United States Nuclear Power

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NRC Section XI Report - November 2006

Site Updates

Presented By:  Mr. Wally Norris, United States Nuclear Regulatory Commission

NRC Report
November 2006

1.    Amendments to 10 CFR 50.55a


A final amendment to 10 CFR 50.55a incorporating by reference the 2001 Edition up to and including the 2003 Addenda of the ASME Boiler and Pressure Vessel Code, was published on October 1, 2004 (69 FR 58804).  The rule became effective on November 1, 2004.


A public meeting was held on Monday, May 15, 2006, during the ASME meetings in Phoenix, AZ, to inform industry representatives of those provisions in the 2004 Edition where questions have been raised by NRC staff and solicit comments from stakeholders and other interested parties.  Publication of the proposed rule for public comment is scheduled for early 2007.


2.    ASME Code Cases - Rulemaking/Regulatory Guides


The current final regulatory guides addressing ASME Code Cases are:


·        Revision 33 to Regulatory Guide 1.84, “Design, Fabrication, and Materials Code Case Acceptability, ASME Section III”


·        Revision 14 to Regulatory Guide 1.147, “Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1”


·        Revision 1 to Regulatory Guide 1.193, “ASME Code Cases Not Approved for Use.”


The guides address the Code Cases in Supplement 12 to the 1998 Edition through Supplement 6 to the 2001 Edition.  The guides are available electronically in the Regulatory Guides Document Collection of the NRC's public Web site at



Draft Revision 2 to Regulatory Guide 1.193 (DG-1135), "ASME Code Cases Not Approved for Use" was published for public comment on Tuesday, June 6, 2006 (71 FR 32615).  The public comment period closed on July 14, 2006.  No public comments were received.  Publication of the final guide will be held, however, to permit review of any comments received on Draft Guides DG‑1134 and DG-1135 for potential impact on DG-1135 (see below).


Draft Revision 34 to RG 1.84, “Design, Fabrication, and Materials Code Case Acceptability, ASME Section III and Draft Revision 15 to Regulatory Guide 1.147, “Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1 were noticed for public comment on October 27, 2006.  The public comment period for the draft guides closes on January 2, 2007.


The staff has completed its review of Supplements 2 through 8 to the 2004 Edition and has begun its review of Supplements 9 and 10.


3.    Joint NRC/ASME Public Meeting


A public meeting will be held from December 12 - 13, 2006, at NRC Headquarters to discuss pressing industry issues to gain an understanding from both the regulatory and industry perspectives in order to develop a suitable path for Code implementation.  Dr. Kimberly Gruss, NRC, and David Waskey, ASME Subgroup on Repair and Replacement Activities, will be the moderators for the meeting.  Following is the proposed agenda:


·        RRA 04-05 (BC 06-852) NRC discussion on legal interpretation of references in Section III and XI to Sections II, V, and IX.


·        RRA 97-11 (BC 04-247) Code Case N-713: Use of Section XI NDE acceptance criteria in lieu of those of the Construction Code for Repair/Replacement Activities.  This will include discussion on RG 1.147 restriction to Code Case 638-1.


·        Discuss select “vague wording” items in recent Section XI publications.


·        RRA 04-07 (BC 06-853) IWA-4461.4.2 NRC concerns with thermal cutting without mechanical metal removal.


·        RRA 05-11 (BC 05-970) NDE requirements regarding Pressure Testing, IWA-4540(a).


·        RRA 99-13 (BC 04-997) Presentation of framework of proposed modifications to Section XI adoption of Section IX temperbead qualification rules.


·        RRA 06-09 (BC 06-859) Eliminate 48 hour hold for SMAW temper bead welding.


·        RRA 05-08 (BC 06-134) Code Case N-638-3: Revise the start of the 48 hour hold to after layer 3 is completed vs weldment completed.


·        Industry discussion regarding weldability issues associated with Alloy 52/152 and current initiatives associated with improving weld quality.


