ML20056A417
| ML20056A417 | |
| Person / Time | |
|---|---|
| Issue date: | 07/31/1990 |
| From: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| References | |
| FRN-55FR29043 AD04-1-026, AD4-1, AD4-1-26, NUREG-1411, NUDOCS 9008070323 | |
| Download: ML20056A417 (75) | |
Text
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4 NUREG-1411 Response to Public Comments Resulting from the Public Wor 1 shop on Nuclear Power Plant License Renewa~
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7 AVAILABILITY NOTICE Availability of Reference Materials Cited in NT Publications Most documents cited in NRC publications will be available from one of the following sources:
1.
The NRC Public Document Room, 2120 L Street, NW, Lower Level, Washington, DC r
20555 2,
The Superintendent of Documents, U.S. Government PrinSno Ifice, P,0, Box 37082, Washington, DC 20013 7082 3.
The National Technical information Service, Springfield, VA 22161 Although the listing that follows represonts the majority of documents cited in NRC publica-tions, it is not intended to be exhaustive.
Referenced documents available for inspection and copying for a fee from the NRC Public Document Room include NRC correspondence and internal NRC memoranda: NRC Office of inspection and Enforcement bulletins, circulars, information notices, inspection and investi-gation noticos: Licensee Event Reports; vendor reports and correspondonce; Commission papers; and app!icant and licensee documents and correspondence.
The following doromonts in the NUREG series are available for purchase from the GPO Sales Program: formal NRC staff and contractor reports, NRC-sponsored conference proceed-ings, and NRC booklets and brochures. Also available are Regulatory Guides, NRC regula-tions in the Code of Federal Regulations, and Nuclear Regulatory Commission issuances.
Documents available from the National TechnicalInfornution Service include NUREG series reports and technical reports prepared by other federal agencies and reports prepared by the Atomic Energy Commission, forerunner agency to the Nuclear Regulatory Commission.-
Documents available from public and special technical libraries include all open literature items, such as books, Joarnal and periodical articles, and transactions. Federal Register noticos, federal and state legislation, and congressional reports can usually be obtained from these libredes.
Documents such as theses, dissertations, foreign reports and translations, and non-NF'O conference proceedings are available for purchase from the organization sponsoring the publication cited.
Single copies of NRC draft reports are available free, to the extent of supply, upon written request to the Office of Information Resources Management, Distribution Section, U.S.
Nuclear Regulatory Commission, Washhoton. DC 20555.
Copies of industry codes and standards used in a substantive manner in the NRC regulatory process are maintained at the NRC Library 7920 Norfolk Avenue, Bethesda, Maryland, and are available there for reference use by the public. Codes and standards are usually copy-righted and may be purchased from the originating organization or, if they are American National Standards, from the American National Standards institute,1430 Broadway, New York, NY 10018.
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R.esponse to Public Comments j
Resulting from the Public Workshop on Nuclear Power Plant License Renewal
'1 Manuscript Completed: May 1990 Date Published: July 1990 1.
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ABSTRACT On October 13, 1989, the U.S. Nuclear Regulatory Commission (NRC) issued an Advance Notice of Proposed Rulemaking on nuclear power plant license renewal.
The notice presented the NRC's preliminey regulatory philosophy and approach for developing license renewal regulations and solicited comments on a number of technical and policy issues.
It also announced plans for a public workshop to discuss the. issues and to receive comments and information.
The workshop was held on November 13-14, 1989., in Reston, Virginia.
This document reports on the NRC's response to the public comments from the workshop and written com-ments on the workshop topics received shortly af ter the workshop.
(The proceed-ings of the workshop were reported in NUREG/CP-0108.)
iii
h TABLE OF CONTENTS Page-w iii ABSTRACT..............................................................
1-1 1.
INTRODUCTION.....................................................
2, SESSIONS 1 AND.S--0VERVIEW 0F r CONCEPTUAL APPROACH TO A LICENSE 2-1 RENEWAL RULE....................................................
2.1 Yankee Atomic Electric Company Responses....................
2-1 j
2.2-Westinghouse Electric Corporation Responses............-.....
2-17 2-20 l
2.3 NRC Staff; Responses.........................................
3, SESSION 2--REACTOR PRESSURE BOUNDARY........................
3-1 4.
SESSION 3--FLUID AND MECHANICAL SYSTEMS.....................
4-1 5.
SESSION 4--SCREENING METHODOLOGY FOR SYSTEMS, STRUCTURES, AND COMPONENTS IMPORTANT TO SAFETY...................................
5-1 6-1 6.
SESSION 6--CONTAINMENTS..........................................
7-1 7.
SESSION 7--ELECTRICAL SYSTEMS....................................
8-1 8.
SESSION 8--ENVIRONMENTAL EFFECTS.............-....................
9-1 9.-
MISCELLANEOUS COMMENTS...........................................
A-1 APPENDIX--Organizations Providing Written Comments....................
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INTRODUCTION On October 13, 1989,' thi U.S. Nuclear Regulatory Commission (NRC) issued an Advance Notice of Propos3d Rulemaking on nuclear power plant license renewal.
LThe notice presented the URC's preliminary regulatory philosophy and approach for developing license. renewal regulations and solicited comments on a number
'of technical and policy-issues.
It also announced plans for a public workshop to discuss _the issues and to receive comments ~and information.' The workshop was held on-November 13-14, 1989, in Reston, Virginia (NUREG/CP-0108, " Proceed-ings of the Public-Workshop on Nuclear Power-Plant License Renewal," U.S.
Nuclear Regulatory Commission, April 1990, proceedings prepared.by the MITRE Corporation).:.This document-(NUREG-1411) reports on the NRC's response.to the public-comments-from the workshop and written comments on the workshop topics received shortly after the workshop.-
The Federal Register notice-(54 FR 41980) for the license renewal workshop stated that written comments;on matters covered by the workshop. received.by December 1,1989, would be considered along with comments made during-the work-shop when. drafting a proposed rule and draft regulatory guide.
Twelve sets of.
written comments were: submitted to the NRC following the. workshop on November 3
13-14, 1989 :NUMARC, Yankee. Atomic Electric Company, and Westinghouse Electric Corporation submitted written comments in response-to the staff questions that were_ prepared to guide _the discussion in each of'the eight workshop. sessions.
The staff; disposition of these comments is presented in the following discus -
.sion, which is'~ arranged by workshop session.
In addition to comments on the individual sessions, the.12 responders provided
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a' total of 25 comments on a variety of topics related to license-renewal.
staff' response'to these comments is addressed in Section.9'of this~ document.
The:12' responders are identified in the appendix.
Copies of the comments are available'for inspection at the NRC Public.0ccument Room, 2120 L Street, NW, E
Washington, OCi s
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2.
SESSIONS 1 AND 5--0VERVIEW 0F A CONCEPTUAL APPROACH TO A LICENSE RENEWAL RULE This section provides the questions and comments for Sessions 1 and 5 from the Yankee Atomic Electric Company (Section 2.1) and the Westinghouse Electric Corporation (Section 2.2).
The staff response to these comments is provided in Section 2.3.
For the remaining sections (Sessions 2, 3, 6, 7, and 8) the ques-tions are provided together with the comments and staff resronse.
2.1 Yankee Atomic Electric Company Responses I.
APPROACH Question 1 Is the approach taken reasonable in light of known technical information?
Response
Pilot plant studies and lead plant technical evaluation reinforce the philo-sophical approach taken by the NRC.
Question 2 Are the two principles stated in the philosophy discussion supported by the rule ~ wording?
Response
We support the use of the two principles expressed in the philosophy, i.e.,
(1) the current' licensing basis should be used for the-renewed license, and (2) the current licensing basis is adequate for the renewal term.
- However, the' conceptual approach does not always implement support for the philosophy Examples:
(1) The philosophy adopts the idea of screen-expressed by the NRC.
ing to focus on age-related degradation of certain equipment; the conceptual approach in Section XX.9(c) does not.
(2)'The philosophy adopts the concept
.of carrying the current licensing basis forward because it provides an adequate leveltof safety; the conceptual approach in Section XX.9(b) requires reanalysis of.the entire current licensing basis.
Question 3 Are there any known technical or safety issues that would argue against the selected approach?
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Response
We do not know of any technical or safety issues that would argue against the selected philosophical approach.
As a matter of fact the more work we do, the more convinced we are of the correctness of this appro,ach.
Question 4 i
What areas of the philosophy need additional clarification?
i
' Response The philosophy requires cla'rification on the following aspects:
Current Licensing Basis (Page 10)
The' focus of license renewal is age-related degradation.
Both the l
philosophy and conceptual approach should clearly state that only a
those aortions of the CLB having to.do with age related degradation aressu) ject to license renewal review and submittal.
SSC Screening (Page 11) 1 The NRC adopts a screening approach that eliminates from further review those SSCs that are effectively. covered by existing ongoing NRC requirements and/or licensee programs _ or are not subject to aging mechanisms.
Yet the NRC subsequently suggests in the conceptual approach that the only screening"that will be allowed is-that which identifies "important.to safety, The conceptual approach assumes that'all-important-to-safety equipment must have a' degradation evaluation as described in Sections XX.9(c)(2), (3), (4), and (5),
Our technical evaluations to date demonstrate that some components--
do not require this level of detailed evaluation.
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Backfit Controls (Page 14)-
l It appears that'the NRC is proposing an interruption of the backfit rule for the license renewal review process.
The backfit rule should govern the review process as well as.the rulemaking, Question 5 I
Is the: schedule for the rulemaking adequate to permit utilities to consider l
-license renewal as an option for ensuring adequate electri~al supply?
Response
No;:the present schedule to issue a final rule in 1992 would leave the lead
? plants in regulatory limbo.
Lead plants require that a final rule be issued
-prior to their applications being filed.
This means that the final rule'should be-issued by April.or May of 1991.
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II.
DEFINITIONOFTHELICENs1NGBASIS Question 1 Has the current licensing basis been adequately defined?
Response
We agree in general with the definition of _ current licensing basis as presented in the :onceptual approach.
However, we recommend that the following phrases be deleted:
"except for_those which have time dependence based on the expected plant life or whose tect-ical evaluation would be affected t/ aging degradation;..."
This phrase is unnecessary because time dependencies and age-related degradation will be reviewed and evaluated under Section XX 9 of the license renewal rule.
... adjudicatory decision;,.."
This phrase is unnecessary because all license conditions ordered by adjudication are routinely incorporated into the license by the NRC staff.
...and other licensee correspondence."
This catch-all phrase is unnecessary because the NRC is merely list-ing a few specific examples of documents that are part of the CLB.
The NRC is not suggesting that the examples are all-inclusive.
Question 2 What requirements, if any, should be included or deleted?
Respor.se See response to Question II.1, Question 3 Are the requirements clear and is it clear how the requirements will be met?
Response
The conceptual approach is not always clect regarding " current licensing basis";
Section-XX.5(d) allows referencing previous applications, etc., that have been filed with the NRC;Section XX.9 appears to contradict XX.5(d).
Sections XX.9(a) and (b) require a description and analysis of the entire current licensing basis, and Section XX.9 requires a new FSAR that preseats the entire design basis for the plant.
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-As discussed in our response to Question I.4, reidentification and reanalysis of the entire current licensing basis is unnecessary.
All that should be required is to review the current licensing basis to identify documents related to design of the systems, structures, and components and to identify / resolve time dependencies.
Question 4 What type and amount of documentation should be required as part of a renewal application?
i Response-i All that should be included is a description of how the current licensing basis i
was reviewed to identify relevant documents and to identify / resolve time 1
dependencies.
This should include:
p Alistingofthecurrentlicensingbasisdocumentsthataddressthe a.
facility s systems, i.tructures, and components, b,
Identification from the documents listed (a), of assumptions or conclusionswhlcharebaseduponanassumedservicelife,orperiod of operation, bounded by the current license term, c.
Description and technical justification for and actions to be taken to resolve time dependencies identified from (b).
j Question 5 What are the problems or issues in meeting the proposed requirements and is regulatory guidance needed in this area?
j
Response
The conceptual approach (Sections T 9(a) and (b)) call for reidentification I
and reanalysis of the entire current licensing basis.
Such an exercise requires i
an enormous amount of resources and time and is inconsistent wi'h the NRC phi-
-losophy expressed.
Since the focus of license' renewal is age-lateddegrada-
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tion, and the NRC has adopted the approach that the level of Jety provided by
. the current licensing basis is the same level of safety c!er ' w.necessary_ for the renewal term, it would be of benefit to both NRC and e:.,licants to avail themselves of existing docketed information whicn already,dentifies the cur-rent licensing basis and has already been analyzed.
h gdlatory guidance, i'i the-form of a discussion in the Statements of Consideration, could serve to clarify the rule on this issue.
6 III.
EXCLUSION OF REGULATORY PROGRAMS FROM REVIEW Question 1 2
Should any identified programs or any other programs be inclu0d or excluded from review during a renewal application review?
If so, identify those pro-l grams'or issues and provide the technical or safety basis for the need to review or for exclusion from redew.
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Response
The initial _ list appears reasonable.
Question _2_
Is it clear how the regulatory requirements of the programs excluded from review will continue to be met during a renewal term?
Response
Continuation of these programs should not be a subject of license renewal.-
Continued NRC oversight of licensee programs is all that is needed.
IV.
ENVELOPE OF SYSTEMS, STRUCTURES, AND COMP 0NENTS TO BE CONSIDERED Question 1 1s equipment "important to safety" adequately defined and comprehensive?
Respot e The proposed definition of equipment "important to safety," based on 10 CFR 50.49, is acceptable with the following exception.
Systems, structures, and components (SSCs) falling within the scope of the draft rule are defined as important to safety in Sections XX.3(c)(1), (2), and (3).
