[Federal Register Volume 75, Number 192 (Tuesday, October 5, 2010)]
[Rules and Regulations]
[Pages 61321-61337]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-24814]
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NUCLEAR REGULATORY COMMISSION
10 CFR Part 50
[NRC 2009-0014]
RIN 3150-AI37
Domestic Licensing of Production and Utilization Facilities;
Updates to Incorporation by Reference of Regulatory Guide
AGENCY: Nuclear Regulatory Commission (NRC).
ACTION: Final rule.
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SUMMARY: The Nuclear Regulatory Commission (NRC) is amending its
regulations to incorporate by reference the latest revisions of two
previously incorporated regulatory guides (RGs) approving new and
revised Code Cases published by the American Society of Mechanical
Engineers (ASME). The RGs which are incorporated by reference are RG
1.84, ``Design, Fabrication, and Materials Code Case Acceptability,
ASME Section III,'' Revision 35, and RG 1.147, ``Inservice Inspection
Code Case Acceptability, ASME Section XI, Division 1,'' Revision 16.
This action allows nuclear power plant licensees, and applicants for
standard design certifications, standard design approvals, and
manufacturing licenses under the regulations that govern license
certifications, and approves the nuclear power plants to use the Code
Cases listed in these RGs as alternatives to requirements in the ASME
Boiler and Pressure Vessel (BPV) Code regarding the construction and
inservice inspection (ISI) of nuclear power plant components.
Concurrent with this action, the NRC is publishing a notice of the
issuance and availability of the RGs in the Federal Register. As a
result of these related actions, the Code Cases listed in these RGs are
incorporated by reference into the NRC's regulations and are deemed to
be legally-binding NRC requirements.
DATES: The rule is effective on November 4, 2010. The incorporation by
reference of RG 1.84, ``Design, Fabrication, and Materials Code Case
Acceptability, ASME Section III,'' Revision 35 (July 2010), and RG
1.147, ``Inservice Inspection Code Case Acceptability, ASME Section XI,
Division 1,'' Revision 16 (July 2010) is approved by the Director of
the Office
[[Page 61322]]
of the Federal Register as of November 4, 2010.
ADDRESSES: You can access publicly available documents related to this
document using the following methods:
NRC's Public Document Room (PDR): The public may examine and have
copied for a fee publicly available documents at the NRC's PDR, Public
File Area O1 F21, One White Flint North, 11555 Rockville Pike,
Rockville, Maryland 20852.
NRC's Agencywide Documents Access and Management System (ADAMS):
Publicly available documents created or received at the NRC are
available electronically at the NRC's electronic reading room at http://www.nrc.gov/reading-rm/adams.html. From this page, the public can gain
entry into 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's PDR
reference staff at 1-800-397-4209, 301-415-4737, or by e-mail to
[email protected].
Federal Rulemaking Web site: Public comments and supporting
materials related to this final rule can be found at http://www.regulations.gov by searching on Docket ID: NRC-2009-0014.
FOR FURTHER INFORMATION CONTACT: Manash K. Bagchi, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, telephone 301-415-2905, or by e-mail [email protected].
SUPPLEMENTARY INFORMATION:
I. Background
II. Response To Public Comments
A. Overview of Public Comments
B. NRC Responses to Public Comments
III. NRC Approval of New and Amended ASME Code Cases
IV. Paragraph by Paragraph Discussion
V. Availability of Documents
VI. Voluntary Consensus Standards
VII. Finding of No Significant Environmental Impact: Environmental
Assessment
VIII. Paperwork Reduction Statement
Public Protection Notification
IX. Regulatory Analysis
X. Regulatory Flexibility Certification
XI. Backfit Analysis
XII. Congressional Review Act
I. Background
The ASME develops and publishes the ASME BPV Code, which contains
requirements for the design, construction, and ISI of nuclear power
plant components, and the Code for Operation and Maintenance of Nuclear
Power Plants (OM Code), which contains requirements for inservice
testing (IST) of nuclear power plant components. In response to BPV and
OM Code user requests, the ASME develops ASME Code Cases which provide
alternatives to BPV and OM Code requirements under special
circumstances.
The NRC approves and/or mandates the use of the ASME BPV and OM
Code in Title 10 of the Code of Federal Regulations (10 CFR) Part
50.55a through the process of incorporation by reference. As such, each
provision of the ASME Codes incorporated by reference into, and
mandated by, 10 CFR 50.55a constitutes a legally-binding NRC
requirement imposed by rule. As noted above, ASME Code Cases represent
alternative approaches for complying with provisions of the ASME BPV
and OM Codes. Accordingly, the NRC periodically amends Sec. 50.55a to
incorporate by reference NRC RGs listing new and revised\1\ ASME Code
Cases which the NRC approves for use as alternatives to the BPV Code
and the OM Code. See 68 FR 40469 (July 8, 2003). It should be noted
that for this particular rulemaking, RG 1.192, ``Operations and
Maintenance Code Case Acceptability, ASME OM CODE,'' is not being
revised because there are no new or revised OM Code Cases considered by
the NRC in this rulemaking. New and revised OM Code Cases published by
the ASME since RG 1.192 was first issued, will be addressed in the next
proposed amendment. This final rule will continue the NRC's practice of
incorporating by reference the RGs listing the most current set of NRC-
approved ASME Code Cases. ASME Code Cases may be approved for use,
either unconditionally or with conditions stated in the relevant RGs.
In developing the RGs, the NRC staff reviews ASME BPV and OM Code
Cases, determines the acceptability of each Code Case, and publishes
its findings in RGs. The RGs are revised periodically as new Code Cases
are published by the ASME. The NRC incorporates by reference the RGs
listing acceptable and conditionally acceptable ASME Code Cases into 10
CFR 50.55a. Currently, NRC RG 1.84, Revision 34, ``Design, Fabrication,
and Materials Code Case Acceptability, ASME Section III''; RG 1.147,
Revision 15, ``Inservice Inspection Code Case Acceptability, ASME
Section XI, Division 1;'' and RG 1.192, ``Operation and Maintenance
Code Case Acceptability, ASME OM Code'' are incorporated into the NRC's
regulations at 10 CFR 50.55a, Codes and standards.
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\1\ ASME Code Cases can be categorized as one of two types: new
and revised. A new Code Case provides for the first time an
alternative to specific ASME Code provisions or addresses a new
need. A revised Code Case is a revision (modification) to an
existing Code Case to address, for example, technological
advancements in examination techniques or to address NRC conditions
imposed in one of the regulatory guides which have been incorporated
by reference into 10 CFR 50.55a.
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II. Response to Public Comments
The NRC published a proposed rule that would incorporate by
reference RG 1.84, Revision 35, and RG 1.147, Revision 16, on June 2,
2009, 74 FR 26303. On the same date, the NRC published a parallel
notice of availability of draft regulatory guides and opportunity for
public comment. See 74 FR 26440. The NRC provided a 75-day public
comment period for both the proposed rule and the draft RGs, which
ended on August 17, 2009.
A. Overview of Public Comments
The NRC received nineteen comment letters on the draft regulatory
guides and three general comments on the proposed rule. The following
table lists the commenters, their affiliation, and the accession number
to locate each comment letter. In addition, the Code Cases for which
each commenter submitted comments are listed. Several general comments
were also received.
Comment Letters Received on Draft: Regulatory Guide 1.84, Revision 35 (DG-1191); Regulatory Guide 1.147,
Revision 16 (DG-1192); REGULATORY GUIDE 1.193, Revision 3 (DG-1193)
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Commenter No. Name Affiliation/abbreviation ADAMS Accession No.
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1........................... Raymond West........... Private Citizen/RW.......... ML091540204
N-513-2/N-513-3.............
2........................... Ronald Clow............ DBA Xcel Energy/Xcel........ ML091700640
N-508-3/N-508-4.............
[[Page 61323]]
3........................... C.L. Funderburk........ Dominion Resources Services, ML091750096
Inc./DRS.
N-513-2/N-513-3.............
4........................... Brian Erler............ American Society of ML092190138
Mechanical Engineers/ASME.
N-71-18, N-416-4, N-504-4, N-
513-2/N-513-3, N-661-1, N-
702, N-747, N-751.
5........................... Edward Gerlach......... Private Citizen/EG.......... ML092190139
Two general comments--N-416-
4, N-504-4, N-638-4, N-661-
1.
6........................... Lee Goyette............ Pacific Gas & Electric ML092190140
Company/PGE.
N-597-2.....................
7........................... Charles Wirtz.......... ASME BPV Standards Committee ML092220042
on Nuclear Inservice
Inspection/CW.
N-619, N-648-1..............
8........................... Robert Sisk............ Westinghouse Electric ML092220043
Company/WECRS.
N-655-1, N-757-1, N-759-2, N-
782, N-759.
9........................... Patrick O'Regan........ Electric Power Research ML092240576
Institute/EPRI.
N-716.......................
10.......................... Kevin Hall............. Private Citizen/KH.......... ML092250165
N-716.......................
11.......................... James Riley............ Nuclear Energy Institute/NEI ML092370059
General comment--N-504-4, N-
508-3/N-508-4, N-597-2.
12.......................... R.M. Krich............. Tennessee Valley Authority/ ML092370060
TVA.
N-520-1/N-520-2, N-702......
13.......................... J.A. Gresham........... Westinghouse Electric ML092370665
Company/WECJAG.
N-655-1, N-757-1, N-759-2, N-
782, N-759.
14.......................... Scott Chesworth........ Structural Integrity ML092370061
Associates, Inc./SIASC.
N-716.......................
15.......................... Miroslav Trubelja...... Structural Integrity ML092370062
Associates, Inc./SIAMT.
N-716.......................
16.......................... Sandra Sowah........... Structural Integrity ML092370063
Associates, Inc./SIASS.
N-716.......................
17.......................... Daniel R. Cordes....... ASME Section XI Subgroup Non ML092370064
Destructive Examination/DC.
N-583.......................
18.......................... Marcus N. Bressler..... Private Citizen/MB.......... ML092400356
N-71-18.....................
19.......................... T.S. Rausch............ PPL Susquehanna, LLC/PPL.... ML092590124
N-416-4, N-504-4, N-638-4...
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Summary of Comments:
The proposed rule provided a 75-day comment period. A total of 19
comment letters were received from four private citizens, four utility
organizations, seven industry groups that provide engineering and
inspection services to the utilities, three associated with the ASME,
and the Nuclear Energy Institute. Three general comments were received
on the proposed rule regarding the need for editorial corrections
(although two of the comments received from different commenters
address the same subject). The majority of the comments received relate
to Section XI Code Cases. Two comments were submitted requesting that
the NRC include later versions of certain Code Cases in the final
guide; 7 comments request that the NRC reconsider conditions on certain
Code Cases; 1 comment requests clarification of a condition; and 3
comments provide additional technical information to justify moving
certain Code Cases from RG 1.193 (Code Cases disapproved for use) to
Regulatory Guide 1.147.
B. NRC Responses to Public Comments on Draft Regulatory Guide
Responses have been organized in two groups: Group I: Adopted
Comments, that includes comments raising issues and concerns directly
related to this rule, and have been adopted; and Group II: Comments not
Adopted, that includes comments raising issues and concerns that are
not directly connected to this particular rule, although they are
generally relevant to this rule but have not been adopted.
Group I--Adopted Comments
General Comments: Edward Gerlach commented (comment EG1) that Table
2 in the proposed rulemaking listed accession numbers for Draft
Regulatory Guides dated April 2009. The NRC's electronic reading room
contains later versions of these Draft Guides dated June 2009.