A final agenda will be published by the NRC one (1) week before the meeting.


4.    Risk-Informed Activities


10 CFR 50.69 - Risk Informed Special Treatment Requirements


A Federal Register Notice of the availability of Regulatory Guide 1.201, “Guidelines for Categorizing Structures, Systems, and Components in Nuclear Power Plants According to Their Safety Significance,” was published on January 27, 2006 (ADAMS No. ML060260361).  Based on a public comment, Revision 1 of Regulatory Guide 1.201 was issued for trial use in May 2006 (ML061090627).


This trial regulatory guide describes a method that the NRC staff considers acceptable for use in complying with the Commissions requirements in §50.69 with respect to the categorization of structures, systems, and components (SSCs) that are considered in risk-informing special treatment requirements.  This categorization method uses the process that the Nuclear Energy Institute (NEI) described in Revision 0 of its guidance document NEI 00-04, "10 CFR 50.69 SSC Categorization Guideline."


This trial regulatory guide does not establish any final staff positions, and may be revised in response to experience with its use.  This will ensure that the lessons learned from regulatory review of pilot and follow-on applications are adequately addressed in the final regulatory guide, and that the guidance is sufficient to enhance regulatory stability in the review, approval, and implementation of probabilistic risk assessments (PRAs) and their results in the risk-informed categorization process required by §50.69.  Trial use is expected to continue through calendar year 2006.


One unresolved issue related to 50.69 is the method to be used to classify passive SSCs primarily for repair and replacement activities.  The ASME has developed Code Case N-752, "Risk-Informed Safety Classification and Treatment for Repair / Replacement Activities in Class 2 and 3 Moderate Energy Systems."  The NRC staff has not endorsed the methods described in the Code Case.


5.    Generic Activities on Material Degradation/PWR Alloy 600/182/82 PWSCC


On May 5, 2006, NRC staff met with representatives from NEI and the Electric Power Research Institute (EPRI) Materials Reliability Project (MRP) to discuss NRC staff comments on the industry guidance for the volumetric and visual inspection of dissimilar metal butt welds in pressurized water reactor (PWR) primary systems (MRP‑139).  MRP‑139, was approved unanimously by the MRP Executive Committee and was issued to the PWR fleet as a "mandatory" action under the NEI 03‑08 Guideline for the Management of Materials Initiative.  The NRR staff previously documented its comments and recommendations on the use of MRP‑139 in a letter dated October 12, 2005, from M. Mayfield (NRC) to A. Marion (NEI).  During the meeting, the MRP representatives discussed proposed responses to address the concerns of the NRC staff.  Discussions included interactions with the NRC, reporting of inspection findings with the NRC, and Spring 2006 inspection results and implications.  MRP representatives indicated that a formal written response to the staff’s concerns documented in the October 12, 2005, letter would be forthcoming.  Based on the MRP’s proposed resolution, 17 of 26 staff comments would be addressed satisfactorily.


In a letter dated September 7, 2005, NEI submitted EPRI MRP Report MRP-169, Rev. 0, Technical Basis for Preemptive Weld Overlays for Alloy 82/182 Butt Welds in PWRs, to the NRC for review and approval of the entire report.  In a letter dated December 15, 2005, NEI supplemented its original request seeking NRC’s review and approval of only those sections of the report pertaining to design requirements, design methodology, and the examination volumes of full and optimized structural pre-emptive weld overlays, i.e., 4.0, Design Requirement, and 7.1, Requirements for Types of Examination for Weld Overlays.  The staff has reviewed MRP-169 and has identified questions and comments which need to be addressed in order to complete the review and prepare a safety evaluation.  These comments and questions were provided to NEI by letter dated August 3, 2006.


