ML20210N039

Final Rule 10CFR50, Monitoring Effectiveness of Maint at Npps

ML20210N039
Person / Time
Issue date:	07/13/1999
From:	Vietticook A NRC OFFICE OF THE SECRETARY (SECY)
To:
References
FRN-64FR38551, RULE-PR-50 NUDOCS 9908100268
Download: ML20210N039 (7)

Text

Federal Register /Vol. 64, No.137/Mond y, July 19,1999/ Rules and Reguhtlons 38551

" Monitoring the Effectiveness of maintenance rule is applicable, and to Nuclear Power Plants." The NRC will make the requirements fully publish a document in the Federal enforceable, the Commission published Register that announces the issuance of proposed revisions to 10 CFR 50.65 in the revised guidance and that specifies the Federal Register on September 30, the effective date. 1998 (63 FR 52201-52206). The 75-day FOR FURTHER MFORetAflON CONTACT: comment period closed December 14, Richard P. Correia, OfHce of Nuclear 1998.

Reactor Regulation, U.S. Nuclear H. Comments on the Proposed Rule Regulatory Commission, Washington, DC 20555-0001, 301--415-1009, e-mail Twenty-nine comments were rpc@nrc. gov. submitted during the comment period, SUPPLEMENTARY INFORt4ATION: and five were submitted after the comment period closed. Copies of the I. Background letters are available for public The NRC's maintenance team inspection and copying for a fee at the inspections of all nuclear power plant Commission's Public Document Room, licensees in the late 1980s found the located at 2120 L Street, NW (Lower lack of consideration of plant risk in Level), Washington, DC. The last public prioritizing, planning, and scheduling comment was received on December 29, maintenance activities to be a common 1998. All comments were considered in weakness. To address that weakness, formulating the final rule. The 34 paragraph (a)(3) of 10 CFR 50.65, the comments were submitted by 26 maintenance a ule, currently includes utilities with operating power reactors, the provision that "(1)n performing one utility with a decommissioning NUCLEAR REGULATORY monitoring and preventive maintenance status facility, three nuclear industry COMMISSION activities, an assessment of the total - service companies or consultants, one plant equipment that is out of service individual, one State agency, NEI, and 10 CFR Part 50 should be taken into account to one law firm representing several RIN 3150-AF96 determine the overall effect on utilities. Twenty-nine commentors performance of safety functions." The endorsed the NEI comments. NEI stated  ;

Monitoring the Effectiveness of maintenance rule was issued on July to, in its comment letter that the industry l Maintenance et Nuclear Power Plante 1991 (56 FR 31306), ge' era'ly supports the Commission's i During plant visits in mid 1994, intent in the proposed rule but has a AGENCY: Nuclear Regulatory several NRC senior managers sicpressed number of significant concerns that Commission. concerns that licensees were increasing should be addressed before rulemaking ACTION: Final rule, both the amount and frequency of proceeds. Of the commentors who did maintenance performed during power not endorse the NEI comments, one

SUMMARY

The Nuclear Regulatory operation without adequately evaluating (combined State a8encies) supported the Commission (NRC)is amending its safety when planning and scheduling concept of the proposed rule and power reactor safety regulations to these maintenance activities. The NRC provided comments to enhance it, and reqdire that licensees assess the effect of Executive Director for Operations (EDO) two others (an individual and a utility) equipment maintenance on the plant's addressed these concerns regarding the provided recommendations in specific capability to perform safety functions safety implications of performing areas to enhance the proposed rule. Two before beginning maintenance activities maintenance while at power to the of the commentors (a consultant and a on structures, systems, and components President of the Institute of Nuclear consulting firm) stated that the rule was (SSCs) within the scope of the Power Operations (INPO)in a letter unnecessary and presented supporting maintenance rule. The amendments dated October 6,1994. In this letter, the reasons.

clarify that these requirements apply EDO noted that it appeared that some under all conditions of operation, The comments have been grouped licensees were either not following under the following general topics:

including shutdown, and that the INPO guidelines for the conduct of assessments are to be used so that the 1. Rule issuance maintenance and management of

"*8ue, a g increase in risk that may result from the outages or had adopted only portions of *s'.m*[3,3 { ned maintenance activity will be managed to the guidance. The EDO als 3. Scope issues ensure that the plant is not recommended that INPO support the 4. Suggestions for wording modifications inadvertently placed in a condition of Nuclear Energy Institute (NEI) and 5. Regulatory controls overlapping technical significant risk or a codition that appropriate utility managers during specifications would degrade the pernrmance of meetings with NRC senior managers to 6. Performing assessments safety functions to an uracceptable discuss the concerns they raised during 7. Assessing and managing risk level. These amendments permit the site visits. 8. Emergent maintenance requirements i!censees to limit the scope of the The growing amount of on-line 9. Documentation of the assessment assessments to SSCs that a risk- maintenance (i.e., maintenance during N"N 'IN'#'Y d

j l

informed evaluation process has shown to be significant to public health and ower operations) being performed by ficensees and the quality of pm-N 8'[,'

, t y en sis c sYestYma'tes b

13. Appilcation to cfecommissioning plants safety, maintenance assessments have merited EFFECTIVE DATE:The final rule becomes the Commission's concern. To address Summaries of the grouped comments a effective 120 days after issuance of this enneern, to clarify the plant and discussions of the NRC responsesg 9 Revision 3 to Regulatory Guide 1.160,

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operating conditions under which the follow.