Response: The accession numbers in Table 2 of the final rulemaking
have been corrected to reflect the final versions of the regulatory
guides. In addition, the accession numbers for all the documents have
been verified.
Comment: Two commenters acknowledge that the titles of Code Cases
N-712 and N-730 in Table 1 of the proposed rule had been inadvertently
switched and should be corrected (comments EG2 and NEI3).
Response: The NRC agrees that there was an error in the rulemaking
table. This table is not included in the final rulemaking, and no
further NRC action is necessary.
RG 1.84
Code Case N-71-18
Comment: Two comments (ASME 1 and ASME 2) were received from the
American Society of Mechanical Engineers on Code Case N-71-18,
``Additional Materials for Subsection NF, Class 1, 2, 3, and MC
Component Supports Fabricated by Welding, Section III, Division 1.''
The first comment (ASME1) was that the NRC proposed to impose the same
conditions on Code Case N-71-18 as were imposed
[[Page 61324]]
on Code Case N-71-17, and some of the conditions are not appropriate to
Revision 18 as certain references have changed (conditions (3) and
(4)).
The second comment (ASME2) was that there appears to be confusion
regarding whether or not the Code Case applies to component supports
(condition 6). Marcus Bressler also commented on this Code Case
(comment MB1) stating that conditions (1) and (2) aren't applicable to
Revision 18 because the Code Case has no materials listed with a
minimum tensile strength above 125 ksi.
Response: The NRC agrees with the ASME that the paragraphs
referenced in conditions (3) and (4) should be modified. When Code Case
N-71-17 was revised as Code Case N-71-18, certain references were
rearranged. The editorial corrections have been made in the final guide
so that the conditions are consistent with the references in the
revised Code Case. The requirements for weld filler material hydrogen
content were moved to paragraph 4.2 (previously in paragraph 5.3), and
the requirements for postweld heat treatment were moved from paragraphs
16.2.1 and 16.2.2 to paragraphs 15.2.1 and 15.2.2 (paragraphs 16.2.1
and 16.2.2 no longer exist). As noted by the commenter, the conditions
in Draft RG 1.84 should have been modified to be consistent. The
conditions have been corrected in the final guide. With regard to the
ASME's second comment (and similar comment from Marcus Bressler) on
condition (6), the NRC's understanding of the intent of the provisions
in the Code Case is not in agreement with the commenter's
understanding, (i.e., that the fracture toughness requirements as
listed in this Code Case address Class 1, Class 2, and Class 3
component supports in addition to piping supports). The NRC believes
that the fracture toughness requirements listed in Code Case N-71-18
apply only to piping supports. Implementation of this Code Case was
approved by the NRC on this basis. Cognizant NRC staff will initiate
discussions with the appropriate ASME committees.
The NRC agrees with Marcus Bressler that Code Case N-71-18 does not
list materials with a minimum tensile strength exceeding the value of
125 kilograms per square inch. However, the NRC believes that
conditions (1) and (2) are appropriate for this Code Case because they
provide a cautionary note that high strength materials are susceptible
to brittleness and stress corrosion cracking. As such, the NRC declines
to adopt the comment related to conditions (1) and (2), and no change
was made to the RG as the result of this comment.
RG 1.147
Code Case N-416-4
Comment: Three commenters (comments ASME3, EG3, and PPL1) requested
that the NRC should not adopt the proposed condition requiring that
when using Code Case N-416-4 ``Alternative Pressure Test Requirement
for Welded or Brazed Repairs, Fabrication Welds or Brazed Joints for
Replacement Parts and Piping Subassemblies, or Installation of
Replacement Items by Welding or Brazing, Classes 1, 2, and 3, Section
XI, Division 1,'' that Nondestructive Examination (NDE) be performed
for welded or brazed repairs and fabrication and installation joints as
specified by the methods and acceptance criteria of the applicable
subsection of the 1992 Edition of Section III. The commenters believe
that the Section III NDE requirements are overly conservative relative
to the NDE requirements of Section XI.
Response: The NRC disagrees that the condition is not needed. The
NRC does not believe that an adequate argument was provided to justify
deletion of the condition to require that NDE be performed for welded
or brazed repairs and fabrication and installation joints in accordance
with the methods and acceptance criteria of the applicable subsection
of the 1992 Edition of Section III.
As discussed in the proposed rule for Draft Regulatory Guide DG-
1192 for certain welding repairs or replacements, the previous version
of this Code Case (Code Case N-416-3) permitted a system leakage test
to be performed in lieu of performing a hydrostatic pressure test
provided that certain requirements are met. A requirement was that NDE
be performed on welded repairs, and that fabrication and installation
of joints be as specified by the methods and acceptance criteria of the
applicable subsection of the 1992 Edition of Section III. When Code
Case N-416 was originally developed, the NRC agreed to the performance
of system leakage testing in lieu of hydrostatic testing provided that
NDE performed in conjunction with the repair met the requirements of
the 1992 Edition of Section III. The requirement to perform NDE under
Section III was removed when Code Case N-416-4 was issued.
The NRC believes that many analyses of the effectiveness and
reliability of the later NDE requirements have demonstrated the
inadequacies of earlier Code NDE requirements. Improvements in NDE have
significantly increased the probability of detecting defects. With
regard to leakage tests, the NRC staff's position was that even though
the primary purpose of a leakage test is the leak-tightness of the
primary pressure boundary, some additional assurance of primary
boundary integrity was provided by the higher pressure hydrostatic
test. Based on the industry conclusions that: the increased stress from
a hydrostatic test is extremely unlikely to cause a subsurface defect
to grow through-wall (and therefore, leak during a test) and the
stresses involved in a hydrostatic test are similarly unlikely to cause
leakage even with the presence of a through-wall flaw, the need for
effective and reliable NDE is even greater.
Because the NRC has determined that pressure tests are not adequate
for ensuring structural integrity (i.e., adequate component repair and
replacement), the NRC believes it to be paramount that high quality NDE
be performed. Thus, the NRC rejects the argument that the lower quality
NDE as conducted to earlier Codes is adequate. Accordingly, the NRC
declines to adopt the comment, and no change was made to the RG as the
result of this comment.
Code Case N-504-3, N-504-4
Comment: Four commenters (comments ASME4, EG4, NEI2, and PPL2)
believe that all of the conditions the NRC proposed for Code Case N-
504-4, ``Alternative Rules for Repair of Class 1, 2, and 3 Austenitic
Stainless Steel Piping, Section XI, Division 1,'' are unnecessary and
should be removed in the final RG. One of the conditions requires that
the provisions of Section XI, Nonmandatory Appendix Q, ``Weld Overlay
Repair of Class 1, 2, and 3 Austenitic Stainless Steel Piping
Weldments,'' Section XI, must also be met in addition to the provisions
of the Code Case was retained from RG 1.147, Revision 15, Code Case N-
504-3. The commenters believe that changes to the Code Case and to
Appendix Q address the NRC's concerns relative to Appendix Q and
therefore this condition is no longer required. With regard to
condition (a), the commenters believe that criteria in Code Case N-504-
4 are more conservative than the proposed condition, and therefore
condition (a) is not required. The commenters believe that conditions
(b) and (c) regarding surface finish are redundant to criteria in Code
Case N-504-4 and Supplement 11 of Appendix VIII. Finally, it was stated
that there is no technical basis for restricting the use
[[Page 61325]]
of radiographic examination (condition (d)).
Response: The NRC disagrees that the conditions should be removed.
It is true that a number of changes were made to the criteria of the
Code Case and to Appendix Q as a result of concerns raised by the NRC.
However, differences remain between Appendix Q and Code Case N-504-4
that were not addressed in the public comments submitted. For example,
Appendix Q has requirements pertaining, in part, to the inspection and
design of a structural weld overlay whereas the Code Case does not.
Until the differences between Appendix Q and N-504-4 are addressed, the
condition to follow Appendix Q must be retained.
It is clear from the comments, however, that condition (a) should
be revised to make the objective clearer. The commenters believe that
the limitations in the Code Case on laminar flaw size are more
conservative than the proposed NRC condition, which indicates that the
intent of the condition was not apparent. It is agreed that Code Case
N-504-4 addresses laminar flaws, but the NRC does not believe that the
provision is stringent or clear.
Condition (a) in the regulatory guide is needed to limit the number
of laminar flaws in the weld overlay. If a weld overlay contains too
many laminar flaws, the flaws may affect the structural integrity of
the weld overlay. Accordingly, condition (a) has been revised to read
``the total laminar flaw area shall not exceed 10 percent of the weld
surface area, and no linear dimension of the laminar flaw area shall
exceed the greater of 3 inches or 10 percent of the pipe
circumference.''
The NRC does not agree with regard to the comment that Code Case N-
504-4 and Supplement 11 to Appendix VIII already address improving the
surface finish of piping welds and therefore conditions (b) and (c) are
unnecessary. The provision in Code Case N-504-4 cited by the
commenters, ``Grinding and machining of the as-welded overlay surface
may be used to improve the surface finish for such examinations'' is
not a requirement and does not specify any criterion that must be met.
Supplement 11, 1.1(c) states, ``The surface condition of at least two
specimens shall approximate the roughest surface condition for which
the examination procedure is applicable.'' Thus, there is no specific
criterion that must be met.
The NRC does not agree regarding the request to delete condition
(d) and the restriction against radiographic testing (RT). Studies have
been conducted indicating that radiography has the potential for
detecting planar flaws with high reliability only under favorable
conditions. Code Case N-504-4 provides alternative provisions for
repairing austenitic stainless steel piping. Thus, the NRC believes
this is a valid concern that planar flaws, typical flaws found during
inservice inspections as opposed to volumetric flaws that result from
fabrication, may not be detected through RT. Especially considering
that digital radiographic testing may be used and factors such as
exposure, screens, magnification, and source-target-detector distances
have yet to be clearly defined. Without supporting technical
information to indicate the reliability of RT for the particular
conditions of interest, the NRC concludes that this condition to Code
Case N-504-4 is necessary.
Code Cases N-513-2, N-513-3
Three commenters (comments RW1, ASME7, and DRS1) requested that
Code Case N-513-3 be approved in final RG 1.147. They assert that
licensees that have updated their inservice inspection (ISI) plans to
the 2004 Edition of Section XI can no longer use Code Case N-513-2
because of limits on its applicability. Code Case N-513-3, which was
recently published by the ASME in Supplement 8 to the 2007 Edition,
addresses the applicability issue.
Response: The NRC agrees with the comment with one condition. Code
Case N-513-2 was unconditionally approved in Revision 15 of RG 1.147.
The applicability of the Code Case was through the 2001 Edition with
the 2003 Addenda. The applicability was purposefully not extended by
the ASME beyond the 2003 Addenda by the ASME because a revision to the
Code Case (N-513-3) had been developed for application to later edition
and addenda. The purpose of the revision to the Code Case (N-513-3) was
to provide additional guidance to evaluate through-wall, nonplanar
flaws. Users of Code Case N-513-2 had found the acceptance criterion
for the branch reinforcement evaluation approach to be ambiguous, and
there was a lack of adequate guidance for dispositioning nonplanar flaw
combinations.
