ML20090K711
| ML20090K711 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/01/1989 |
| From: | Parker T NORTHERN STATES POWER CO. |
| To: | Cleary D NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML19338A517 | List: |
| References | |
| FRN-55FR29043, RULE-PR-2, RULE-PR-50, RULE-PR-54 AD04-1-010, AD4-1, AD4-1-10, NUDOCS 9006060241 | |
| Download: ML20090K711 (9) | |
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Northem Swea Pomr Company fbR 414 Nioonet Mall MitMMpous, MMeseta 65401 1977 TWWone (612) 25500 December 1, 1989 Mr. Donald Cleary Office of Nuclear Reactor Research U S Nuclear Regulatory Comission Vashington, DC 20555 Comments on the Preliminary R*$ulatory Philesophy and
_. Aceroneh for_1,1, cense Renewal karulation The Federal Register, Vol. 54, No. 197, dated October 13, 1989 conta!rmd a notice of a public workshop on technical and policy consideraticas related to nuclear plant license renewal.
The notice also contain:,d a statement of the Preliminary Regulatory Philosophy and Approach ICor Liceve Renawal Regulation.
Wr".tten ecra.ents were invited to be suhleted by C4cember 1, 1989. This letter forvatds those comments.
Northern States Powel da Monticello Nuclear Generat'ng Plant is serving as the lead Boiling Vater Reactor plant in the indu hy k.au Pisnt License Renewal Program. As such we have perticipated 3xtensively in the development of the cornents en the philosophy, conmptua' outline and the responses to the questions on the workshop technical seestons being provided by the Nuclear Management e.nd Resources Council (NUMARQ on this subject and fully endorse thou as expands by.,ur comments contained in Atzachment 1.
Due to time constraints, individual responses to the questions issued in conjunction with ihn vorkshop have not been provided, at this time. As NUMARC respo..ses to the workshop sessions on Overview and Screening Systens are finalized, should we feel the need to provide separate responses, we will propte and forward them to you accordingly.
Please contact us if you have any questions or further inforteation is required on this issue.
l Thomas M Parker Manager Nuclear Support Services c: FRR Monticello Project Manager, NRC Monticello Resident Inspector NRC Attacheent 1 - Comnents on the Preliminaly Re5ulatory Philosophy and Approach for License Renewal Regulation
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COMMENTS ON THE FRELIMINARY MOU1ATORY PHILOSOFRY AND I
APPROACH FOR LICENSE LENEVAL REGULATION CURRDTT LICENSINC RMIS The NRC has developed a preliminary regulatory philosophy which is based on the current licensing basis. Northern States Power agrees with the tvo basic principles that the NRC propsaes to use es the basis for the License Renewal R9gulation. These are:
- 1) The current licensing basis" at a specific reactor provides and maintains a level of safety for operation durin5 the initial term that is sufficient to provide adequate assn;ance of the public health and safety, and conunon defense and security, and that the same level of safety is also adequate for continued i
operation durios any renewal period.
- 2) Any license renewal policy must provide assurance that the level of safety provided by a nuclear power plant's current licensin5 basis will not de5eade daring the renewal period.
I Northern States Power also agrees with the NRC that the licensee must continue to comply with the currett licensing basis as it evolves to assure that adequate protection of the public is continued. This can be done by the continuation of the licer.see programs for ensuring continued safe operation of and the Commission's re5ulatory oversight programs as is the l
the plant, current practice.
Theconceptualoutlineoftheproposedrulestatesthatthelicenlerenewal rule vill require the application to contain a summary of all regulatory 3
requirements and com:nitments so that the current _ licensing basis will be Northern States Power clearly understood and located in one docunent.
believes that this summary of the entire current licensin6 basis need not be l
submitted as part of the application for receval of a license as it-is inconsistent with the NRC philosophy. In item 1 of the NRC philosophy listed above, it is established that the current licensing basis is a continuing The levels of safety which are adequate entity from the initial license term.
to protect the health and safety of the public h' ave been established and the ability to maintain these levels has been demonstrated successfully during the initial license period. An alternative to the conceptual outline would be to provide a listing of the documents which contain the current licensing basis relied upon in the evaluation of systems, structures and components important to safety.