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38552 Federal Register /Vol. 64, No.137/ Monday, July 19,1999/ Rules and Regulations

2. Rule issuance vague, ambiguous, or undefined Response. The NRC disagrees with Comment. One commentor, a utility, terminology and recommended that the these suggested language changes. The stated that they consider the proposed rule be withdrawn and reissued for rule currently applies only to SSCs and NEI and other public comment after substantial within the scope of the rule. A revision rule unneces utilities stated Int theoposed ride, as m dification.NEIand utilitiesindicated to specify that fact is not needed, written, should be with awn. However, that terms such as " risk-significant although this rule is being revised to condition, and " unacceptable level" permit licensees to limit the scope of theI also stated that if the rule is licitly defined. their assessments to SSCs that a risk-should be exharagraph (a)(4) has informed Response. been evaluation process has shown revise and s u ore reworded. Guidance for the revised to be significant to public health and finalizing the changes to the rule. terminology a pears below in Item 4 of

' de safety. Additionally, certain Section III, "T e Final Rule."

t t b n ce ad v maintenance activities are performed that do not remove equipment from that the performance of this type of 3. Scope Issues service but have the potential for assessment is rudent because of Comment. Many commentors stated challenging safety systems. One changesinin ustrymaintenance that assessments required by the example is valve testing on certain practices and findings during NRC proposed rule should apply only to high inspections of maintenance rule safety-significance SSCs. NEI and balance-of-plant systems open vs ves are cycled shut andurink which Programs. When the maintenance rule utilities expressed concerns that the reopened. If such a valve were to was first promulgated in 1991, the NRC scope of SSCs subject to assessments inadvertently stick shut, a transient had not foreseen the significant changes was impractical. Such broad scope could ensue. Those scenarios must be licensees would be making in would dilute attention from high safety- assessed and managed to ensure that the meintenance practices.To enhance significance SSCs by requiring too many risks associated with these activities are operational efficiency, made detailed assessments. properly identified and controlled.

increasingly necessary by the rate Response. Paragraph 50.65(b) defines deregulation of the electric utility the scope of SSCs that are covered by 5. Regulatory Controls Overlappim industry, licensees t re shortening their the rule (with the exception of SSCs for Technical Specifications refueling ou; ages by performing more decommissioning plants). Chapter 11.0 Comment. Several commentors stated maintenance while the plant is at of NUMARC 93-01, " Industry that there is a need to reconcile the power. At power maintenance practicas Guidelines for Monitoring the overlapping regulatory regimes of the have evolved to the point that not only Effectiveness of Maintenance at Nuclear maintenance rule, technical I are major systems, subsystems, and Power Plants," Revision 2, dated April specifications (TS), az.d the components taken offline,but also 1996 (which has been endorsed by configuration risk management program multiple systems, subsystems, and Regulatory Guide 1.160, Revision 2, (CRMP) (described in Regulatory Guide ccmponents are taken offline dated March 1997),is entitled 1.177,"An Approach for Planttruific, simultaneously, Taking systems and " Evaluation of Systems to be Removed Risk-Informed Decisionmaking:

components offline for maintenance from Service." Chapter 11.0 guidance Technical Specifications"). NEI and the could result in an increase in risk makes the evaluation, or assessment, a utilities were mainly concerned with

.because of the reduced capability to three-step process: (1) Identify key plant the overlap of regulatory controls in the mitigate the consequences of an safety functions to be maintained,(2) revised rule and TS.

accident or a transient, compared to risk ideutify SSCs that support key plant Response. The NRC agrees that some th t occu s from expected random safety functions, and (3) consider the overlap exists among these regulatory equipment failures. In addition, overall effect of removing SSCs from controls. Under certain conditions, a although the maintenance rule baseline service on key plant safety functions. plant's TS may allow an SSC to be out inspections of all operating nuclear Requiring, instead of recommending, of service, while a pre-maintenance power plant sites found that all those assessments does not change the assessment proposing the removal of licensnes have implemented programs expectation that the assessments need that same SSC from service raay to perform the assessments, about half only involve SSCs associated with indicate a need to take other actions to of the sites had programs with initiating and mitigating impacts on key preclude that configuration. It is discernable weaknesses in this area, plant safety functions. To codify this Possible that allowed outage times of TS including instances in which,in expectation, paragraph (a)(4) of the final may not be in complete agreement with accordance with the licensees