However, we feel that uniquely identifying certain post-accident monitoring equipment as impor-tant to safety in Section XX.3(c)(3) is. inappropriate.
Such equipment should be identified important to safety)only if they meet the requirements defined in Sections XX 3(c)(1) and XX.3(c (2).
-Additionally, although event initiators are not discussed specifically as part of the "important to safety" definition in the draf t rule, the potential need to address event initiators was discussed by NRC at the workshop. We believe
- cvent initiators should be considered only to the extent that age-related degradation of such equipment affects the ability of safety-related SSCs to Event initiator SSCs, in and of themselves, perform their safety functions.
are not sufficient basis to be considered further for license renewal purposes.
Question 2 Is it clear how the requirements will be met and what problems exist with estab-lishing the envelope of "important to safety?"
Response
The requirement in Section XX 9(c)(1) of identifying systems, structures, and components important to safety, as previously defined in Sections XX.3(c)(1) and XX.3(c)(2), is clear with the following exceptions.
Uniquely identifying
.certain post-accident monitoring equipment in Section XX.3(c)(3) is inappro-priate because equipment important to safety should be selected on the basis of meeting the preceding requirements (i.e., Sections XX 3(c)(1) and 1
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XX.3(c)(2))'.
Additionally, the interpretation of Sections XX.3(c)(1) and XX.3(c)(2)'regarding the treatment of event initiators should be consistent with our response to Question IV.I.
The requirements of Section XX.9(c) of the draft rule do not reflect expressed NRC philosophy regarding components effectively covered by existing programs or not subject to aging mechanisms.
Specifically, the NRC states on page 11 of the letter:
"Those structures, systems, and components that are effectively covered by existing ongoing NRC requirements and/or licensee programs, or are i
not subject to aging mechanisms, need not be addressed in the application." -It is not clear where credit for these structures, systems, and components is i
factored into Section XX.9(c) of the draft rule.
Question 3 i
Is it clear that this rule requires the review of mild environment electrical equipment in systems important to safety'to the identified degradation mechanisms?
Response
Hild environment-electrical equipment, along with other electrical components, would be reviewed-for degradation mechanisms only if identified as important to safety and not subject to an effective maintenhnce program.
" Mild environment" electrical equipment are those electrical components that Are important to safety but in a location that would at no time be significantly more severe than the environment that would occur during normal plant operation.
These components were selected for application to the specific severe conditions based upon-sound engineering practices and manufacturer's recommendations.
Degradations are managed by preventative maintenance practices, based upon the history and surveillance of the components, y
V.
DEGRADATION MECHANISMS
' Question 1
-Are there any additional known degradation mechanisms which should be included in a license renewal rule? - If so, identify the mechanism and cite references to technical information describing the mechanism.
Response
The_ rule should not include a list of " degradation mech nisms," except +.o provide examples of aging phenomena that cause " age-related degradation." This list should he included in Section XX.3 as part of a definition of " age-related
-degradation."
Question 2
.Is it clear how the. requirements for identifying'the mechanisms will be met or is there a need for additional regulatory guidance in this area or are defini-tions needed for the categories of the degradation mechanisms?
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Response
Sectiu XX 9(c)(3) should require the licensee to determine which "imgortant to and are safety" components are not covered by " established effective programs subject to significant "lige-related degradation" during the renewal term.
Section~ XX.3 should provide definitions of an " established effective program" and " age-related degradation." The definition " age-related degradation should provide examples of degradation.
No further guidance is needed.
Question 3 Should definitions of the mechanisms be included in the rule?
Response
The rule should define " age-related degradation." This definition should provide examples of aging.phenocena or " degradation mechanisms" which cause such degradation.
It is not necessary to define each mechanism, or provide further guidance.
Such information is available from the published literature.
VI.
SEVERE ACCIDENTS
-Question 1 Should the staff require a completion of the Individual Plant Examination as a precondition to submission of a renewal application?
Response
d not precondition submission of a renewal application with The Commission sho completion =of the JE and should not precondition the rule with' completion of If the NRC concludes _that a generic letter is not sufficient to the IPE.
ensure resolution of the severe accidents. issue, NRC should condition the plant-specific license to ensure resolution.
Question 2 Should severe accidents have any additional role in a decision on tenewal of an operating license?
Response
The focus of-license renewal.is age-related degradation.
Severe accident resolution is not related to age-related degradation issues, nor are severe accidents part of the current licensing basis.
Therefore, severe accidents.
should have _no role in a decision on renewal of an OL.
Question 3 Are the-requirements clear and is it clear how the requirements can be met?
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- Response l
As we have previously stated, severe accident resolution should be treated seperately from license renewal; therefere, in our_ view, this question is moot.
Question-4 What are the problems or issues in meeting the proposed requirement and is additional regulatory guidance needed in this area?
Response
See response to Question VI.3.
' Question S
- Should the Accident Management _ Program be required to be in place?
Response
Because severe accident resolution is not related to age-related degradation, an Accident Management Program should not be required to be in place prior to license renewal issuance.
Implementation of the Accident Management Program is plant-specific.
The schedule should not be tied to license renewal.
- However, if the NRC insists on such implementation prior to renewal _ license issuance, then the actual plant-specific license should be conditioned rather than generically in the license renewal rule.
-VII.. CONTENT OF APPLICATION Question 1 j
'Are the requirements for what should be submitted clear and is it clear how those requirements are to be met?
Response
.The scope of..the requirements exceeds what is needed to support license renewal.
See answer.to Question VIII.3 below.
Question 2 Should a new FSAR be submitted ~in support of a renewal application or an
. addendum to the existing document?
-' Response
- The NRC should require: an addendum to a facility's FSAR.
This report should describe the methodology and results of an analysis to' ensure that age-related degradation has~ been identified and will be effectively managed throughout the renewal term.
Once approvea by the NRC, this document would be maintained as
- a. controlled document and updated annually.
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Question 3 What amcunt of documentation of data, analyses, and program changes should be provided in the application? Should th: rule propose the types of information that can-be retained in auditable forms at e nlicant locations?
Response
The amount of documentation required by Section XX.9 should be sufficient L
to describe the methodology, implementation process, and results of the evaluation of age-related degradation.
This should include the following:
Review of the cerent licensing basis (CLB) a.
(1) Description of how CLB was reviewed to identify what portion is relevant to this analysis.
(a) List of the pertinent documents.
(2) -Description of how the relevant portion of the CLB was reviewed for time dependencies.
(a) List and brief description of time dependencies identified.
(3) Description of results of evaluation of time dependencies, including identification of action to be taken, if any, and justificationthatactionissufficient.
b.
Plant Review.(Screening)
(1) Description of methodology
- and criteria used to identify systems, structures, and components that are:
(a) Important to safety; (b) Not subject to existing effective replacement, refurbishment, or inspection programs; and (c) Subject to potentially significant agt related degradation during the license renewal period.
(2) Description of plant-specific implementation of the methodology and criteria for an example system.
(3) Summary of results, including:
(a) Overall results for each review step.
(b) List of components, by system or structure, identified for evaluation.
"The NUMARC NUPLEX methodology is an example of an acceptable review process, i
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Evaluations
-(1) Description of evaluations of components identified in Section b(4)(b), including:
(a) Descri'stion of methodology used to determine if specir.1 actions are needed to ensure that the effects of ar,e-related degradation have been identified and will be effectively managed throughout~the renewal term.
(b) Summary of results, including:
List of components, by system or structure, for which special actions are necessary, including description of the necessary action and justifi-cation it will be sufficient.
List of components, by system or structure, for which no special action is necessary, with justification, d.
Implementation Plan (1) - Descriation of plans for implementing actions, resulting from the evaluations, with schedule for implementation.
(2) Identification of actions that will require NRC review in accordance with 10 CFR 50.;3.
2.
All other information that-is needed to document or support results of the analysis should be retained by the applicant in auditable form.
This
-should include:
a.
Plant-review results for each system, structure, and component.
b.
Basis for dispositioning of each system, structure, and component.'
c.
Documentation of evaluations of each component identified from the plant review, d.
Details of implementa m,. plans.
e.
Description of actions taken that did not require NRC review, withjustification.
Question 4 Is additional regulatory guidance needed in this area and should publicatica of additional guidance in this a'.ea be linked to publication of the final rule?
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5.i Response-The NRC should be able.to provide sufficient guidance for the lead plants in the Statement of Considerations to the rulemaking and in the final rule.
If
-it is_ decided that additional guidance is-needed for subsequent applications, it should_be developed later based upon the lead plant experience.
It should not be tied to issuance of the final rule, as such a schedule may unnecessarily delay the lead plants.
Question 5 Is more detail needed to provide a regulatory framework in the conceptual rule for a well-defined and acceptable-screening process?
j
Response
Section XX.9(c) does not describe a plant review (screening) process consistent with the NRC's stated philosophy.
Accordingly, Sections XX.9(c)(1) through XX 9(c)(5) should be restated to be consistent with this philosophy.
It should i
include requirements for review of the current licensing basis, plant review, 1
evaluations, and development of an implementation rlan, as described in-the answer to Question VII.3 above.
l VIII.
CERTIFICATION OF COMPLIANCE Question 1-Is.the requirement clear, and is it clear how the requirement will be met?
lj
Response
The NRC staff has properly embraced the CLB as an acceptable concept for license renewal._ The NRC should take the next logical step and conclude, as;a generic finding under the rulemaking, that the CLBs for the nation's nuclear power plants are sufficient for license renewal.
If this were done, it would not be necessary to demonstrate on an individual plant basis CLB compliance and certification of compliance.
This would' leave the effects of age-related degradation-as the proper focus of each license renewal application.
Question 2 Should the:NRC require applicants for renewal licenses to describe deviations from the SRP as is required of initial OL applicants?
l
Response
1 No;'an exercise.to describe deviations from the SRPs. as required for certain o
OL applicants, is contrary to the philosophy express J by the NRC regarding the current licensing basis.
The NRC has adopted the premise that the level of safety that is provided by the current licensing basis is sufficient for a renewed term.
Therefore, only those changes to the current licensing basis that are related to management and mitigation of age-related degradation should be the subject of evaluation for license renewal.
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IX.
ENVIRONMENTAL INFORMATION Question 1 Should the staff prepare a generic environmental statement which would discuss and envelop as many environmental issues as possible and which would then be used as a cited reference and preclude litigation in any future licensing proceeding?
Response
The scope of the environmental assessment must be balanced against the need to provide an environmental analysis sufficient to support a final rule in April 1991. We recommend that, in parallel to the EA effort for the Part 50 rulemak-i ing, the NRC also conduct a more extensive environmental assessment to support
^
a Part 51 rulemaking that would generically address as many issues as possible.
-Question 2 Need for separate rulemaking on Part 51 or with proposed rule?
Response
The only change in Part 51 necessary to issue the Part 50 license renewal rule is an administrative correction to 10 CFR 51.20(b)(2) to recognize that an
{
environmental assessment is sufficient for an individual license renewal.
Beyond that, any changes to Part 51 should be undertaken in parallel to the Part 50 effort to ensure that the final license renewal rule is issued by May 1991, prior to the date of the lead plant submittals.
X.
STANDARDS FOR ISSUANCE OF A RENEWAL LICENSE Question 1 l
Is it clear what the standards require and how the standards can be satisfied?
Response
t
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The focus of license renewal is age-related degradation.
Therefore, the only i
standards required should relate to age-related degradation.
The NRC staff has properly embraced the CLB as an acceptable concept for li:ense renewal.
The NRC should take the next logical step and conclude, as a gene'ic finding under the rulemaking, that the CLBs for the nation's nuclear power plants are sufficient i
for license renewal.
If this were done, it would not be 1ecessary to make any findings regarding the CLB on an individual plant basis, leaving the effects of age-related degradation as the proper focus of each license renewal application, j
Question 2 Do the specified standards provide reasonable assurance that a facility can be operated beyond its initial term or subsequent renewal terms? If not, what additional standards should be established for the issuance of renewal licenses?
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Response
See response to Question X.1.
Question 3 Should a limit be placed on the number of renewals permitted at any one facility?
Response
There should be no limit on the number of renewals permitted at any one facility.
The decision by the NRC to renew a license should be based on whether the level of safety provided by the current licensing basis can be maintained in any subsequent renewal.
XI.
POSTPONEMENT OF COMPLIANCE IN-THE AREAS OF DECOMMISSIONING AND FUEL MANAGEMENT Question 1 Should a license renewal rule include an automatic postponement of the existing requirements, or should it be necessary to have the renewal applicant specifi-cally request a postponement or exemption from the stated requirements?
Response
Postponement should be automatic.
Question 2 Is the postponement period reasonable or should it be more limited in time, e.g., for 1 year or 2 years only?
Response
The postponement period should be tied to the review period, not the expiration-of the initial OL.
XII.
MAINTENANCE, SURVEILLANCE, AND RECOR0 KEEPING Question 1 What, if any, maintenance practices should be required by a license renewal rule (such as reliability-centered maintenance)?
Response
Reliability-centered maintenance is one of a number of approaches to maintenance.
Specific methodology (approaches) to provide a desired result should not be part of any rule.
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Question 2 What type of process should be required by this regulation to ensure that future changes in the maintenance or surveillance programs do not reduce the effective-ness of these programs in monitoring plant degradation mechanisms?
Response
Where activities have been added for purposes of managing and mitigating 1
age-related degradation, these activities will be uniquely identified.
Any changes to such activities will be controlled per an administrative process to ensure the continued effectiveness of the programs.
Question 3 What specific standards for maintenance practices should be developed and issued in a regulatory guide related to license renewal?
Response
j No specific standards for maintenance practices should be developed and issued in a regulatory guide related to license renewal.
Maintenance practices applic-able to the satisfactory operation of the specific plant for the original licer se will provide a satisfactory program throughout the renewal period.