The NRC has reviewed the additional guidance resulting in Code Case
N-513-3 and has determined that the additions are indeed clarifications
and not technical changes. However, the NRC does not agree with one
change regarding the time frame for repairs. Accordingly, Code Case N-
513-3 has been conditionally approved in the final RG. Code Case N-513
was developed to reduce the number of plant shutdowns required to
immediately correct insignificant degradation in Class 2 or 3 lower
energy piping (maximum operating temperature of 200 [deg]F and maximum
operating pressure of 275 psig). Revisions 0 through 2 of the Code Case
stated that certain flaws may be acceptable without performing a repair
or replacement activity for a limited period, not exceeding the time to
the next scheduled outage. The time frame for temporary acceptance of
the degradation was modified in Code Case N-513-3 from ``next scheduled
outage'' to ``not to exceed 26 months from the initial discovery of the
condition.'' The basis for NRC approval of the original time frame was
that the degraded condition would be monitored and evaluated during
continued operation, and operation was only approved until plant
shutdown. Once the plant was shut down, it was expected that the
degraded piping would be repaired. The extension of the time frame to
26 months from the discovery of the condition could permit operation
through several outages. The NRC believes that the original time frame
is prudent. The Class 2 and 3 systems addressed by the Code Case
contain safety-significant components, and repairs should be performed
at the first opportunity. Accordingly, Revision 3 of the Code Case has
been included in the final guide with the condition that the repair or
replacement activity must be completed during the next scheduled
outage.
Code Case N-583
Comment: A commenter (comment DC1) requests that the NRC consider
the removal of the conditions on the use Code Case N-583, ``Annual
Training Alternative, Section XI, Division 1,'' requiring practice ``6
months prior'' to performing exams, and leave ``as-is'' in the case to
``annually.'' The commenter further suggests that if this is not
acceptable, then a 6-month ``proficiency'' similar to the ``annual
proficiency'' specified and implemented by ASNT CP-189 should be
adopted. The commenter states that performing the practice on specimens
with actual cracks is definitely beneficial, and that the ASME should
adopt this position. However, after 10 years of implementation, the
twice yearly requirement of the ``hands on'' practice has become
significantly burdensome, specifically with logistics and cost of
implementation, particularly for owners and vendors who generally
employ the PDI qualified individuals.
Response: The NRC disagrees with the comment that the condition
requiring practice six months prior to performing examinations should
be deleted.
[[Page 61326]]
With respect to the commenter's recommendation to adopt a 6-month
proficiency examination, the NRC believes this may be a viable option,
but it would be more appropriate if the initiative and the technical
basis for such an approach were developed by the industry. The NRC
believes that the current requirement is justified. EPRI has conducted
several studies on the relationship of education, training, and
experience. The correlation was at best low and in some instances (such
as experience versus ability to detect intergranular stress corrosion
cracking (IGSCC)), the data showed a negative correlation. For example,
a group of twelve ultrasonic examiners with approximately one-year of
ultrasonic examination experience but with three weeks of quality
training had a pass rate of 92.7 percent on the IGSCC detection
practical examination. However, the success rate of individuals with
experience averaging in excess of 7.7 years was only 37.6 percent.
One of the major keys to effective training is to perform a
detailed task and skills analysis to determine the NDE parameters that
impact detection performance. A number of these parameters such as
illumination levels and calibration procedures are addressed in the
conventional training course outlines. However, most outlines do not
address the more subtle parameters such as visual search procedures and
ultrasonic manual scanning techniques to assure coverage and effective
beam orientation, nor do the outlines address the evaluation of subtle
ultrasonic signal characteristics such as signal rise, decay time, and
pulse duration. As appropriate, these issues must be identified and
included in the training provided to examiners. Computer-based
training, through the use of animations, simulation, and actual data,
is evolving as an effective way to transfer this information.
In addition, many individuals do not routinely perform
examinations, or they may not have recently had to interpret signals
from cracks. Signals can be difficult to interpret. Although programs
employ ``qualified'' personnel using qualified'' procedures, operating
experience, round robin trials, and research results have shown that
skills will diminish without frequent training. Personnel and
procedures must not only be qualified, but must also be effective.
Experience and studies indicate that the examiner must practice on a
frequent basis to maintain the capability for proper interpretation. In
addition, these studies have shown that this capability begins to
diminish within approximately 6 months if skills are not maintained.
Class room instruction is not sufficient to maintain an examiner's
skills in this highly specialized skill area. Examiner training needs
to focus on hands-on training with flawed specimens.
With respect to the commenter's other recommendation to adopt a 6-
month proficiency examination, the NRC believes this may be a viable
option, but it would be more appropriate if the initiative and the
needed technical basis for such an approach were developed by the
industry. Accordingly, no changes are being made to the conditions at
this time.
Code Case N-638-4
Comments: Two commenters (comments EG5 and PPL3) believe that Code
Case N-638-4, ``Similar and Dissimilar Metal Welding Using Ambient
Temperature Machine GTAW Temper Bead Technique, Section Xl, Division
1,'' addresses the NRC's concern that the Section XI examination volume
and acceptance criteria were not appropriate for the subject weld
repair. Paragraph 4(a) of the Code Case requires that the examination
of the repair be performed as specified by and meet the acceptance
criteria of the Construction Code or Section III. Therefore, the
condition is no longer necessary.
Response: The NRC disagrees that Code Case N-638-4 addresses the
issue. The commenter is correct that paragraph 4(a)(4) of Code Case N-
638-4 specifies the acceptance criteria for the surface and volumetric
examination as the Construction Code or Section III; however, Code Case
N-638-4 still does not specify that a demonstration must be performed
with representative samples that shows the ultrasonic examination
technique is capable of detecting construction type flaws in the
repaired volume. Thus, a condition is required to address this issue.
Based on the public comments received, the NRC believes that condition
(1) on Code Case 638-4 should be revised to be clearer. Accordingly,
the condition has been reworded to explicitly require demonstration
with construction type flaws. Further, as a result of the review of the
public comments, the NRC realizes that an additional issue must be
addressed. Paragraph 3(d) of the Code Case establishes a maximum weld
interpass temperature, and paragraph 3(e) requires that the weld
interpass temperature be determined through one of the methods listed
in subparagraphs (e)(1), (e)(2), and (e)(3). Subparagraph (e)(1) lists
methods by which the temperature may directly be determined,
subparagraph (e)(2) provides a method to calculate the weld interpass
temperature, and subparagraph (e)(3) allows the use of a test coupon to
determine the maximum weld interpass temperature. Code Case N-638-4
does not restrict or choose one method over another. Ensuring that the
weld interpass temperature is not exceeded is important in obtaining a
quality weld (e.g., in terms of corrosion resistance, notch toughness).
Direct measurement is the most reliable method for ensuring that the
maximum temperature is not exceeded. The NRC recognizes that direct
measurement is not always feasible, but direct measurements should be
used whenever possible before alternatives such as those described in
paragraphs 3(e)(2) and 3(e)(3) are used. This position is consistent
with past precedent on this issue. Thus, a second condition has been
added in the final guide stating that ``The provisions of paragraphs
3(e)(2) or 3(e)(3) may only be used when it is impractical to use the
interpass temperature measurement methods described in 3(e)(1), such as
in situations where the weldment area is inaccessible (e.g., internal
bore welding) or when there are extenuating radiological conditions.''
Accordingly, the condition (1) of the Code Case 638-4 in final
Revision 16 to RG 1.147 has been revised to read as follows:
``Demonstration of ultrasonic examination of the repaired volume is
required using representative samples which contain construction type
flaws.''
Code Case N-661-1
Comments: Two commenters (comments ASME5 and EG6) stated that Code
Case N-661-1, ``Alternative Requirements for Wall Thickness Restoration
of Class 2 and 3 Carbon Steel Piping for Raw Water Service, Section XI,
Division 1,'' addresses the NRC's concerns discussed in the proposed
rule.
Therefore, the conditions that address root cause and weld overlays
can be deleted. The commenters stated that the only issue that may need
clarification is the definition of ``cycle or refueling outage.''
Response: The NRC agrees that condition (b) on the Code Case can be
deleted. The NRC staff has reassessed paragraph 1(d) of the Code Case
and agrees that it addresses the issue of multiple repairs to the same
location through weld overlay. The NRC disagrees however, that
condition (a), ``if the root cause of the degradation has not been
determined, the repair is only acceptable for one cycle,'' can be
deleted. The NRC believes that the condition is still required to
provide the needed clarity on two issues. First, the
[[Page 61327]]
second sentence of paragraph 7(b) of the Code Case uses the term
``cause'' rather than ``root cause.'' These terms have specific meaning
to licensees. The NRC has determined that for the purpose of
maintaining safety, it is appropriate to require a root cause analysis
which is more rigorous than merely inferring the ``cause'' of the
degradation. The second issue relative to clarity is the use of the
term ``one fuel cycle.'' As discussed in the proposed rule, it is
unclear what one fuel cycle actually infers if a repair is performed in
mid-cycle. It may be interpreted that the repair is acceptable for the
remainder of the current fuel cycle plus the subsequent fuel cycle. In
addition, other terms are used in the Code Case such as ``one cycle.''
Although the Code Case provision and regulatory guide condition (a) are
otherwise nearly identical, the NRC believes that for the sake of
clarity and to ensure that a suitable re-inspection frequency has been
established when the cause of the degradation is unknown or when the
potential for hydrogen cracking exists due to the welding conditions,
the condition is needed so that users are clear that what is meant is
by ``next refueling outage.''
With regard to condition (c) which states ``When through-wall
repairs are made by welding on surfaces that are wet or exposed to
water, the weld overlay repair is only acceptable until the next
refueling outage,'' the NRC has the same concern regarding ``next
refueling outage.''
While it is agreed that paragraphs 4(c) and 5(b) of the Code Case
deal with the technical issues, the term one cycle is used.
Accordingly, the NRC is retaining this condition in the final RG to
ensure that it is clear that the requirement applies at the next
refueling outage.
Code Case N-716
Comment: Five commenters (comments EPRI1, KH1, SIASC1, SIAMT1, and
SIASS1) suggested that the NRC conditionally approve Code Case N-716,
``Alternative Piping Classification and Examination Requirements,
Section XI, Division 1,'' in the final Revision 16 of RG 1.147. The NRC
has conditionally approved requests from four plants to use provisions
similar to those in the Code Case. Based on the approvals, lessons
learned from the pilot plant applications, as well as a number of
follow-on applications, the lessons learned could be incorporated into
the final Revision 16 of RG 1.147 to allow plants to use this Code Case
in the short term. Approval of the Code Case for generic use will not
only result in a substantial reduction in worker exposure and radwaste,
but will also reduce unnecessary NRC staff burden, as compared to
waiting until the Code Case is revised by ASME and subjected to further
NRC review.
Response: The Code Case has not been included in final Revision 16
to RG 1.147. The NRC is continuing to gain experience with the review
of risk-informed inservice inspection (RI-ISI) programs based, in part,
on Code Case N-716. The NRC staff has not yet systematically identified
all differences between the method described in the Code Case and those
approved at individual licensees, nor has the staff received any such
description by industry.
One issue not yet explored in the plant specific submittals is the
application of Revision 2 of RG 1.200, ``An Approach for Determining
the Technical Adequacy of Probabilistic Risk Assessment Results for
Risk-Informed Activities,'' which expands the scope of initiating
events whose evaluation is required to be consistent with the ASME/ANS
RA-Sa-2009 PRA Standard.
The review of EPRI Topical Report 1018427, ``Nondestructive
Evaluation: PRA Technical Adequacy Guidance for RI-ISI Programs'' is
proceeding according to schedule. A request for additional information
(RAI) was transmitted to EPRI on September 15, 2009. An NRC staff
endorsed document describing acceptable PRA quality requirements for
RI-ISI will be necessary for the NRC to endorse some version of Code
Case N-716 in RG 1.147. Accordingly, Code case N-716 has not been
included in the final revision 16 of RG 1.147.