• own rule contains a second sentence as reasonable out-of-service times resulting programs, assessments should have follows:"The scope of the assessment from the required asse'ssments.

been made but were not. may be limited to structures, systems, However, TS limiting conditions for The NRC agrees that it is appropriate and components that a risk-informed Operation were,in part, developed to 12 revise Regulato Guide 1.160 to evaluation pmcess has shown to be address random single failures of plant incorporate clari g guidance before significant to public health and safety." SSCs; they were not intended to be used the final rule's ive date. by licensees as rationale for removing 4.Suggest2 nsfoWording Accordingly, Revision 3 to Re6ulato multiple SSCs from service to perform Guide 1.160 will be prepared for pub ic Modifications on.line maintenance. In general, TS may comment and will be published in final Comment. Five commentors provided serve as a e-analyzed assessment, form 120 days before the effective date suggestions clarifying regulatory text. when us with sound judgement, of the rula. Two of these commentors stated that the when a licensee proposes to remove a plant configuration should be defined as single SSC from service for

2. New, Vague, Ambiguous, Undefined "SSCs within the scope of the rule," and maintenance. Paragraph (a)(4)is Terminologyin the Proposed Rule three commentors suggested limiting the intended to cause the licensee to Comment. Most commentors scope of maintenance activities to those determine its options and follow a identified concerns related to the that result in removing equipment from prudent course of action. Nevertheless, proposed rule's introduction of new, service. while performing on-line or shutdown I

Federal Register /Vol. 64, No.137/ Monday, July 19,1999/Ruhs and Reguhtions 38553 maintenance, the licensee will remain are not completed immediately, the its intended function (expressed) as a in conformance with its TS. plant could be at greater risk. fraction (usually as percent) of the total In NRC staff requirements Response. Under the revised rule, an time that the function may be memorandum dated June 29,1998, for assessment is required to be initiated demanded." Also according to that SECY-98-067, the Commission directed following the discovery of emergent document, under the definitien of the NRC staff to take actions to ensure failures or changes in plant conditions " unavailability," is the following that CRMP regulatory guidance to determine the safety impact of the statement: "An SSC that is required to conforms to the provisions of the final failure or the changein plant be available for automatic operation maintenance rule. After revisions to the conditions. For additional information must be available and respond without maintenance rule are completed, the on this subject, please see the human action." Additionally,in the NRC will expeditiously support licensee discussion in item 4 of Section III, "The instance where an SSC is taken out of requests to remove the CRMP Final Rule," below. service for testing but could be requirements from plant TS. manuall activated, the NRC has

9. Documentation of the Assessment

6. Performing Assessments " '

Comment. Three utility commentors oper tor's wr t en pr t specifies a Comment. NEI and the utilities stated that the proposed rule is not single action that would permit an expressed the need for clarification of exPlicit enough regarding assessment

, automatic initiation of the out-of-service when an assessment would be required, documentation expectations. SSC in the event of an accident or the level of complexity necessary in the Response. The rule has no explicit transient during the test, the SSC could assessment, and the criteria to be used documentation requirements. Instead, be mnsidered available. (Meeting to evaluate the adequacy of the the rule emphasizes performance. A Summary-November 19,1991, NRC/

assessment process. licensee a assessment process is ex ected to identify the impact on NUMARC Public Meeting on the Response. Please refer to the discussion in Item 4 of Section III, "The sagety that is caused by the erformance Development of Guidance Documents of meintenance. Licensees s ould use for the Implementation of the Final Rule," below, Maintenance Rule (10 CFR 50.65), R.P.

7. AssessingandManagingRisk fo a s t s v st $e C*"*I*' OfSce oiNuclear Reactor Comment. Three commentors requirement for an assessment has been- Regulation, memorandum to E.W.

ex ressed similar views related to high- acknowledged and performed f" da activities. One noted that, under fg*g o ht N n1 3 1991.)

adequately. NRC expectations are that a suitable controls, a shorter time in a licensee will have a requirement for the The NRC's ex ectation is that, by procedure, the dedicated operator is more risk-significant configuration ma assessments and an explanation of the be safer than a longer time in a less ris > process tr ,e followed in its stationed at the equipment and is ready 9 e significant configuration. Another noted maintenane rula program, along with a and that high risk-significant activities adon ualified to Perform in a moment. that siny'e An acceptab descriptio ' of ar.,essment tool (s) to be

