[Federal Register Volume 71, Number 208 (Friday, October 27, 2006)]
[Proposed Rules]
[Pages 62947-62954]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-18024]


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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

RIN 3150-AH80


Incorporation by Reference of American Society of Mechanical 
Engineers Boiler and Pressure Vessel Code Cases

AGENCY: Nuclear Regulatory Commission.

ACTION: Issuance and Availability of Proposed Regulatory Guides.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is proposing to 
amend its regulations to incorporate by reference the latest revisions 
of two previously incorporated regulatory guides (RGs) that approve 
Code Cases published by the American Society of Mechanical Engineers 
(ASME). Specifically, these are Revision 34 of RG 1.84, ``Design and 
Fabrication Code Case Acceptability, ASME Section III'' (temporarily 
designated as Draft Regulatory Guide DG-1133), and Revision 15 of RG 
1.147, ``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1'' (temporarily designated as Draft Regulatory Guide DG-
1134). This proposed action would allow licensees to use the Code Cases 
listed in the regulatory guides as alternatives to requirements in the 
ASME Boiler and Pressure Vessel (BPV) Code regarding the construction 
and inservice inspection of nuclear power plant components.
    Toward that end, the NRC has issued for public comment drafts of 
the two revised guides in the agency's Regulatory Guide Series. This 
series has been developed to describe and make available to the public 
such information as methods that are acceptable to the NRC staff for 
implementing specific parts of the NRC's regulations, techniques that 
the staff uses in evaluating specific problems or postulated accidents, 
and data that the staff needs in its review of applications for permits 
and licenses.

DATES: Submit comments on the guides by January 2, 2007. Comments 
received after this date will be considered if it is practical to do 
so, but the Commission is able to ensure consideration only of comments 
received on or before this date.

ADDRESSES: The NRC staff is soliciting comments on Draft Regulatory 
Guides DG-1133 and DG-1134. Comments may be accompanied by relevant 
information or supporting data. Please mention the draft guide number 
(DG-1133 or DG-1134) in the subject line of your comments. Comments 
submitted in writing or in electronic form will be made available to 
the public in their entirety through the NRC's Agencywide Documents 
Access and Management System (ADAMS). Personal information will not be 
removed from your comments. You may submit comments by any of the 
following methods.
    Mail comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001.
    E-mail comments to: [email protected]. You may also submit comments 
via the NRC's rulemaking Web site at http://ruleforum.llnl.gov. Address 
questions about our rulemaking Web site to Carol A. Gallagher (301) 
415-5905; e-mail [email protected].
    Hand-deliver comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission, 11555 Rockville 
Pike, Rockville, Maryland 20852, between 7:30 a.m. and 4:15 p.m. on 
Federal workdays.
    Fax comments to: Rules and Directives Branch, Office of 
Administration, U.S. Nuclear Regulatory Commission at (301) 415-5144.
    Copies of the draft regulatory guides specified in this rulemaking 
and other publicly available documents related to the proposed rule 
incorporating these regulatory guides, including public comments 
received, can be viewed electronically on public computers in the NRC 
Public Document Room (PDR), located at One White Flint North, 11555 
Rockville Pike, Rockville, Maryland Room O-1 F21, and open to the 
public on Federal workdays from 7:45 a.m. until 4:15 p.m. The PDR 
reproduction contractor will make copies of documents for a fee. 
Selected documents, including public comments on the proposed rule, can 
be viewed and downloaded electronically via the NRC's rulemaking Web 
site at http://ruleform.llnl.gov. In addition, the draft regulatory 
guides can be viewed and downloaded electronically on the NRC's public 
Web site under Draft Regulatory Guides in the Regulatory Guides 
document collection of the NRC's Electronic Reading Room at http://www.nrc.gov/reading-rm/doc-collections/.
    Publicly available NRC documents created or received in connection 
with the rulemaking (including the draft regulatory guides) are also 
available electronically via the NRC's Electronic Reading Room at 
http://www.nrc.gov/NRC/reading-rm/adams.html. From this site, the 
public can gain entry into the NRC's Agencywide Document Access and 
Management System (ADAMS), which provides text and image files of NRC's 
public documents. If you do not have access to ADAMS or if there are 
problems in accessing the documents located in ADAMS contact the NRC 
Public Document Room (PDR) Reference staff at 1-800-397-4209, 301-415-
4737 or by e-mail to [email protected].
    Further information about obtaining the draft regulatory guides and 
other rulemaking-related documents, including a list of ADAMS accession 
numbers, can be found in the ``Availability of Documents'' Section 
under the SUPPLEMENTARY INFORMATION heading.

FOR FURTHER INFORMATION CONTACT: Wallace E. Norris, Office of Nuclear 
Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 
20555-0001, telephone (301) 415-6796, e-mail [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The American Society of Mechanical Engineers (ASME) develops and 
publishes the Boiler and Pressure Vessel Code (BPV Code), which 
contains the Code requirements for the design, construction, and 
inservice inspection (ISI) of nuclear power plant components, and the 
Code for Operation and Maintenance of Nuclear Power Plants (OM Code), 
which contains Code requirements for inservice testing (IST) of nuclear 
power plant components. In response to BPV and OM Code user requests, 
the ASME develops Code Cases which provide alternatives to BPV and OM 
Code requirements under special circumstances.

Discussion

    The NRC staff reviews ASME BPV and OM Code Cases, determines the 
acceptability of each Code Case, and publishes its findings in 
regulatory guides. These regulatory guides are revised periodically as 
new Code Cases are published by the ASME. The NRC incorporates by 
reference the regulatory guides listing acceptable and conditionally 
acceptable ASME Code Cases in 10 CFR 50.55a.

[[Page 62948]]

    The NRC is proposing to incorporate by reference Revision 34 of RG 
1.84, ``Design and Fabrication Code Case Acceptability, ASME Section 
III'' (temporarily designated as Draft Regulatory Guide DG-1133), and 
Revision 15 of RG 1.147, ``Inservice Inspection Code Case 
Acceptability, ASME Section XI, Division 1'' (temporarily designated as 
Draft Regulatory Guide DG-1134). Revision 34 of RG 1.84 would supersede 
the incorporation by reference of Revision 33 and Revision 15 of RG 
1.147 would supersede the incorporation by reference of all previous 
revisions of the guide (Revisions 0 through 14). To make Regulatory 
Guide 1.147 easier to use, the staff made an effort to ensure that the 
tables of annulled Code Cases in Revision 15 were all inclusive. The 
result should be that licensees will no longer have to refer to 
multiple versions of this regulatory guide in managing Code Case usage 
in their ISI programs. RG 1.192, ``Operation and Maintenance Code Case 
Acceptability, ASME OM Code'' (June 2003), has not been revised because 
the ASME has not published any new OM Code Cases since the last NRC 
staff review.
    Concurrent with this action, the NRC is publishing a notice of 
availability of the proposed rulemaking, which incorporates these draft 
regulatory guides by reference. Interested parties may submit comments 
to the NRC on the proposed rulemaking in accordance with the 
instructions published in the Federal Register notice announcing its 
availability.