Code Case N-751
The American Society of Mechanical Engineers (comment ASME6) does
not believe that Code Case N-751, ``Pressure Testing of Containment
Penetration Piping, Section XI, Division 1,'' should be conditioned
because the Construction Code, which may or may not have included
provisions for NDE of piping welds in penetrations, continues to apply.
Therefore, the presence or absence of specific NDE provisions in the
Construction Code should not be a reason to condition the use of the
Code Case.
Response: The NRC disagrees that specific nondestructive
examination (NDE) requirements are not needed. As discussed in the
proposed rule, the Code Case would allow an Appendix J Type C test to
be performed as an alternative to the ASME Code requirement to pressure
test piping that penetrates a containment vessel, if the piping and
isolation valves that are part of the containment system are Class 2
and the balance of the piping system is outside the scope of Section
XI. The NDE requirement associated with the system leakage test was
removed from Section XI paragraph IWA-4540 of the 2003 Addenda (and
later edition and addenda of the ASME Code). In addition, for plants
that used the ASME B31.1 Code for construction, there was no
requirement to volumetrically examine certain piping components during
fabrication.
Section XI requires NDE per the construction code as part of repair
and replacement activities. Thus, if a B31.1 plant or a licensee using
the 2003 Addenda or later performs a repair to certain Class 2 or Class
3 piping, there is no requirement to perform NDE. Volumetric
examination after repair or replacement is required to ensure high
quality welds. It was stated in the public comments that the industry
has concluded that pressure tests are not adequate for ensuring
structural integrity (i.e., adequate component repair and replacement).
Therefore, it is paramount that high quality NDE be performed.
Volumetric examination ensures high quality welds capable of performing
their design function for the life of the component. Therefore, the
condition on the use of Code Case N-751 that when a 10 CFR part 50,
Appendix J, Type C test is performed as an alternative to the
requirements of IWA-4540 (IWA-4700 in the 1989 edition through the 1995
edition) during repair and replacement activities, nondestructive
examination must be performed as specified by IWA-4540(a)(2) of the
2002 Addenda of Section XI has been retained in the final RG.
Group II--Comments not Adopted
Code Case N-508-4
Comment: Two commenters (comments Xcel1 and NEI4) requested that
Code Case N-508-4 be listed in the final RG because the Code Case would
be beneficial to the industry.
Response: The NRC declines the suggestion to adopt Code Case 508-4
in the final guide. It would not be appropriate to include Revision 4
to the Code Case in the final guide without first having sought public
comment on such a significant expansion of the scope of the Code Case.
Code Case N-508-3, which was unconditionally approved in Revision 15 of
RG 1.147, allowed snubbers and relief valves to be rotated from stock
and installed on components for the purpose of testing or preventive
maintenance. Code Case N-
[[Page 61328]]
508-4 was published by the ASME in Supplement 8 to the 2007 Edition,
and it significantly expands the list of components through the
addition of pumps, control rod drive mechanisms, and pump seal
packages. The Code Cases listed in this supplement will be considered
in the next draft of RG 1.47 giving the public an opportunity to
comment on the appropriateness of the scope change of the Code Case.
With regard to including Code Case N-508-4 in the next draft guide,
NRC staff have reviewed Code Case N-508-4 and identified an issue. It
was realized that when Section XI is used to govern snubber examination
and testing, Footnote 1, which was later added to the Code Case,
conflicts with Subsection IWF, Section XI, up to and including the 2004
Edition through 2005 Addenda. Footnote 1 directs the user to implement
the ASME and OM Code for snubber examination and testing.
The OM Code was developed in order to have a separate Code for the
development and maintenance of provisions for the IST of pumps and
valves. In 1990, the ASME published the initial edition of the OM Code,
thereby transferring responsibility for these provisions from Section
XI to the OM Committee. While the use of the OM Code is an option under
10 CFR 50.55a(b)(3)(v), the examination and testing requirements for
snubbers are also provided in the 2005 Addenda and earlier editions and
addenda of Section XI. There is no conflict for licensees who have
adopted the 2006 Addenda or later editions and addenda of Section XI.
Other than expansion of the list of components that may be rotated from
stock and installed on components for the purpose of testing or
preventive maintenance, Revisions 3 and 4 of the Code Case are
identical. Thus, Code Case N-508-4 as presently constructed would have
to be conditioned that Footnote 1 would not apply when the ISI Code of
record is earlier than Section XI, 2006 Addenda, and Section XI
requirements are used to govern the examination and testing of
snubbers.
Code case N-520-2
Comment: Tennessee Valley Authority suggested that Code Case N-520-
2, ``Alternative Rules for Renewal of Active or Expired N-type
Certificates for Plants Not in Active Construction,'' be included in
the final RG rather than the Code Case N-520-1 which was listed in the
draft regulatory guide. Case N-520-2 is representative of the current
nuclear plants for which construction is likely to be renewed.
NRC Response: The NRC declines at this time to adopt the changes in
the final guide as suggested by the commenter. The objective of Code
Case N-520-1 was to address situations where construction on a nuclear
power plant was halted and thus interrupted ASME Code activities but
the Certificate Holder maintained their certificate. Code Case N-520-1
provides guidance on what a Certificate Holder has to do to document
and stamp the completed construction work that was performed. Code Case
N-520-2 is different however, in that it addresses the situation where
the Certificate Holder let its N-type certificates expire.
The revised Code Case would allow an organization with an expired
Certificate to secure an ASME Temporary Certificate of Authorization.
While the NRC recognizes that the temporary certificate would only
apply in situations where the plant was kept in an appropriate state
where completion could be restarted at a later date and that the
temporary certificate would be issued solely for the purpose of
finishing the documentation and stamping required for the construction
completed prior to work being stopped, the NRC has determined that the
public should have an opportunity to comment on this change before a
final decision is made. Accordingly, Code Case N-520-2 and the
suggestion provided by the commenter will be discussed in the next
proposed rule.
The NRC notes that the wording of Code Case N-520-2 may create
confusion regarding the relationship between the Authorized Nuclear
Inspection Agency (ANIA) and the Authorized Nuclear Inspector (ANI).
Accordingly, it is suggested that the wording of the Code Case be
modified to clearly indicate that the ``ANIA'' is an Authorized Nuclear
Inspection Agency and the ANIA employs the ANI.
Code Case N-597-2
Comment: Two commenters (comments PGE1 and NEI1) suggest that the
method used to evaluate local degradation for Code Case, N-597-2,
``Requirements for Analytical Evaluation of Pipe Wall Thinning, Section
XI, Division 1,'' should be the same as that used in Code Case N-513-2,
``Evaluation Criteria for Temporary Acceptance of Flaws in Moderate
Energy Class 2 or 3 Piping, Section XI, Division 1.'' The commenters
argue that the NRC has conditionally approved Code Case N-513-2 with an
evaluation methodology to allow licensees to temporarily accept flaws
in moderate energy Class 2 or 3 piping whereas condition (2) on Code
Case N-597-2 would require NRC approval for any amount of local
degradation beyond that calculated by the hoop stress equation.
The commenters believe that the N-513-2 methodology could be used
for N-597-2 to eliminate the need for NRC approval in certain
situations.
Response: The NRC declines the suggestion to adopt the Code Case N-
513-2 methodology in Code Case N-597-2 in the final guide. It would not
be appropriate to include such a significant expansion of the scope of
the Code Case in the final guide without first having sought public
comment. While the NRC agrees that the flaw evaluation methodology for
analyzing piping degradation contained in Code Case N-513-2 could under
certain circumstances be applied for a Code Case N-597-2 evaluation
(i.e., both Code Cases address the analytical evaluation of pipe wall
thinning), the NRC disagrees with the commenters that through-wall
leakage should be included in the scope of such an evaluation.
Code Case N-597 was not developed to address leakage, (i.e., it is
focused only on analytical evaluation of wall thinning). The temporary
acceptance of through-wall leakage is governed by other Code Cases such
as N-513-2. The addition of leakage as a condition to Code Case N-597
as suggested would imply that leakage could be justified on a permanent
basis. In addition, Code Case N-597-2 is applicable to all ASME Code
Class piping, which would include high energy piping. Code Case N-513-2
is limited to Class 2 and 3 moderate energy piping. The NRC has only
approved temporary acceptance of flaws for moderate energy Class 2 or 3
piping (maximum operating temperature does not exceed 200[deg]F
(93[deg]C) and maximum operating pressure does not exceed 275 psig (1.9
MPa). Finally, such a change would redefine the defense-in-depth
concept.
Rather than performing inspections to detect flaws before
structural integrity is compromised, degradation would in effect be
managed after leakage is discovered. Thus, no changes have been made in
the final guide as a result of the comments.
Code Case N-619, Code Case N-648-1
Comment: One commenter (number 7) requests that the NRC reconsider
the conditions placed on Code Case N-619, ``Alternative Requirements
for Nozzle Inner Radius Inspections for Class 1 Pressurizer and Steam
Generator Nozzles, Section XI, Division 1,'' and Code Case N-648-1,
``Alternative Requirements for Inner Radius Examination of Class 1
Reactor Pressure Vessel Nozzles, Section XI, Division 1.''
[[Page 61329]]
The commenter believes that the conditions on the two Code Cases
requiring a wire standard to demonstrate the resolution capability of
remote visual examination systems should be changed to the ASME 0.044
inch characters because characters have been recognized to be a better
resolution standard (comment CW1). The commenter also raised a question
regarding the use of Section XI Table IWB-3512-1 (comment CW2). The
condition on Code Case N-619 state that licensees may perform a visual
examination utilizing the allowable flaw length criteria of Table IWB-
3512-1. The commenter believes it is unclear how allowable flaw lengths
can be determined from Table IWB-3512-1. The commenter suggested that
the same acceptance criteria approved by the NRC for Code Case N-648-1
be applied to Code Case N-619 since both Code Cases address the
examination of the inner nozzle radius. Finally, the commenter believes
that the condition on Code Case N-648-1 addressing the examination
volume can be deleted as it describes the same volume required to be
examined by the Code Case (comment CW3).
Response: The NRC declines at this time to adopt the changes in the
final guide as suggested by the commenter. It would not be appropriate
to adopt significant changes to visual testing resolutions standards in
the final guide without first having sought public comment.
The NRC agrees that characters have been demonstrated to be a
better resolution standard than the 1-mil wire standard. However, the
NRC cannot at this time support modifying the criteria in the RG on
these Code Cases to change to the ASME 0.044 inch characters as
suggested. While the NRC staff ultimately supports the replacement of
the wire resolution standard, the staff believes that the shift to
characters should be part of broader changes to the visual testing
provisions as related to Code Cases N-619 and N-648-1.
Visual examinations are used in certain situations as alternatives
to volumetric and/or surface examination tests where it is not possible
to conduct volumetric examination (e.g., where there are limitations
due to access or geometry) or to reduce occupational exposure in high
radiation fields. Visual testing experts believe that if the camera and
lighting were sufficient to resolve a 12 [mu]m (0.0005 in.) diameter
wire, then the camera system had a resolution sufficiently high for the
inspection. Subsequent investigation of the effectiveness and
reliability of visual examinations has shown that the wire resolution
standard is not sufficient to determine the visual acuity of a remote
system, (i.e., there are important differences between visually
detecting a wire and a crack). Research conducted at the Pacific
Northwest National Laboratory (PNNL) showed that other calibration
standards be adapted for visual testing such as reading charts and
resolution targets. Results supporting this recommendation were
published in NUREG/CR-6943, ``A Study of Remote Visual Methods to
Detect Cracking in Reactor Components.''