As a result of specific plant evaluations, enhancements may be required to the
_ practices to monitor identified potential degradation.
There enhancements will be plaat-unique and not adaptable to generic regulation.
Questiot 4 What types and amount of documentation of existing or newly proposed maintenance practices should be submitted as part of a renewal application?
Response
I The application should include specification of the criteria used in the plant review to determine whether existing maintenance practices qualify as estab-lished effective replacement, refurbishment, or inspection programs.
The application should also include a dascription of newly proposed maintenance practices.
This description should be sufficient to justify the basis for dis-positioning of components identified for evaluation (from the plant review).
See response to Question VII.3.
Question 5 What types of documentation can provide a verification of in situ equipment 3
condition and how much onsite inspection should be performed to validate the documentation?
Response
Various levels of analysis and/or inspection of actual conditions can be used to determine the degradation mechanisms that may be acting on system components, q
2-14
R; i
Management methods need only be demonstrate'd for-components with an identified
~
_ potential _for si_gnificant degradation.
Flexibility:in determinirig the optimum method of managing identified degradation is key, with trending used only where proved beneficial, sl t
o.
Question 6 iU What, if any, use and participation in NPROS should be required in a license
_l renewal application?
Response
NPRDS participation should not be referred to in rule.
Participation in NPRDS'should only be considered in the broader cw.6 ext of using past industry experience as-insight into component performance.
l Question 7 What steps should be-required as part of a license renewal to ensure that t
programmatic aspects =of an enhanced maintenance program are effectively
- implemented?
Response
Where activities'have been added'for purposes of managing and mitigating:
age related degradation,,these activities will be uniquely identified.
Any a
changes to such activities will be controlled by an administrative process to.
ensure the continued effectiveness of the programs.
Question 8 What credit, if any, should be given for. voluntary adoption and implementation of an industry standard for maintenance?.
6
Response
Utilization of industry standards is independent of renewal process and " credit"-
is not applicable.
- Question 9 What type of. information should be included or required of maintenance records for license 4 renewal?
Response
For' existing maintenance practices, records for license renewal should be the same as required to support the original license.. Regulatory audits, reviews, and surveillance have verified the existence-and adequacy of the records through-i out the life of the original l cense.
2-15
e For newly proposed maintenance practices, records will be kept as necessary to ensure that the required actions have been taken.
Question 10 What specific requiremer+.s should be included for monitoring aging effects on specific critical components?
RESPONSE
Various levels of analysit and/or inspection of actual conditions can be used to determine the degradation mechanisms that may be acting on system components.
Management methods need only be demonstrated for components with an identified potential for significant degradation.
Flexibility in determining the optimum method of managing identified degradation is key, with trending used only where proved beneficial.
Question 11 Should the proposed license renewal rule require a program for tracking mainte-nance records (performance trending) on specific safety-related equipment in order to monitor system performance, and how soon prior to submittal of the licensee renewal request should such a program be implemented?
Response
Various levels of analysis and/or inspection of actual conditions can be used to determine the degradation mechanisms that may be acting on system components.
Management methods need only be demonstrated for components with an identified potential for significant degradation.
Flexibility in determining the optimum method of managing identified degradation is key, with trending used only where proved beneficial.
Question 12 When inspections have not been made or operating history records and trending information documentation have not been maintained, what alternative measures can be taken to justify extended life?
Response
Management of an identified degradation mechanism can also be fulfilled by several methods, including:
Further analysis to demonstrate that the projected degradation is acceptable because of existing component design margin.
Demonstrating that the current level of examination of the component is adequate to ensure that the identified degradation mechanism does not impact safety or implementing enhanced examination, as necessary.
In many cases, trending of material condition or rate of degradation can be very important in ensuring continued safety.
2-16
E Modifications to operating practices.
Replacement or refurbishment of the component.
Question 13 Can components which are " routinely maintained" be excluded from license renewal considerations unless there are agreed upon reliability goals for these components?
Response
1 i
Components that are " routinely maintained" can be excluded from license renewal considerations without agreed upon reliability goals providing:
(1) the main-
~
tenance addresses the potential age-related degradation mechanisms to which the component is subject; or (2) the maintenance provides assurance that the:
component-significant safety functions are being adequately addressed.
Further-more, NRC oversight of licensee prog" rams ensures adequate management and mitiga-tion of age-related degradation for routinely maintained" components.
2.2 Westinghouse Electric Corporation Responses 1.
APPROACH Question 1
-Is the approach taken reasonable in light of known technical information?
Resoonse The first principle set forth as a foundation for the proposed regulatory policy for license renewal in the referenced Federal Register notice is fundamentally j
i sound.
Tne second principle, however, seems to focus on the wrong objective.
Rather than providing assurance that the level of safety provided by the plant's current licensing basis will not degrade during the renewal period, the policy should provide assurance that the level of safety provided by the current licens-ing basis will not degrade to the point that the required level of safety is not l
met.. If the second principle is revised to reflect this, the approach is a reasonable one in light of the current technology and experience base.
Question 2 Are the two principles stated in the philosophy discussion supported by the rule wording?
l
Response
No, there are a number of areas-in the conceptual approach that are inconsistent with the two principles notwithstanding our proposed revision of the second principle. The conceptual approach should be revised wherever necessary to con-I form to the two principles.
The following are examples of areas in the concep-tual approach that are inconsistent with the principles:
2-17
r The conceptual approach does not focus on age-related degradation of structures, systems, and components.that are not_ effectively covered by existing ongoing NRC requirements and/or license programs.
Although the current licensing basis is a matter of record via the FSAR and other' supporting information in each plant docket, the cun-l ceptual approach would require the recertification of the current design basis and require a description and analysis of how the plant complies with its current licensing basis.
The NRC currently has extensive programs dealing with license amendments, licensee docu-1 mentation of changes that do not require license amendments, annual f
FSAR updates, reporting of unusual events and occurrences, and inspection and enforcement.
These provide reasonable assurance that t
plants continue to comply with their respective current licensing I
basis.
Thus,_the requirements with regard to identification of and compliance with the current licensing basis are inconsistent with i
the stated principles and should be deleted in their entirety.
j In the NRC presentation in Session 1, non-safety grade " initiators" were characterized as examples of SSCs important to safety.
This is inconsistent with the definition provided in XX.3(c)(2), which we agree j
is the appropriate definition to be applied consistent with the two i
principles.
Question 3 Are there any known technical or safety issues that would argue against the selected approach?
Response
2 Based on our experience and studies that have been performed in connection with plant life extension, we do not believe that-there are any technical or safety _
issues that would argue against the selected approach.
.l Question 4 What areas of the philosophy need additional clarification?
Response
i 9
Westinghouse supports the philosophy that the current licensing basis is f
adequate to provide reasonable assurance of protection to the public health and safety.
Each plant for which an initial operating lit.ense was issued was found by the NRC to be safe for operation; i.e., operation of the plant could-be achieved with reasonable assurance of the public health and safety.
There-after, throughout the operating life of each plant, the NRC has required that this standard be maintained. Where appropriate, improvements and modifications J
to individual plants have been required by the NRC in order to make certain that the standard continues to be met.
Thus, for a plant to continue operating, NRC must be assured that the public health and safety is protected using the-d reasonable assurance standard.
Accordingly, the current licensing basis for a plant provides reasonable assurance of the public health and safety with respect 1
2-18
g i
to such plant.
Westinghouse, therefore, believes that the current licensing basis should be used for license renewal.
Consistent with this position, the license renewal rule should not make it a prerequisite that a license renewal applicant must comply with future regulatory requirements which are currently under consideration by the Commis m n for
'i future adoption, but which may or may not be adopted by the Commission.
The renewal decision should depend on the considerations set forth in 10 CFR Sec-tion 50.40(a) of the Commission's regulations in regard only to those factors
{
which are significant for license renewal, i.e., age-related degradation.
BACKFIT CONTROLS In connection with the issue of application of the NRC backfit rule in the license renewal process, Westinghouse generally supports the comments filed on i
behalf of the Nuclear Utility Backfitting and Reform Group ("NUBARG") by letter from Nicholas S. Reynolds, Esq., and Daniel F. Ste ger, Esq., Counsel to NVBARG, i
to the NRC dated December 1, 1989. We add the following comments.
The Federal Register notice states that the staff intends to propose a change i
to the backfit rule (10 CFR Section 50.109) "to specifically designate the issuance of a renewal license as an event af ter which the requirements of the backfit rule would apply." Although Westinghouse agrees that a technical change to the backfit rule is required to eliminate any ambiguity and make cer-tain that the backfit rule applies to the renewal license, there is an implica-tion in the Federal Register notice that there would be an interruption of the backfit rule and the rule might not apply during the license renewal review process.
Westinghouse believes that the backfit rule should apply throughout the renewal process.
The backfit rule was adopted to bring stability and certainty to the regulatory process. - Suspension or elimination of the backfit rule during review for plant life extension would introduce the ultimate in uncertainty.
The purpose of the backfit rule was not to prevent required changes.
- Rather, the purpose of the backfit rule was procedural, to provide a rational decision-making process and to instill a discipline on the determinations as to when l
changes are required'in regulatory requirements above the minimum and when backfits are required to the plants.
As applied to plant life extension, the discipline of the backfit rule should apply in determining what is required with respect to those things that are central to plant life extension, namely, age-related degradation.
The backfit rule would require a hard analysis of the benefits to be derived from any pro-posed changes to a plant that relate to age-related degradation and the cost of implementing those changes.
There.is no justification for requiring backfits that cannot be rationally supported, and there is no justification for opening up the entire plant to backfits without benefit of the analysis required by the backfit rule.
2-19
[
o F
r l
There may be some modifications necessary in connection with plant life-extension to bring a-facility into compliance with the_ license or rules or orders of_the
~ Commission-or in conformance with' written commitments _by:the licensee. :In.such, case,= the backfit rule analysis would not be required and the backfit standard would not apply where the. staff made an eppropriate finding and documented its-
.j H
evaluation of that finding.
This is contemplated by:the backfit. rule itself..
However, in-connection with plant life extension, the-facility will have been operating and will therefore meet the current licensing basis, and it would be i
an" unusual situation where this exception to the backfit rule would be applicable.
2.3 NRC Staff Responses 2.3.1. Yankee: Atomic Electric Company (YAEC)
I.
APPROACH
~
Question 1 - Response not required.
Question 2 -The principle of using the current licensing basis for the renewal-license,'with.the exception of aging degradction concerns, has been clearly-stated _and implemented in the revised conceptual rule.
The licensee must iden-tify.those systems and structures important to license renewal:(ITLR) including
-l those BOP components whose failures can challenge the functions of the safety-related-components as defined-in 54.3(a).
The revised 54,21 is-general enough to permit a licensee to determine his ITLR, list by deterministic, prob-abilistic, or hybrid approaches for screening methodologies.
Reanalysis _of the-entire current: licensing basis is not_ required, t
guestion 3 r.esponse not required.
Question 4
-The staff believes that each. licensee must identify the current:
licensing basis appropriate to its plant.
The: licensee must,also provide an.
1 evaluation demonstrating that:he has'an effective program to manage aging of'
. structures-and components ITLR.. The method used by licensees for screeni_ng-is 7
subject to review by the staff.
Acceptable screening methodologies _may be discussed-in a staf f regulatory guide.or.in a _ safety evaluation _ report (SER)
.ontan(industry technical-report (ITR) if the staff and NUMARC can agree on the:
. criteria co'ntained in the ITR..In any event, some. structures and components-i
- may 'notirequire detailed evaluation if-exempted by screening methodology found acceptable to the staff.
The staff does not agree that the backfit process should apply-to the license.
- renewal rule: development since it believes that it.is developing rules to ensure
" adequate protection"' for. the r_enewed license period.
~
-Question 5 - The staff has revised its schedule and expects to issue the final Trule in May of 1991.
'II. ~ DEFINITION 0F.THE LICENSING BASIS
-Questions 1 and 2 - All phrases that YAEC recommends be deleted have been deleted.
2-20
l Question 3 - The conceptual approach has been clarified.
Identification of the current licensing basis is still required; however, certification of how the facility complies is no longer required.
The staff disagrees that identifica-tion should not be required.
Since facilities differ, only the licensee knows what each facility has installed and has made commitments on, and therefore each licensee must identify the licensing basis in the renewal application.
Question 4 - The conceptual rule has been clarified.
After identifying the current licensing basis, licensees perform an integrated plant review demon-strating that they evaluated the facility systems and components susceptible to aging degradation to ensure that the current licensing basis will be main-tained for the extended term.
This is in general agreement with the YAEC recommendation.
Question 5 - Reanalysis of the current licensing basis is no longer required..
The Statement of Considerations will further clarify the role of an " established ef fective program" and what it must accomplish.
III.
EXCLUSION OF REGULATORY PROGRAMS FROM REVIEW Questions 1 and 2 - General agreement with YAEC comment.
IV.
ENVELOPE OF SSC Question 1 - The staff disagrees with YAEC's proposed definition of important to safety (ITS), which the staff now calls important to license renewal (ITLR).
Any non-safety-related equipment that can prevent or challenge a safety func-tion accomplishment must be included as ITLR, irrespective of event initiator (s).
Question 2 - The staff believes post-accident monitoring instrumentation, as defined in 10 CFR 50.49(b)(3), must be included.
The revised conceptual rule in 54.3(a) further categorizes ITLR by establishing a list of structures and components that are subject to an established effective program to manage aging.
Question 3 - Those mild environment items of electrical equipment, ITLR, which are not in an "ef fective program," would be monitored.
There is no apparent.
disagreement with the YAEC proposal.
V.
9EGRADATION MECHANISMS.
Questions 1 and 3 - The staff agrees that a specific list of degradation mechanisms is not required in the rule.
However, better definition cf aging and its associated phenomena as suggested in Question 3 is needed.