Exelon Nuclear Generation Company (Exelon) elected to install pre-emptive weld overlays on their Byron Station (Byron) Unit 1 pressurizer valves and surge line during their fall 2006 outage.  The weld overlays are intended to address inspectability issues with the original welds and reduce the susceptibility of the welds to PWSCC.  Because the weld overlays are not addressed in the ASME Code Section XI, Exelon requested and NRC staff approved the applicable relief requests.  During ultrasonic examination (UT) of the weld overlays, flaws larger than the acceptance criteria were found in three of the six overlays.  Exelon requested that they be permitted to operate with the flaws in service, while they investigated the  root cause of the flaws and automated grinding and welding repair methods to reduce radiation exposure.  The NRC staff indicated that Exelon’s proposal would be acceptable provided that the flaws were repaired prior to the application of weld overlays on  Byron 2 in April 2007.  The licensee opted to keep Byron 1 shutdown and has commenced the repairs.


6.    New Reactor Licensing Activities


North Anna Early Site Permit (ESP)


On August 15, 2006, the staff completed Supplement 1 to the Final Safety Evaluation Report (FSER) in accordance with the review schedule identified in its letter to Dominion dated

May 4, 2006.  By letter dated August 15, 2006, the staff issued the supplement to Dominion.


Public Release of DG-1145


Draft Regulatory Guide DG-1145, “Combined License Applications for Nuclear Power Plants (LWR Edition) was made available for public comment on September 1, 2006.  This regulatory guide provides guidance to new reactor license applicants regarding the information to be submitted in a combined license (COL) application.  Users can currently access DG-1145 using the following link: http://www.nrc.gov/reading-rm/doc-collections/reg-guides/power-reactors/draft-index.html .


EPR Digital Instrumentation and Controls Meeting


On August 31, 2006, NRC staff met with AREVA NP to discuss digital instrumentation and control topics for the U.S. Evolutionary Power Reactor (EPR) as a part of the ongoing pre-application review.  Topics discussed at the meeting included (1) an overview of the protection system architecture, redundancy and, functional diversity, (2) the priority actuation and control system, and (3) control room displays and human-machine interface.  AREVA NP also outlined several instrumentation and control and human factors topical reports that they plan to submit between December 2006 and June 2007.  Technical issues the staff raised as areas needing additional justification included PS inter-divisional communication, and safety to non-safety system interfaces and communication because the proposed design concepts have not been previously reviewed and approved by NRC staff.


Acceptance Review of Vogtle Early Site Permit (ESP)


On September 19, 2006, the staff completed its acceptance review of the Early Site Permit (ESP) application for the Vogtle ESP site and concluded that the application is acceptable for docketing.  The staff issued Southern Nuclear Operating Company a letter of acceptance with the review schedule attached.  This starts the staff’s 20 month review schedule for issuance of the Final Safety Evaluation report (FSER) and the Final Environmental Impact Statement (FEIS).  A notice of acceptance has been forwarded to the Federal Register.


Meeting with NEI and Industry to Discuss Infrastructure Development Schedules


On September 21, 2006, NRC held a public meeting on the Standard Review Plan (SRP) and Regulatory Guide (RG) update plans and schedules.  NRC’s plans and schedule for updating the SRP sections and RGs by the end of March 2007 appeared to be generally well-received by the public in attendance.  While SRP sections will not be issued as draft revisions for public comment, final revisions would be available for comment.  Staff informed the public that comment resolution could inform the technical bases for alternatives to SRP acceptance criteria that satisfy regulations.  Staff provided plans for the RGs being updated.  Specifically, NRC issued a general Federal Register notice on September 22, 2006 (71 FR 55517) announcing availability of Regulatory Guides for comment over the next several months. 


Plans and schedules for these updates can be found on the NRC website at:  http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/


Letter of Intent for Exelon COL


By letter dated September 29, 2006, Exelon informed the NRC of its intent to submit a COL application in November 2008.  Exelon is currently in the process of selecting both a technology and a site.  They are currently evaluating both the GE ESBWR and the Westinghouse AP1000, and are considering various site locations within the state of Texas.


