising your concerns. Your willingness to bring your concerns first to your management's attention, and then to mine through the DPO process, contributed to the development of the recommendation for an enhancement to the NRR mission. In accordance with Management Directive 10.159, "The Differing Professional Opinions Program," a summary of the issue and its disposition will be included in the Weekly Information Report to advise interested employees of the outcome.
The staff reviewed and documented the approval of the application of LBB technology for reactor coolant system cold leg breaks that could affect the ECCS recirculation sump strainer for Oconee, Units 1 and 2, pursuant to the draft Standard Review Plan 3.6.3, "Leak-Before-Break Evaluation."
In reaching my decision, I reviewed the panel's report and discussed the report with the panel chair. I understand that you did not have any comments with regards to the panel's report issued on November 13, 2006. Based on these reviews, I agree with the conclusions of the panel. The panel provided one recommendation. My decision regarding its recommendation, and the rationale for the decision, is provided below.
RECOMMENDATION: The staff should develop a knowledge management document describing the NRC's policy and practice on the application of LBB.
Decision: Agree with the recommendation. The staff will review its existing documents and enhance the understanding on the application of LBB by developing a knowledge management document as appropriate.
Rationale: This DPO issue demonstrated that the application of LBB technology involves many regulatory developments over time and may not be apparent and easily understood. A knowledge management document that would clearly restate and present all the background and developments to the application LBB technology would enhance the effectiveness and efficiency on the part of the staff and the inspectors as they perform technical reviews and inspections related to the LBB issues.
I would like to express my appreciation to you for having first brought your concerns up through your first and second line supervisors. I commend your willingness to subsequently use the DPO Program in raising your concerns. Your willingness to bring your concerns first to your management's attention, and then to mine through the DPO process, contributed to the development of the recommendation for an enhancement to the NRR mission. In accordance with Management Directive 10.159, "The Differing Professional Opinions Program," a summary of the issue and its disposition will be included in the Weekly Information Report to advise interested employees of the outcome.
DISTRIBUTION W. Kane, OEDO R. Pedersen, DPOPM M. Weber, NRR T. Liu, NRR J. Grobe, NRR M. Caruso, NRR A. Csontos, RES Adams Accession Number: ML070440171 OFFICE NRR/TA NRR/OD NAME T. Liu J. Dyer DATE 2/16/07 2/17/07 OFFICIAL RECORD COPY
