United States Nuclear Power

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NRC Section XI Report – August 2009

Site Updates

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

NRC Report
August 2009

1.         Amendment to 10 CFR 50.55a – ASME Code Edition/Addenda


A final rule was published in the Federal Register [73 FR 52730] on September 8, 2008, incorporating Section III and Section XI of the 2004 Edition of the American Society of Mechanicals Engineers (ASME) Boiler and Pressure Vessel Code into Title 10, Part 50.55a, of the Code of Federal Regulations (10 CFR 50.55a).  The effective date of the rule was October 10, 2008.


An amendment to the above rule was published in the Federal Register [73 FR 57235] on October 2, 2008, to correct several paragraph references.


A direct final rule has been developed to revise the augmented examination requirements relative to Code Case N-729-1.  During the public comment phase of the proposed rulemaking to incorporate by reference the 2004 Edition into 10 CFR 50.55a, a commenter recommended a change in the percentage of axially oriented flaws for the Code Case N-729-1 specimen set.  Following the publication of the final rule, the commenter requested withdrawal of his recommendation.  The direct final rule will adopt the recommendation for withdrawal by modifying paragraph 10 CFR 50.55a(g)(6)(ii)(D)(4)(ii) to read “At least 20 percent and no more than 60 percent of the flaws shall be oriented axially.”  The final rule is scheduled to be published early August 2009.


The NRC staff has begun its review of the 2005 Addenda through the 2008 Addenda.  These edition/addenda will be included in the next proposed rulemaking which is scheduled to be published for public comment at the end of 2009.  The NRC staff plans to incorporate the comprehensive inspection requirements of ASME Code Case N-770 by reference into this proposed rule.  The NRC staff also plans to explicitly address endorsement of non-mandatory appendices in this proposed rule.


2.         ASME Code Case Rulemaking/Regulatory Guides


On June 2, 2009, Draft Revision 35 to RG 1.84, “Design, Fabrication, and Materials Code Case Acceptability, ASME Section III,” draft Revision 16 to RG 1.147, “Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1,”and draft Revision 3 to RG 1.193 “ASME Code Cases Not Approved for Use,” were published in the Federal Register (74 FR 26303) for public comment.  The guides address Code Cases from Supplement 2 to the 2004 Edition through Supplement 0 to the 2007 Edition (Supplement 0, 2007 Edition also serves as Supplement 12 to the 2004 Edition).  The public comment period closes on August 17, 2009.


The NRC staff has completed its review of Supplements 1 - 7 to the 2007 Edition.  Supplement 8 to the 2007 Edition is currently under review.  Draft Revision 36 to RG 1.84, draft Revision 17 to RG 1.147, draft Revision 2 to RG 1.192, and draft Revision 4 to RG 1.193 are currently being reviewed by the cognizant NRC offices.  The draft guides address Supplements 1 – 7 to the 2007 Edition.  The goal is to publish these guides for public comment shortly after Revision 35 to RG 1.84, Revision 16 to RG 1.47, and Revision 3 to RG 1.193 have been published as final guides.


The staff is considering addressing the issues raised by Raymond A. West in a petition for rulemaking dated December 14, 2007, and revised on December 19, 2007, in the proposed rulemaking for Revision 17 of Regulatory Guide 1.147.


3.         Risk-Informed Activities


Public Workshop on NUREG-1855


An NRC memorandum dated June 16, 2009 (ML091660505), summarizes an NRC and EPRI public workshop held on May 5-6, 2009, with the industry on NUREG-1855 “Guidance on the Treatment of Uncertainties Associated with PRAS in Risk-Informed Decision Making” (ADAMS Accession No. ML090970525) and EPRI 1016737 “Treatment of Parameter and Model Uncertainty for Probabilistic Risk Assessments” (available at EPRI.com searching for 1016737).  A draft version of Appendix A to NUREG-1855 was also discussed (ADAMS Accession No. ML090930698).  The meeting had over 70 participants including representatives from industry (owners groups, vendors, utilities, consultants etc.) and National Aeronautics and Space Administration.