However, as also discussed in the reports, other parameters such as
crack size, lighting conditions, camera resolution, and surface
conditions were assessed. The NRC concluded from the investigation that
a significant fraction of the cracks that have been reported in nuclear
power plant components are at the lower end of the capabilities of the
visual testing equipment currently being used. Code Case N-619
addresses the examination of the nozzle inner radius of Class 1
pressurizers and steam generators.
Code Case N-648-1 provides an alternative for examining the inner
radius of Class 1 reactor vessel nozzles. The NRC investigation of
crack opening dimensions of service-induced cracks in nuclear
components included thermal fatigue, mechanical fatigue, and stress
corrosion cracks. The NRC concluded that current visual testing systems
may not reliably detect a significant number of these cracks
(approaching 50% under certain conditions). Research at PNNL showed
that detection of these cracks under field conditions is strongly
dependent on camera magnification, lighting, inspector training, and
inspector vigilance.
While this research supports the use of characters in lieu of a
wire standard, the research also shows that other changes are warranted
to visual testing as related to these two Code Cases. The NRC believes
that such significant changes to visual testing criteria should be
undertaken by the ASME and industry in a coordinated manner.
With regard to comment CW2 that it is unclear how allowable flaw
lengths can be determined from Table IWB-3512-1, the NRC agrees that
the condition to determine allowable flaw length criteria could be
improved, and public comments will be specifically sought on Code Case
N-619 in the next proposed rule on this issue.
Finally, it is agreed that the condition requiring the examination
of the surface between points M and N is unnecessary because Code Case
N-648-1 already requires this examination. However, the NRC will have
to request public comment on Code Case N-648-1 regarding this issue in
the next proposed rule.
Code Cases N-655-1, N-757-1, N-759-1, N-782
Comment: Westinghouse Electric Company (comments WECRS1 and
WECJAG1) identified four Code Cases used in the AP1000 design that were
not included in the draft of RG 1.84. The commenter suggested that the
Code Cases be included in the next revision of RG1.84, (i.e., Code Case
N-655-1, ``Use of SA-738, Grade B, for Metal Containment Vessels, Class
MC, Section III, Division 1),'' Code Case N-757-1, ``Alternative Rules
for Acceptability for Class 2 and 3 Valves, NPS 1 (DN25) and Smaller
with Welded and Nonwelded End Connections other than Flanges, Section
III, Division 1,'' Code Case N-759-2, ``Alternative Rules for
Determining Allowable External Pressure and Compressive Stresses for
Cylinders, Cones, Spheres, and Formed Heads, Section III, Division 1,''
and Code Case N-782, ``Use of Code Editions, Addenda, and Cases Section
III, Division 1.''
Response: The NRC does not agree that these Code Cases should be
included in the final RG. The Code Cases referenced in the comment are
not currently listed in the latest AP1000 Design Control Document
(DCD). In addition, public comment has not yet been sought on these
Code Cases. Accordingly, the NRC will consider including Code Cases N-
655-1, N-757-1, N-759-2, and N-782 in the next draft RG (DG-1230;
proposed Revision 36 to RG 1.84), which is currently under development.
If Westinghouse includes the above ASME Code Cases in its next revision
to the AP1000 DCD, then the NRC staff will provide an evaluation of the
acceptability of using these four ASME Code Cases in a supplement to
its Final Safety Evaluation Report for the AP1000 design certification
amendment as alternatives to the regulations under Sec. 50.55a(a)(3).
For the reasons set forth above, the NRC declines to adopt the
comment and no change was made to the RG as the result of this comment.
Code Case N-702
Comment: Two commenters (comments ASME8 and TVA2) request that Code
Case N-702, ``Alternative Requirements for Boiling Water Reactor (BWR)
Nozzle Inner Radius and Nozzle-to-Shell Welds, Section XI, Division
1,'' be conditionally accepted in the final RG. The NRC approved use of
the Code Case with certain criteria in a Safety Evaluation of BWRVIP-
108: BWR
[[Page 61330]]
Vessel and Internals Project, Technical Basis for the Reduction of
Inspection Requirements for the Boiling Water Reactor Nozzle-to-Vessel
Shell Welds and Nozzle Blend Radii,'' EPRI Technical Report 1003557,
October 2002 (ADAMS Accession No. ML023330203). The commenters believe
that these criteria provide a basis for the NRC to conditionally
approve the Code Case in RG 1.147.
Response: The NRC declines at this time to adopt the changes in the
final guide as suggested by the commenter. It would not be appropriate
to generically adopt the alternative nozzle examination requirements
without first having sought public comment on this Code Case. The NRC
agrees, however, that the NRC staff's Safety Evaluation (dated December
18, 2007, ADAMS Accession No. ML073600374) provides a basis for
approving Code Case N-702 in RG 1.47. Code Case N-702 will be addressed
the next draft guide.
Code Case N-747
Comment: The American Society of Mechanical Engineers (comment
ASME9) believes that the basis for listing Code Case N-747, ``Reactor
Vessel Head-to Flange Weld Examinations, Section XI, Division 1,'' in
DG-1193 (Code Cases not approved for use) was flawed, and the Code Case
should be unconditionally accepted in final Revision 16 of RG 1.147.
Response: The NRC declines at this time to adopt the changes in the
final guide as suggested by the commenter. It would not be appropriate
to adopt the Code Case in the final guide without first having sought
public comment. Nonetheless, the NRC staff has reviewed the additional
information provided by the ASME regarding the expected fluence levels
of reactor vessel head-to-flange welds and believes that an adequate
technical basis has been provided to support a conclusion that the
fracture toughness will remain high. Code Case N-747 will be addressed
in the next draft guide.
Code Case With Proposed Conditions--No Public Comments
In the proposed rule, the NRC proposed to condition Code Case N-
570-1. No public comments were received on the proposed conditions to
the Code Case. Thus, no changes have been made to the proposed adoption
of Code Case N-570-1.
Section III
Code Case N-570-1, Alternative Rules for Linear Piping and Linear
Standard Supports for Classes 1, 2, 3, and [Metal Cladding (MC)],
Section III, Division 1. Code Case N-570-1 references American National
Standards Institute (ANSI)/American Institute of Steel Construction
(AISC) N690-1994 s1, ``Supplement No. 1 to the Specification for the
Design, Fabrication, and Erection of Steel Safety-Related Structures
for Nuclear Facilities.'' However, the AISC issued Supplement 2 on
October 6, 2004. Supplement 2 supersedes Supplement 1. The updated
supplement (Supplement 2) is consistent with NRC positions and
requirements for new reactor support design. Thus, the NRC is
conditioning Code Case N-570-1 to require that ANSI/AISC N690-1994 s2,
``Supplement No. 2 to the Specification for the Design, Fabrication,
and Erection of Steel Safety-Related Structures for Nuclear
Facilities,'' be used when this code case is implemented.
III. NRC Approval of New and Amended ASME Code Cases
This final rule incorporates by reference the latest revisions of
the NRC RGs that list acceptable and conditionally acceptable ASME BPV
Code Cases. RG 1.84, Revision 35 would supersede Revision 34 (October
2007); and RG 1.147, Revision 16 would supersede Revision 15 (October
2007). RG 1.192 (June 2003) would not be revised because there have
been no new OM Code Cases published by the ASME since the last NRC
review.
The ASME Code Cases which are the subject of this rulemaking are
the new revised Section III and Section XI Code Cases listed in
Supplements 2 through 11 to the 2004 BPV Code, and Supplement 0
published with the 2007 Edition of the BPV Code (Supplement 0 also
serves as Supplement 12 to the 2004 Edition) of the code. The NRC
followed a three-step process to determine acceptability of new and
revised ASME Code Cases and the need for conditions on the uses of
these Code Cases. This process was employed in the review of the ASME
Code Cases which are the subject of this final rule. First, NRC staff
actively participated with other ASME committee members with full
involvement in discussions and technical debates in the development of
new and revised Code Cases. This included a technical justification in
support of each new or revised Code Case. Second, the NRC committee
representatives distributed the Code Case and technical justification
to other cognizant NRC staff to ensure an adequate technical review.
Finally, the proposed NRC position on each Code Case is reviewed
and approved by NRC management as part of the rulemaking amending 10
CFR 50.55a to incorporate by reference new revisions of the RGs listing
the relevant ASME Code Cases and conditions on their use. This
regulatory process, when considered together with the ASME's own
process for development and approval of ASME Code Cases, provides
reasonable assurances that the NRC approves for use only those new and
revised ASME Code Cases (with conditions as necessary) which provide
reasonable assurance of adequate protection to public health and safety
and which do not have significant adverse impacts on the environment.
Code Cases Approved Unconditionally for Use
The NRC concludes, in accordance with the process for review of
ASME Code Cases, that each of the ASME Code Cases listed in Table 1 is
technically adequate and consistent with current NRC regulations.
Table 1--Unconditionally Approved Code Cases
------------------------------------------------------------------------
Code Case No. Code supplement Code case title
------------------------------------------------------------------------
ASME B&PV Code, Section III
------------------------------------------------------------------------
N-4-12........................ 4................ Special Type 403
Modified Forgings or
Bars, Class and CS,
Section III,
Division 1.
N-284-2....................... 12............... Metal Containment
Shell Buckling
Design Methods,
Class MC, Section
III, Division 1.
N-373-3....................... 3................ Alternative postweld
heat treatment
(PWHT) Time at
Temperature for P-
No. 5A or P-No. 5B
Group 1 Material,
Classes 1, 2, and 3
Section III,
Division 1.
N-621-1....................... 3................ Ni-Cr-Mo Alloy
Unified Numbering
System (UNS) N06022)
Weld Construction to
800[deg]F, Section
III, Division 1.
[[Page 61331]]
N-699......................... 8................ Use of Titanium Grade
2 (UNS R50400) Tube
and Bar, and Grade 1
(UNS R50250) Plate
and Sheet for Class
1 Construction,
Section III,
Division 1.
N-725......................... 4................ Design Stress Values
for UNS N06690 With
Minimum Specified
Yield Strength of 35
Ksi (240 Mpa),
Classes 2 and 3
Components, Section
III, Division 1.
N-727......................... 9................ Dissimilar Welding
Using Continuous
Drive Friction
Welding for Reactor
Vessel Control Rod
Drive Mechanism
(CRDM)/Control
Element Drive
Mechanism
(CEDM)Nozzle to
Flange/Adapter
Welds, Class 1,
Section III,
Division 1.
N-732......................... 5................ Magnetic Particle
Examination of
Forgings for
Construction,
Section III,
Division 1.
N-736......................... 8................ Use UNS S32050 Welded
and Seamless Pipe
and Tubing,
Forgings, and Plates
Conforming to SA-249/
SA-249M, SA-479/SA-
479M, and SA-240/SA-
240M, and Grade
CK35MN Castings
Conforming to ASTM A
743-03 for
Construction of
Class 1, 2, and 3
Components, Section
III, Division 1.
N-738......................... 6................ NDE of Full
Penetration Butt
Welds in Class 2
Supports, Section
III, Division 1.