The second item of the NRC philosophy requires that the level of safety in the license renewal term wil.1 not decrease below the level of adequate safety-basis. The focus of which has been estabitsbed in the current licensin5 Northern States Power's license renswal program is the evaluation and management of significant age related degradacion of 'systerns, structures and The license application will address this consideration by c on:ponents.
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ATTACHMENT 1 Page 2 of 7 including those portions of the current licensing basis Which are pertinent to the evaluation of the management of age related degradation.
Paragraph XX 9(b) of the conceptual outline states that the application shall include certification of compliance with the current licansing basis. As stated in the NRC philosophy, compliance can be assured for the renewal tern by the licensee's programs for ensuring continued safe operation of the pisnt and the Commission's regulatory oversight programs. For those portions of the current licensing basis which will be submitted because they are pertinent to the evaluation of the management of age-related degradation, an oath or affirmation vould be sufficient.
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SYSTEMS. STRUCTUPES AND COMPONENT EVALUAT1Q3 I
In the conceptual outline, the NRC staff gave its position on the licensee's actions required to provide assurance that systems, structures and components important to continued safe plant operation will not be degraded.by aging mechanisms. The three main premises which outline the NRC's philosophical j
position are:
1.
Those systems, structures, and components that are effectively covered by existing ongoing NRC requirements and/or licenses programs, or are not subject to agin5 rechanisms need not be addressed in the application.
I 2.
The scope of syntans, stinctures and components to be addressed st;l probably be similar so that identified in the rulemaking for environment qualification of safety related electrical equipment.
3.
Licensees would be required to identify viere existing programs are utilized to monitor degradation mechanisms to provide reasonable assurance that replacement or refurbishment schedules for degrading equipment are being developed or service ' lifetime for equipment establishad.
In paragraph XX.9 of the conceptual outline, the NRC's approach to facilitate the above policy is given. This approach includes identification of systems and structures important to sarety. This approach further tuyuituw identification of the following for all components which make up these systems the dest n requirements; functions and and structures important to safety; 5
environmental conditions under'which the equipment must operate; determination of all the applicable d*5radation mechanisms;.descriptien of measures taken to manage these degradation mechanisms; and finally a description and technical basis for monitoring effects of all relevant age related degradation mechanisms. The level of deta11'and type of technical data-requested by the.
conceptumi outline is inconsistent with the philosophy which'is intended to focus reviews on systems, structures and components which are important to safety and are subject to si nificant a5e related de5radation mechanisms 5
durins the reneval period.
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Vhile the information requested under XX.9 would certainly provide an adequate basis for review of a'.ag for thesa systec.s. structures, and components, it goes well beyond the informatiot necessary. The information requested should be focused to provide only that necessary to evaluate tb.v c systems, structures and components whose safety function can be aftected by age related The approach outlined by the industry in its report "Hethodology degradation.
to Evaluate Plant Equipment for 1.icense Renewal" which was forwarded to the NRC staff on October 6, 1989, provides the criteria to determine the
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documentation and is consistent appropriate 1e.*e1 of evaluation and resul' tin 5 I
i with the NRC philosophy. The following is a synopsis of this methodology.
The initial step of the industry methodology identifies the systems and structures relied upon to operate the plant safely which basically corresponds I
to the NRC menff approach to the initial step of identifying systems, structures, and components that are important to safety..Jnder the NRC staff approach, a listing of all components which make up those systems and structures important to safety would be necessary as well as providing all of l
the information requested in XX 9(c). The industry methodology does not requite all of the information requested in XX.9(c) at this level.
The next set of steps in the industry appros:h evaluate the important to sofoty systems and structures at the component level.
The first component step determines which cosponents do not contribute to the safety function of the system or structure and whose failure would not preclude performance of the safety function.
For :omponents which are dispositioned at this step, the documentation which needs to be provided is that necess'ary to support a determination that the cemponent does not contribute to the system's safety function, and the determination that if the component fatied it would not preclude the system from performing its cafety function.
The second stop identifies those components which are subject to established, refurbishment or inspection programs.