EPRI Topical Report – NDE Evaluation for Risk-Informed ISI


By letter dated June 11, 2009 (ML091550335), the NRC notified EPRI that it had accepted for review Topical Report 1018427, “Nondestructive Evaluation: Probabilistic Risk Assessment Technical Adequacy Guidance for Risk-Informed In-service Inspection Programs.”  The NRC staff expects to issue its request for additional information by October 6, 2009, and issue its draft safety evaluation by September 6, 2010.


Phased Approach to Probabilistic Risk Assessment Quality Regulatory Guide 1.200


The increased use of probabilistic risk assessments (PRAs) in the NRC’s regulatory decisionmaking process requires consistency in the quality, scope, methodology, and data used in such analyses.  A key aspect of implementing a phased approach to PRA quality is the development of PRA standards and related guidance documents.  To achieve that objective, professional societies, the nuclear industry, and the staff have undertaken initiatives to develop national consensus standards and guidance on the use of PRA in regulatory decisionmaking.


Certain ASME and ANS standards applying to at-power internal events, internal fire events, and external events were combined into a single joint standard, “Standards for Level 1/Large Early Release Frequency (LERF) Probabilistic Risk Assessment Standard for Nuclear Power Plant Applications” (ASME/ANS RA-S-2008).  Regulatory Guide 1.200, “An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities,” Revision 2, was issued in March 2009 (ML090410014).


Staff Response to ACRS on Regulatory Guide 1.200


On May 8, 2009, NRC staff responded by letter to the ACRS (ML091120398) regarding ACRS recommendations relative to Draft Final Revision 2 to Regulatory Guide (RG) 1.200.  The ACRS noted that: (1) national consensus PRA standards provide specific guidance on what the risk assessment should include, but the existing guidance on how to perform PRA is spotty; (2) NUREG-0492, “Fault Tree Handbook,” is an excellent resource but should be updated to include refinements in fault tree analysis and associated computer codes; (3) NUREG/CR-2300, “PRA Procedures Guide, A Guide to the Performance of Probabilistic Risk Assessments for Nuclear Power Plants” is archaic and updated guidance for the broad range of PRA activities is sorely needed; and (4) although NUREG-1855 provides good guidance for the identification of sources of model uncertainty, it lacks guidance on quantification of model uncertainty.  The letter to the ACRS described the staff’s effort to review current PRA guidance documents including the various NUREGs, with a view to determining what PRA guidance needs to be developed or updated.  The staff will evaluate whether the identified guidance is better suited to be developed as a staff effort, as part of an industry collaborative effort, as a separate industry effort, or as a separate national consensus standard effort.  The staff noted that, in addition to NUREG-1855, it had already published several guidance documents on specific topics such as parameter estimation (NUREG/CR-6823), human reliability analysis (NUREG-1792 & NUREG-1842) and fire PRA (NUREG/CR-6850).  This effort is in keeping with the staff plan in achieving the Commission’s phased approach to PRA quality (SECY-04-0118 and SECY-070042, ML041470505 and ML063630346, respectively), which includes identification and development of guidance documents for achieving the needed PRA quality for risk-informed activities.  The staff is also planning to pursue the feasibility and benefit of developing guidance on quantification of model uncertainty.


ASME Letter to NRC on Implementation of ASME/ANS PRA Standard, RA-Sa-2009


On May 5, 2009, a letter was received by the NRC from Bryan A. Erler, Vice President, ASME Nuclear Codes and Standards (ML091330603), providing an update on the timing for implementation of the requirements for latest version of the ASME/ANS PRA Standard, RA‑Sa‑2009.  The letter described the next steps in moving forward to fully implement the standard.  With the publication of Addendum A to Revision 1 of the standard, users were given the guidance to expand their PRAs to address risk from fires within the plant and from external hazards (e.g., seismic, high winds, external floods), and to have peer reviews performed on those portions of the PRA.  With regard to timing, the letter suggests that updating the base internal events model will take six to twelve calendar months depending on the current state of the user's PRA and the scope of the user's existing risk-informed applications that are required to be updated.  Expanding the base PRA model to address other contributors will take 1 ½ calendar years at a minimum.  Performing a peer review of the updated and expanded PRA model involves preparing for the review, performing the actual review, and documenting the results of the review takes six to twelve calendar months.  Last, factoring the results of the peer review back into the PRA model may take an additional six to twelve calendar months or more, depending on the nature of the peer review.  The letter also noted that ASME Standards Technology LLC is also involved in developing training on Addendum A of the Standard and the current focus is on internal events and internal flood.  The purpose of the training will be to provide the necessary interpretation of the requirements such that the peer reviews can be performed in a consistent manner.