The staff believes that distinction should be made between age-related degradation and aging mechanisms, as specified in 54.3(a) of the revised rule.
Question 2 - The conceptual rule has been revised to require that systems, structures, and components important to license renewal be covered by an
" established effective program."
i 2-21
r
.l r
p VI.
SEVEREiACCIDENTS-l A' severe accident closure requirement has _ been removed from the conceptual. rule.
VII.
CONTENT OF APPLICATION Questions 1,. 2, and 3 - The conceptual rule has been modified to ' permit the use of t6e existing FSAR or a separate FSAR.
l'he contents of a license renewal application have been previously covered..An application should cover the a
current licensing basis, appropriate aging degradation, and screening.
The areas of disagreement pertain to how the screening process should work to i
remove ITLR structures and components from the list required to be monitored:
1 for aging _ degradation (aging management).. The NUMARC methodology for screen-l ing is currently under review.
It may prove to be acceptable if it is appro-priately revised in accord with staff comments,=
1 Quest' ion 4 - There is agreement with the concept of providing the necessary-regulatory guidance on the license renewal application and appropriate screen-ing with the final rule.
Additional guidance, if thought to be necessary, can follow the lead plant experience.
The Industry Technical Reports will play; yet-undetermined roles in the process.
If found'to be usable, they will assist in providing guidance.
Question 5 - The staff believes that the screening process issue has been resolved by the revised conceptual rule describing an " effective established program" and the revised 54.21,.which describes how the screening process would work.
VIII.
CERTIFICATION OF COMPLIANCE Questions 1 and 2 - A generic finding will' be made that current licens.ing bases are adequate, provided aging-degradation:is managed.
Life assessment will require licensees to reconcile original designs and operating service experience with the propo~ sed extended lifetime.
' IX.
ENVIRONMENTAL INFORMATION
/
Questions 1 and 2 - The staff currently believes that a generic environmental document can beleveloped-in parallel with the rulemaking as the basis for a change to Part 51.
A draft generic environmental document and proposed change to Part 51 could be completed for publication in May 1991 and the final docu-ment.in April 1992.
The staff does not agree'with YAEC responses.
X.
STANDARDS FOR ISSUANCE OF A RENEWED LICENSE
' Questions 1, 2, and 3 - It is believed that the revised 6 54.29 agrees with the y
YAEC recommendations.
However, utilities will be required to identify their ITLR structures: and components and then provide their aging management programs to the staff.
The revised rule no longer limits the number of renewals of j
licenses as suggested by YAEC.
i i
2-22
p.
{
l XI.
POSTPONEMENT OF COMPLIANCE IN THE AREAS OF DECOMMISSIONING AND FUEL MANAGEMENT Quastions 1 and 2 - The proposed rule addressed these concerns by amending 55 50.54(bb) and 50.82 in such a way that licensees who filed sufficient renewal applications but have not yet received final determinations on their applica-tions would not need to file either the interim spent-fuel trending plan or the application for termination and accompanying detailed decommissioning The Commission does not believe that any change to paragraph 50.75(f) report.
is necessary since the current wording may be interpreted to exclude licensees who have filed renewal applications from the requirements for submission of the interim funding reports.
X11.
MAINTENANCE, SURVEILLANCE, AND RECORDKEEPING Question 1 - The staff has not required maintenance by this rule but has stated that the established effective program defined in paragraph 54.3(a) must include maintenance, surveillance, trending, and recordkeeping to manage aging degradation.
Questions 2 and 3 - Results of the aging management program will be required to be trended and maintained and controlled.
This is part of the 54.3(a) program.
Maintenance practice standards are not required where the aging management program is effectively controlled.
Questions 4, 5, and 6 - Documentation and NPRDS data usage.
The staff position on management of aging includes identification of when and where aging degrada-tion may occur, identification of aging stressors that induce those aging-mechanisms that may be present, and finally.the appropriate aging mechanisms that may be present and are monitored and trended.
The YAEC responses are far too vague to understand if they meet the above.
2.3.2 Westinghouse Electric Corporation I.
APPROACH Question 1 - Westinghouse recommends that the second principle be revised to state that the level of safety will not degrade to the point that the required level is not met rather than to state that the level of safety provided by the current licensing basis will not degrade.
The staff believes that definitions While individual structures and components have levels of safety are important.
that may vary with time during their respective lifetimes, depending on repair or replacement schedules, the current licensing basis in effect provides a lower limit, which is the required minimum acceptable level, fixed with time.
Westing-house apparently believes that the current licensing basis (CLB) level c' safety is above the minimum level.
The staff believes its position is correct a d is citing a required minimum level that is fixed with time.
This appears to be a matter of definitions.
Figure 1 should assist in understanding these concepts.
Question 2 - The revised conceptual approach does focus on the aging management of structures and components.
Identification of the current licensing basis by each licensee continues to be needed (see YAEC response to Q4).
Westinghouse uses the term "non-safety grade initiators" as an example of SSC important to 2-23
LEVEL OF SAFETY a
)a 1
\\ sx Q NN'NNx
\\
w sx
\\
\\.
\\
T CURRENT j \\;
\\
LICENSING BASIS
\\\\
\\
g h
_ - ';;- _l;] ^_
ADEOUATE
\\p\\
7_ - '
RENEW FORTY YEAR LICENSE MARK Figure 1 License renewal concepts.
l
i
)
i safety with which they disagree.
Initiating events in non-safety grade compo-i nents and systems that can lead to safety system-failures do cause the non-The staff safety grade item to be included in an aging management program.
disagrees with the Westinghouse discussion.
Question 3 - Agree with Westinghouse comments.
Question 4 - There is no apparent disagreement with the response to Question 4.
The staf f is not requiring, as a prerequisite to license renewal, compliance with new requirements.
The need for severe accident compliance has been removed from the rule.
BACKFIT CONTROLS The staff can be said to be using the philosophy of the backfit rule in its Aging management of structures and components important to license approach.
renewal is believed by the staff to be the minimum necessary to achieve a level of adequate protection.
The Commission position on backfit considerations is discussed in Sections IV.k and VII of the Statement of Considerations.
2-25
3.
SESSION 2--REACTOR PRESSURE BOUNDARY Question 1 Since the surveillance programs required by Appendix H of 10 CFR 50 to monitor radiation embrittlement of reactor vessels generally have been designed for a 40 year period, what additional requirements should be implemented to comply with this appendix for the extended life?
Response
NUMARC - No further requirements, but utilities planning to operate beyond 40 years may have to augment their surveillance programs to meet Appendix H requirements.
Yankee Atomic Electric - Continuation of plant-specific surveillance programs for the renewal period will not be necessary because research and industry surveillance efforts will continue and be adequate to define trends.
Westinghouse - No additional requirements are needed, but several options could be employed, including better use of the third capsule, changing the withdrawal schedule or putting in reconstituted specimen capsules.
A flux reduction l
program is also suggested.
Staff Response We believe that the Appendix H requirements for surveillance programs are not adequate unless it can be demonstrated that the plant surveillance program results adequately cover the entire renewal period.
In the latter case, how-ever, we believe that additional surveillance dosimetry will be-needed for the renewal period. We know that many plants will reach the PTS screening criterion at or just after the end of 40 year life so they will have to take additional actions required by the PTS rule.
Because flux reduction efforts and other potential changes in fuel loadings are so plant specific, some continuation of the surveillance program to obtain surveillance data from each plant should be needed for adequate evaluations.
The staff agrees that using reconstituted specimen capsules could be an effective approach to the additional surveillance requirement.
Finally, we reiterate the need for consideration of additional dosimetry beyond normal 40 year requirements and compliance with provisions to address annealing as an option for continued operation.
Questiod In view of the uncertainties involving the material properties of aged cast austenitic stainless steel, what measures are needed to assure safe operation of components manufactured of this material during extended plant life?
3-1
Response
NUMARC - No additional measures appear to be needed.
Yankee Atomic Electric - Ongoing NRC and industry research will better define any potential concerns that may need to be addressed.
Westinghouse - Utilities could assure themselves that degraded material is not a problem in their plants or could show that leak-before-break will occur for cast components.
Ongoing NRC and industry research will better define any potential concerns that may need to be addressed.
Staff Response The staff agrees in general with the first part of Westinghouse's response, that utilities need to evaluate their cast stainless steel components to assure themselves that the materials are not subject to undue degradation.
The ongoing research will only define problems and ranges of degradation.
The utilities must use the research to determine if such degradation has occurred and what fixes are required.
It is not clear that leak-before-break analyses would be persuasive in addressing concerns about this degradation mechanism.
Question 3 Do the current ISI and IST programs adequately address aging mechanisms in the reactor pressure boundary systems and components?
l
Response
NUMARC - Yes.
Further, forthcoming industry reports will identify known and potential aging mechanisms.
Yankee Atomic Electric - Essentially yes.
Different kinds of analysis and inspection can be used to determine degradation; management methods then must be employed to resolve the issue and ensure safety.
Westinghouse - The ASME Section XI Special Working Group on Plant Life Extension plays a pro-active role to review situations and recommend Code changes when believed ne::essary.
Staff Response The ASME Section XI Special Working Group on Plant Life Extension is expected to continue an ef fective process in recommending appropriate Code revisions to accommodate license renewal.
Current ISI procedures do not directly measure degradation that may result in reduced toughness or reduced fatigue capacity, but research should continue to address these areas and seek improvement that could be later used during extended life operation.
Question 4 Many operating plants with piping that cracked due to IGSCC have had weld over-lay repairs.
While this repair is safe for current opp ~tions, NDE is difficult 3-2
and stress patterns have changed in the piping system. What bases exist to permit continued use of such piping for extended plant life?
Response
NUMARC - NVREG-0313 is adequate for application for extended service.
Yankee Atomic Electric - This issue is plant specific and should not be
' addressed in the rule.
Westinghouse - No comment.
Staff Response Based on service experience, NRC has on a case-specific basis permitted continued operation with weld overlays.
The staff considers weld overlays to be a nonpermanent repair procedure and will continue its periodic case-specific review into a plant's extended life operation.
NDE research is continuing with the expectation that improved methods for the inspection of overlays can be developed and implemented.
As new research information from the program at the Argonne National Laboratory on IGSCC in piping becomes available, it will be considered for use as a permanent repair method.
Question 5 Since plants have used less efficient NDE techniques than are available today, should they be rebaselined with modern techniques? Should ISI intervals and the extent of sampling remain the same? Considering loss of toughness with aging, should flaw acceptance standards be modified? Because of uncertainties in the level of degradation and in the effectiveness of ISI, should continuous monitoring NDE techniques be applied during extended life?
Response
NUMARC - Rebaselining need not be done, nor inspection intervals changed.
Flaw acceptance standards need not be changed.
The use of continuous' monitoring should only be addressed on a case basis.
Yankee Atomic Electric - The ASME Code Section XI should not develop.special requirements dealing with license renewal, and it should continue to play a Continuous monitoring pro-active role in addressing age-related degradation.
should only be addressed on a case basis.
Westinghouse - Agreement with both NUMARC and Yankee positions.
Staff Response The staff believes that rebaselining for license renewal will not be necessary provided that the entire inspection sample required by the 1989 Edition and Addenda of Section XI of the ASME Code for an inspection interval has been per-formed using qualified personnel, procedures, and equipment as specified in Appendices VII and VIII of Section XI at least once prior to applying for license renewal.
Should any portion not be done using Appendices VII and VIII 3-3
i of Section XI before~ applying for license renewa!, it should be inspected using the above procedures prior to operation in the extended life term.
Question 6 Existing fatigue requirements do not take into account the accelerated damage
/
caused by water environment and higher temperatures of LyR plants.
What provi-sions should be required to permit operating life to be safely extended without lj more definitive knowledge of this effect and how should taese provisions affect the application of Miner's rule and the S-N curves appliec' in the ASME design code incorporated by reference into the NRC regulations? Ohould-NDE techniques-be used that give measures of remaining fatigue life and levels of toughnect?
Response
NUMARC - The code S-N curves are already conservative, so they do not need to be changed for license renewal.
NUMARC claims that fatigue damage can be evalua-ted for temperature and environmental factors using ASME Section XI Appendix A curves.
The staff notes that these curves are for crack growth rate, not initia-tion.
One cannot skip over this difference by simply offering to assume an initial crack so that the growth laws apply.
What size crack? Can it be-detec-ted?- NDE techniques for measures of remaining fatigue life should be used on a component and situation-specific basis.
Yankee Atomic Electric - A restatement of NUMARC's position.
Westinghouse - Although the PVRC is addressing the issue of environmental effects on S-N fatigue curves, they probably still are conservative.
NDE methods to address fatigue will probably not be required.
Staff Response The current margins of 2 on stress and 20 on cycles in the S-N curves of-Section III of the ASME Code were incorporated to address data scatter and not specific-ally to address the difference in the operating environments of an actual operat-ing light' water reactor and the specimens from which the original data were obtained.
Hence, these margins may not be conservative when sufficient-addi-tional experimental data become available incorporating the environmental effects (water environment and temperature) and the loading characteristics of actual service.
Such new data may-lead to changes in the current fatigue design pro-cedures and will need to be considered-for operation in both normal term and extended life term operation when available.
Question 7 Are there any kinds of tests that should be done to demonstrate integrity and operability to qualify for extended life?
Response
NUMARC - The currently required tests on the pressure beundary remain sufficient to continue to demonstrate integrity and operability for extended plant life.
3-4
o Yankee Atomic Electric - Normal management of age-related degradation will reveal any additional necessary tests.
Westinghouse - No additional integrity and operability tests are believed to be required to qualify for extended life.
Staff Response We do not see the need for additional tests beyond those already noted in the discussion above.
f 3-5
)
4.