Code Cases N-659 and N-460

    The NRC staff is currently considering a proposed licensee action 
to use Code Case N-659, ``Use of Ultrasonic Examination in Lieu of 
Radiography for Weld Examination, Section III, Division 1,'' and Code 
Case N-460, ``Alternative Examination Coverage for Class 1 and Class 2 
Welds, Section XI, Division 1,'' in an unanticipated manner. Because 
the proposed licensee action was received after Draft Regulatory Guides 
DG-1133 and DG-1134 had been published but prior to their release, the 
NRC is proposing to add conditions to the use of these Code Cases in 
the final guides, unless public comments are received that indicate 
that the staff's proposed technical bases for the conditions are not 
applicable, incorrect, unnecessary to provide reasonable assurance of 
adequate protection to public health and safety and common defense and 
security, or otherwise not justified in light of the increase in 
protection to public health and safety or common defense and security 
that would be provided by imposition of the conditions.

Code Case N-659

    Originally, concerns had been raised relative to the calibration 
block requirements in the Code Case, and two conditions had been 
developed for inclusion in the proposed Draft Regulatory Guide DG-1133. 
The proposed licensee action, however, has raised three new concerns 
that relate to the licensee's intended use of the Code Case and the 
capabilities of UT and RT as test methods. Currently, Section III 
requires that radiographic testing (RT) examinations be performed after 
the fabrication of certain Class 1, Class 2, and Class 3 welds. The 
ASME approved Code Case N-659 as an alternative to the requirements of 
Section III that would permit manufacturers of nuclear power plant 
components to use ultrasonic testing (UT) examinations in lieu of RT. 
However, depending on flaw type (i.e., volumetric or planar) and 
orientation, RT and UT are not equally effective for flaw detection and 
characterization. RT is effective in detecting volumetric type flaws 
(i.e., slag and porosity), and in detecting planar type flaws with 
large openings (i.e., lack of fusion and large cracks in high stressed 
areas), and which are oriented in a plane parallel to the x-ray beam. 
RT is effective in all materials common to the nuclear industry in 
detecting the type of flaws generated during construction. Thus, RT is 
a good tool to detect workmanship type defects (construction flaws) and 
ensures an acceptable level of weld quality and safety. In contrast, UT 
is effective in detecting and sizing planar type flaws in ferritic 
steels and to a lesser extent in wrought austenitic steels. With 
specific technique development and personnel training on construction 
flaws, UT can also be used to detect volumetric type flaws such as slag 
or porosity. UT is of limited value in detecting flaws in cast 
stainless steels. Finally, UT requires more surface scanning area than 
RT to perform examinations.
    During the NRC staff's assessment of the proposed licensee action, 
concerns were raised relative to the capability of UT, as it would be 
employed, to detect workmanship type defects and ensure an acceptable 
level of weld quality. The first concern is with regard to the option 
provided by the Code Case to use either Section V, Article 5, with two 
additional construction flaws, or Section XI, Appendix VIII, with a 
blind add-on demonstration to existing configuration specific 
qualifications that contains at least three construction type flaws. 
The addition of only two or three construction flaws to a demonstration 
is not sufficient to capture the variety of flaws common to 
construction or to statistically evaluate procedure effectiveness and 
personnel skills. Section V prescriptive-based requirements are less 
effective in detecting flaws than performance-based Appendix VIII 
requirements. Section V qualifications are based on identifying known 
machined reflectors that display good acoustic responses, which do not 
address inspection reliability. Performance-based qualifications 
require blind demonstrations on mockups having flaws with realistic UT 
responses and a statistically sufficient number of representative flaws 
and non flawed volumes to establish procedure effectiveness and 
personnel skill. The statistical approach to qualification has been 
shown to improve the reliability of inspections and probability of 
detection, and to reduce the number of false calls.
    The second concern is the provision of the Code Case to use the 
second leg of the ultrasound metal path (V-path) to achieve two 
direction scanning from only one side of the weld. Single side 
examinations of the welds have been successfully performance 
demonstrated on planar flaws in ferritic carbon steel but have not been 
reliably demonstrated for planar flaws in austenitic stainless steel 
and nickel alloys. Single side examinations have not been demonstrated 
for construction flaws for any material.
    The third concern is the requirement in the Code Case to only 
examine half of the through-wall thickness (\1/2\ t) from each side of 
the weld to verify that the welding process did not compromise the 
integrity of the base material surrounding the weld. For thin-walled 
parts and components, \1/2\ t may not be sufficient to capture any 
degradation associated with the welding process.
    To address the three new concerns discussed above, the NRC proposes 
to place additional conditions on the use of Code Case N-659 in the 
final guide. In Paragraph (a) of Code Case N-659, the greater of \1/2\ 
t or \1/2\-inch from the widest portion of the weld shall be used, and 
any use of the second leg of the ultrasonic metal path shall be 
qualified by a performance-based demonstration. In lieu of Paragraphs 
(b) and (d), the following shall be used: Procedures and personnel 
shall be qualified with blind performance demonstrations on 
representative mockups in terms of material, wall-thickness, diameter, 
surface roughness, and configuration of the weldment being examined. A 
minimum of 10 construction type flaws are required for a personnel 
qualification and the

[[Page 62949]]

equivalent of three personnel qualifications required for a procedure 
qualification.
    At least 70% of the flaws shall be located along the base metal-to-
weld fusion zone on both sides of the weld. The flaws shall be randomly 
distributed throughout the weld thickness. Each flawed and unflawed 
volume shall be defined in independent grading units. The flaws shall 
be representative of the variety of construction flaws common to the 
welding process and material being examined. The demonstration must 
show the capability to detect flaws having a minimum 2% through-wall 
depth and within the flaw length acceptance of NB-2553(c). The 
demonstration detection acceptance criteria shall be:

----------------------------------------------------------------------------------------------------------------
              Detection test acceptance criteria                       False call test acceptance criteria
----------------------------------------------------------------------------------------------------------------
                                                    Minimum
        Number of flawed grading units             detection    Number of unflawed grading units  Maximum number
                                                   criteria                                       of false calls
----------------------------------------------------------------------------------------------------------------
10............................................               8  15..............................               2
11............................................               9  17..............................               3
12............................................               9  18..............................               3
13............................................              10  20..............................               3
14............................................              10  21..............................               3
15............................................              11  23..............................               3
16............................................              12  24..............................               4
17............................................              12  26..............................               4
----------------------------------------------------------------------------------------------------------------

    Flaws shall be detected and located within 1.0-inch of true length 
and width location and within 10% of true through-wall depth location 
or within 10% of the sound beam metal path, whichever is greater. All 
other reported flaws within false call grading units shall be false 
calls.
    A minimum of 10 flaws shall be used for sizing with a random 
distribution of lengths greater than and less than the applicable NB-
2553(c) acceptance standard. The maximum flaw length shall not exceed 
200% of the acceptance standard. For qualification, all flaws shall be 
correctly identified as acceptable or unacceptable.
    Procedures shall identify the equipment and essential variable 
settings used for the qualification. An essential variable is any 
variable that has an effect on the results of an examination. The 
procedure shall be requalified when an essential variable is changed 
outside the demonstrated range.

Code Case N-460

    Code Case N-460 provides alternative requirements for the inservice 
examination of Class 1 welds (Section XI, IWB-2500) and Class 2 welds 
(Section XI, IWC-2500) when the entire examination volume cannot be 
examined due to interference by another component or part geometry. The 
licensee proposed to apply this Code Case in conjunction with Code Case 
N-659 in those instances when the entire examination volume or area 
cannot be examined following fabrication, repair or replacement. The 
NRC does not believe that it is appropriate to use Code Case N-460 for 
repair and replacement during construction and replacement 
(fabrication) activities because a construction or replacement weld 
should be designed for complete access for examination. Thus, the NRC 
proposes to condition the use of Code Case N-460 in the final guide 
such that the Code Case can only be applied when performing inservice 
examinations in accordance with a Section XI inservice inspection 
program.

Evaluation of Code Cases

1 Purpose and Structure of This Evaluation

    This evaluation lists the Code Cases and explains NRC's rationale 
for any limitations. The evaluation also explains the ASME and 
regulatory processes concerning Code Cases. The evaluation addresses 
Proposed Revision 34 to Regulatory Guide 1.84 (DG-1133), ``Design, 
Fabrication, and Materials Code Case Acceptability, ASME Section III,'' 
and Proposed Revision 15 to Regulatory Guide 1.147 (DG-1134), 
``Inservice Inspection Code Case Acceptability, ASME Section XI, 
Division 1.'' For these revisions, the NRC staff reviewed the Code 
Cases in Supplement 7 through Supplement 12 to the 2001 Edition and 
Supplement 1 to the 2004 Edition of the American Society of Mechanical 
Engineers (ASME) Boiler and Pressure Vessel Code (BPV Code). The 
regulatory guides do not address Code Cases pertaining to high-
temperature gas-cooled reactors; certain requirements in Section III, 
Division 2, that are not endorsed by the NRC; liquid metal; and 
submerged spent fuel waste casks. The proposed disposition of each Code 
Case is listed below. For Code Cases determined to be conditionally 
acceptable, the basis for the determination is summarized to afford 
users of the ASME Code an opportunity to comment on the proposed 
disposition and basis.

2 Discussion of ASME Process

    Code Cases provide alternatives, developed and approved by ASME, to 
the applicable provisions of the ASME BPV Code. For the purposes of 
this evaluation, Code Cases can be categorized as one of three types: 
new, revised, or reaffirmed (it should be noted that after the review 
of the supplements addressed in this evaluation, the ASME made a 
determination to end the use of three-year terms for Code Cases and 
therefore, the latest supplements do not contain reaffirmed Code 
Cases). A new Code Case addresses for the first time a specific need. 
Existing Code Cases may be revised (modified) to address, for example, 
technological advancements in examination techniques, or to address NRC 
limitations and modifications. Code Cases still in use but not 
requiring revision may be reaffirmed (approved) without change by the 
ASME. As noted above, subsequent to the NRC review of the Code Cases in 
the subject supplements, the ASME made a determination to eliminate 
expiration dates for Code Cases. Thus in the future, Code Cases will no 
longer require reaffirmation (i.e., new 3-year terms). This change is 
not expected to affect the NRC Code Case review process, nor result in 
significant modification of the regulatory guides.
    With regard to Code Cases conditioned by the NRC, it should be 
noted that the Subcommittee on Nuclear Power (Section III) and the 
Subcommittee on Nuclear Inservice Inspection (Section XI) have 
instructed working groups to review these Code Cases, and determine 
whether changes

[[Page 62950]]

to the Code Cases are appropriate. For example, Code Case N-613 was not 
approved for use by the NRC because certain provisions conflicted with 
requirements in 10 CFR 50.55a. Section XI revised the Code Case in a 
manner acceptable to the NRC and Code Case N-613-1 was approved in 
Revision 14 of Regulatory Guide 1.147. Revisions to other Code Cases 
are expected to be published by the ASME in the near future with the 
expectation that many of them can be unconditionally approved by the 
NRC.

3 Discussion of Regulatory Process

    New Code Cases that are determined to be acceptable by the NRC are 
approved as published by the ASME and may be used in the design, 
construction, and ISI of components and their supports for water-cooled 
nuclear power plants. When a determination is made that the provisions 
of a new Code Case need to be augmented, that Code Case is 
conditionally approved. These Code Cases are acceptable to the NRC 
within the limitations and modifications described in the relevant 
regulatory guide. Unless otherwise stated, limitations recommended by 
the NRC staff are in addition to the conditions specified in the Code 
Case. A discussion of the basis for the limitation or modification is 
provided, and the NRC invites public comment on these conditions. A 
determination may be made that a new Code Case is unacceptable for use 
by licensees. Code Cases determined to be unacceptable are listed in 
Proposed Revision 2 of Regulatory Guide 1.193, ``ASME Code Cases Not 
Approved for Use.'' A summary of the basis for the determination is 
provided in the regulatory guide, and the NRC invites public comment on 
the basis for the disapproval. Revised Code Cases were modified by the 
ASME, and the NRC compares the revised Code Case to the original Code 
Case (that has become part of the regulations through the incorporation 
by reference process), and a determination is made whether the revised 
Code Case is acceptable, conditionally acceptable, or unacceptable. 
Reaffirmed in the context of the regulatory guides means that a Code 
Case was approved in a previous version of a regulatory guide. The 
status of a revised Code Case remains unchanged in the regulatory guide 
unless additional information becomes available (e.g., emerging issue) 
indicating that a regulatory change in position is warranted.