"* th' should be reco ized and avoided, used and . heir limitations, where ractic , and limited in duration implezr suting procedures, and explicit C"

g 7, h or( vp when ey are necess . The third unacceptable action would be rackin8in direction covering instances when the noted that the propos rule does not a breaker or, in some instances, opening plant configuration is or .9 proposed t address situations in which failure to a manud gate vdve.

be outside the span of the nessment perform a maintenance activity may tool. Further, the assessment process is With respect to risk-informing the have a greater impact on risk than expected to be incorporated into the maintenance rule definition of performing the high safety-significant mautenance planning and scheduling availability, the reliance of initial activity, procas and into work package availability performance measures on Response. The NRC agrees that the requirements. Moreover, c6ntrol room Probabilistic risk assessment (PRA) data proposed rule precluded entering risk- operators, who are expected to Provided such a basis, flowever,in signihcant configurations, no matter the understand, use, and know the quality maintenance programs, l duration, when, in fet, situations may limitations of the assessment tools, availability is monitored to identify and exist that would yield a net safety generally use and maintain a variety of trend the performance of equipment, benefit by performing maintenance in a documents, such as logs and checklists, thereby permitting certain conclusions risk-significant configuration for a short that contain information relating to out. to be drawn about the effectiveness of time. The rule has been revised to of-service SSCs. the equipment's maintenance program.

require licensees to understand their Paragraph (a)(3) of the rule requires that options with respect to risk and to m Mnidon o@adaW the prevention of SSC failures l manage their maintenance activities Comment. Three commentors stated (reliability) through maintenance is l

according to their best judgment, that the definition of availability will be appropriately balanced against the considering insights from operating key to this rulemaking. They also stated objective of minimizing unavailability.

experience and deterministic and that the availability definition should Omitting unavailability time from the probabilistic analyses. take into account the time required to maintenance effectiveness ,

restore the functionality of an SSC and determination analysis is flawed logic.

8. Emergent Maintenance Requirements should also be risk informed. Omitting unavailability time because,in l' Comment. Two commentors stated Response. A defmition of availability an accident scenario, the equipment that the proposed rule does not address for licensee maintenance rule programs may not be needed for the time it may expectations for revising assessments is set forth in NUMARC 93-01, Revision take to restore its safuty function upon the discovery of a previously 2, which was endorsed by the NRC in recognizes the role of the equipment but unknown condition requiring Regulatory Guide 1.160, Revision 2, of masks the actual requirement for maintenance (emergent maintenance). March 1997. According to that maintenance. The maintenance rule They also expressed concerns that if document, availability is "[t)he time requires licensees to monitor the certain emergent maintenance activities that a(n) SSC is capable of performing effectiveness of their maintenance I

38554 Federal Register /Vol. 64, No.137/ Monday, July 19,1999/ Rules and Regulations programs. Omitting significant details, controls the degree of complexity of the may result from the proposed such as how much maintenance time an proposed configuration and thereby maintenance activities." Separatinc the SSC requires in order to attain the contmla thelevel of sophistication assessment requirement from the long-objective of preventing failures,is required for the assessment. term review requirement in paragraph contrary to the purpose of the rule. Consequently, the licensee should not (a)(3) will more clearly distinguish Note also that maintenance rule propose to enter a plant configuration between the two types of activity.

" availability" is not technical the complexity of which exceeds the The intent of this requirement is to specification " operability." licensee's ability to assess. have licensees appropriately assess the 21.Backfit and Regulatory Analyses 23. Application to Decommissioning a vi atw$1 recd y Comment. One commentor stated that Plants inadvertently, result in equipment being the regulatory analysis does not justify Comment. One commentor presented taken out of service and then, using the expansion of the maintenance rule concerns regarding the application of insights from the assessment, suitably to " normal shutdown operations" and the rule to plants in a decommissioning minimize the time needed for the that a revision of the analysis to better status. The commentor requested that, proposed maintenance activities while consider such expansion would show as part of this rulemaking, the NRC also controlling the configuration of the through backfit considerations that the remove the applicability of the rule to total plant to maintain and support the expansion is not justified. Another decommissioning status plants key plant safety functions.

commentor also presented a concern following some modest level of fission Risk is the result of the likelihood of that the overallimplications of the rule product decay, an event with due consideration of the were not supported by the backfit Response. This rulemaking is focused consequences of that same event. The analysis. on requiring pre-maintenance term " risk" is used to address what can Response.The new preamble to the assessments of plant risk. However, the go wrong,its likelihood, and its rule is an introductory sentence NRCis considering the issue in a consequences. The risk perspective can clarifying that the rule applies under all separate rulemakir.g activity. be assessed deterministically or operating conditions, including normal probabilistically.