SESSION 3--FLUID AND MECHANICAL SYSTEMS Question 1 What additional criteria should the proposed license renewal rule and associated regulatory guidance contain regarding periodic surveillance and preventative maintenance to ensure the operability of mechanical equipment importart to safety and fluid system performance beyond their initial design life?
Responses NUMARC - NUMARC's comments were specific.
For the vast majority of systems and components, NRC's presently required specifications for periodic inspec-tions and maintenance were sufficient into the renewal period, for those components identified by the " screening process" as subject to significant age-related degradation that cannot be handled by existing programs, a " flexible process to provide for aging management is required."
Yankee Atomic Electric Comaany - Yankee's comments were, in general, similar to NUMARC's,glayingonthetaemethatonlythosepiecesofequipment"important to safety, and selected as subject to age-related degradation and not already subjecttoeffectiveprogramsforagingmanagementneedconsiderationfernew aging management programs.
They emphasized flexibility" in approach and the use of trending where proved beneficial.
Westinghouse Electric Corporation - Westinghouse's comments were in line with NUMARC's and Yankee's.
" Additional action" beyond the utility's " routine maintenance" programs was not specified.
Staff Response There are weaknesses in the presently regulated inservice inspection require-This is a "now" issue and is not within the purview of license renewal ments.
iulemaking. Work is ongoing to correct this issue and the resultant improve-ments will apply to " renewed" as well as presently licensed plants.
In general, the staff agrees with the comments, with the stipulation that trending may be a requirement for all aging management programs for the identified components.
Question 2 What type of augmented inspections and/or analyses are needed to address aging mechanisms in pumps and valves, such as:
Detection of degradation in pump and valve internals (e.g., erosion and corrosion due to flow turbulence and chemical attacks)?
4-1
Detection of possible cumulative fatigue of pump shafts which may lead to cracking?
Detection of possible cumulative fatigue effects to valve discs and hinges due to cyclic stresses and impact loading from valve operation and flow excitations?
t Responses NUMARC - NUMARC'S position is that no new augmented inspections and/or analyses are needed to address the aging mechanisms in pumps and valves id?ntified by this question.
NUMARC claims that all safety-related pumps and valves are sub-
}
ject to " effective NRC regulations and licensee programs" and that licensee programs are continually being updated.
Yankee Atomic Electric Company - Yankee's positian is that " analyses and/or inspections of actual conditions can be utilizea to determine degradation mechanisms." Further aging management of an identified aging mechanism can be used to justify continued operation, modification, and/or refurbishment /
replacement.
Westinghouse Electric Corporation - Westinghouse basically agrees with NUMARC in that "no augmented inspections or analyses are needed to address aging mecha-nism in pumps and valves." They further state that "the single failure criteria adequately cover the consequences of aging of pumps and valves in nuclear plants."
Staff Response Basically, the staff is in agreement with Yankee's response.
Additional analyses and/or inspections may be required for pumps and valves operating in the license renewal period.
As discussed under Question 1, there are weak-nesses in the presently required IST procedures, and these weaknesses are being addressed.
However, even beyond the development and application of effective IST procedures, there still ramains the question of determining the residual life c,f pump and valve bodies and internals.
This can be done analytically or empirically.
However, it is clear that no determination of gradual aging degradation of components can be accomplished withoat an effective inspection for workability program (today's problem) and ef'ective trending, recordkeeping, and analyses (tomorrow's problem).
Question 3 What should the proposed license renewal rule require regarding functional testing of systems important to safety as a prerequisite for license renewal, e
recognizing that such functional testing may not have been performed previously as part of the original licensing basis?
Responses j
NUMARC - NUMARC'S position is that no new functional testing is required.
If license renewal requires modification then, as now, functional testing is required.
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Yankee Atomic Electric Company - Functional testing may be a recommended proce-dure as part of an overall aging management program for specific items.
It should not be mandated in general.
Westinghouse Electric Corporation - Functional testing should not be required as a general procedure for license renewal.
Staff Response The staff concurs that functional testing, in general, should not be a requirement for license renewal.
Question 4 In light of the great variability in the treotment of fatigue in the design of Class 1 (or quality group A) piping and components, there is a need that license extension requirements be based on operating history of individual plants.
How should the NRC confirm that Class 1 components have not exceeded their original fatigue design requirements? Also, should the industry address this issue in a topical report?
Responses e
NUMARC - Each of the Industry Technical Reports (ITRs) that are being prepared for map r plant systems, structures, and components will deal directly, among Further, all other components that are not screened other things, with fatigue.
out (including quality group A) must account for fatigue.
Because of this, there is no need for a specific ITR treating fatigue in general.
Yankee Atomic Electric Company "Each plant will be responsible for demonstrat-ing continued adequacy with respect to fatigue to confirm that original design limits were not exceeded or to set appropriate limits.
ASME Section XI is presently adding words to permit different methods of ensuring fatigue perform-Certainly, use of actual plant data on loads must be used.
- However, ance.
other methods for fatigue evaluation such as the use of crack growth methodology coupled with enhanced inspection and monitoring methods should be allowed..
Because of the differences in the fatigue lives of the different components, systems, and structures (CSS) and because of the presently developing Sec-tion XI approach, no topical report on fatigue is required.
Westinghouse Electric Corporation - Utilities are presently using actual plant load and transient data for evaluating various components in their systems.
This should be the case for all Class I components for license renewal.
In many cases, occurrences of auxiliary system events can usually be inferred from the-Because of the primary system data, with appropriate conservatisms added.
planned work on improved fatigue requirements by the PVRC and the ASME, and the fact that each ITR and each component or structure not screened out will address fatigue, Westinghouse sees no need for a separate topical report on fatigue.
Staff Response In general, the staff concurs with the respondents' comments.
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Luestion5 How can the residual fatigue life for Class 2 and 3 piping and components be determined for license renewal?
Responses NUMARC - NUMARC maintains that fatigue analyses for Class 2 and 3 piping and components were not and are not needed for the design anc' construction of new j
plants and that, following the procedures in the ASME B8 N Code, Section 111, J
for these components, the loads are low enough and the su uctures sturdy enough to ensure structural adequacy for any license renewal period.
Further, expeci-ence has shown that similar components in fossil fuel plants, subject to similar loads, have fatigue exhibited lives in excess of 40 years.
Yankee Atomic Electric fompany - The content of Yankee's comments generally 1
follow those of NUMARC, above, with the additional note that " older plants with piping designed to ASA B31.1 did not distinguish between classes in considering fatigue." However, Yankee did note that selected Class 2 and 3 piping may war-I rant a fatigue evaluation based on localized conditions.
"The need for such an evaluation will be component-specific, as identified in the component review process."
1 Westinghouse Electric Corporation - Westinghouse's comments were in general accord with the above two responses, with the added comment that "..., Class 2 i
,and Class 3 safety system components (SSCs) are designed to GDC's which require that their safety function can be accomplished assuming a single component failure."
Staff Response In general, the staff concurs that, for Class 2 and 3 SSCs, no specific, overall, fatigue analysis should be required.
However, all Class 2 and 3 SSCs should be subject to the screening process, and those that show as important to safety should be subject to an effective fatigue analysis.
Such an analysis might be conducted using existing, actual plant load and transient histories, where avail-able, and conservatively constructed histories otherwise.
It should be noted that, in the case of aged equipment, no reliance can be placed on the assumption of single component failure due to the potential for common mode failure of aged equipment.
Question 6 Existing fatigue requirements do not take into account the accelerated damage caused by water environment and higher temperatures of LWR plants.
What provi-sions should be required to permit operating life to be safely extended without more definitive knowledge of this effect, and how should these provisions affect the application of Miner's rule and the S-N curves applied in the ASME design i
code incorporated by reference into the NRC regulations? Should NDE techniques be used that give measures of remaining fatigue life and levels of toughness?
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Responses NUMARC "No special license renewal provisions are believed to be required to account for possible inadequacies in fatigue design analyses as may be reflected 4I in S-N curves or Miner's rule as specified in ASME Section Ill." Basically, the f
NDE requirements of ASME Section XI should apply during the license renewal period, and.these requirements also permit the use of enhanced methods and g
periods of inspection if needed based upon evaluation.
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Yankee Atomic Electric Company - Yankee's comments agreed with those of NUMARC i
above.
Westinghour.e Electric Corporation "The PVRC is currently addressing the issue of the effect of the reactor environment on the S-N curves currently used in the ASME Section Ill." Regardless, Westinghouse believes that the present " safety" factors of either 2 on stress or 20 on cycles, coupled with what Westinghouse believes has been a very conservative design practice as regards transient loads, has resulted in fatigue designs for most SSCs that are extremely conservative and that any change in the S-N curves to reflect the actual high-temperature, water environment will not impact on present design adequacies for extended life operation.
Westinghouse believes that a non-destructive method to assess fatigue will probably not be required.
Staff Response Theeffectofhigh-temp'erature, hot-waterenvironmentontheASMESectionIII S-N curves is "today's problem, and as pointed out above, will be worked on by the PVRC.
It should also be noted that the NRC has been working on this issue for several years.
Nevertheless, since it is "today's" problem, coupled with the fact that no definitive answers are in hand, and won't be for the foresee-able future, this issue should not be part of the license renewal requirements.
Since NDE techniques that can give measures of remaining fatigue life (as dif-ferentiated from fatigue crack growth) do not exist and there is no prognosis for its development, this latter question is moot.
Question 7 Are there any kinds of proof tests or hot functional tests that should be done to demonstrate integrity and operability to qualify for extended life?
Responses NUMARC - Proof tests of operating and unmodified components and hot functional tests of systems are not necessary for license renewal.
However, if such tests are required, they must be technically justified and the testing codified, with relevant time scales, as "today's" problem and not an issue for license renewal.
Yankee Atomic Electric Company - Yankee's comments concur with NUMARC's above.
Westinghouse Electric Corporation - Westinghouse's comments concur with NUMARC's.
They_further note that early findings from the NRC's NPAR program shows that
" frequent testing may, in some cases, be more detrimental than helpful."
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Staff;kesponse L'
The staff concurs with the-opinions of: the responders. -It should be noted that ll
- the Westinghouse comments regarding the NPAR findings on the frequency of test-L ing are not appropriate here,-since we are dealing with the-possibility of "one
- time" new benchline tests-for Llicense renewal.
Again note that this problem is "
"today's" problem'7 If'neW functional tests are required to ensure structural adequacy for safety and functional operability, such testing should not be-
' limited to license renewal.
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SESSION 4--SCREENING METHODOLOGY FOR SYSTEMS, STRUCTURES, AND COMPONENTS IMPORTANT TO SAFETY Question 1 Is the scope of the systems covered by the conceptual rule adequate to assure safety?
Comment
- In general, the scope was considered adequate.
Exceptions to this general conclusion were:
the unnecessary (explicit) identification of post-accident monitoring equipment; and the inappropriate inclusion of event initiators, which should be considered only if age-related degradation of related equipment were to affect the ability of safety-related systems, structures, and components (SSCs) to perform their function.
Staff Reeponse With respect to equipment associated with potential initiators, the staff believes that these should continue to be included.
Aging-related degradation of such equipment can potentially increase the frequency of challenges to safety systems and thereby increase the frequencies of accidents.
The explicit identification of post-accident monitoring equipment was included to be consistent with the types of (quipment considered in the equipment quali-fication regulations (10 CFR 50.49).
Upon further review, the staff believes that this explicit identification is not necessary.
Question 2 Are the requirements clear?
Comment In general, the requirements were considered clear.
Exceptions to this general conclusion were:
the unnecessary (explicit) identification of post-accident monitoring equipment; the inappropriate inclusion of event initiators; and the need to incorporate statements on the exclusion of components effectively covered by existing programs or not subject to aging.
Suen statements were included in the oreliminary regulatory philosophy accompanying the conceptual ruie, but not in the conceptual rule itself.
- All written comments on Session 4 were submitted by the Yankee Atomic Etcetric Company.
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l Staff Roponse Staff responses to the first two exceptions are provided in the response to Question 1 of this section.
With respect to the last exception, the conceptual rule will be modified to
(
be consistent with the preliminary regulatory philosophy.
That is, the rule I
will indicate that components that are effectively covered by existing programs ornotsubjecttoagingcanbeexcluded.
Question 3 15 it clear how the screening process in the rule works, and is it clear how the requirements of the rule will be met?
Comment The screening process was considered clear except for the issue of exclusion of components effectively cov< red by existing programs or not subject to aging.
Staff Response The rule will be made consistent with the regulatory philosophy.
That is, the rule will allow the exclusion of SSCs covered by effective existing programs or notsubjecttoaging.
1 Question 4 Should the regulations permit the use of screening methods that are based on probabilistic risk assessments?
If yes, describe the type of assessment and the specific role of the risk assessment.
If no, provide an explanation for your answer.
Comment The use of probabilistic risk assessment should be permitted for both screening and for component-specific evaluations.
Staff Response The use of probabilistic risk assessment (PRA) will be permitted in certain f
3 parts of the screening method.
Specifically, PRA will be permitted for use in determining what SSCs are input to the screening process.
However, unless adequate data can be provided to demonstrate the absence of age-related degradation (e.g., quantitative trending analysis on the failure ratus of systems and components), PRA will not now be permitted to be used to screen out SSCs.
However, as aging research progresses, it may be possible to use PRA techniques more widely to screen out components.
Question 5 Should experimental aging models be required in probabilistic risk assessments to estimate aging degradation effects?
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f Comments Other methods exist that Experimental aging models should not be required.
better address such effects.
Staff Response The use of experimental aging models will not be required.
However, as discussed in the staff response to the previous question, adequate analytical models and data to demonstrate the absence of significant aging degradation would be necessary if PRA was to be used to screen out SSCs.
As noted above, adequate data could be provided from, for example, quantitative trending analysis of failures rates of systems and components.