10 CFR 50.46a Rule to Redefine the Large-Break LOCA


The NRC intends to publish a revised proposed rule that would establish alternative, risk-informed regulations for emergency core cooling system performance during large-break loss-of-coolant accidents (LOCAs).  The rule would also establish procedures and acceptance criteria for evaluating changes in plant design and operation based upon the results of the new analyses of ECCS performance.  Licensees who perform LOCA analyses using the risk-informed alternative requirements could find that their plant designs are no longer limited by certain parameters associated with previous large break LOCA analyses.  The new requirements could enable some licensees to propose a wide scope of design or operational changes up to the point of being limited by some other parameter associated with any of the required accident analyses.


An initial proposed rule was published on November 7, 2005, (70 FR 67598).  However, the nature of the changes made to the rule to incorporate modified Commission guidance made it necessary to allow additional stakeholder comments before issuing a final rule.  The changes made in the revised proposed rule are generally intended to increase the defense-in-depth provided for pipe breaks larger than the transition break size and to modify the risk-informed assessment process required for plant changes made under the rule to more closely follow the existing risk-informed guidance in RG 1.174.


The revised proposed rule was made public on April 16, 2009 (www.regulations.gov).  The NRC is planning to issue the revised proposed rule in late-June or early-July 2009 for public comments.  The final rule is scheduled to be issued in mid-2010.





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


In February 2008 NRC issued Temporary Instruction (TI-172) for regional staff to verify that all pressurized water reactors (PWRs) with dissimilar metal (DM) butt welds are implementing Materials Reliability Program (MRP)-139, “Primary System Piping Butt Weld Inspection and Evaluation Guidelines.”


In 2006 ASME started the development of a Code Case for inspection of Alloy 82/182 butt welds.  The Code Case was recently completed.  The staff is preparing the next proposed update to 10 CFR 50.55a and plans to incorporate requirements that will impose Code Case N‑770 with conditions.  The NRC staff has provided comments on the Code Case related to these proposed conditions.  


The NRC staff continues to monitor and evaluate operating experience to ensure that the current inspection schedules are adequate.


The NRC staff is preparing a position paper that will detail the requirements that are applicable to licensees that install weld overlays on welds in systems approved for “Leak-Before-Break” in accordance with the requirements of 10 CFR 50, Appendix A, General Design Criterion 4.  The position paper will address the regulatory requirements applicable to NRC staff review and approval of the LBB analyses that have to be updated to reflect the revised weld configuration of a weld overlay.  The NRC staff is planning to hold a public meeting in September 2009 to discuss this position paper.


5.         New Reactor Licensing Activities


The New Reactor Licensing public web-site [http://www.nrc.gov/reactors/new-reactor-licensing.html] has a list of expected new nuclear power plant applications, and an estimated schedule by fiscal year for new reactor licensing applications.


New Reactor Licensing Status


As of July 20, 2009, the status of new reactors licensing under10 CFR Part 52 is as follows:


Design Certification


NRC has issued four design certifications to date (ABWR, System 80+, AP600, and AP1000).  These are certified in 10 CFR Part 52, Appendices A, B, C, and D, respectively.  The NRC is currently reviewing four design certifications:


·                    General Electric-Hitachi’s ESBWR (first passive BWR)

·                    AREVA’s EPR (evolutionary pressurized-water reactor)

·                    Mitsubishi Heavy Industries’ US-APWR (advanced pressurized water reactor)

·                    AP1000 Revision 17 (first amended design certification)


Early Site Permits (ESP)


NRC has issued three ESPs to date (Clinton, Grand Gulf, and North Anna).  The NRC’s review of the last ESP in house (Vogtle) is essentially complete, and the NRC staff is awaiting the Atomic Safety and Licensing Board’s decision expected to be issued in mid-August 2009.  To date, there have been no ESPs submitted for greenfield sites.