shutdown. The Commission intended III.The Final Rule in general, a risk assessment is the rule to apply to all operating The final rule amends 10 CFR 50.65 necessary before all planned conditions, and it has been as follows: maintenance activities. Assessments implemented by the NRC staff 1. An intmductory paragraph has should also be perfonned when an consistent with such an interpretation. been added to 10 CFR 50.65 clarifying unexpected SSC failure initiates Moreover, Section 11.2.3 of NUMARC that the rule applies under all required maintenance activities or when 93-01 specifically states that conditions of operation, including changes to plant conditions affect a

assessment applies during all modes of shutdown. This introductory language previously performed assessment.

plant operation." The overall reads as follows: "The requirements of However, the reevaluation of a previous implications of the rule were aneued in this section am applicable during all assessment should not interfere with, or the backfit analysis for the original conditions of plant operation, including delay, the plant staff's taking timely maintenance rule, which was issued normal shutdown operations." The actions to restore the appropriate SSC to July 10,1991, intent of this paragraph is to ensure that service or taking compensatory actions assessments are performed before necenary to ensure that plant safety is

12. Regulatory Analysis Cost Estimotes maintenance activitts when the plants maintained. If the SSC is restored to Comment. One commentor raised the are shut down as well as when the service before performing the concern that if facilities are required to plants are at power. (Note that the word assessment, the assessment need not be develop numerical models for every "section," as used in this rulemaking, conducted.

combination oflow safety-significance means all of S 50.65.) Assessments may vary from simple SSCs, the cost ofimplementing the 2. The second sentence in paragraph and straightforward to highly complex.

program would be significantly higher (a)(3) has been revised as follows: "The llowever, the degree of sophistication thar. estimated in the regulatory evaluations shall take into account, required for the assessment analysis. where practical, industry-wide notwithstanding, the NRC intends that Response.The NRC does not expect operating experience." The change was the assessment process will examine the licensees to develop numerical models made only to simplify the language and plant condition existing before the for aneuing all possible combinations is purely editorial. commencement of the maintenance oflow risk-significant SSCs.The 3. The last sentence of paragraph activity, examine the changes expected regulatory analysis states that the (a)(3), containing the current, non. by the proposed maintenance activity, complexity of assassments to be mandatory provision for performing and identify the increase in risk that performed can vary, depending upon safety assessments,is deleted. The may result from the maintenance the conaguration of SSCs to be revised paragraph (a)(3) now contains activity. The assessments are expected maintained on line or out of service. It only the requirement for periodic, to provide insights for identifying and was presumed that auessments programmatic, long-term review. limiting risk-significant maintenance involving SSCs having little bearing on 4. A new paragraph,(a)(4), has been activities and their durations.

safety could be performed in an added requiring the performance of The level of complexity necessary in uncomplicated, deterministic manner assessments. The first sentence of the the assenment would be expected to and that the cost of the overall program new (a)(4) paragraph states: "Before differ from configuration to would be dominated by the need for performing maintenance activities configuration. When a licensee proposes nuessment of combinations of SSCs, (including but not limited to to perform maintenance on a single SSC which, when taken out of service surveillance, post-maintenance testing, from service for maintenance while no simultaneously, could have an advene and corrective and preventive other SSC is out of service, a simple effect on the safe operation of the maintenance), the licensee shall assess deterministic assessment may suffice. If facility. Additionally, the licensee and manage the increase in risk that the SSC is covered by TS, a r,ualitative l

l

Federal Register /Vol. 64, No.137/ Monday, July 19,1999/ Rules and Regulations 38555 assessment based on TS allowed outaga maintenance activities. The effective conditions of operation, including time ~periinent to the SSC and the control of potentially significant risk normal shutdown; by making editorial informed judgement of a trained, increase due to an unexpected failure of revision to the second sentence of licensed operator is sufficient. When another risk-important SSC can be paragraph (a)(3): by deleting the last one SSC is out of service and the reasonably assured by planning for sentence of paragraph (a)(3); and by licensee proposes to remove a second contingencies, or coordinating, creating a new paragraph, (a)(4), that SSC from service for maintenance, the scheduling, monitoring, and modifying requires licensees to assess and manage assessment could be simplified tinough the duration of planned maintenance the risk that may result from proposed the use of a table of results for pre- activities. maintenance activities and gives analyzed combinations, typically high 5. The second sentence in the new licensees an option to limit the scope of safety-significance SSCs paired against (a)(4) paragraph states: "The scope of SSCs subject to the assessments, each other. However, more detailed the assessments may be limited t assessments are required if a licensee structures, systems, and components The Needfor the Proposed Action proposes to remove multiple SSCs from that a risk informed evaluation process Formerly, paragraph (a)(3)of the service during power operations or to has shown to be significant to public maintenance rule was in the form of a remove from service systems necessary health and safety." In response to public recommendation because it read as to maintain safe shutdown during comments on the proposed rule, this follows: "(1)n performing monitoring shutdown or startup operations. These second sentence has been added so that and preventive maintenance activities, more detailed assessments are expected licensees may reduce the scope of SSCs an assessment of the total plant ,