Question 6 What are any additional issues or problems that might arise in meeting the proposed requirements, and how can these concerns be dealt with through regule-tory instruments?
Comment The conceptual rule requires the generation of large amounts of information that Credit for can be shown to be unnecessary to support the screening process.
existing programs to manage aging degradation or demonstration of the absence of aging degradation for certain SSCs should be permitted in the rule to help focus the screening process and make the overall license renewal process more efficient.
Staff Response As indicated in the staff response to Question 3, the rule will be made consistent with the preliminary cegulatory philosophy, permitting credit for existing, effective aging-degradaT. ion management programs and the demonstration of the absence of aging degradation.
Question 7 Can defense in depth be incorporated into the screening methods?
Comment The SSCs defined in the conceptual rule encompass the essence of the defense-in-depth principle.
Staff Response The staff agrees with this comment.
Question 8 How should the NRC judge the adequacy of an aging data model for use in PRA?
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Comment As discussed in the comment on Question 5, an aging data model should not be required.
Better methods are available to deal with this issue.
t Staff Response r
c The' staff agrees that an aging model will not be required for license renewal.
(
The staff expects that the screening process will rely heavily on traditional engineering (deterministic) analysis methods.
In parallel, the staff expects i
i to continue research in the incorporation of aging offects in PRA, including analysis of' existing data on aging effects, and the adequacy of models to esti-i mate those effects. Thus, later license renewal applications may be able to i
make wider use of PRAs with aging models incorporated.
Question 9 What, if any, should be the role of a mandatory _ plant-specific data base in l
Comment t
Data bases may be beneficial in license renewal activities, but should not be mandatory.
Staff Response As discussed in the staff response to Question 4, adequate plant-specific data (e.g.. from quantitative trends analysis) would be required to support the use of PRA'to screen out SSCs.
Data bases to assess the effectiveness of maintenance programs may also be necessary.
Question 10 i
What types of data analysis should be used to detect increasing failure rates of components?
Comment Trending-should be considered an option for data analysis.
Staff Response As indicated in staff responses in previous questions, data analysis will play a role in the use of PRA to screen out SSCs.
Trending analysis would be an
-acceptable approach for such data analysis.
Question 11
~
-It is well-known that the data used in PRAs can change the results as well as the ranking of the contributors to core damage frequency.
If a PRA is used-in license renewal, what role should plant-specific data play in this area? How much data are required for plant-specific application?
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Comment Plant-specific data should be used in PRAs to the extent that such data are available and required by the process.
Staff Response The use of plant-specific data to update the generic data is recognized as a very important element of modern PRAs, either performed for license renewal or other purposes.
The staff agrees that they should be used to the extent possible.
Question 12 PRAs normally do not include passive components as basic events in the logic models.
How should passive components be treated in PRA for license renewal?
Comment Passive components not considered in 'he PRAs should be evaluated deterministically.
Staff Response The staff agrees that passive components should be evaluated deterministically for license renewal purposes.
The staff also expects that future research will include the consideration of the risk impact of passive component aging.
Later license renewal applications may benefit from such research to permit wider use of PRA.
Question 13 If a PRA is used in a screening process for license renewal, how should the human error probabilities be treated so that the PRA reflects the design and not the human actions?
Comment Treatment for human error in PRAs for license renewal should be no different than for PRAs performed for other purposes.
Staff Response The staff agrees.
Question 14 To what level of detail does a PRA need to be performed for use in license renewal? Does specific guidance exist for performing a PRA for license renewal?
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Comment Specific guidance for license renewal PRA is not required or needed.
The level of detail should be commensurate with the scope of PRA use in the renewal process.
Staff Response i
Given the role of PRA in the screening process (discussed in previous staff responses), the staff agrees that specific guidance for license renewal PRAs (viz, those performed for other purposes) is not required.
However, as aging research progresses, it may become appropriate to use PRA to a greater extent in license renewal-application.
As such, the development of specific guidance may become appropriate in the future.
Question 15 What is the role of Level I PRA in license renewal? Level II?
Level III?-
Comment Use of PRA is appropriate for screening and to support component-specific evaluations.
The level of PRA needed should be appropriate to the license renewal activity for which it provides support.
Staff Response In the PRA role supported by the staff (as described in previous responses),
the use of Level I and II information as input to the screening process is appropriate.
It is not now apparent that level III information is necessary, e
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SESSION 6--CONTAINMENTS t-Question 1 What additional measures should be taken to monitor and address anticipated and unanticipated structural degradations (including the loss of prestressing forces) such that an acceptable level of safety 16 maintained during the extended life?
Responses Yankee Atomic Electric Company - Additional measures are not necessary related to license renewal rulemaking.
Existing monitoring and design considerations (Appendix J and Section XI with the code enhancements currently being implemen-ted) effectively address structural degradation.
NUMARC - Three containment-related Industry Reports (irs) are being prepared, they are:
PWR Containments, BWR Containments, and Class I Structures.
i The evaluation of a potential loss of prestressing force in the tendons of prestressed concrete containments was included in these evaluations.
For those aging degradation mechanisms that were determined to be potentially significant t
for the extended license term, the provisions of Section XI of the ASME Code, in particular Subsections IWE and IWL, were considered, along with current regu-lations and regulatory guidance.
It was found that, with a few exceptions the i
currentregulatoryrequirements, guidance,andindustrypracticeweresufficient to manage the effects of aging degradation throughout the license renewal term, without any reduction in the level of safety.
The exceptions are typified by.
the potential degradation of those portions of reinforced or prestressed con-cretecontainments,oroffreestandingsteelcontainments,thataresubjectto corrosion from aggressive chemical attack and that are not readily accessible to inspection.
For such situations, corrosion prevention procedures are recom-mended, including ground-water monitoring or protective coatings.
As an. alter-native, a safety consequence evaluation for excessive local degradation in an inaccessible region is recommended.
Type A integrated leak rate testing limits are then used as the basis for determining whether the consequences of this excessive local degradation are acceptable.
Staff Response The NRC staff disagrees with the industry consensus that the inspection requirements provided in ASME Subsections IWE and IWL of the ASME Code can be made sufficient for monitoring and addressing anticipated and unanticipated structural degradations provided that certain enhancements (which in the case of Subsection IWE have been identified and discussed with the appropriate ASME committees) to these subsections are incorporated.
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We also disagree with NUMARC that a Type A test is the basis for determining whether the consequences of excessive local degradation are acceptable.
The design limits on wall thickness would be exceeded long before a Type A test indicated problems, Question 2 For what additional degradation environments or. mechanisms should containments be monitored or inspected? Also, how can detrimental long-term chemical inter-actions in concrete containment be measured and predicted in the future?
Responses Yankee Atomic Electric Company - In general, most plants do not require any further monitoring or inspections.
Examination in accordance with ASME B&PV Code provides for the necessary monitoring of the environments or mechanisms-that can degrade concrete.
There are no known long term, internal chemical interactions that cause significant degradation of concrete.
Plausible damaging chemical reactions among the concrete, aggregate, water, and admixtures only occur in the rela-tively short term.
External water chemistry impact on containment concrete is applicable only to sites with aggressive ground water.
ACI literature provides techniques for detecting and monitoring degradation, if existent.
NUMARC - Both the PWR Containments and Class I Structures irs have attempted to evaluate the effects of all plausible aging degradation mechanisms.
The results of the Class I Structures evaluations are not yet complete, but it is expected that monitoring or inspection procedures currently in place will be effective tions.y potentially significant aging degradation mechanism, with a few excep-for an Those' exceptions are or will be identified in the two irs, and are typi-fied by the potential for corrosion from a9gressive chemical attack in regions that are inaccessible to inspection.
It is also expected that current contain-ment pressure testing requirements, such as those of 10 CFR 50, Appendix J, will suffice for monitoring the effects of long-term concrete deterioration.
Visual inspection of containment surfaces provides early indications of deterioration where such surfaces are readily accessible to visual inspection.
Monitoring of ground water, in order to ensure that the environmental conditions for aggressive
- chemical attack have been prevented, is an alternative for those regions that are not readily inspected.
Staff Response 4
In general, the NRC staff agrees with the NUMARC position on this question.
Additional monitoring or inspections beyond the current regulations (including improved Subsections IWE and IWL) are not needed unless a facility has unique conditions or design features.
For example, consideration should be given to an alkalinity test of concrete (especially for non prestressed concrete structures) in harsh environmental conditions.
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Question 3 Prior to granting a license renewal, should the licensee be required to implement (a) containment leak rate qualification test, (b) containment structural integ-rity test, and (c) containment configuration (including foundation) surveillance?
For other Category I structures (including ultimate heat sink, water retaining structures), what type of surveillance should be required for detection of H'.'ely degradations during extended license?
Responses Yankee Atomic Electric Company - Neither a containment leak rate qualification test, a containment structural integrity test, nor a one-time containment con-figuration surveillance should be a prerequisite for license renewal.
Further-more, foundations are not susceptible to degradation unless the chemistry of the ground water is much more severe than that assumed in the original design.
10 CFR 50, Appendix A, Criterion 45, requires inspections of structures that function as part of the cooling water system (s).
Regulatory Guide 1.127 pro-vides adequate gdJance for the performance of the inspection.
For other Cate-cory I structures, surveillance of selected components should be performed.
4n industry report on Class I structures is now being developed.
Each plant should identify the components that are important to safety and subject to an environment that can cause age-related degradation and should establish an appropriate surveillance program to monitor these components.
NUMARC - No additional testing beyond the three ILRTs per 10-year interval has been identified as being needed to ensure containment performance throughout the license renewal period.
Furthermore, no need for structural integrity esting, beyond that provided by 10 CFR 50, Appendix J ILRTs, has been identified.
Con-
. figuration surveillance has not been identified as an issue.
The industry report dealing with other Category I structures is not yet complete; therefore, it is premature to anticipate the additional surveillance requirements that might arise from a review of plausible degradation mechanisms and their effects on such structures during the extended license term.
Staff Response The NRC staff agrees that rebaselining. inspections of the containment and structural integrity tests are unnecessary for license renewal.
However, there are certain required inservice inspections that may be deferred.until the end of an inspection interval.
These should be completed prior to startup under licensing renewal.
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SESSION 7--ELECTRICAL SYSTEMS Question 1 What should tne proposed license renewal rule and associated regulatory guidance contain regarding additional criteria for testing, analysis, or replacement of electrical equipment currently included in the 10 CFR 50.49 Equipment Qualifica-tion Program which is qualified for a life less than the original license term plus the reaewal period but is not subject to periodic replacement?
Responses NUMARC - NUMARC's position is that the current EQ requirements, which specify i
given periods of qualified life, is all that is required and that no new EQ requirements for important to safety e~iipment for license renewal be required.
Yankee Atomic Electric Company - Yankee concurs with NUMARC's response.
Staff Response It is the staff's opinion, as stated on page 11 of the ANPR on license renewal rulemaking, that those SSCs that are effectively covered by existing ongoing NRC requirements need not be addressed in the license renewal application.
NRC EQ programs specif Any operation of qualified SSCs beyond the " life" y a given " qualified life."specified requires requalification.
Thus, no special EQ requirements for important to safety SSCs should be required for license
- renewal, Question 2 What additional programs are necessary to address aging degradation issues associated with electrical equipment important to safety but located in mild environments? What should the proposed license renewal rule or other associated regulatory guidance require with regard to additional qualification or operabil-ity verification for electrical equipment in mild environments which had a design life less than the license renewal period but which is not subject to periodic replacement?
Responses for electrical equipment important NUMARC - No new EQ requirements are necessary"Such equipment is covered by cur-to safety but located in mild environments.
rent NRC requirements." All existing programs and SSCs will be evaluated by a screening procedure to determine their effectiveness for addressing aging degra-dation processes that may affect them during the license renewal period.
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i Yankee Atomic Electric Company - Basically concurs in NUMARC's comments.
Staff Response The staff concurs with the comments of both NUMARC and Yankee, with the added proviso of emphasizing the importance and the necessary effectiveness of the screening methodology to be applied.
Question 3 Licensees have identified electrical components important to safety that have been assumed to have a life expectancy of 40 years but have been found to fail, or otherwise become unreliable, after 5 to 10 years in service.
To what extent
.has the industry identified electrical equipment that is known to exhibit high failure rates in less than 40 years and what should be done to ensure reliable L
equipment performance to support license renewal?
Responses NUMARC - Basically concurs in NRC's stated position that "today's" problems should not be an issue for license renewal (e.g., must be solved today).
Yankee Atomic Electric Company - Yankee went into considerable depth, pointing out the many procedures already in place to handle today's problem.
But their bottom line was that the problems as defined in Question 3 are "today's" problem and should not be an issue in license renewal.
Staff Response The staff has already gone on record stating that the only technical issues that should be addressed are those that are related to aging degradation, specifically those that will only occur during the renewed license period.
"Today s" problem will be handled during the present license period.
Any unanticipated safety issue defined, whether during the first license period or during the period of renewed license, will be handled immediately as a safety issue at the time of definition.
Question 4 Most cable has been qualified by manufacturers for 40 years.
The 40 year life was predicated on certain installed and application conditions (including.
l environmental stressors, cable electrical loading, and cable mechanical loading) l for which the cable was designed.
Given that manufacturers have provided cer-tain important initial parameters for new cable, what kind of program should be proposed that could be instituted to establish the in situ condition of cables and the potential degradation that would take pir:ce beyond the current design life?
In addition, what in situ monitoring methods would be useful for an aging assessment of circuit breakers, relays, reactor protection systems, and electrical distribution systems?
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Responses NUMARC - Experience has shown that cables are highly reliable, based on conservative design and good installation practices coupled with good qualifi-cation practices.
NUMARC is developing an IR on In-Containment Cable that con-siders in situ monitoring as one of several options available for managing cable degradation during a license renewal term.