For components effective replacement, to be dispositioned at this step, the doeurentation which needs to be provided l
1s that necessary to support determination of the component's safety the de5tadation mechanisms which could preclude that component function (s),
from performing that safety function (s), and the program (s) which ensure that function is being maintained.
The third step identifies those components which 'are not subject to significant a5e-related degradation (deterministically) or if agin5 resulted in component failure would not have a significant impact on risk (probabilistically). For components to be dispositioned at this step.would require documentation which references documents that provide the basis for the conclusion that the component is not subject to significant age related degradation or provides the risk assessment results.
The final step of the industry approach identifies the options for dispositioning the components which remain after the previous steps of the The components which remain at this point in the evaluction c;s thodology.
process are those which contribu. to the ability of a system to perform its 60-ce a
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ATTACHMENT 1 Ps5* 4 of 7' safety function or can preclude a system frca performing that safety function and for whit.h it has not been demonstrated that degradation mechanism is being managed effectively or that the component is not subject to significant age related degradation, various options to disposition the remaining components from the evaluation are available. These include, among other options, enhancement of existing pro 5 rams, detailed aging evaluations, periodic replacement of the component or trendin5 of critical paraceters. Depending on the option chosen, various levels of the documentation required by IX.9(c) would be provided.
Na believe that the industry methodology provides a systematic method for determining the (mount of evaluation and documentation necessary to ensure that aging,during the renewal period will not diminish plant safety below the acceptable level provided by the current licensing basis. The detailed documenta': ion for all the steps in this process would be available for review and audit by the NRC staff. The industry tiethodology is currently bein5 demonstrated by Monticello Nuclear Generating Plant, the lead boiling water reactor plant. The pilot system report when complete will be submitted to the, NRC staff for review. We request that following NRC staff review of the report that the industry nothodology be incorporated into the proposed license renewal regulation.
We do not believe that Lt is necessary to list the degradation mechanisms in the license renoval rule. The industry evaluation methodology and the industry reports both require identification of the significant degradation mechanisms for those components determined to be important to safety.
These industry methods and reports are sufficient to assure all important-degradation mechanisms are considered. If inclusion of these mechonisms in the rule is necessary, they should be more clearly defined r9d categorized by component type (i.e. electrical, fluid,...).
We also do not think that there is a need to addres: +.se systems, structures, and components which would be included oy m.e basis-of their solely being a trip initiator. The loss of availability from these systems, structures, and components will advarsely affect plant economics. Attention to deBradation of these structures,-systems, and components, will be an important part of the overall plant life extension program, ENVIRONMENTAL ISSUES Northern States Power agrees with the NRC staff position on environmental issues, that in order to comply with the National Environmental Policy Act (NEPA), an environne. ital assessment is required at a minimum to support license renewal rulemakins. We believe the scope. of this environmental assessment should be limited to the rule itself.i In that way its completion could coincide with the cocpletion of the rulemaking in May,'1991 to meet the schedule of the lead plants license renoval submittal.
In parallel with the preparation of the environmental assessment to support license renewal rulemaking. the hT.C should pursue the development of a generic 60>9e d
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ATTACHMENT 1 Pale 5, of ?
environmental assessment or environmental survey to bound the environmental impacts of license renewal. The use of parallel paths for the renewal rule and this generic envirorusental assessment will reduce-the risk that this generic environmental assessment will delay the issuance.of the renewal rule.
The staff's intention to adopt the findings from this. generic environmental assessment as a rule is supported.
Items such as severe accidents could be handled generically and the results placed in a table in 10 cm $1.
The findings could then be utilized in individual license renewal proceedings. It is requested that this generic environmedtal assessment be completed in parallel with the rulemaking so that the lead plants may take advantage of.
this generic-resolution of as many_ environmental'f.ssues as possible.
Northern $tates Power also agrees _ with the NRC that an environmental assessment as opposed to an environmental impact. statement should be prepared for submittal with individual license renewal applications.. This.would require the modification of 10 cm $1.20.b 2 to allow the preparation of an environmental assessment which would assess the need for-an environmental Continued plant _ operation during the renewal period should impact statement.
not result it. significant environmental impacts which would require an environmental impact statement.