4 List of Code Cases and Summary of Bases

    4.1 Acceptable Code Cases: The Code Cases in Supplement 7 through 
Supplement 12 to the 2001 Edition and Supplement 1 to the 2004 Edition 
listed below are acceptable to the NRC. The supplement in which a Code 
Case appears is listed in brackets behind the Code Case Number (e.g., 
[S7] means Supplement 7).
    4.2 Section III Code Cases.

                                Code Case
------------------------------------------------------------------------
             Number                    Type                Title
------------------------------------------------------------------------
N-7-1 [S7].....................  Reaffirmed.....  High Yield Strength
                                                   Steel, Section III,
                                                   Division 1, Class 1.
N-60-5 [S12]...................  Reaffirmed.....  Material for Core
                                                   Support Structures,
                                                   Section III, Division
                                                   1.
N-122-2 [S7]...................  Reaffirmed.....  Procedure for
                                                   Evaluation of the
                                                   Design of Rectangular
                                                   Cross Section
                                                   Attachments on Class
                                                   1 Piping, Section
                                                   III, Division 1.
N-131-1 [S7]...................  Reaffirmed.....  Material for Internal
                                                   Pressure Retaining
                                                   Items for Pressure
                                                   Relief Valves,
                                                   Section III, Division
                                                   1, Class 1, 2, and 3.
N-133-3 [S7]...................  Reaffirmed.....  Use of SB-148 Alloys
                                                   952 and 954, Section
                                                   III, Division 1,
                                                   Class 3.
N-154-1 [S7]...................  Reaffirmed.....  Projection Resistance
                                                   Welding of Valve
                                                   Seats, Section III,
                                                   Classes 1, 2, and 3.
N-160-1 [S7]...................  Reaffirmed.....  Finned Tubing for
                                                   Construction, Section
                                                   III, Division 1.
N-208-1 [S8/9].................  Reinstated.....  Fatigue Analysis for
                                                   Precipitation
                                                   Hardening Nickel
                                                   Alloy Bolting
                                                   Material to
                                                   Specification SB-637
                                                   N07718 for Section
                                                   III Division 1, Class
                                                   1 Construction.
N-243 [S7].....................  Reaffirmed.....  Boundaries Within
                                                   Castings Used for
                                                   Core Support
                                                   Structures, Section
                                                   III, Division 1.
N-315 [S7].....................  Reaffirmed.....  Repair of Bellows,
                                                   Section III, Division
                                                   1.
N-318-5 [S7]...................  Reaffirmed.....  Procedure for
                                                   Evaluation of the
                                                   Design of Rectangular
                                                   Cross Section
                                                   Attachments on Class
                                                   2 or 3 Piping,
                                                   Section III, Division
                                                   1.
N-319-3 [S7]...................  Reaffirmed.....  Alternate Procedure
                                                   for Evaluation of
                                                   Stresses in Butt
                                                   Welding Elbows in
                                                   Class 1 Piping,
                                                   Section III, Division
                                                   1.
N-369 [S8/9]...................  Reaffirmed.....  Resistance Welding of
                                                   Bellows, Section III,
                                                   Division 1.
N-373-2 [S1]...................  Reaffirmed.....  Alternative PWHT Time
                                                   at Temperature for P-
                                                   No. 5 Material,
                                                   Section III, Division
                                                   1, Classes 1, 2, and
                                                   3.
N-391-2 [S1]...................  Reaffirmed.....  Procedure for
                                                   Evaluation of the
                                                   Design of Hollow
                                                   Circular Cross
                                                   Section Welded
                                                   Attachments on Class
                                                   1 Piping, Section
                                                   III, Division 1.
N-392-3 [S1]...................  Reaffirmed.....  Procedure for
                                                   Evaluation of the
                                                   Design of Hollow
                                                   Circular Cross
                                                   Section Welded
                                                   Attachments on
                                                   Classes 2 and 3
                                                   Piping, Section III,
                                                   Division 1.
N-405-1 [S12]..................  Reaffirmed.....  Socket Welds, Section
                                                   III, Division 1.
N-452 [S8/9]...................  Reaffirmed.....  Specialized
                                                   Subcontracted Welding
                                                   Process (Electron
                                                   Beam Welding),
                                                   Section III, Division
                                                   1.
N-454-1 [S10]..................  Reaffirmed.....  Nickel-Chromium-
                                                   Molybdenum-Copper
                                                   Stainless Steel (UNS
                                                   N08925 and N08926)
                                                   Wrought Fittings for
                                                   Class 1 and 3
                                                   Construction, Section
                                                   III, Division 1.
N-455-1 [S10]..................  Reaffirmed.....  Nickel-Chromium-
                                                   Molybdenum-Copper
                                                   Stainless Steel (UNS
                                                   N08925 and N08926)
                                                   Forged Flanges and
                                                   Fittings for Class 1
                                                   and 3 Construction,
                                                   Section III, Division
                                                   1.
N-469-1 [S7]...................  Reaffirmed.....  Martensitic Stainless
                                                   Steel for Class 1, 2,
                                                   and 3 Components,
                                                   Section III, Division
                                                   1.
N-500-2 [S1]...................  Revised........  Alternative Rules for
                                                   Standard Supports for
                                                   Classes 1, 2, 3 and
                                                   MC, Section III,
                                                   Division 1.
N-505 [S1].....................  Reaffirmed.....  Alternative Rules for
                                                   the Examination of
                                                   Butt Welds Used as
                                                   Closure Welds for
                                                   Electrical
                                                   Penetration
                                                   Assemblies in
                                                   Containment
                                                   Structures, Section
                                                   III, Division 1.
N-511 [S1].....................  Reaffirmed.....  Design Temperature for
                                                   Atmospheric and 0-15
                                                   psi Storage Tanks,
                                                   Section III, Division
                                                   1.
N-520-1 [S8/9].................  Reaffirmed.....  Alternative Rules for
                                                   Renewal of N-type
                                                   Certificates for
                                                   Plants Not in Active
                                                   Construction, Section
                                                   III, Division 1.
N-539 [S12]....................  Reaffirmed.....  UNS N08367 in Class 2
                                                   and 3 Valves, Section
                                                   III, Division 1.
N-564-2 [S7]...................  Reaffirmed.....  UNS J93380, Alloy
                                                   DC3MWCuN, Class 2 and
                                                   3 Construction,
                                                   Section III, Division
                                                   1.
N-579 [S7].....................  Reaffirmed.....  Use of Nonstandard
                                                   Nuts, Class 1, 2, and
                                                   3, MC, CS Components
                                                   and Supports
                                                   Construction, Section
                                                   III, Division 1.