N-741......................... 7................ Use of 22Cr-5Ni-3Mo-N
(Alloy UNS S32205
Austenitic/Ferritic
Duplex Stainless
Steel) Forgings,
Plate, Welded and
Seamless Pipe
Tubing, and Fittings
to SA-182, SA-240,
SA-789, A 790-04a,
SA-815, Classes 2
and 3, Section III,
Division 1.
N-744......................... 11............... Use of Metric Units
Boiler and Pressure
Vessel Code, Section
III, Division 1.
N-746......................... 8................ Use of 46Fe-24Ni-21Cr-
6Mo-Cu-N (UNS
N08367) Bolting
Materials for Class
2 and 3 Components,
Section III,
Division 1.
N-756......................... 12............... Alternative Rules for
Acceptability for
Class 1 Valves, NPS
(DN 25) and Smaller
with Nonwelded End
Connections Other
than Flanges,
Section III,
Division 1.
N-759......................... 11............... Alternative Rules for
Determining
Allowable External
Pressure and
Compressive Stresses
for Cylinders,
Cones, Spheres, and
Formed Heads,
Section III,
Division 1.
------------------------------------------------------------------------
ASME B&PV Code, Section XI
------------------------------------------------------------------------
N-494-4....................... 7................ Pipe Specific
Evaluation
Procedures and
Acceptance Criteria
for Flaws in Piping
that Exceed the
Acceptance
Standards, Section
XI, Division 1.
N-496-2....................... 2................ Helical-Coil Threaded
Inserts, Section XI,
Division 1.
N-666......................... 9................ Weld Overlay of Class
1, 2, and 3 Socket
Welded Connections,
Section XI, Division
1.
N-686-1....................... 12............... Alternative
Requirements for
Visual Examinations
VT-1, VT-2, and VT-
3, Section XI,
Division 1.
N-705......................... 11............... Evaluation Criteria
for Temporary
Acceptance of
Degradation in
Moderate Energy
Class 2 or 3 Vessels
and Tanks, Section
XI, Division 1.
N-706-1....................... 12............... Alternative
Examination
Requirements of
Table IWB-2500-1 and
Table IWC-2500-1 for
Pressurized Water
Reactor (PWR)
Stainless Steel
Residual and
Regenerative Heat
Exchangers, Section
XI, Division 1.
N-712......................... 2................ Class 1 Socket Weld
Examinations,
Section XI, Division
1.
N-730......................... 11............... Roll Expansion of
Class 1 Control Rod
Drive Bottom Head
Penetrations in
Boiling Water
Reactors (BWR),
Section XI, Division
1.
N-731......................... 5................ Alternative Class 1
System Leakage Test
Pressure
Requirements,
Section XI, Division
1.
N-733......................... 6................ Mitigation of Flaws
in NPS 2 (DN 50) and
Smaller Nozzles and
Nozzle Partial
Penetration Welds in
Vessels and Piping
by Use of a
Mechanical
Connection
Modification,
Section XI, Division
1.
N-735......................... 11............... Successive Inspection
of Class 1 and 2
Piping Welds,
Section XI, Division
1.
N-739......................... 11............... Alternative
Qualification
Requirements for
Personnel Performing
Class CC Concrete
and Post-tensioning
System Visual
Examinations,
Section XI, Division
1.
N-753......................... 10............... Vision Tests, Section
XI, Division 1.
------------------------------------------------------------------------
Code Cases Approved for Use With Conditions
---------------------------------------------------------------------------
\2\ The NRC reviews every Code Case to ascertain if each of the
Code Cases is technically adequate and consistent with current NRC
regulations. As a result of such reviews, the NRC may conclude that
certain Code Cases are technically adequate or require supplemental
guidance. In such cases, the NRC imposes limitations, modifications,
and provisions on those Code Cases but is now substituting the word
``Conditions'' throughout 10 CFR 50.55a.
---------------------------------------------------------------------------
As a result of the NRC staff's review, the NRC concludes that
certain Code Cases are technically inadequate or require supplemental
guidance. Accordingly, the NRC is imposing conditions \2\ upon the use
of these Code Cases, and they are listed in Table 2.
[[Page 61332]]
Table 2--Conditionally Approved Code Cases
----------------------------------------------------------------------------------------------------------------
Code Case No. Code supplement Code case title Condition
----------------------------------------------------------------------------------------------------------------
ASME B&PV Code, Section III
----------------------------------------------------------------------------------------------------------------
N-71-18...................... Revision 18 of the Code Additional Materials for (1) The maximum measured
Case was not new to Subsection NF, Class 1, ultimate tensile strength
Draft Revision 35 of 2, 3, and MC Component (UTS) of the component
Regulatory Guide 1.84. Supports Fabricated by support material must not
The Code Case is listed Welding, Section III, exceed 170 Ksi in view of
in this table because a Division 1. the susceptibility of high-
public comment was strength materials to
received suggesting brittleness and stress
editorial corrections. corrosion cracking.
(2) Certain applications may
exist where a UTS value of
up to 190 Ksi could be
considered acceptable for a
material and, under this
condition, the Design
Specification must specify
impact testing for the
material. For these cases,
it must be demonstrated by
the applicant that:
(a) The impact test
results for the material
meet Code requirements,
(b) The material is not
subject to stress
corrosion cracking by
virtue of the fact that:
(i) A corrosive
environment is not
present, and
(ii) The component that
contains the material
has essentially no
residual stresses or
assembly stresses, and
(iii) It does not
experience frequent
sustained loads in
service.
(3) In the last sentence of
paragraph 4.2, reference
must be made to paragraph
4.5.2.2, ``Alternative
Atmosphere Exposure Time
Periods Established by
Test,'' of the AWS D1.1 Code
for the evidence presented
to and accepted by the
Authorized Inspector
concerning exposure of
electrodes for longer
periods of time.
(4) Paragraph 15.2.2 is not
acceptable as written and
must be replaced with the
following: ``When not
exempted by 15.2.1 above,
the post-weld heat treatment
must be performed in
accordance with NF-4622
except that ASTM A-710 Grade
A Material must be at least
1,000 [deg]F (540 [deg]C)
and must not exceed 1,150
[deg]F (620 [deg]C) for
Class 1 and Class 2 material
and 1,175 [deg]F (640
[deg]C) for Class 3
material.
(5) The new holding time at
temperature for weld
thickness (nominal) must be
30 minutes for \1/2\ inch or
less, 1 hour per inch for
thickness over \1/2\ inch to
5 inches, and for
thicknesses over 5 inches, 5
hours plus 15 minutes for
each additional inch over 5
inches.
(6) The fracture toughness
requirements as listed in
this Code Case apply only to
piping supports and not to
Class 1, Class 2, and Class
3 component supports.
N-570-1...................... 8....................... Alternative Rules for The provisions of ANSI/AISC
Linear Piping and N690-1994 s2, ``Supplement
Linear Standard No. 2 to the Specification
Supports for Classes 1, for the Design, Fabrication,
2, 3, and MC, Section and Erection of Steel of
III, Division 1. Safety-Related Structures
for Nuclear Facilities,''
must be met.
----------------------------------------------------------------------------------------------------------------
ASME B&PV Code, Section XI
----------------------------------------------------------------------------------------------------------------
N-416-4...................... 4....................... Alternative Pressure Nondestructive examination
Test Requirement for shall be performed on welded
Welded or Brazed or brazed repairs and
Repairs, Fabrication fabrication and installation
Welds or Brazed Joints joints in accordance with
for Replacement Parts the methods and acceptance
and Piping criteria of the applicable
Subassemblies, or subsection of the 1992
Installation of Edition of Section III.
Replacement Items by
Welding or Brazing,
Classes 1, 2, and 3,
Section XI, Division 1.
N-504-4...................... 10...................... Alternative Rules for The provisions of Section XI,
Repair of Class 1, 2, Nonmandatory Appendix Q,
and 3 Austenitic ``Weld Overlay Repair of
Stainless Steel Piping, Class 1, 2, and 3 Austenitic
Section XI, Division 1. Stainless Steel Piping
Weldments,'' must also be
met. In addition, the
following conditions shall
be met: (a) The total
laminar flaw area shall not
exceed 10 percent of the
weld surface area, and no
linear dimension of the
laminar flaw area shall
exceed the greater of 3
inches or 10 percent of the
pipe circumference; and (b)
radiography shall not be
used to detect planar flaws
under or masked by laminar
flaws.
[[Page 61333]]
N-638-4...................... 11...................... Similar and Dissimilar Ultrasonic examination shall
Metal Welding Using be demonstrated for the
Ambient Temperature repaired volume using
Machine GTAW Temper representative samples which
Bead Technique, Section contain construction type
XI, Division 1. flaws.
N-661-1...................... 7....................... Alternative Requirements (1) If the cause of the
for Wall Thickness degradation has not been
Restoration of Class 2 determined, the repair is
and 3 Carbon Steel only acceptable until the
Piping for Raw Water next refueling outage.
Service, Section XI, (2) When through-wall repairs
Division 1. are made by welding on
surfaces that are wet or
exposed to water, the weld
overlay repair is only
acceptable until the next
refueling outage.
N-751........................ 11...................... Pressure Testing of When a 10 CFR Part 50,
Containment Penetration Appendix J, Type C test is
Piping, Section XI, performed as an alternative
Division 1. to the requirements of IWA-
4540 (IWA-4700 in the 1989
edition through the 1995
edition) during repair and
replacement activities,
nondestructive examination
must be performed in
accordance with IWA-
4540(a)(2) of the 2002
Addenda of Section XI.
----------------------------------------------------------------------------------------------------------------
ASME Code Cases Not Approved for Use
ASME Code Cases which are currently issued by the ASME but not
approved for generic use by the NRC are listed in RG 1.193, ASME Code
Cases Not Approved for Use. The Code Cases which are not approved for
use include Code Cases on 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. RG 1.193 is
not incorporated by reference into Sec. 50.55a. The RG is prepared by
the NRC as a resource for stakeholders, allowing them to easily
identify Code Cases which the NRC has not approved for use as a generic
matter. Listing of a Code Case in RG 1.193 does not preclude an
applicant or licensee from seeking individual, case-by-case NRC
approval to use a listed Code Case.
IV. Paragraph-By Paragraph Discussion
Overall Considerations on the Use of ASME Code Cases
This final rule amends 10 CFR 50.55a to incorporate by reference RG
1.84, Revision 35, which supersedes Revision 34, and RG 1.147, Revision
16, which supersedes Revision 15. The following general guidance
applies to the use of the ASME Code Cases approved in the latest
versions of the regulatory guides which are incorporated by reference
into 10 CFR 50.55a as part of this rulemaking.
The endorsement of a Code Case in NRC RGs constitutes acceptance of
its technical position for applications which are not precluded by
regulatory or other requirements or by the recommendations in these or
other RGs. The applicant and licensee are responsible for ensuring that
use of the Code Case does not conflict with regulatory requirements or
licensee commitments. The Code Cases listed in the RGs are acceptable
for use within the limits specified in the Code Case. If the RG states
an NRC condition on the use of a Code Case, then the NRC condition
supplements and does not supersede any condition(s) specified in the
code case, unless otherwise stated in the NRC condition.
ASME Code Cases may be revised for many reasons, (e.g., to
incorporate operational examination and testing experience; and to
update material requirements based on research results). On occasion,
an inaccuracy in an equation is discovered or an examination, as
practiced, is found not to be adequate to detect a newly discovered
degradation mechanism. Hence, when an applicant or a licensee initially
implements a Code Case, 10 CFR 50.55a requires that the applicant or
the licensee implement the most recent version of that Code Case as
listed in the RGs incorporated by reference. Code Cases superseded by
revision are no longer acceptable for new application unless otherwise
indicated.