Westinghouse I&C Meeting


NRR staff attended meetings with Westinghouse on October 3, 4, and 5, 2006, to discuss Westinghouse's plans to update its design certification document (DCD), design changes and supplemental design information, COL information item closure, and completion of selected DAC-ITAAC.  At the meetings, Westinghouse outlined its plans to prepare and submit several topical reports to address the above areas as a part of its pre-application activities to support the design centered approach.  Westinghouse has prepared, and made available for NRC review, its documentation for the software planning phase for its protection and monitoring system DAC-ITAAC.  The intent is that a successful completion of NRC review would satisfy the software planning phase ITAAC for closure.  Westinghouse indicated that the activities for its system definition phase of software development would be complete in December, 2006.  Westinghouse also demonstrated a prototype of its AP-1000 control room.  The staff visited the Westinghouse I&C equipment test facility to observe the assembling and testing of the "Common Qualified Platform" protection system equipment which is similar to AP1000 system.


ESBWR Design Certification Status Meeting


On October 12, 2006, the staff conducted a public meeting with General Electric (GE) to discuss the status and schedule for the ESBWR design certification review.  The staff discussed the content of its October 5, 2006, letter, which established a third milestone for issuance of RAIs (January 31, 2007), and reaffirmed its schedule for issuance of the SER with open items (October 11, 2007).  GE discussed their planned revisions to the design control document (DCD) to incorporate RAI responses, design changes, and resolution of many of the COL action items currently contained in the DCD.  GE also discussed plans to submit additional topical reports aimed at reducing the scope of design acceptance criteria (DAC).  Finally, GE discussed plans to coordinate future revisions of the DCD with revisions to the COL applications after they are submitted.


Public Meeting on 10 CFR Part 52 Final Rule


On October 25, 2006, a public meeting was held for the purpose of answering stakeholder questions about the draft final rule language for 10 CFR Part 52, "Licenses, Certifications, and Approvals for Nuclear Power Plants," and for other 10 CFR Parts affected by the Part 52 rulemaking.  On September 28, 2006, the NRC made the draft final rule language publicly available.  The staff and OGC answered stakeholder questions about the draft final rule language and outlined several changes to the rule that have been made since the draft final rule language was made available.


Supplemental Proposed Rule on Limited Work Authorizations


On October 17, 2006, a supplemental proposed rule for 10 CFR Part 52, "Licenses, Certifications, and Approvals for Nuclear Power Plants," was published for comment in the Federal Register  (71 FR 61330).  This supplement addresses requirements related to limited work authorizations.  The primary purposes of the supplemental proposed rule are to revise the definition of construction and to reform the limited work authorization (LWA) process in 10 CFR 50.10(e).  This would remove the need for construction permit and combined license applicants, and holders of early site permits to obtain a limited work authorization to conduct certain pre-construction activities.  The proposed rule is also available on the NRC's rulemaking Web site at http://ruleforum.llnl.gov, by following these links:  Proposed Rules - Licenses, Certifications, and Approvals for Nuclear Power Plants (RIN 3150-AG24) - Rulemaking Text and Other Documents.  Comments on the proposed rule will be accepted through November 16, 2006.


Clinton Early Site Permit (ESP)


On October 17, 2006, the Staff filed the "Prefiled Direct Testimony" in the Clinton early site permit (ESP) case that is before the ASLB.  The next major milestone is the Clinton ESP hearing beginning November 7, 2006, in Decatur, Illinois.  Oral limited appearance statements before the Board will be held on the evening of November 8, 2006, in Clinton, Illinois.


AP1000 Design‑Centered Working Group (DCWG) Public Meeting


On October 24, 2006, NRC staff participated in a meeting with the AP1000 DCWG to discuss Technical Support Center (TSC) location issues and anticipated submission of a technical report associated with containment leak rate testing.  The AP1000 design currently has the TSC associated with a single unit, stakeholders expressed interest in consolidating TSCs for multiple‑unit sites into a single TSC.  It was decided that a further and complete discussion of TSC location issues would entail a separate safeguards‑level meeting which would likely involve NSIR and other DCWGs.  The DCWG also stated that they will be identifying option B of Appendix J in developing their containment leak rate testing program.