[[Page 62951]]

 
N-607 [S1].....................  Reaffirmed.....  Transfer of Welder,
                                                   Welding Operator,
                                                   Brazer, and Brazing
                                                   Operator
                                                   Qualifications
                                                   Between Owners,
                                                   Section XI, Division
                                                   1.
N-610 [S1].....................  Reaffirmed.....  Alternative Reference
                                                   Stress Intensity
                                                   Factor (K1R) Curve
                                                   for Class Components,
                                                   Section III, Division
                                                   1.
N-611 [S12]....................  Reaffirmed.....  Use of Stress Limits
                                                   as an Alternate to
                                                   Pressure Limits
                                                   Subsection NC/ND-
                                                   3500, Section III,
                                                   Division 1.
N-620 [S1].....................  Reaffirmed.....  Rules for Class 1 Type
                                                   M Pumps, Section III,
                                                   Division 1.
N-621 [S1].....................  Reaffirmed.....  Ni-Cr-Mo Alloy (UNS
                                                   N06022) Welded
                                                   Construction to
                                                   800[deg]F, Section
                                                   III, Division 1.
N-625-1 [S12]..................  Reaffirmed.....  Ni-Cr-Mo Alloy (UNS
                                                   N06059) Welded
                                                   Construction to
                                                   800[deg]F, Section
                                                   III, Division 1.
N-632 [S7].....................  Reaffirmed.....  Use of ASTM A572,
                                                   Grades 50 and 65 for
                                                   Structural
                                                   Attachments to Class
                                                   CC Containment
                                                   Liners, Section III,
                                                   Division 1.
N-635-1 [S8/9].................  Revised........  Use of 22Cr-5Ni-3Mo-N
                                                   (Alloy UNS S31803)
                                                   Forgings, Plate, Bar,
                                                   Welded and Seamless
                                                   Pipe, and/or Tube,
                                                   Fittings, and Fusion
                                                   Welded Pipe With
                                                   Addition of Filler
                                                   Metal, Classes 2 and
                                                   3, Section III,
                                                   Division 1.
N-642 [S7].....................  Reaffirmed.....  Alternative Rules for
                                                   Progressive Liquid
                                                   Penetrant Examination
                                                   of Groove Welds in P-
                                                   No. 8 Materials 3/16
                                                   in. (5mm) Thick and
                                                   Less Made by
                                                   Autogenous Machine or
                                                   Automatic Welding,
                                                   Section III, Division
                                                   1.
N-644-1 [S8/9].................  Revised........  Weld Procedure
                                                   Qualification for
                                                   Procedures Exempt
                                                   From PWHT in Classes
                                                   1, 2, and 3
                                                   Construction, Section
                                                   III, Division 1.
N-646 [S10/12].................  Reaffirmed.....  Alternative Stress
                                                   Intensification
                                                   Factors in
                                                   Circumferential
                                                   Fillet Welded or
                                                   Socket Welded Joints
                                                   for Class 2 or 3
                                                   Piping, Section III,
                                                   Division 1.
N-650 [S12]....................  Reaffirmed.....  Use of SA-537, Class 2
                                                   Plate Material in Non-
                                                   pressure Boundary
                                                   Application Service
                                                   700[deg]F to
                                                   850[deg]F, Class 1 or
                                                   CS, Section III,
                                                   Division 1.
N-692 [S10]....................  New............  Use of Standard
                                                   Welding Procedures,
                                                   Section III,
                                                   Divisions 1 and 2.
N-698 [S11]....................  New............  Design Stress
                                                   Intensities and Yield
                                                   Strength for UNS
                                                   N06690 With a Minimum
                                                   Specified Yield
                                                   Strength of 35 ksi
                                                   (240Mpa), Class 1
                                                   Components, Section
                                                   III, Division 1.
N-703 [S1].....................  New............  Use of Strain Hardened
                                                   Austenitic Material
                                                   at Lower Design
                                                   Stress Values for
                                                   Class 1 Valves,
                                                   Section III, Division
                                                   1.
N-710 [S1].....................  New............  Use of Zirconium Alloy
                                                   UNS R60702, Bars,
                                                   Forgings, Plate,
                                                   Seamless and Welded
                                                   Fittings, Seamless
                                                   and Welded Tubing,
                                                   and Seamless and
                                                   Welded Pipe, for
                                                   Class 3 Construction,
                                                   Section III, Division
                                                   1.
------------------------------------------------------------------------