Combined License (COL) Applications

NRC is currently reviewing 17 COL applications (27 new reactor units):

·                    1 ABWR         South Texas Project 3 and 4

·                    7 AP1000      Bellefonte 3 and 4, William S. Lee Station 1 and 2, Shearon Harris 2 and 3, Vogtle 3 and 4, V.C. Summer 2 and 3, Levy County 1 and 2, and Turkey Point 5 and 6**

·                    5 ESBWR      North Anna 3 and Grand Gulf 3*, River Bend 3*, Victoria County 1 and 2*, Fermi 3

·                    3 EPR             Calvert Cliffs 3, Nine Mile Point 3, Bell Bend

·                    1 US-APWR   Comanche Peak Units 3 and 4


*     The reviews of the FSARs for these COL applications are on hold pending possible selection of another standard design.

**    Turkey Point 5 and 6 are currently undergoing an acceptance review.


NRO Quality and Vendor Branch Activities


The New Reactor Licensing public web-site [http://www.nrc.gov/reactors/new-reactor-licensing.html] has a list of expected new nuclear power plant applications and an estimated schedule by fiscal year for new reactor licensing applications.


NRO Vendor Inspection


The NRO vendor inspection program is described in Inspection Manual chapter (IMC) 2507, “Construction Inspection Program, Vendor Inspection.”  This IMC will be implemented by various Inspection procedures (IPs) including:


IP 43002:  Routine Inspections of Nuclear Vendors;

IP 43003:  Reactive Inspections of Nuclear Vendors;

IP 43004:  Inspection of Commercial-Grade Dedication Programs;

IP 43005:  NRC Oversight of Third Party Organizations Implementing Quality Assurance

                   Requirements; and

IP 36100:  Inspection of 10 CFR Parts 21 and 50.55(e) Programs for Reporting Defects and



FY 09 Vendor Inspection Plans


  • Commercial Grade Dedication organizations
  • Forgings suppliers for AP1000, EPR
  • Manufacturing for SG tubes AP1000 and EPR
  • Manufacturing for ESBWR reactor pressure vessel
  • Manufacturing for valves (all new reactor Design Centers)
  • STP alternate Vendor & ABWR component fabrication in Japan
  • Modular Construction Facilities


Vendor Inspection Reports completed, issued and planned inspections


  • Vogtle COL QA Implementation Inspection, Birmingham AL, March 2009 – issued
  • Wyle Labs, Huntsville, AL, March 13 -17, 2009 -- issued
  • Conval Inc, Somers CT,  Valves, April 21-22, 2009 – issued
  • VC Summer QA Implementation Inspection, Jenkinsville, SC, June 2009 – issued
  • Flowserve Raleigh, Raleigh, NC, July 2009 – completed
  • JSW, Muroran Japan, July 2009 – completed
  • Toshiba, Japan, July 2009 – completed
  • Creusot Forge, Le Creusot, France, July 2009 – completed
  • Tioga Pipe, Easton, PA –August 2009 - announced


Vendor Inspections continue to identify findings related to commercial grade dedication activities and inadequate Part 21 programs for evaluating and reporting of defects that could cause a substantial safety hazard.


Previously issued NRC inspection and trip reports can be located at:






There are several on-going activities in license renewal.  Current status of applications and approvals is:


  • 54 units approved (Vogtle 1 & 2 issued in June
  • 12applications (18 units) under review

o       2 (2 units) awaiting final approval (Pilgrim and Vermont Yankee)

o       1 (2 units) completed ACRS full committee (Beaver Valley 1 & 2)

o       3 (5 units) awaiting  ACRS full committee (TMI 1 and Indian Point 2 & 3 planned 9/09, Susquehanna 1 & 2 planned 10/09)

o       1 (2 units) completed ACRS subcommittee (Prairie Island 1 & 2 planned 7/09)

o       5 (7 units) awaiting ACRS subcommittee (Kewaunee 4/10, Cooper 5/10 and Duane Arnold 5/10, Crystal River 6/10, Palo Verde 9/10

  • 9 applications with scheduled application dates

o       August 2009 – Salem 1 & 2 and Hope Creek

o       October – December 2009 – STARS

o       January 2010 – Columbia

o       April – June 2010 – Seabrook

o       August 2010 – Davis Besse

o       October – December 2010 – South Texas Project 1 & 2

o       January 2011 – Waterford

o       September 2011 – Limerick 1 & 2

o       Others staggered out to 2017


One plant entered the operating period beyond 40 years, Oyster Creek as of April 9.