Section III of the ASME BPV Code applies only to new designs and
construction of new plants. The edition and addenda to be used in the
design and/or construction of a plant are selected based on the date of
the construction permit, combined license, design certification, or
manufacturing license and are not changed thereafter, except
voluntarily by the applicant or the licensee (unless prohibited by
applicable NRC finality provisions in 10 CFR Part 52) or as otherwise
permitted under 10 CFR Part 52). Hence, if a Section III Code Case is
implemented by an applicant or a licensee and a later version of the
Code Case is incorporated by reference into 10 CFR 50.55a and listed in
the RGs, then the applicant or the licensee may use either version of
the Code Case (subject, however, to whatever change requirements apply
to its licensing basis, (e.g., 10 CFR 50.59).
The ISI and OM IST programs for a 10 CFR Part 50 operating license
or 10 CFR Part 52 combined license must be updated every 10 years to
the latest edition and addenda of Section XI and the OM Code,
respectively, that were incorporated by reference to 10 CFR 50.55a and
in effect 12 months prior to the start of the next inspection and
testing interval. Licensees who were using a Code Case prior to the
effective date of its revision may continue to use the previous version
for the remainder of the 120-month ISI or IST interval. This relieves
licensees of the burden of having to update their ISI or IST program
each time a Code Case is revised by the ASME and approved for use by
the NRC. Because Code Cases apply to specific editions and addenda and
because Code Cases may be revised because they are no longer accurate
or adequate, licensees choosing to continue using a Code Case during
the subsequent ISI interval must implement the latest version
incorporated by reference into Sec. 50.55a and listed in the RGs.
The ASME may annul Code Cases that are no longer required, are
determined to be inaccurate or inadequate, or have been incorporated
into the BPV or OM Codes. If an applicant or a licensee applied a Code
Case before it was listed as annulled or expired, the applicant or the
licensee may continue to use the Code Case until the applicant or the
[[Page 61334]]
licensee updates its construction Code of Record (in the case of an
applicant, updates its application) or until the licensee's 120-month
ISI/IST update interval expires, after which the continued use of the
code case is prohibited unless NRC approval is granted under Sec.
50.55a(a)(3). If a Code Case is incorporated by reference into Sec.
50.55a and later annulled by the ASME because experience has shown that
the design analysis, construction method, examination method, or
testing method is inadequate; the NRC will amend Sec. 50.55a and the
relevant RG to remove the approval of the annulled Code Case.
Applicants and licensees should not begin to implement such annulled
Code Cases in advance of the effective date of the final rulemaking.
Concurrent with this action, the NRC is publishing in the Federal
Register Notices of availability of these RGs listing acceptable ASME
BPV Code Cases.
Section 50.55a(b)
In paragraphs (b) and (b)(4) of Sec. 50.55a, the reference to the
revision number for RG 1.84 is changed from ``Revision 34'' to
``Revision 35.'' In paragraph (b)(5) of Sec. 50.55a, the reference to
the revision number for RG 1.147 is changed from ``Revision 15'' to
``Revision 16.''
Sections 50.55a(f)(2), (f)(3)(iii)(A), (f)(3)(iv)(A), (f)(4)(ii),
(g)(2), (g)(3)(i), (g)(3)(ii), (g)(4)(i), and (g)(4)(ii)
In paragraphs (f)(2), (f)(3)(iii)(A), (f)(3)(iv)(A), (f)(4)(ii),
(g)(2), (g)(3)(i), (g)(3)(ii), (g)(4)(i), and (g)(4)(ii) of Sec.
50.55a, the reference to the revision number for RG 1.147 is changed
from ``Revision 15'' to ``Revision 16.''
V. Availability of Documents
The NRC is making the documents identified below available to
interested persons through one or more of the following:
Public Document Room (PDR): The NRC PDR is located at 11555
Rockville Pike, Public File Area O-1F21, Rockville, Maryland 20852.
Federal Rulemaking Web Site: Public comments and supporting
material related to this final rule can be found at http://regulations.gov by searching on the Docket ID NRC-2009-0014.
The NRC's Public Electronic Reading Room:
The NRC's public electronic reading room is located at http://www.nrc.gov/reading-rm.html.
Table 2
----------------------------------------------------------------------------------------------------------------
Document PDR Web e-Reading Room
----------------------------------------------------------------------------------------------------------------
Final Rule Regulatory Analysis............... X X ML100560131
RG 1.84, Revision 35......................... X X ML101800532
RG 1.147, Revision 16........................ X X ML101800536
RG 1.193, Revision 3......................... X X ML101800540
Public Comments.............................. X X ML100670356
Safety Evaluation Report EPRI Report (BWRVIP- X X ML073600374
108) (December 18, 2007) BWR Nozzle-to-
Vessel Welds and Nozzle Inner Radius.
----------------------------------------------------------------------------------------------------------------
VI. Voluntary Consensus Standards
The National Technology Transfer and Advancement Act of 1995,
Public Law (Pub. L.) 104-113, requires Federal agencies to use
technical standards developed or adopted by voluntary consensus
standards bodies unless the use of such standards is inconsistent with
applicable law or is otherwise impractical. In this action, the NRC is
amending its regulations to incorporate by reference RGs that list ASME
BPV Code Cases approved by the NRC. ASME Code Cases, which are ASME-
approved alternatives to the provisions of ASME Code editions and
addenda, are developed by the ASME whose members (including the NRC and
utilities) have broad and varied interests. Therefore, ASME Code Cases
are national consensus standards as defined in Pub. L. 104-113 and OMB
Circular A-119.
The NRC reviews each Section III and Section XI Code Case published
by the ASME to ascertain whether it is consistent with the safe
operation of nuclear power plants. Those code cases found to be
acceptable are listed in the RGs that are incorporated by reference in
Sec. 50.55a(b). Those that are found to be unacceptable are listed in
RG 1.193, but licensees may still seek NRC's approval to apply these
Code Cases through the relief request process permitted in Sec.
50.55a(a)(3). Other Code Cases, which the NRC finds to be conditionally
acceptable, are also listed in the RGs that are incorporated by
reference along with the conditions under which they may be applied. If
the NRC did not conditionally accept ASME Code Cases, it would
disapprove these Code Cases entirely. The effect would be that
licensees would need to submit a larger number of relief requests,
which would be an unnecessary additional burden for both the licensee
and the NRC. For these reasons, the treatment of ASME BPV and OM Code
Cases and any conditions placed on them in this final rule does not
conflict with any policy on agency use of consensus standards specified
in OMB Circular A-119.
The NRC is aware of other voluntary consensus standards that exist
in other countries that generally address the subjects covered by the
ASME Codes and Code Cases. However, the ASME Code is itself recognized
internationally. The adoption of those other voluntary consensus
standards would not materially advance the underlying objectives of the
NTTAA. Accordingly, the NRC is incorporating by reference and approving
the use the ASME Code Cases, instead of incorporating by reference and
approving the use of other countries voluntary consensus standards that
address nuclear power plant piping design, construction, maintenance
and in-service inspection.
VII. Finding of No Significant Environmental Impact: Environmental
Assessment
This final rule action stems from the Commission's practice of
incorporating by reference the RGs listing the most recent set of NRC-
approved ASME Code Cases. The purpose of this action is to allow
licensees to use the Code Cases listed in the RGs as alternatives to
requirements in the ASME BPV Code for the construction and ISI of
nuclear power plant components. This action is intended to advance the
NRC's strategic goal of ensuring adequate protection of public health
and safety and the environment. It also demonstrates the agency's
commitment to participate in the national consensus standards process
under the National Technology Transfer and Advancement Act of 1995,
Pub. L. 104-113.
[[Page 61335]]
The National Environmental Policy Act (NEPA) requires Federal
government agencies to study the impacts of their ``major Federal
actions significantly affecting the quality of the human environment''
and prepare detailed statements on the environmental impacts of the
action and alternatives to the action (United States Code, Vol. 42,
Section 4332(C) [42 U.S.C. Sec. 4332(C)]; NEPA Sec. 102(C).
The Commission has determined under NEPA, as amended, and the
Commission's regulations in Subpart A of 10 CFR Part 51 that this final
rule would not be a major Federal action significantly affecting the
quality of the human environment. Therefore, an environmental impact
statement is not required.
As alternatives to the ASME Code, NRC-approved Code Cases provide
an adequate level of safety. Also, use of NRC-approved Code Cases does
not change the probability or consequences of accidents compared to the
usage of ASME Code Cases. There are also no significant, non-
radiological impacts associated with this action because no changes
would be made affecting non-radiological plant effluents and because no
changes would be made in activities that would adversely affect the
environment.
The determination of this environmental assessment is that there
will be no significant offsite impact to the public from this action.
VIII. Paperwork Reduction Act Statement
This final rule increases the burden on licensees applying ASME
Code Case N-730 to maintain repair records of the current control dive
bottom head penetrations in BWRs for the life of the reactor vessel (10
CFR 50.55a). The public burden for the information collection
associated with Code Case N-730 is estimated to average 5 hours per
request. In addition, the adoption of ASME Code Cases will result in
fewer relief requests, a burden hour savings of 20 hours per request.
Because the burden for the information collections in this rule is
insignificant, Office of Management and Budget (OMB) clearance is not
required. Existing requirements were approved by OMB, approval number
3150-0011.
Send comments on any aspect of these information collections to the
Information Services Branch (T-5 F52), U.S. Nuclear Regulatory
Commission, Washington, DC 20555-0001, or by Internet electronic mail
to [email protected] and to the Desk Officer, Ms. Christine
Kymn, Office of Information and Regulatory Affairs, NEOB-10202 (3150-
0011), Office of Management and Budget, Washington, DC 20503.
Public Protection Notification
The NRC may not conduct or sponsor, and a person is not required to
respond to, a request for information or an information collection
unless the requesting document displays a currently valid OMB control
number.
IX. Regulatory Analysis
The ASME Code Cases listed in the RGs to be incorporated by
reference provide voluntary alternatives to the provisions in the ASME
BPV Code for design, construction, and ISI of specific structures,
systems, and components used in nuclear power plants. Implementation of
these Code Cases is not required. Licensees use NRC-approved ASME Code
Cases to reduce unnecessary regulatory burden or gain additional
operational flexibility. It would be difficult for the NRC to provide
these advantages independently of the ASME Code Case publication
process without expending considerable additional resources.
The NRC has prepared a regulatory analysis addressing the
qualitative benefits of the alternatives considered in this proposed
rulemaking and comparing the costs associated with each alternative.
The regulatory analysis is available to the public as indicated under
the ``Availability of Documents'' Portion of this document.
X. Regulatory Flexibility Certification
Under the Regulatory Flexibility Act of 1980 (5 U.S.C. 605(b)), the
Commission certifies that this final rule would not impose a
significant economical impact on a substantial number of small
entities. This final rule would affect only the licensing and operation
of nuclear power plants. The companies that own these plants are not
``small entities'' as defined in the Regulatory Flexibility Act or the
size standards established by the NRC (10 CFR 2.810).
XI. Backfit Analysis
The provisions in this final rule allow applicants and licensees to
voluntarily use NRC-approved ASME Code Cases, sometimes with
conditions. Thus, the NRC finds that this final rule does not involve
any provisions that constitute backfitting as defined in 10 CFR
50.109(a)(1), or otherwise violate the issue finality provisions in 10
CFR Part 52. Accordingly, a backfit analysis has not been prepared for
this rule.