    4.3 Section XI Code Cases.

                                Code Case
------------------------------------------------------------------------
             Number                    Type                Title
------------------------------------------------------------------------
N-307-3 [S1]...................  Reaffirmed.....  Revised Ultrasonic
                                                   Examination Volume
                                                   for Class 1 Bolting,
                                                   Table IWB-2500-1,
                                                   Examination Category
                                                   B-G-1, When the
                                                   Examinations Are
                                                   Conducted from the
                                                   End of the Bolt or
                                                   Stud or from the
                                                   Center-Drilled Hole,
                                                   Section XI, Division
                                                   1.
N-334 [S8/9]...................  Reaffirmed.....  Examination
                                                   Requirements for
                                                   Integrally Welded or
                                                   Forged Attachments to
                                                   Class 2 Piping at
                                                   Containment
                                                   Penetrations, Section
                                                   XI, Division 1.
N-416-3 [S1]...................  Reaffirmed.....  Alternative Pressure
                                                   Test Requirement for
                                                   Welded Repairs or
                                                   Installation of
                                                   Replacement Items by
                                                   Welding, Class 1, 2,
                                                   and 3, Section XI,
                                                   Division 1.
N-432-1 [S1]...................  Reaffirmed.....  Repair Welding Using
                                                   Automatic or Machine
                                                   Gas Tungsten-Arc
                                                   Welding (GTAW) Temper
                                                   Bead Technique,
                                                   Section XI, Division
                                                   1.
N-460 [S8/9]...................  Reaffirmed.....  Alternative
                                                   Examination Coverage
                                                   for Class 1 and Class
                                                   2 Welds, Section XI,
                                                   Division 1.
N-491-2 [S8/9].................  Reaffirmed.....  Rules for Examination
                                                   of Class 1, 2, 3, and
                                                   MC Component Supports
                                                   of Light-Water Cooled
                                                   Power Plants, Section
                                                   XI, Division 1.
N-508-3 [S11]..................  Revised........  Rotation of Serviced
                                                   Snubbers and Pressure
                                                   Relief Valves for the
                                                   Purpose of Testing,
                                                   Section XI, Division
                                                   1.
N-513-2 [S1]...................  Revised........  Evaluation Criteria
                                                   for Temporary
                                                   Acceptance of Flaws
                                                   in Moderate Energy
                                                   Class 2 or 3 Piping,
                                                   Section XI, Division
                                                   1.
N-534 [S8/9]...................  Reaffirmed.....  Alternative
                                                   Requirements for
                                                   Pneumatic Pressure
                                                   Testing, Section XI,
                                                   Division 1.
N-537 [S1].....................  Reaffirmed.....  Location of Ultrasonic
                                                   Depth-Sizing Flaws,
                                                   Section XI, Division
                                                   1.
N-545 [S1].....................  Reaffirmed.....  Alternative
                                                   Requirements for
                                                   Conduct of
                                                   Performance
                                                   Demonstration
                                                   Detection Test of
                                                   Reactor Vessel,
                                                   Section XI, Division
                                                   1.
N-553-1 [S1]...................  Reaffirmed.....  Inservice Eddy Current
                                                   Surface Examination
                                                   of Pressure Retaining
                                                   Pipe Welds and Nozzle-
                                                   to-Safe End Welds,
                                                   Section XI, Division
                                                   1.
N-566-2 [S1]...................  Reaffirmed.....  Corrective Action for
                                                   Leakage Identified at
                                                   Bolted Connections,
                                                   Section XI, Division
                                                   1.
N-573 [S8/9]...................  Reaffirmed.....  Transfer of Procedure
                                                   Qualification Records
                                                   Between Owners,
                                                   Section XI, Division
                                                   1.
N-586-1 [S1]...................  Revised........  Alternative Additional
                                                   Examination
                                                   Requirements for
                                                   Classes 1, 2, and 3
                                                   Piping, Components,
                                                   and Supports, Section
                                                   XI, Division 1.
N-600 [S1].....................  Reaffirmed.....  Transfer of Welder,
                                                   Welding Operator,
                                                   Brazer, and Brazing
                                                   Operator
                                                   Qualifications
                                                   Between Owners,
                                                   Section XI, Division
                                                   1.
N-609 [S1].....................  Reaffirmed.....  Alternative
                                                   Requirements to
                                                   Stress-Based
                                                   Selection Criteria
                                                   for Category B-J
                                                   Welds, Section XI,
                                                   Division 1.
N-641 [S7].....................  Reaffirmed.....  Alternative Pressure-
                                                   Temperature
                                                   Relationship and Low
                                                   Temperature
                                                   Overpressure
                                                   Protection System
                                                   Requirements, Section
                                                   XI, Division 1.

[[Page 62952]]

 
N-643-2 [S1]...................  Revised........  Fatigue Crack Growth
                                                   Rate Curves for
                                                   Ferritic Steels in
                                                   PWR Water
                                                   Environment, Section
                                                   XI, Division 1.
N-649 [S1].....................  Reaffirmed.....  Alternative
                                                   Requirements for IWE-
                                                   5240 Visual
                                                   Examination, Section
                                                   XI, Division 1.
N-651 [S1].....................  Reaffirmed.....  Ferritic and
                                                   Dissimilar Metal
                                                   Welding Using SMAW
                                                   Temper Bead Technique
                                                   Without Removing the
                                                   Weld Bead Crown for
                                                   the First Layer,
                                                   Section XI, Division
                                                   1.
N-652-1 [S12]..................  Revised........  Alternative
                                                   Requirements to
                                                   Categorize B-G-1, B-G-
                                                   2, and C-D Bolting
                                                   Examination Methods
                                                   and Selection
                                                   Criteria, Section XI,
                                                   Division 1.
N-665 [S8/9]...................  New............  Alternative
                                                   Requirements for Beam
                                                   Angle Measurements
                                                   Using Refracted
                                                   Longitudinal Wave
                                                   Search Units, Section
                                                   XI, Division 1.
N-683 [S8/9]...................  New............  Method for Determining
                                                   Maximum Allowable
                                                   False Calls When
                                                   Performing Single-
                                                   Sided Access
                                                   Performance
                                                   Demonstration in
                                                   Accordance With,
                                                   Appendix VIII,
                                                   Supplements 4 and 6,
                                                   Section XI, Division
                                                   1.
N-685 [S8/9]...................  New............  Lighting Requirements
                                                   for Surface
                                                   Examination, Section
                                                   XI, Division 1.
N-686 [S8/9]...................  New............  Alternative
                                                   Requirements for
                                                   Visual Examinations,
                                                   VT-1, VT-2, and VT-3,
                                                   Section XI, Division
                                                   1.
N-695 [S10]....................  New............  Qualification
                                                   Requirements for
                                                   Dissimilar Metal
                                                   Piping Welds, Section
                                                   XI, Division 1 (Note:
                                                   N-695 was approved in
                                                   Revision 14 to
                                                   Regulatory Guide
                                                   1.147).
N-696 [S10]....................  New............  Qualification
                                                   Requirements for
                                                   Appendix VIII Piping
                                                   Examinations
                                                   Conducted From the
                                                   Inside Surface,
                                                   Section XI, Division
                                                   1.
N-697 [S11]....................  New............  Pressurized Water
                                                   Reactor (PWR)
                                                   Examination and
                                                   Alternative
                                                   Examination
                                                   Requirements for
                                                   Pressure Retaining
                                                   Welds in Control Rod
                                                   Drive and Instrument
                                                   Nozzle Housings,
                                                   Section XI, Division
                                                   1.
N-700 [S11]....................  New............  Alternative Rules for
                                                   Selection of Classes
                                                   1, 2, and 3 Vessel
                                                   Welded Attachments
                                                   for Examination,
                                                   Section XI, Division
                                                   1.
------------------------------------------------------------------------