to involve probabilistic analyses where subject to the pre-maintenance equipment that is out of service should possible, and to also include assessment to thoso SSCs which, l

he taken into account to determine the i considerations of key plant safety singularly or in combination, can be overall efrect on performance of safety functions to be maintained and defense shown to have a significant effect on the functions." The Commission believes in depth. performance of key plant safety that the performance of this type of The NRC believes that an appropriate functions. The focus of the assessments assessment is prudent. The maintenance assessment and management process should be on the SSCs modeled in the - rule baseline inspections, performed at should include the following licensco's pRA, in addition to all SSCs each operating nuclear power plant site, considerations: evaluated as risk significant (high found that all licensees have

a. The likelihood that the maintenance safety-significance) by the licensee's implemented programs to perform the activity will increase the frequency of an maintenance rule expert panel, assessments. However, about half of the initiatin6 event: Typically, these SSCs have been sites had programs with discernable

b. The probability that the activity will affect analyzed as causing potential initiating weaknesses in this area, including the ability to mitigate the trutlating event; events, if failed, and as accident instances in which, in accordance with c.The probability that the activity will affect mitigators, or as high safety-significance the licensee's own programs, the ability to trialntain containinent SSCs with their support systems. Such assessments should have been made but

d. er multiple trains are effected; SSCs may be identified by operating were not. Because of the hortatory

e. liow probabilistic insights are used: expenance or by deterministic or nature of the assessment provision in

f. Ilow non probabilletic insights are used; probabilh, tic analyses. S 50.65(a)(3), the Commission cannot Component and system dependencies: . ensure that licensees perform the k Measures to prevent concurrent " #8 # ssessments. Moreover, licensoes are unavailabilities of equipment necessary for d *f.P[ d free to remove the performance of the accident mitigation: Assessment assessments from their programs as they

1. Methods to determine the duration of the The Commission has determinod so desire. This final rule permits the activity and account for the projected under the National Environmental Commission to ensure tha' licensees

).1he a a tical basis for allowed PUlICI Gem.ACt of 1969, as amended, and the perform the assessments, as appropriate.

en m#hm m Mpd A had% b PMMMd4 configurations (quantitative or qualitative consideration); of 10 CFR Part 51 that this final rule is safety assessments from paragraph (a)(3)

k. Provisions for accommodating not a major Federal action significantly and creating for it a new, separate configurations not encompassed by affecting the quality of the human paragraph (a)(4), disassociates the new preanalyzed, acceptable configurations: environment and, therefore, an requirement from the more time-and environmental impact statement is not dependent requirement for evaluating

1. Scope and quality of analysis for quantified required. The environmental assessment the program and the program's that forms the basis for this effectiveness at maintaining an in general, it is the NRC's expectation determination reads as follows: appropriate balance between reliability th'at the processes for managing the risk and availability for each SSC. In the are scrutable and control the risk Identification of the Proposed Action new paragraph, the requirement for increase of the proposed maintenance The Commission is amending its assessment performance is stipulated to activdes. This process should include regulations to require commercial ensure that licensees will perform those an understanding of the nature (i.e., nuclear power plant licensees to assessments. There were questions affecting the core damage, or large early perform assessments of changes to the regarding when the assessments are to release frequency) and significance of plant's status that would result from be performed, which plant conditions the risk implications of a maintenance maintenance activities before are to be evaluated, how the configuration on the overall plant pefnrming the maintenance activities assessments are to be used, and which baseline risk level, For example, risk- on struchres, svstems, and components SSCs are sub}ect to the assessments. The significant plant configurations should (SSCs) witi&. the scope of10 CFR new paragraph (a)(4) was revised to generally be avoided, as should 50.65, the maintenance rule. Thus, the describe that the assessments are to be conditions where a key plant safety maintenance rule has been modified by performed before proposed maintenance function would be significantly adding an introductory sentence to activities and are to examine pre-degraded while conducting clarify that the rule applies under all maintenance plant conditions and

38556 Federal Regist:r/Vol. 64, No.137/ Monday, July 19,1999/ Rules and Regulations s:cpected changes as a result of the Paperwork'Redueflon act Statement safety or the common defense and proposed maintenance activities. The This final rule does not contain a new security at a cost that is justified by the assessments may be limited to SSCs that or an amended information collecdon increased protection.