List of Subjects in 10 CFR Part 50
Antitrust, Classified information, Criminal penalties, Fire
protection, Incorporation by reference, Intergovernmental relations,
Nuclear power plants and reactors, Radiation protection, Reactor siting
criteria, Reporting and recordkeeping requirements.
0
For the reasons set forth in the preamble, and under the authority of
the Atomic Energy Act of 1954, as amended; the Energy Reorganization
Act of 1974, as amended; and 5 U.S.C. 552 and 553, the NRC is adopting
the following amendments to 10 CFR Part 50.
PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION
FACILITIES
0
1. The authority citation for Part 50 is revised to read as follows:
Authority: Secs. 102, 103, 104, 105, 161, 182, 183, 186, 189, 68
Stat. 936, 937, 938, 948, 953, 954, 955, 956, as amended, sec. 234,
83 Stat. 444, as amended (42 U.S.C. 2132, 2133, 2134, 2135, 2201,
2232, 2233, 2236, 2239, 2282); secs. 201, as amended, 202, 206, 88
Stat. 1242, as amended, 1244, 1246 (42 U.S.C. 5841, 5842, 5846);
sec. 1704, 112 Stat. 2750 (44 U.S.C. 3504 note); Energy Policy Act
of 2005, Pub. L. 109-58, 119 Stat. 194 (2005). Section 50.7 also
issued under Pub. L. 95-601, sec. 10, 92 Stat. 2951 as amended by
Pub. L. 102-486, sec. 2902, 106 Stat. 3123 (42 U.S. C. 5841),
Section 50.10 also issued under secs. 101, 185, 68 Stat. 955, as
amended (42 U.S.C. 2131, 2235); sec. 102, Pub. L. 91-190, 83 Stat.
853 (42 U.S.C. 4332). Sections 50.13, 50.54(d), and 50.103 also
issued under sec. 108, 68 Stat. 939, as amended (42 U.S.C. 2138).
Sections 50.23, 50.35, 50.55, and 50.56 also issued under sec.
185, 68 Stat. 955 (42 U.S.C. 2235). Sections 50.33a, 50.55a and
Appendix Q also issued under sec. 102, Pub. L. 91-190, 83 Stat. 853
(42 U.S.C. 4332). Sections 50.34 and 50.54 also issued under sec.
204, 88 Stat. 1245 (42 U.S.C. 5844). Sections 50.58, 50.91, and
50.92 also issued under Pub. L. 97-415, 96 Stat. 2073 (42 U.S.C.
2239). Section 50.78 also issued under sec. 122, 68 Stat. 939 (42
U.S.C. 2152). Sections 50.80-50.81 also issued under sec. 184, 68
Stat. 954, as amended (42 U.S.C. 2234). Appendix F also issued under
sec. 187, 68 Stat. 955 (42 U.S.C. 2237).
0
2. Section 50.55a is amended by revising paragraphs (b) introductory
text, (b)(4) introductory text, (b)(5) introductory text, (f)(2),
(f)(3)(iii)(A), (f)(3)(iv)(A), (f)(4)(ii), (g)(2), (g)(3)(i),
(g)(3)(ii), (g)(4)(i), and (g)(4)(ii) to read as follows:
Sec. 50.55a Codes and standards.
* * * * *
(b) Section III and XI of the ASME Boiler and Pressure Vessel Code
and the ASME Code for Operation and
[[Page 61336]]
Maintenance of Nuclear Power Plants, which are referenced in paragraphs
(b)(1), (b)(2), and (b)(3) of this section, were approved for
incorporation by reference by the Director of the Office of the Federal
Register pursuant to 5 U.S.C. 552(a) and 1 CFR part 51. NRC Regulatory
Guide 1.84, Revision 35, ``Design, Fabrication, and Materials Code Case
Acceptability, ASME Section III'' (July 2010); NRC RG 1.147, Revision
16, ``Inservice Inspection Code Case Acceptability, ASME Section XI,
Division 1'' (July 2010); and RG 1.192, ``Operation and Maintenance
Code Case Acceptability, ASME OM Code'' (June 2003), have been approved
for incorporation by reference by the Director of the Office of the
Federal Register pursuant to 5 U.S.C. 552(a) and 1 CFR part 51. These
RGs list ASME Code cases that the NRC has approved in accordance with
the requirements in paragraphs (b)(4), (b)(5), and (b)(6) of this
section. Copies of the ASME Boiler and Pressure Vessel Code and the
ASME Code for Operation and Maintenance of Nuclear Power Plants may be
purchased from the American Society of Mechanical Engineers, Three Park
Avenue, New York, NY 10016. Single copies of NRC RG 1.84, Revision 35;
1.147, Revision 16; and 1.192 may be obtained free of charge by writing
the Mail and Messenger Services, U.S. Nuclear Regulatory Commission,
Washington, DC 20555-0001; or by fax to 301-415-2289; or by e-mail to
[email protected]. Copies of the ASME Codes and NRC RGs
incorporated by reference in this section may be inspected at the NRC
Technical Library, Two White Flint North, 11545 Rockville Pike,
Rockville, MD 20852-2738, or at the National Archives and Records
Administration (NARA). For information on the availability of this
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.
* * * * *
(4) Design, Fabrication, and Materials Code cases. Applicants and
licensees may apply the ASME Boiler and Pressure Vessel Code cases
listed in NRC RG 1.84, Revision 35 without prior NRC approval subject
to the following:
* * * * *
(5) In-service Inspection Code cases. Licensees may apply the ASME
Boiler and Pressure Vessel Code cases listed in RG 1.147, Revision 16,
without prior NRC approval subject to the following:
* * * * *
(f) * * *
(2) For a boiling or pressurized water-cooled nuclear power
facility whose construction permit was issued on or after January 1,
1971, but before July 1, 1974, pumps and valves which are classified as
ASME Code Class 1 and Class 2 must be designed and be provided with
access to enable the performance of inservice tests for operational
readiness set forth in editions and addenda of Section XI of the ASME
Boiler and Pressure Vessel Code incorporated by reference in paragraph
(b) of this section (or the optional ASME Code cases listed in NRC RG
1.147, Revision 16 or RG 1.192 that are incorporated by reference in
paragraph (b) of this section) in effect 6 months before the date of
issuance of the construction permit. The pumps and valves may meet the
inservice test requirements set forth in subsequent editions of this
Code and addenda which are incorporated by reference in paragraph (b)
of this section (or the optional ASME Code cases listed in NRC RG
1.147, Revision 16 or RG 1.192 that are incorporated by reference in
paragraph (b) of this section), subject to the applicable limitations
and modifications listed therein.
(3) * * *
(iii) (A) Pumps and valves, in facilities whose construction permit
was issued before November 22, 1999, which are classified as ASME Code
Class 1 must be designed and be provided with access to enable the
performance of inservice testing of the pumps and valves for assessing
operational readiness set forth in the editions and addenda of Section
XI of the ASME Boiler and Pressure Vessel Code incorporated by
reference in paragraph (b) of this section (or the optional ASME Code
cases listed in NRC RG 1.147, Revision 16 or RG 1.192 that are
incorporated by reference in paragraph (b) of this section) applied to
the construction of the particular pump or valve or the Summer 1973
Addenda, whichever is later.
* * * * *
(iv)(A) Pumps and valves, in facilities whose construction permit
was issued before November 22, 1999, which are classified as ASME Code
Class 2 and Class 3 must be designed and be provided with access to
enable the performance of inservice testing of the pumps and valves for
assessing operational readiness set forth in the editions and addenda
of Section XI of the ASME Boiler and Pressure Vessel Code incorporated
by reference in paragraph (b) of this section (or the optional ASME
Code cases listed in NRC RG 1.147, Revision 16, that are incorporated
by reference in paragraph (b) of this section) applied to the
construction of the particular pump or valve or the Summer 1973
Addenda, whichever is later.
* * * * *
(4) * * *
(ii) Inservice tests to verify operational readiness of pumps and
valves, whose function is required for safety, conducted during
successive 120-month intervals must comply with the requirements of the
latest edition and addenda of the Code incorporated by reference in
paragraph (b) of this section 12 months before the start of the 120-
month interval (or the optional ASME Code cases listed in NRC RG 1.147,
Revision 16 or RG 1.192 that are incorporated by reference in paragraph
(b) of this section), subject to the conditions listed in paragraph (b)
of this section.
* * * * *
(g) * *
(2) For a boiling or pressurized water-cooled nuclear power
facility whose construction permit was issued on or after January 1,
1971, but before July 1, 1974, components (including supports) which
are classified as ASME Code Class 1 and Class 2 must be designed and be
provided with access to enable the performance of inservice examination
of such components (including supports) and must meet the preservice
examination requirements set forth in editions and addenda of Section
XI of the ASME Boiler and Pressure Vessel Code incorporated by
reference in paragraph (b) of this section (or the optional ASME Code
cases listed in NRC RG 1.147, Revision 16, that are incorporated by
reference in paragraph (b) of this section) in effect 6 months before
the date of issuance of the construction permit. The components
(including supports) may meet the requirements set forth in subsequent
editions and addenda of this Code which are incorporated by reference
in paragraph (b) of this section (or the optional ASME Code cases
listed in NRC RG 1.147, Revision 16, that are incorporated by reference
in paragraph (b) of this section), subject to the applicable
limitations and modifications.
(3) * * *
(i) Components (including supports) which are classified as ASME
Code Class 1 must be designed and be provided with access to enable the
performance of inservice examination of these components and must meet
the preservice examination requirements set forth in the editions and
addenda of Section XI of the ASME Boiler and Pressure Vessel Code
incorporated by reference in paragraph (b) of this section (or the
optional ASME Code cases listed
[[Page 61337]]
in NRC RG 1.147, Revision 16, that are incorporated by reference in
paragraph (b) of this section) applied to the construction of the
particular component.
(ii) Components which are classified as ASME Code Class 2 and Class
3 and supports for components which are classified as ASME Code Class
1, Class 2, and Class 3 must be designed and be provided with access to
enable the performance of inservice examination of these components and
must meet the preservice examination requirements set forth in the
editions and addenda of Section XI of the ASME Boiler and Pressure
Vessel Code incorporated by reference in paragraph (b) of this section)
applied to the construction of the particular component.
* * * * *
(4) * * *
(i) Inservice examination of components and system pressure tests
conducted during the initial 120-month inspection interval must comply
with the requirements in the latest edition and addenda of the Code
incorporated by reference in paragraph (b) of this section on the date
12 months before the date of issuance of the operating license (or the
optional ASME Code cases listed in NRC RG 1.147, Revision 16, that are
incorporated by reference in paragraph (b) of this section), subject to
the conditions listed in paragraph (b) of this section.
(ii) Inservice examination of components and system pressure tests
conducted during successive 120-month inspection intervals must comply
with the requirements of the latest edition and addenda of the Code
incorporated by reference in paragraph (b) of this section 12 months
before the start of the 120-month inspection interval (or the optional
ASME Code cases listed in NRC RG 1.147, Revision 16, that are
incorporated by reference in paragraph (b) of this section), subject to
the conditions listed in paragraph (b) of this section.
* * * * *
Dated at Rockville, Maryland, this 14th day of September 2010.
For the Nuclear Regulatory Commission.
Cynthia D. Pederson,
Acting Director, Office of Nuclear Reactor Regulation.
[FR Doc. 2010-24814 Filed 10-4-10; 8:45 am]
BILLING CODE 7590-01-P