    4.4 Conditionally Acceptable Code Cases: The Code Cases listed 
below are acceptable to the NRC subject to the limitations and 
modifications listed. Notations have been made to indicate the 
conditions duplicated from previous versions of the regulatory guides.
    4.5 Section III.
     Code Case N-62-7 [S7].
    Type: Reaffirmed.
    Title: Internal and External Valve Items, Section III, Division 1, 
Classes 1, 2, and 3.
    Code Case N-62-7 was conditionally approved in Revisions 32 and 33 
to RG 1.84. This Code Case was reaffirmed by the ASME. No changes have 
been made to the conditions in proposed Revision 34 to the guide.
     Code Case N-71-18 [S8/9].
    Type: Reaffirmed.
    Title: Additional Materials for Subsection NF, Class 1, 2, 3, and 
MC Component Supports Fabricated by Welding, Section III, Division 1.
    Code Case N-71-18 was conditionally approved in Revision 33 to RG 
1.84. This Code Case was reaffirmed by the ASME. No changes have been 
made to the conditions in proposed Revision 34 to the guide.
     Code Case N-155-2 [S7].
    Type: Reaffirmed.
    Title: Fiberglass Reinforced Thermosetting Resin Pipe, Section III, 
Division 1.
    Code Case N-155-2 was conditionally approved in Revisions 32 and 33 
to RG 1.84. This Code Case was reaffirmed by the ASME. No changes have 
been made to the conditions in proposed Revision 34 to the guide.
     Code Case N-249-14 [S10/12].
    Type: Reaffirmed.
    Title: Additional Materials for Subsection NF, Class 1, 2, 3, and 
MC Component Supports Fabricated Without Welding, Section III, Division 
1.
    Code Case N-249-14 was conditionally approved in Revision 33 to RG 
1.84. This Code Case was reaffirmed by the ASME. No changes have been 
made to the conditions in proposed Revision 34 to the guide.
    4.6 Section XI.
     Code Case N-504-2 [S8/9].
    Type: Reaffirmed.
    Title: Alternative Rules for Repair of Class 1, 2, and 3 Austenitic 
Stainless Steel Piping, Section XI, Division 1.
    Section XI, Nonmandatory Appendix Q, ``Weld Overlay Repair of Class 
1, 2, and 3 Austenitic Stainless Steel Piping Weldments,'' addresses 
the repair of Class 1, 2, and 3 austenitic stainless steel pipe 
weldments that have experienced stress corrosion cracking through the 
deposition of weld overlay reinforcements on the outside of the pipe, 
and provides examination requirements for such overlays. Comments 
provided by NRC staff representatives to the ASME Code were 
incorporated into Nonmandatory Appendix Q, and the NRC committee 
representatives ultimately approved this appendix. Code Case N-504 has 
a similar scope to that of nonmandatory Appendix Q, i.e., reducing a 
flaw to an acceptable size by increasing the pipe wall thickness 
through the deposition of a weld overlay on the outside of the pipe. 
Nonmandatory Appendix Q specifies the NDE methods and acceptance 
criteria to be used when making such weld overlays. Additionally, 
requirements have been specified for the extent and frequency of ISI, 
and for sample expansion. These requirements have been adopted in Code 
Case -504-3 (to be considered in the next RG revision). Thus, the same 
requirements should be used for the use of Code Case N-504-2. Thus, 
Code Case N-504-2 has been conditioned to require that the provisions 
in the nonmandatory appendix also be met. The appendix is available on 
the ASME Web site at http://cstools.asme.org/csconnect/ 
CommitteePages.cfm?Committee=O10000000.
     Code Case N-517-1 [S1].
    Type: Reaffirmed.
    Title: Quality Assurance Program Requirements for Owners, Section 
XI, Division 1.
    Code Case N-517-1 was conditionally approved in Revisions 13 and 14 
to RG 1.147. This Code Case was reaffirmed by the ASME. No changes to 
the conditions have been made in proposed Revision 15 to the guide.
     Code Case N-532-3 [S12].
    Type: Revised.
    Title: Alternative Requirements to Repair and Replacement 
Documentation Requirements and Inservice Summary Report Preparation and 
Submission as Required by IWA-4000 and IWA-6000, Section XI, Division 
1.
    Code Case N-532-1 was conditionally approved in Revisions 13 and 14 
of Regulatory Guide 1.147. Revision 2 of the Code Case was not approved 
for use, however, because of a publishing error and the need for a 
clarification. Revision 3 of the Code Case corrects the error. The 
publishing error was that the Code

[[Page 62953]]