Revision of Generic Aging Lessons Learned (GALL) Report (NUREG-1801)


NRC has an on-going internal activity to develop an update of the GALL report and the License Renewal Standard Review Plan (SRP.  This revision is comprehensive in nature, including consideration of aging management programs (AMPs), aging management review (AMR) line items from the GALL tables, and the SRP.  Sources of information for the proposed revisions are:


  • Interim Staff Guidance documents
  • Comments from the industry (Nuclear Energy Institute)
  • Plant operating experience (generic communications, etc.)
  • Lessons learned and precedents from LRA reviews
  • The NRR RES Proactive Materials Degradation Assessment (PMDA)


The tentative schedule is:


  • October 2009 – documents available on web
  • February 2010 – draft GALL and SRP available for public comment
  • December 2010 – final revised GALL and SRP issues


Technical Issues


Recent reviews and plant operating experience have identified issues in the following areas:


  • Neutron Absorbers – Interim Staff Guidance (ISG) under development for Boral and other neutron absorber materials
  • Buried Piping – Recent operating experience, including tritium releases
  • Metal Fatigue – Additional information routinely requested for NRC reviews
  • Containment Liner – Corrosion identified at several plants
  • Medium Voltage Cables – Cables in submerged environment not qualified for continuous submergence


7.         EPRI TOPICAL REPORT 1006596


A public meeting was held on Tuesday, August 4, 2009, at NRC headquarters between the NRC, NEI and EPRI to discuss EPRI Topical Report 1006596, “Materials Reliability Program (MRP): Pressurized Water Reactor Internals Inspection and Evaluation Guidelines” (MRP-227 – REV. 0).  The meeting is scheduled from 8:30 a.m. – 4:00 p.m. in the Commissioners' Conference Room O1F16/O1G16.  The purpose of the meeting is to discuss the current status, potential requests for additional information, and next steps to support the NRC staff’s review of TR MRP-227.  The meeting contact is Tanya Mensah, NRR/DPR, 301-415-3610, TME@nrc.gov.  The meeting notice and agenda are located in ADAMS (ML091880325).


8.         NESCC Panel Meeting, June, 2009


The National Institute of Standards and Technology (NIST) hosted a meeting on June 1, 2009, to discuss the formation of the Nuclear Energy Standards Coordination Collaborative.  The group is being formed by NIST, the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE), with sponsorship and coordination by the American National Standards Institute (ANSI).  The NESCC is intended to provide a forum for coordination and collaboration among standards developing organizations (SDOs) and other stakeholders in the development of nuclear energy-related standards.


The NESCC will promote identification of standards needed by the nuclear industry, and will recommend a prioritization and collaboration of efforts to revise or create such standards.  The panel aims to reduce redundant work effort among SDOs by reducing overlap among standards.  It also will facilitate development of joint and/or complementary standards, where appropriate, to address specifically identified gaps, and to do so in a timely manner.  In addition, the NESCC plans to coordinate with other national, regional, and international efforts addressing nuclear energy-related standards to promote international global compatibility and to avoid conflicting standards.


At the June meeting, the NESCC Draft Charter was discussed and finalized.  Proposed organizational structure and working methods, including the formation of topical Task Groups, were discussed.  Several participants (representing ASME, ANS, and NRC) presented some technical areas that they thought could warrant formation of a task group.  Discussions are expected to continue between meetings.  The meeting report is available on the NESCC website, at: http://www.ansi.org/standards_activities/standards_boards_panels/nescc/overview.aspx.  The next NESCC meeting is tentatively scheduled for the week of December 7th, 2009.


9.         Meeting on PWSCC Mitigation Activities


A public meeting was held on August 05 – 07, 2009, between the NRC staff and representatives of the nuclear power industry regarding industry sponsored primary water stress corrosion cracking (PWSCC) mitigation activities.  The purpose of the meeting was to discuss NRC and utility perspectives on PWSCC mitigation, and activities and issues related to, among other things, weld overlays, finite element analysis validation, and mitigation stress improvement processes.

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