a risk-informed evaluation process has uirement subject to the requirements When the maintenance rule was shown to be significant to public health or7the Paperwork Reduction Act of 1995 issued, the NRC had not foreseen the and safety. The assessments are to be (44 U.S.C. 3501 et seq.). Existin rate deregulation of the electric utility used to manage the increase in risk that requirements were approved the industry and the changes to may result from the maintenance Office of Management and Bu get maintenance practices that licensees activity. (OMB), approval number 3150-0011. would make to enhance operational EnvironmentalIrnpacts of the Proposed efficiency. Specifically of concern is the gction PublicPmtection Notificatw, n significant increase in maintenance This final rule requires that if a means used to impose an while the plant is at power, permitting commercial nuclear power plant infonnation collection does not display chortened refueling outages. At-power licensees perform certain assessments of a currently valid OMB control number, maintenance practices have evolved to the status of plant uipment before the NRC may not conduct or sponsor, the point that multiple systems, trains, and a person is not r uired to respond and components are simultaneously out performin ropos maintenance to, the information col ection. of service. Compared to the risk that activities.T e purpose of this change is occurs imm expected random to increase the effectiveness of the RegulatoryAnalysis maintenance rule by requiring licensees .

equipment failures, the risk of an The Commission has prepared a final accident or transient caused by taking t" regulatory analysis for this rule. The systems, trains, and components offline (1) Perform an assessment of the plant analysis examined the costs and benefits for maintenance or from performing conditions before the proposed of the alternatives considered by the maintenance on systems, trains, or maintenance and the changes expected Commission for revising 10 CFR 50.65, components while they remain on line to result from the proposed maintenance the maintenance rule. Those alternatives could be increased.

activity; were to (1) make no change to the rule, The objective of this rule is to require (2) require the safety assessments that-(2) Ensure that the assessments are performed when the plant is shut down currently recommended in paragraph (1) Licensees assess the im act of as well as at power; and (a)(3) of the rule, and (3) make equibment maintenance on the capa ility of the plant to perform key (3) Manage the increase in risk that [3fo'f ",'$,'*h,[,j'y[,aragr ed Pl ant safety functions; and may result from the proposed the selection of Alternative 2 as t e maintenance activity, (2) Licensees use the remalts of the preferred course of action. Details of the assessment before undertaking The Commission believes that proper alternative selection are contained in mamtenance activities at operating implementation of the rule will reduce the latory analysis, which is nuclear power plants to manage the the likelihood and consequences of an aval e for inspection in the NRC Public Document Room,2120 L Street increase in ris caused by those accidental release of radioactive acmes, material caused by imprudently NW (Lower Level), Washington, DC.

Thus, the rule adds a new paragraph, prioritized, planned, or scheduled Single co les of the analysis may be maintenance. obtained from Richard P. Correia, Offico (a)(4), that requires the erformance of The determination of this of Nuclear Reactor Regulation, U.S.

NuclarR o '

j,g a sessm nts sp s at s p of environmental assessment is rtiat there '

assessments covers proposed will be no significant offsite impact to 2 55 001,301 ,

maintenance activities, specifies that the the public from this action. The NRC 1009, e-mail rpc@nrc. gov.

scope of SSCs to be assessed may be has also committed to complying with Regulatory Flexibility Certification limited to those that a risk-informed Executive Order (EO) 12898. " Federal in accordance with the Regulatory evaluation process has shown to be

) Actions to Address Environmental Flexibility Act of 1980 (5 U.S.C. 605(b)), significant to public health and safety, Justice in Minority Populations and the Commission certifies that this final and specifies that the increase in risk Low-income Pspulations, dated rule will not have a significant that may occur from the maintenance February 11,1994, in all its actions. The economic impact on a substantial activity must be managed.

NRC has determined that there are n number of small entities. This rule This final rule also adds an disproportionate, high, or adverse affects only the operation of nuclear introductory sentence to 10 CFR 50.65 impacts on minority or low-income power lants.The companies that own clarifying that the rule applios under all populations in the letter and spirit of these p ants do not fall within the scope conditions of operation, including EO 12898, the NRC requested public normal shutdown; revises the second of the defmition of small entities set comment on any environmental justice forth in the Regulatory Flexibility Act or sentence of paragraph (a)(3) to simplify c ansiderations or stions that the the size standards adopted by the NRC the language; and deletes the last public thinks may related to this rule (to CFR 2.810). sentence of paragraph (a)(3) of the rule.

but somehow were not addressed. No The details of this backfit analysis public comments on this issue were Backfit Analysis have been incorporated in the regulatory received. As required by 10 CFR 50.109, the analysis. For the reasons elaborated in States Consulted and Sources Used Commission has completed a backfit the regulatory analysis, which also analysis for this final rule. The contains cost information, the The NRC sent a copy of the proposed Commission has determined, on the Commission concludes that this rule to every State Liaison Officer and basis of this analysis, that backfitting to modification to the maintenance rule requested his or her comments on the comply with the requirements of this will result in a substantial increasein environmental assessment. No rule provides a substantial increase in the overall protection to the public comments were received on this issue. protection to the public health and health and safety, and that the net costs l

Federal Register /Vol. 64, No.137/ Monday, July 19,1999/ Rules and Regulations 38557 of the rule are justified in view of this Appendix Q also issued under sec.102, Pub.

increased level of safety, L 91-190,83 Stat. 853 (42 U.S.C 4332).