NUMARC believes that the industry present aging management programs are effective in handling all the other com-ponents specified.
All components will be subject to the accepted screening methodology that should identify those electrical SSCs that have aging degrada-tion not being presently addressed by an effective program.
These latter will, of course, then be subject to license renewal considerations.
Yankee Atomic Electric Company - Basically concurs with NUMARC's opinion.
Staff Response The staff concurs with the opinions expressed above.
Question 5 What requirements should the NRC issue as part of a license renewal package for electrical equipment important to safety?
Responses NUMARC - None.
All issues presently addressed.
(See response to Question 2.)
Yankee Atomic Electric Company - None.
Identification of important to safety electrical equipment that needs attention during the license application will be accomplished through use of the approved screening methodology.
For those I
electrical SSCs identified, effective aging management programs will be established as part of the renewed license.
Staff Response The staff concurs with the opinions of the responders.
Question 6 What should the proposed license renewal rule require regarding the functional testing of electrical equipment important to safety as a prerequisite for license renewal, recognizing that such functional testing may not have been performed previously as part of the original licensing basis?
Responses NUMARC - None.
Any electrical SSCs found in need of aging management as a resultof.thescreeningprocesswillbesubjecttoanagingmanagementprogram as part of the new license.
A11 other electrical SSCs are governed by existing regulations.
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r-Yankee Atomic Electric Company - Basically' concurs with NUMARC's opinion.
Staff Response
- The st.aff agrees that no new functional testing should be a general part of the license renewal process unless as a part of the aging management program proposed for those electrical SSCs identified by the approved screening method as subject to aging degradation in the license renewal period, o
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SESSION 8--ENVIRONMENTAL EFFECTS Question 1 Is there any compelling reason not to permit the NRC the option of preparing an environmental assessment rather than an environmental impact statement (or supplement to) in individual relicensing actions as now required in 10 CFR 51?
Responses NUMARC - NUMARC stated that the NRC should modify Section 51.20(b)(2) to allow an environmental assessment to be conducted for each individual plant renewal.
NUMARC elaborated further that a licensee will be providing sup)1emental infor-mation to update existing data and environmental analyses and tlat an environ-mental impact statement should only be required if that is the conclusion resulting from the environmental assessment conducted at that plant.
Northern States Power Company - Northern States Power supported modification of 10 CFR 51.20(b)(2) to allow the preparation of an environmental assessment.
Northern States Power stated that continued plant operation during the renewal period should not result in significant environmental impacts that would require an environmental impact statement.
Yankee Atomic Electric Company - The majority of environmental impacts have already occurred during the initial operating term.
Studies to date indicate that the impacts associated with a renewal term are minimal and can be readily dealt with in an environmental assessment (EA).
If the EA does demonstrate that the impacts are significant, then the NRC is required to do an environmental impact statement.
Therefore, an EIS will be conducted if necessary, i
Staff Response The staff is in agreement that 10 CFR Part 51 should be modified to permit the NRC the option of preparing an environmental assessment.
Environmental analyses t
in support of the Part 54 rulemaking indicate that there is a reasonable potential that no significant environmental impacts could be a finding at some plants that might apply for relicensing.
The National Environmental Policy Act would then be served more efficiently if an environmental assessment were permitted, rather than requiring a more costly environmental impact statement.
The environment would be no less protected because, if significant impacts were identified, an environmental impact statement would be developed.
No reasons not to permit an option of preparing an environmental assessment were identified.
Question 2 To what extent might a generic environmental impact statement reduce the number and scope of environmental issues which would need to be addressed in individual relicensing actions?
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Responses i
NUMARC - NUMARC did not directly address this question.
However, NUMARC did state that an evaluation of potential generic environmental issues should be conducted to be embodied in a rule.
NUMARC went on to discuss in some detail the results of a NUMARC NUPLEX Working Group study, " Study of Generic Environ-mental Issues Related to License Renewal," dated May 9, 1989.
Generally, impacts were determined to be small or of no significance.
Environmental topics were structured according to Regulatory Guide 4.2.
All the topics discussed were l
found to be amenable to some degree of generic assessment, including those that might require additional site-specific assessment in relicensing a specific plant.
Northern States Power Company - Northern States Power stated that items such as severe accidents could be handled generically and disposed of in a rule.
No further elaboration is provided.
Yankee Atomic Electric Company - The response of Yankee Atomic Electric is that an environmental assessment should be done supporting a generic Part 51 rulemaking.
The response, however, does not directly address the question asked.
Staff Response The staff is using the term generic environmental document rather than generic environmental impact statement until the precise legal and procedural function of the document is identified.
The staff believes that a generic environmental study and accompanying Part 51 rule change will reduce the number and scope of environmental issues that would need to be addressed in individual relicensing actions.
The extent to which this objective will be a:hieved will be determined by the generic environmental study now in progress.
The environmental assessment of the proposed Part 54 rule found that the environmental impacts associated with repair, replacement, or refurbishment in general would be of the same magnitude as those experienced during other main-tenance or replacement activities conducted during the previous operation on the plants.
Also, the environmental impacts associated with plari operation during the renewal term would be generally the same as during the previous operation because basic plant operating parameters would not, in general, be expected to change.
The staff believes that a generic rulemaking on Part 51 will substantially reduce the number and scope of environmental issues that would need to be addressed in individual relicensing actions.
l Question 3 l-What are the advantages and disadvantages of concurrent NEPA (10 CFR Part 51) l and health and safety (10 CFR Part 50) rulemakings? Should these rulemakings be combined ar.d pursued on the same schedule?
Responses NUMARC - NUMARC supports 10 CFR Part 51 generic rulemaking but takes the position that the NRC should not allow the license renewal rulemaking, and parallel 8-2
" environmental survey" rulemaking, to delay the processing of, and NRC deter-mination on, lead plant license renewal applications.
NUMARC supports the separation of the two rulemakings and acceleration of the license renewal (10 CFR Part 50) rulemaking.
Other than timing relative to the lead plants, no advantages and disadvantages were identified.
Northern States power Company - Northern States Power stated that the use of parallel, but separate, paths for the renewal rule and the generic environmental assessment will reduce the risk that the generic environmental assessment will delay the issuance of the renewal rule.
Northern States Power requettu U6t the generic environmental rulemaking be completed so that the lead plants may take advantage of the generic resolution of as many environmental issues as possible.
Yankee Atomic Electric Company - Yankee Atomic Electric stated that a Part 51 rulemaking should envelop generic environmental impacts in parallel with the environmental assessment for the Part 50 license renewal rulemaking, so the final license renewal rule can be issued by May 1991.
No additional advantages or disadvantages were identified.
Staff Response The staff has separated the license renewal (Part 54) rulemaking schedule from that of the generic environmental rulemaking (Part 51).
This allows the license renewal rulemaking to proceed on a schedule that would have the final rule pub-lished in May 1991, prior to the scheduled submittal of the first license renewal application.
The generic environmental rulemaking would continue on a schedule that is reasonable relative to the extent of the analysis required and the level of public involvement desired by NRC.
This rulemaking would be completed prior to completion of the staff's review of the first renewal application and would be available for the staff's environmental review of that application.
Question 4 What are the potential sources of environmental-effects from relicensing?
Responses NUMARC - NUMARC referred to the report of the NUMARC NVPLEX Working Group " Study of Generic Environmental Issues Related to License Renewal," dated May 9, 1989, previously submitted to NRC.
Seven initiators of environmental effects were assessed.
These are:
heat discharge; chemical and biocide discharges; routine radiological emission--gaseous, liquid, and solid; decommissioning and dis-mantling; radiological emissions due to accidents; uranium fuel cycle; con-struction at the plant site, No additional initiators applicable to license renewal were identified by the NUMARC study.
Yankee Atomic Electric Company - Yankee Atomic Electric cited the same seven environmental initiators referred to in the NUMARC response.
8-3
Staff Response i
The staff agrees with the NUMARC list of initiators that was taken from Regulatory' Guide 4.2, " Preparation of Environme ntal Reports for Nuclear Power Stations.
Several additional initiators shoule be added, including severe accidents (which should be considered in addition to accidents from postulated events), station water use, sanitary and other waste, and low-level waste included as part of the uranium fuel cycle.
In addition, initiators of socioeconomic effects such as tax payments local plant expenditures, and employment that arenotincludedintheinitIatorspreviouslymentionedshouldbeincluded.
Question 5 What are the potential magnitudes and significances of such environmental effects?
Responses NUMARC - NUMARC supplied the following statement:
"With regard to the scope and magnitude of impacts,d releases associated with the NUMARC study found the routine radiological impacts from gaseous and liqui the period of plant license renewal to be comparable to the impacts of currently operating plants.
Increases in population density at some sites might result in an increase in i
potential rists due to accidents, but the NUMARC study determined that these increases were small in comparison with the variability in risks among plants, and very small in comparison with the overall uncertainty in the calculations.
The impacts from the non-radiological releases were found to be of no significance, as well as those impacts due to the ultimate decommissioning and dismantling of the plants at the end of the renewed license term.
These impacts were estimated using generic data and conservative assumptions.
For example, a population growth rate of 2 percent per year was assumed around all sites.
Individual license renewal applications will need to identify any plant-specific conditions that do not fall within the envelope of garameters used in this generic study and assess their environmental impacts.
4 Yankee Atomic Electric Company - Yankee Atomic Electric supplied the following statement:
" Heat Discharges - Thermal systems and releases have not changed significantly since original plant design and are not likely to change significantly in the future.
The National Pollutant Discharge Elimination System (NPDES) permits process under the Clean Water Act ensures that thermal impacts are kept within an acceptable range.
This is an ongoing process with permit review by the U.S.
Environmental Protection Agency at least every five years.
Therefore, thermal discharges need not be evaluated as part of the PLEX process.
l Chemical and Biocide Discharge - Chemical discharges to the aquatic environment i
are small.
They will likely continue at the same level during plant license 8-4
renewal or decrease with improvements in technology.
Regardless, the NPDES permit process governs these types of discharges also.
Routine Radiological Emissions - The designs of radwaste treatment systems have changed substantially from original designs.
Accordingly, radiological releases have decreased, future releases are likely to remain the same or possibly decrease further.
Decommissionina - The increased inventories of long-lived radionuclides will not measurably change plant radiation fleids.
Therefore, the generic decommis-sioning and dismantling studies prepared by the NRC will continue to be appli-cable after license renewal.
Also, since utilities have financial arrangements for decommissioning after 40 years, deferment due to license renewal further discounts the present value of utility resources required--a PLEX benefit.
Radiological Emissions Due to Accidents - PLEX is not expected to result in changes to radionuclide inventories, release fractions, or atmospheric disper-sion factors.
Increases in nearby populations may cause an increase in popula-tion doses, however; but these doses are small, and an increase in these doses, I
because of an increase in population, is not significant.
Uranium Fuel Cycle - Spent fuel storage will be precluded by the establishment of a waste repository.
However, if the repository is delayed, onsite storage will be necessary.
High-density racks and Dry Cask Storage System are likely options.
Assessments of the environmental impacts performed to date j
demonstrate them to be negligible.
Construction at the Plant Site - Plant construction during operation has occurred to varying degrees at each plant, but at a greatly reduced level as compared to original plant construction.
The environmental effects of plant construction during PLEX are expected to be comparable or less than during l
plant operation, which has been relatively small."
Staff Response The staff will assess the potential magnitude and significance of environmental effects of license renewal, in detail, in the generic environmental rulemaking (Part 51).
A general understanding of the likely environmental impacts associ-as pained in developing the environmental assessment ated with relicensing w(Part 54) rulemaking.The staff anticipates that environ-(NUREG-1398) for this mental impacts from license renewal will be much the same as those experienced Activities associated with license renewal during the initial operating term.
are expected to fall within the range of experience during the initial operating Modifications, repairs, and replacements undertaken in each plant would term.
likely not entail changes to the overall design of the plant; thus, basic plant operating parameters, such as thermal performance, power outaut, and fuel utili-zation would not, in general, be expected to change during t1e renewal term.
Occupational exposure and both radiological and nonradiological releases from the plant after the renewal are not expected to differ in kind or magnitude from those experienced during operation prior to license renewal.
Activities required for license renewal will ensure that the risk of accidents will not increase during the renewed term.
These impacts would, however, continue to be experienced for an additional 20 years of plant operation.
B-5
The staff intends to more thoroughly bound the magnitude and significance of the set of possible environmental effects across the range of nuclear plants and sites in a study supporting the Port 51 generic environmental rulemaking.
Question 6 What experiential knowledge, studies, and data are available to perform generic evaluations of potential environmental effects?
R,esponses NUMARC - NUMARC presented a list of the types of information and the sources IIt that information and data currently available to perform generic evaluations of potential environmental effects.
The discussion is structured according to Regulatory' Guide 4.2, " Preparation of Environmental Reports for Nuclear Power Stations, and summarizes material in the NUMARC report, " Study of Generic Environmental Issues Related to License Renewal," dated May 9, 1989.
One hundred and seventeen references are cited in that report.
In its response NUMARC identified areas where information is not readily available, thus requir-ing special studies or surveys of the industry.
Yankee Atomic E1.tric Company - Yankee Atomic Electric referred to the NUMARC generic report "<, numerous plant environmental impact statements, 316 demonstratiot
.d utility data.
Staff Response Considerable experiential knowledge, studies, and data are available to perform generic evaluations of potential environmental effects associated with relicens-ing.
The environmental effects of nuclear power plants have been well studied and documented.
A major challenge of a generic study will be to ensure that information drawn upon and findings derived therefrom encompass the full range of plant and site diversity.
Question 7 To what extent would such environmental effects differ from those experienced during the initial term of operation?
Responses NUMARC - See NUMARC response to Question 5.