1 SEVERE ACCIDENTS The conceptual outline states that the staff is considering requirements related to severe accidents that must be satisfied before -submission-of a renoval application takes place.- Northern States. Power feels that severe j
accident closure should not be included as a precondition to license renewal.
Northern States Power will be submitting a response to Ceneric Qtter 88 20
" Individual Plant Eaamiantion for Severe Accident Vulnerabilities 10 cm 50.54(f)" as a process of closing this issue; L Severe accidents are also -
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outside the scope of license renewal rulemaking because they are not connected t
to age related degradation.
In grouping severe accident issues with license renewal, the renewal process could be-. greatly delayed which:could adversely J
effect the lead plants.
The-accident management programs are currencly being ad/.ressed by7 the NUMARC
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As part of.its'functionJ the-group is-working group on-severe accidents.
addressing the definitten and enhancement-of existing plant specific' accident
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management capabilities.. It' has recently' issued " Guidelines for Evaluatin'g Accident Management capabilities" in draf t form 'as part of Its vork.
EqKFIT RU M Northern States-Power supports the NRC's intention to change the Backfit. Rule.
10Cm 50.109 to remove the ambiguity pertaining to the applicability of the backfit rule during the' license renewal ter:s - -It will; then be clear that. the:
rule will be in effect during the ' license renewal period.
However,, the sesff's position of removing the backfit rule during' the This evaluation of the application for license. renewal is 'not acceptable.
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ATTACHMENT 1 Page ( of 7 vould leave the licensees open to requiremnts that are beyond the scope of license renewal, our desire to have the backfit ruta apply is not to prevent needed changes. R aher, it is because it provides a disciplined and structured process for the licensee and NRC staff alike to evaluate changes necessary to manage a8e reelated degradation during the renewal term.
710BABILISTIC RISP ASSESSMEVP Northern States Power feels that Level I *and II Probabilistic Risk Assessments are useful and may be beneficial but should not be required as a regulatory decision mechanism. We do not feel that a probabilistic approach to evaluate systems, structures and components should be required at this time as there are no esta..ished, recognized criteria for acceptance of probabilistic risk assessment results. Use of probabilistic risk assessments should be at the optien of the license renewal applicants.
Northern States Power believes that a level III probabilistic risk assessment would not be of value to the license renewal program. A levol III probabilistic risk assessment eencerns off site risks vnich are now covered by existing programs that are contained in the current licensing basis. These programs are updated as needed and will continue to be relevant into the renewal term.
STANDARDS FOR REN M L OF LICENSE Northern States Power's position on licenso renewal is' that it is not an issuance of a new license, but an extension of the existing license. The findings in 10 CFR 50.57(a) were c'ade when the initial operatin5.J.icense vre granted and served as the core of the current licensing basis. As stated in the NRC's philosephy, this licensing basis has evolved over time to provide ongoin5 assurance that the original conclusion of adequate protection of the health and safety and common defense and security continues to remain valid.
This philosophy does not lead one to conclude that the current licensing basis requires a re review to again demonstrate adequacy. We believe that the findings required under 10 CFR 50.57(a) can be continued through the renewal term. As such, the only findings which the NRC needs to make to support issuance of a renewed license is that age related degradation is being managed and vill not affect health and safety of the public during the renewed license term. Therefore, section XX.19(a) should be _ deleted from the license renewal rule as it is inconsistent with the NRC's renewal philosophy.
Sections XX.19(b) and XX.19(c) should also be deleted as they are enveloped by section XX.19(d).
Section XX.15(o) should be modified to include only those systems, structures, and components whose safety function can be affected by age-related degradation.
ISSUANCE OF REN WED LICENSE In section XX.21 of the conceptual outline of the license renewal rule, it states that the renewal term should be lirited to 20 years. There is no basis given for this 20 year Iimitation. Northern States Power supports the l
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l position that the applicant say arply for a longer renewal term if it can demonstrate the technical basis justifying plant operation during that length j
l of time. The NR,C shosid include in this section a Frovision for additional renovel ters(s) upon expiration of the existing license renovel ters.
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l Also in section Y.X.21(b) the state ent ' estimated useful life of the factitty" should be deleted. Useful 11(e is an econosto determination which I
should be made by the holder of the iteense.
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