Sections 50.34 and 50.54 also issued under Small Business ilegulatory Enforcement sec. 204,88 5 tat.1245 (42 U.S.C. 5844).

Fairness Act Sections 50.58,50.91, and 50.92 also issued in accordance with the Small under Pub. L 97-415,98 Stat. 2073 (42 Business Regulatory Enforcement U.S.C 2239). Section 50.78 also issued under Fairness Act of 1996, the NRC has sec.122,68 Stat. 939 (42 U.S.C 2152).

determined that this action is not a Sections 50.80-50.81 also issued under sec.

major rule and has verified this 184,68 Stat. 954, as amended (42 U.S.C determination with the Office of 2234). Appendix F also issued under sec.

Information and Regulatory Affairs of 187,68 Stat. 955 (42 U.S.C 2237).

OMB*

2. In S 50.65, an introductory N;tlonal Tecimology Transfer and paragraph is added, paragraph (a)(3) is Advancement Act revised, and a new paragraph (a)(4) !s The National Technology Transfer added to read as follows:

and Advancement Act of 1995, Pub. L' 104-113, requires that Federal agencies 5 50.65 Requirements for monitoring the effectiveness of maintenance et nuclear use technical standards developed or power plants.

adopted by voluntary consensus st*ndards bodies unless the use of such The requirements of this section are a standard is inconsistent with applicable during all conditions of plant cpplicable law or is otherwise operation, including normal shutdown impractical. There are no industry operations.

consensus star 2dards that apply to the area of maintenance. Thus, the

(,) . . . -

p ovisions of the Act do not apply to (3) Performance and condition this rulemaking. monitoring activities and associated goals and preventive maintenance List of Subjects in 10 CFR Part 50 activities shall be evaluated at least Antitrust, Classified information, every refueling cycle provided the

( Criminal penalties, Fire protection, interval between evaluations does not Int:rgovernmental relations, Nuclear exceed 24 months. The evaluations shall power plants and reactors, Radiation take into account, where practical, protection, Reactor siting criteris, industry-wide operating experience.

R: porting and recordkeepin8 Adjustments shall be made where requirements. necessary to ensure that the objective of For the reasons set out in the preventing failures of structures, preamble and under the authority of the Atomic Energy Act of 1954, as amended; systems, and components through maintenance is appropriately balanced th3 Energy Reorganization Act of 1974, against the objective of minimizing as amended; and 5 U.S.C. 552 and 553, unavailability of structures, systems, thz NRC is adopting the following and components due to monitoring or c.mendments to 10 CFR Part 50.

preventive maintenance.

PART 50--DOMESTIC LICENSING OF (4) Defore performing maintenance l PRODUCTION AND UTILIZATION activities (including but not limited to i

FACILITIES surveillance, post-maintenance testing,

1. The authority citation for Part 50 and corrective and preventive continues to read as follows: maintenance), the licensee shall assess and manage the increase in risk that Authority: Secs. 102,103,104,105,181, 182,183,188,189,68 Stat. 936,937,938, may result from the proposed 948,953,054,955,958, as amended, sec. maintenance activities. The scope of the 234,83 Stat. 444, as amended (42 U.S.C assessment may be limited to structures, 2132,2133,2134,2135,2201,2232,2233, systems, and components that a risk-2238,2239,2282); secs. 201, as amended, informed evaluation process has shown 202,200,08 Stat.1242, as amended.1244, to be significant to public health and 1248 (42 U.S.C 5841,5842,5846).

Section 50.7 also issued under Pub. L 95- safetU j 601, sec.10,92 Stat. 2951 (42 U.S.C 5851).

Section 50.10 also issued under secs.101, Dated at Rockville, Maryland, this 13th day 185,68 Stat. 955, as amended (42 U.S.C of July,1999, 2131,2235), sec.102, Pub. L 91-190,83 Stat.

853 (42 U.S.C 4332). Sections 50.13, For the Nuclear Regulstory Commission.

50.54(dd), and 50.103 also lasued under sec. Annette Vietti-Cook, 108,68 Stat. 939, as amended (42 U.S.C Secretary of the Commission.

2138). Sections 50.23,50.35,50.55, and 50.56 (FR Doc. 99-18325 Filed 7-16-99; 8:45 amj tlso issued under sec.185,68 Stat. 955 (42 U.S.C 2235). Sections 50.33a,50.55a and a m coot w w l