7.    Examination of Cast Austenitic Stainless Steel


A draft NUREG/CR report was completed in December 2005 on the application of an inside diameter surface eddy current (ET) method to detect surface-breaking cracks in centrifugally and statically cast piping.  The report is scheduled to be published in December 2006.


The ET technique was successful at detecting all open cracks in the Westinghouse Owners Group (WOG) specimens, and provided insights on discrimination of cracks in the presence of geometrical and metallurgical features.  Results from this work will be presented to the cognizant ASME Code committees during the November 2006 meetings.


Measurements of coherent ultrasonic noise from the microstructure of vintage centrifugally cast piping segments on loan from Westinghouse, IHI Southwest, Inc. and EPRI is planned.  These measurements will help to understand the nominal background noise one might expect from piping in the field, evaluating how to determine these noise properties on field piping, and how this noise may impact detection capability of the technique.


8.    ACRS Review of NUREG‑1824


On October 5, 2006, staff from the Offices of Nuclear Regulatory Research (RES) and Nuclear Reactor Regulation (NRR), with support from the Electric Power and Research Institute (EPRI) and National Institute for Standards and Technology (NIST), briefed the Advisory Committee on Reactor Safeguards (ACRS) on RES efforts related to developing NUREG‑1824, "Verification and Validation of Selected Fire Models for Nuclear Power Plant Application."  This report documents a joint RES and EPRI program to verify and validate (V&V) five different fire models to be used by the NRC and industry when performing fire analysis.  NUREG‑1824 is expected to be issued in January 2007.


9.    7th Annual Meeting of the International Nuclear Graphite Specialists


On September 11-13, 2006, Office of Nuclear Regulatory Research (RES) staff participated in the subject meeting during which nuclear graphite specialists from the U.S., United Kingdom, Germany, France, South Korea, China, Japan, the Netherlands, and South Africa shared technical information on nuclear graphite structure and properties, irradiation behavior, properties modeling, component reliability estimations, material specification and testing standardization for graphite properties, and international Gen IV activities to gather data on nuclear graphite.  The information obtained by the staff from this meeting will be used to develop regulatory guidance for new reactor designs and as input to the advanced reactor research plan.  The proceedings of this meeting will be published in a special edition of the Journal of Nuclear Materials in 2007.


10.    NEI White Paper on Operational Leakage


On August 16, 2006, NRC staff met with representatives from NEI and various utilities to discuss industry concerns with Regulatory Issue Summary (RIS) 2005‑20, “Revision to Guidance Formerly Contained in NRC Generic Letter 91-18, 'Information to Licensees Regarding Two NRC Inspection Manual Sections on Resolution of Degraded and Nonconforming Conditions and on Operability.”  These concerns were provided in an NEI White Paper dated May 2, 2006.


At the meeting NRC staff indicated that it believed the principal concern of industry to be the default definition of inoperability contained in RIS 2005-20, Appendices C.11 and C.12.  NRC staff indicated that it agreed that increased flexibility is needed in the operability determination for leaking Class 2 and 3 components.  In these cases an immediate initial determination should be followed by a prompt determination.  With respect to the prompt determination, NRC staff proposed that revised guidance be developed that would contain a specific time frame for flaw geometry characterization by non-destructive examination and for the engineering analysis.  The specific time frame would be based on the safety significance of the leaking train but would be no longer than a reasonable time frame in which these actions can be completed.  The NRC staff also noted that any revised guidance should indicate that utilities provide the NRC with the methodology for engineering analysis, if approved Code methods are not used. 


Industry participants indicated agreement with the NRC’s proposed approach for revising the guidance.  Industry participants indicated a willingness to develop proposed input to the guidance prior to the next meeting.  The next meeting on this subject is tentatively scheduled for the week of November 13, 2006.

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