Yankee Atomic Electric Company - In response to this question, Yankee Atomic Electric stated:
"Nonradiological effects would be no different, provided the same cooling system is maintained.
Radiological effects could differ only to the extent that disposal options change and on-site storage is increased." Additional detail is provided in their response to Question 5.
8-6
+
(
Staff Response Based on the progtammatic review undertaken for the environmental assessment i
supporting the Part 54 rulemaking, the staff anticipates that the environmental effects during the renewed term will be essentially the same as during the initial term.
See the staff response to Question 5.
The extent to which there will be variation of effects among sites will be determined in the Part 51 generic environmental rulemaking.
Question 8 What should be the focus and scope of analysis of severe accident consequences in a generic environmental impact statement?
Responses Yankee Atomic Electric Company
" Discussion of severe accidents and SAMDAs i
analogous to that done recently for Limerick and Comanche Peak could provide sufficient detail to permit treatment of severe accidents for the purpose of issuing the renewal rule.
Individual plant licensing actions may be able to reference this material."
Staff Response The staff believes that a generic disposition of severe accident consequences can be based on a bounding of severe accident attributes for the current population of nuclear power plants during their additional term of operation.
These attributes include source term, probability of release, dispersion, path-ways, health effect, and economic costs.
The analysis should use the extensive body of studies on severe accidents already available and should explicitly account for_.the potential effects of IPEs and severe accident management plans on accident probabilities and releases.
Question 9' Should plant-specific Level III PRAs be required in the NEPA severe accident consequence analysis?
Responses NUMARC - NUMARC does not favor requiring PRAs for license renewal.
One problem
~ited for this use of PRA is that commonly accepted methods for incorporating c
age-related degradation are yet to be developed.
In addition, NUMARC stated, "from an environmental standpoint, the off-site risks have been and will continue to be addressed in on-going programs that are established in the CLB."
Yankee Atomic Electric Com?any - Yankee Atomic Electric observed that it was demonstrated in the Comancle Peak evaluation that information from a plant-specific level III PRA is not necessary for discussion of severe accidents in renewal reviews, b
8-7
Staff Response The staff believes that plant-specific Level III PRAs should not be specifically required of the applicant or statf in NEPA severe accident consequence anal-ysis.
The use of accepted consequence models and plant-specific input, includ-ing plant-specific source term estimates, should be encouraged but not required.
Question 10 To what extent should future availability of spent fuel storage capacity be a consideration in the generic environmental impact statement?
Response
Yankee Atomic Electric Com)any - The findings of the Waste Confidence Decision update, now in progress, siould be adopted.
Staff Response Long-term storage of spent fuel after decommissioning of a plant at the end of the renewal term is covered by the Waste Confidence Decision update.
The staff will attempt to generically handle storage of spent fuel during the renewed operating term as part of the Part 51 rulemaking.
Question 11 What should be the focus and scope of analysis of alternatives to relicensing the current generation of LWRs?
Response
Yankee Atomic Electric Company "The focus and scope of alternatives to renewal licensing should recognize the fact that the plant exists and alternative siting does not have to be done.
Sufficient information should be supplied for the NRC to make findings showing a reasonable need for power and the cost of renewal power is either competitive with the new generation or required for other reasons, such as fuel diversity and air quality."
Staff Response The Atomic Energy Act of 1954 and the implementing regulations of the Commission provide that operating licenses may be renewed upon expiration of their 40-year term.
The staff has found nu substantive technical reason or other policy moti-vation to foreclose the license renewal option for every plant.
For the reli-censing of individual plants, not granting a renewed license is an alternative that must be considered.
Specific issues that would require analysis include need for power fron, the facility, alternative sources of power and their environmental effects, and alternative substitute sources of energy and their environmental effects.
Question 12 What role might utilities and Federal and State agencies play in the process of developing a generic environmental impact statement?
8-8
Re:ponse NUMARC - In May 1989, NUMARC provided the report, " Study of Generic Environmental Issues Related to License Renewal," dated May 9, 1989.
At the public workshop on November 14, 1989, William H. Rasin, Director, Technical Division, offered NUMARC auspices for coordinating the collection of plant-specific data from industry.
Subsequently, on January 31, 1990, NUMARC met with the staff to begin identification of the data to be compiled.
Ya.nkee Atomic Electric Com an "NRC should ensure that States and other Federal agencies are solTc1 e for written comments on the draft environmental assessment issued with the proposed rule.
Additionally, States may wish to adopt the environmental assessment and involve themselves in the future survey to satisfy statutory requirements."
Staff Response The staff is working to vavelop a list of site-specific information that can be most appropriately cc.npiled by utilities.
This list will be provided to NUMARC.- The staff will meet with appropriate environmental staff from other Federal agencies to enlist their support in identifying and furnishing studies and other information f rom agency files and to enlist their support in scoping the generic study.
Thi staff also will contact all appropriate State agencies to enlist their participation in scoping, review, and identification of relevant studies and informatien.
l l
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l 1
l 8-9 l
i 1
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t
9.
MISCELLANEOUS COMMENTS The following presents the staff response to the miscellaneous comments that were submitted following the workshop.
The number (s) at the end of each comment identifies the responder (s) making the comment (see-list of responders in the appendix).
Comment 1 Four responders stated that the NRC should accelerate its schedule for issuance
'of the final rule so that it would be available for the lead plant applications (1,2,3,4).
One responder encouraged the NRC to resist efforts to rush the schedule (5).
Response
The NRC plans to issue the final rule by May 31, 1991.
This date precedes the anticipated submittal of the two lead plant license renewal applications.
, Comment 2 Six responders indicated that resolution of severe accident issues should not be considered in the license renewal rule (1, 3, 5, 8, 9, 11).
Response
l The severe accident closure requirement has been removed from the conceptual l
rule.
Comment 3 l
Five responders stated that the backfit rule should apply throughout-the license renewal process to ensure regulatory stability (1, 2, 8, 10, 11).
-Response The staff position on backfit considerations is discussed in Sections IV.k and VII of the Statement of Considerations.
Comment 4 It11s important that the staff has criteria against which to judge an application so a timely review can be performed (2).
Response _
The staff agrees with this comment; an appropriate regulatory guide and standard review plan guidance are scheduled to be issued by April 1992.
9-1 i
r Comment 5 The NRC should consider additional changes to 10 CFR Part 2 (hearings) to limit room for abuse of the process (2).
Response
The staff position on hearings is presented in Section IV.j of the Statement of Considerations.
The proposed rule does not include any special hearing procedures for license renewal.
Comment 6 Six responders indicated that they agreed with the NUMARC positions presented at the workshop and provided in followup correspondence (3, 7, 8, 9, 11, 12).
Response
No response is recuired.
The NUMARC comments are considered in the appropriate sections of this cocument.
Comment 7 Seven comments were received regarding the current licensing basis (CLB).
Five indicated that it was not necessary to resubmit the CLB or certify compliance I
with the CLB (3, 6 8 9,11).
One responder indicated that the NRC should holdfirmtherequIrem,enttosubmittheCLB(5).
One responder stated that the CLB is not a technically valid reference from which to project a safety risk in the future (4).
Response
The staff position regarding the CLB is presented in Section IV.b of the Statement of Considerations.
Comment 8 One responder submitted comments regarding the maintenance of the current level of safety during the extended life of the plant.
It was indicated that the level of safety is a subjective term, and the basic concept of maintaining a level of safety runs contrary to many NRC and industry pronouncements regarding o
age degradation (4).
Response
The staff disagrees with this comment.
The staff's programs to maintain the current level of safety at operating plants are discussed in Section IV.a in the Statement of Considerations.
Comment 9 The philosophical basis for the proposed ruling is weak and anticipated appli-cation of the backfit rule may result in an erodiiig of assessment of risk (4).
9-2
Responsg The staf f's regulatory philosophy and approach to the license renewal rule are discussed in Section IV.a of tN Statement of Considerations.
Comment 10 The screening criteria should consist of the NUMARC proposed methodology in combination with NRC results of SALP evaluations (5).
Response
The NUMARC screening methodology is still under review by the staff.
- However, the staff does not agree that the results of SALP evaluations should be considered for this purpose.
Comment 11 It is recommended that PRA methodologies and insights be a part of the rulemaking (5).
Response
The staff disagrees with this comment.
There is no provision in the proposed rule to require a PRA.
However, the Commission understands that most plants will have completed a plant-specific PRA as part of the Individual Plant Examination program.
Additional staff comments on the use of PRAs are provided in response to Question 4, Session 4.
t Comment 12 The NRC.should explore development of installed instrumentation designed to detect age-related failure mechanisms for key components (5).-
' Response Although the staff agrees with the intent of this comment, it should be recognized that such instrumentation is generally beyond the current state of the art.
It should be noted that the revised rule requires that licensees pro-
. vide a program to manage age-related degradation (54.15(b)) for-all systems and structures important to license renewal that are not subject to an established effective program to ensure continued performance of its safety function.-
Comment 13 The NRC should continue the practice of adopting appropriate sections of the ASME Code as-they apply to nuclear power plants and continue to allow the ASME committees to identify, in the ASME Code, the appropriate inspection criteria for.the degradation mechanisms (5).
Response
The NRC staff agrees with the comment.
9-3
h Comment 14 An interactive and cooperative effort between the NRC and the electric utility industry is encouraged (7).
Response
[
The NRC staff agrees with this comment.
Comment 15 It is not necessary that a complete reanalysis of all systems, structures, and components important to safety be included in the application for license renewal (8, 11).
1
Response
The NRC staff agrees with this comment and has modified the proposed rule accordingly.
Comment 16 The NRC should pursue the development of a generic environmental assessment or environmertal survey to bound the environmental impacts of license renewal.
The generic environmental assessment should be completed in parallel with the rule-making so that the lead plants may take advantage of the generic resolution of as many environmental issues as possible (8).
Response
A draft generic environmental document is scheduled to be published for comment by May 1991; the final document should be published by April 1992.
This date 6
is before the anticipated completion of the staff review of the lead plant license renewal applications.
3 Comment 17 License renewal is not an issuance of a new license, but an extension of the existing license -(8).
Response
The NRC staff disagrees with this comment; the renewal license should be the issuance of a new license.
Comment 18 The renewal term should not be limited to 20 years if the applicant can demonstrate the technical basis justifying plant operation for a longer renewal term (8).
9-4
r-
Response
The staff believes that the maximum term of a renewa1' license should be limited to 20 years beyond the expiration of the existing operating license.
This position is discussed in Section IV.g of the Statement of Considerations.
Comment 19 The license renewal rulemaking should focus primarily on plant material conditions and address age-related degradation over the renewal term (9).
Response
In general the staff agrees with this comment.
Comment 20 The rulemaking should not succumb to pressures for resolving current regulatory issues as part of license renewal.
Also, the level of protection should not be allowed to degrade over the renewal term (9).
Response
the staff agrees with this comment.
[omment21 The detailed contents of a license renewal application are more appropriately specified in a regulatory guide rather than in the license renewal rule (9).
Rpsponse The staff agrees with this comment; the regulatory guide is scheduled to be issued by April 1992.
Conment 22 The license renewal rule should define the terms " current licensing basis" and
" renewal" or " license renewal" (9).
Response
" Current licensing basis" and " renewal term" are defined :n the staff's revised rule.
Comment 23 The portion of the FSAR submitted with each application should be limited to changes in the FSAR to accommodate age-related degradation (11).
9-5
t F
Response
I The staff disagrees that the FSAR should be limited as specified in the comment.
The contents of the FSAR are described in Section 54.15 of the staff's revisod rule.
Comment 2_4 The proposed rulemaking determination should be expanded to conclude that, based on the NRC's continuing regulatory oversight activities and the existing record of saie operation, the CLBs for the nation's population of operating light-water nuclear power reactors are sufficient'to support the issuance of a renewal license subject only to ret ew for the effects of age-related degradation (11).
Response
The staff is in limited agreement with this statement.
The standard for
[
issuance of a renewed license is given in 54.29 of the revised rule.
i Comment 25 Section XX.19(e), concerning the establishment of a trending program is an unnecessary repetition of XX.19(d).
The appropriate actions under XX 19(d),
that would be taken with respect to degradation of SSC would include identifi-r cation, evaluation, and trending of the effects of age-related degradation.
Therefore, XX.19(e) should be deleted (11).
Response
The staff continues to believe that a requirement for a trending program should be specified, as stated in Section 54.21(a)(4) of the revised rule.
f v
i i
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-l 96 i
r APPENDIX ORGANIZATIONS PROVIDING WRITTEN COMMENTS 1.
Nuclear Management and Resources Council (NUMARC) 2.
Yankee Atomic Electric Company 3.:
B&W Owners Group 4.:
J. B. Gardner, i st eltant 5.
Illinois Department of Nuclear Safety C.
United States Department of Energy 7,
Pennsylvania Power and Light Company 8.
Northern States Power Company 9.
Grove Engineering, Inc.
10.
Bishop Cook, Purcell & Reynolds (on behalf of the Nuclear Utility l
Backfitting and Reform Group)
=
11.
Commonwealth Edison Company
- 12. Westinghouse Electric Corporation i
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IEE*E BIBLIOGRAPHIC DATA SHEET g
(5,0 uurructkun our t e reve,se) h NUREG-1411 e, mit AND SUB1mL
-Response to Public Comments Resulting from the Public 3
nan ntPOni Pumsnto Workshop on Nuclear Power Plant License Renewal l
uma u.a July 1990
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10 SUPPLLMLNT ARY NOf t5 11, ASSI R ACT tJuo.,edi er hwi On October 13. 1989, ths. '.S. Nuclear Regulatory Commission (NRC) issued an Advance Notice of Proposed lemaking ca nuclear power plant license renewal.
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nns etted comments on a nunber of technical and olans for a public workshop to discuss the issues
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