Case referenced new ASME Code Paragraph IWA-6350 which was not yet in 
print when the Code Case was published. The clarification reconciled 
Footnote 1 and Table 4 of the Code Case regarding the applicable 
edition and addenda. The revisions are acceptable to the NRC staff.
    The NRC's concern with N-532-1 regarding the timeliness of 
submittal of inspection findings to the regulatory authority is 
applicable to subsequent revisions of the Code Case and is being 
considered by the ASME. The ASME Code requires that inspection findings 
be submitted to the regulatory authority within 90 calendar days of the 
completion of each refueling outage. The Code Case relaxes this 
requirement, potentially up to 3 years. The Code Case time frame for 
submittal should be the same as that for the ASME Code, especially 
since the burden associated with generating the report would be much 
less under the Code Case. The NRC supports the reduction in report size 
but cannot support the time frame relaxation. Thus, the condition for 
N-532-1 in Revisions 13 and 14 of the guide is retained for N-532-3 in 
proposed Revision 15.
     Code Case N-554-3 [S8/9].
    Type: Revised.
    Title: Alternative Requirements for Reconciliation of Replacement 
Items and Addition of New Systems, Section XI, Division 1.
    Code Case N-554-2 was conditionally approved in Revisions 13 and 14 
to RG 1.147. The NRC staff was concerned that the Code Case would 
permit licensees to purchase material for use in safety-related 
applications that did not meet the requirements of Appendix B to 10 CFR 
part 50. The NRC staff had similar concerns with the provisions of 
Section XI, Paragraph IWA-4200. The ASME made changes to IWA-4200 that 
the NRC staff initially determined to be acceptable. The ASME then 
modified Code Case N-554-2 (resulting in Revision 3) to make it 
consistent with IWA-4200 in the belief that this would satisfy the 
NRC's concerns. During the NRC staff review of the revised Code Case 
(N-554-3) relative to the NRC's previous concerns, questions were 
raised whether the new language of IWA-4200 and hence N-554-3, 
adequately addressed the NRC's concerns. The NRC staff and the 
cognizant ASME committees are actively engaged to resolve the 
questions. Thus for this revision to the guide, N-554-3 is approved 
subject to the same condition as that for N-554-2.
     Code Case N-583 [S8/9].
    Type: Reaffirmed.
    Title: Annual Training Alternative, Section XI, Division 1.
    Code Case N-583 was conditionally approved in Revisions 13 and 14 
to RG 1.147. This Code Case was reaffirmed by the ASME. No changes to 
the conditions have been made in proposed Revision 15 to the guide.
     Code Case N-593 [S8/9].
    Type: Reaffirmed.
    Title: Alternative Examination Requirements for Steam Generator 
Nozzle to Vessel Welds, Section XI, Division 1.
    Code Case N-593 was conditionally approved in Revisions 13 and 14 
to RG 1.147. This Code Case was reaffirmed by the ASME. No changes to 
the conditions have been made in proposed Revision 15 to the guide.
     Code Case N-597-2 [S11].
    Type: Revised.
    Title: Requirements for Analytical Evaluation of Pipe Wall 
Thinning, Section XI, Division 1.
    Code Case N-597-1 was conditionally approved in Revision 13 to RG 
1.147. Users of the Code Case discovered several errors in the 
formulas. It was determined that the errors resulted from formatting/
publishing difficulties. Revision 2 to the Code Case corrects these 
publishing errors, but the cognizant ASME working group is still 
considering the NRC's concerns that resulted in the conditional 
acceptance of N-597-1.
    These concerns are: (1) The Electric Power Research Institute 
(EPRI) developed Report 202L-R2, April 1999, ``Recommendations for an 
Effective Flow Accelerated Corrosion Program,'' for developing the 
inspection requirements, the method of predicting the rate of wall 
thickness loss, and the value of the predicted remaining wall 
thickness. The Code Case which should contain such guidance/
requirements does not; (2) the Code Case is not clear relative to the 
allowable minimum wall thickness; (3) the Code Case lacks adequate 
evaluation criteria for Class 1 piping that does not meet the ASME 
Code; and (4) the Code Case lacks adequate criteria addressing the rate 
of wall thickness loss to be used to determine a suitable inspection 
frequency when immediate repair or replacement is not required so that 
repair or replacement occurs prior to reaching allowable minimum wall 
thickness, tmin.
    The cognizant ASME working group is still considering these 
concerns. Hence, no changes have been made to the particular Code Case 
provisions in question in Code Case N-597-2. Thus, the conditions will 
be retained in proposed Revision 15.
     Code Case N-638-1 [S8/9].
    Type: Revised.
    Title: Similar and Dissimilar Metal Welding Using Ambient 
Temperature Machine GTAW Temper Bead Technique, Section XI, Division 1.
     Code Case N-647 [S11].
    Type: Reaffirmed.
    Title: Alternative to Augmented Examination Requirements of IWE-
2500, Section XI, Division 1.
    Code Case N-647 was conditionally approved in Revisions 13 and 14 
to RG 1.147. This Code Case was reaffirmed by the ASME. No changes to 
the conditions have been made in proposed Revision 15 to the guide.
     Code Case N-648-1 [S1].
    Type: Reaffirmed.
    Title: Alternative Requirements for Inner Radius Examination of 
Class 1 Reactor Vessel Nozzles, Section XI Division 1.
     Code Case N-659 [S7].
    Type: New.
    Title: Use of Ultrasonic Examination in Lieu of Radiography for 
Weld Examination, Section III, Division 1.
    The Code Case requires demonstration of the ultrasonic examination 
procedure on a qualification block or specimen. For piping, if material 
of the same product form and specification is not available, the Code 
Case permits the use of a calibration block of similar chemical 
analysis, tensile properties, and metallurgical structure. Additional 
guidance is not provided, however, to fully define ``similar chemical 
analysis.'' This raises a concern that the calibration block material 
may not be truly representative of the material to be ultrasonically 
examined; the calibration block material could be easier to examine. 
Hence, two conditions would be added to ensure that the calibration 
block material is within the range of chemical composition of the 
component and has similar insonification and examination 
characteristics to the component to be examined. These conditions are 
being added to ensure that the procedure qualification is adequately 
demonstrated.
     Code Case N-694-1 [S1].
    Type: Revised.
    Title: Evaluation Procedure and Acceptance Criteria for PWR Reactor 
Vessel Upper Head Penetration, Section XI, Division 1.
    Code Case N-694-1 provides acceptance criteria and fracture 
evaluation methods (crack-growth rate calculations) to disposition 
flaws in PWR reactor pressure vessel Alloy 600 control rod drive 
mechanism (CRDM) nozzles and bottom mounted instrumentation 
penetrations (BMIs).

[[Page 62954]]

Because of the safety significance of cracking in these penetrations, 
the NRC had an independent review of the Code Case performed. The 
review, which was performed by Engineering Mechanics Corporation of 
Columbus (Emc2), and documented in its report dated April 
30, 2004, ``Predicting Axial Crack Growth in Control Rod Drive 
Mechanism Tubes,'' [ML060060548], determined that the crack-growth 
rates calculations specified in the Code Case were not conservative 
enough and underpredict crack growth. The report states that, 
``Credible crack-growth predictions rely highly on an accurate 
determination of the crack-driving force.'' To develop the data needed 
for its review of the Code Case, Emc2 performed parametric 
finite element studies on axial cracks in CRDM J-groove weld residual 
stress fields and determined that under certain applications, published 
K-solutions, used in Code Case N-694-1, would under predict crack 
growth, so much so, that cracks could grow through-wall prior to the 
performance of the next inspection.
    The cognizant ASME working group is currently reviewing the report. 
On the basis of the report, the NRC proposes to condition Code Case N-
694-1 to require more accurate crack-growth rate calculations to ensure 
that the frequency of examination is appropriate for these 
penetrations.

Availability of Documents

    The NRC is making the documents identified below available to 
interested persons through one or more of the following means:
    The NRC Public Document Room (PDR) is located at 11555 Rockville 
Pike, Public File Area O-1 F21, Rockville, Maryland.
    The NRC's interactive rulemaking Web site is located at http://ruleforum.llnl.gov. Selected documents may be viewed and downloaded 
electronically via this Web site.
    The NRC's Public Electronic Reading Room is located at http://www.nrc.gov/reading-rm.html.

----------------------------------------------------------------------------------------------------------------
                    Document                       PDR      Web                    e-Reading room
----------------------------------------------------------------------------------------------------------------
Proposed Regulatory Guide 1.84, Rev. 34 (DG-          X        X   ML061210377
 1133).
Proposed Regulatory Guide 1.147, Rev. 15 (DG-         X        X   ML061210404
 1134).
----------------------------------------------------------------------------------------------------------------

* * * * *

    Dated at Rockville, Maryland, this 30th day of June, 2006.

    For the U.S. Nuclear Regulatory Commission.
Brian W. Sheron,
Director, Office of Nuclear Regulatory Research.
 [FR Doc. E6-18024 Filed 10-26-06; 8:45 am]
BILLING CODE 7590-01-P