[Federal Register Volume 63, Number 189 (Wednesday, September 30, 1998)]
[Proposed Rules]
[Pages 52201-52206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-26204]



[[Page 52201]]

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NUCLEAR REGULATORY COMMISSION

10 CFR Part 50

RIN 3150-AF95


Monitoring the Effectiveness of Maintenance at Nuclear Power 
Plants

AGENCY: Nuclear Regulatory Commission.

ACTION: Proposed rule.

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SUMMARY: The Nuclear Regulatory Commission (NRC) is proposing to amend 
its power reactor safety regulations to require that licensees assess 
the cumulative effect of out-of-service equipment on the plant's 
capability to perform safety functions before beginning any maintenance 
activity on structures, systems, or components within the scope of the 
maintenance rule. The amendments would also clarify that the proposed 
rule applies under all conditions of operation including normal 
shutdown, that the safety assessments include both the plant conditions 
before and those expected during planned maintenance activities, and 
that the safety assessments are to be used to ensure that the plant is 
not placed in a condition of significant risk or a condition that would 
degrade the performance of safety functions to an unacceptable level.

DATES: Submit comments by December 14, 1998. Comments received after 
this date will be considered if it is practical to do so, but the 
Commission is able to ensure consideration only for comments received 
on or before this date.

ADDRESSES: Mail comments to: The Secretary of the Commission, U.S. 
Nuclear Regulatory Commission, Washington, DC 20555-0001. Attention: 
Rulemakings and Adjudications Staff.
    Deliver comments to: 11555 Rockville Pike, Rockville, Maryland, 
between 7:30 a.m. and 4:15 p.m. on Federal workdays.
    You may also provide comments via the NRC's interactive rulemaking 
web site through the NRC home page (http://www.nrc.gov). From the NRC 
home page, select ``Rulemaking'' from the tool bar. The interactive 
rulemaking website may then be accessed by selecting ``Rulemaking 
Forum.'' This site possesses the ability of uploading comments as files 
(any format) if your web browser supports that function. For 
information about the interactive rulemaking site, contact Ms. Carol 
Gallagher, 301-415-5905, e-mail [email protected].
    Certain documents related to this rulemaking, including comments 
received, may be examined at the NRC Public Document Room, 2120 L 
Street NW. (Lower Level), Washington, DC. These same documents also may 
be viewed and downloaded electronically via the interactive rulemaking 
website established by NRC for this rulemaking.

FOR FURTHER INFORMATION CONTACT: Richard P. Correia, Office of Nuclear 
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC 
20555, 301-415-1009, e-mail [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The NRC's Maintenance Team Inspections of all nuclear power plant 
licensees in the late 1980s found the lack of consideration of plant 
risk in prioritizing, planning, and scheduling maintenance activities 
to be a common weakness. To address that weakness, paragraph (a)(3) of 
10 CFR 50.65, the maintenance rule, currently includes the provision 
that ``(I)n performing monitoring and preventive maintenance 
activities, an assessment of the total plant equipment that is out of 
service should be taken into account to determine the overall effect on 
performance of safety functions.'' The maintenance rule was issued on 
July 10, 1991.
    During plant visits in mid-1994, several NRC senior managers 
expressed concerns that licensees were increasing both the amount and 
frequency of maintenance performed during power operation without 
adequately evaluating safety when planning and scheduling these 
maintenance activities. The NRC Executive Director for Operations (EDO) 
addressed these concerns regarding the safety implications with 
performing maintenance while at power to the president of the Institute 
of Nuclear Power Operations (INPO) in a letter dated October 6, 1994. 
In this letter, the EDO noted that it appeared that some licensees were 
either not following INPO guidelines for the conduct of maintenance and 
management of outages or had adopted only portions of the guidance. The 
EDO also recommended that INPO support NEI and appropriate utility 
managers during meetings with NRC senior managers to discuss the 
concerns they raised during the site visits.
    The growing amount of on-line maintenance (i.e., maintenance 
performed during power operations) being performed by licensees and the 
inadequate pre-maintenance safety evaluations have raised the 
Commission's concern.

Discussion

    The nuclear power industry has changed since the 1991 issuance of 
the maintenance rule. Rate deregulation of the electric utility 
industry will likely cause all nuclear power plants to seek ways to 
operate more efficiently. One mechanism for increasing efficiency is 
shortening refueling and maintenance outages. Licensees have come to 
realize that performing more maintenance at power can lead to shorter 
refueling outages and the reduction or elimination of mid-cycle 
maintenance outages.
    Licensees have relied upon their individual plant technical 
specifications to help assure safe operation of the plant when 
equipment is out of service. However, the removal of multiple pieces of 
equipment, especially safety-related equipment, from service can 
undermine the fundamental premise of the technical specifications for a 
plant, which is to provide adequate protection against random failures.
    During plant visits in mid-1994, several NRC senior managers had 
concerns with the fact that licensees were increasing both the amount 
and frequency of maintenance performed during power operations. Some 
licensees were limiting the planned maintenance to a single train of a 
system while others would allow multiple equipment in other systems 
within a single train to be out of service as long as it did not 
violate the plant's technical specifications. However, allowable outage 
times specified in technical specifications are based upon a random 
single failure in a system and a judgement of a reasonable time to 
effect repairs before plant shutdown is required. Technical 
specifications were not intended to address allowable outage times for 
multiple equipment being out of service at the same time. Further, it 
can not be implied that it is acceptable to voluntarily remove 
equipment from service to perform on-line maintenance on the assumption 
that such actions are bounded by a worst case single failure which is a 
plant specific design requirement that is contained in a number of the 
general design criteria (GDC) in 10 CFR 50, Appendix A. The NRC senior 
managers also had concerns with the fact that on-shift personnel, 
planning and scheduling personnel, and licensee management lacked an 
understanding of the relative safety importance of safety systems or 
combinations of equipment that would have risk significance if taken 
out of service. It appeared that risk insights from plant specific 
Individual Plant Examination (IPE)

[[Page 52202]]

results, whose purpose was to improve licensee understanding of the 
plant's safety and to address potential vulnerabilities, were not fully 
utilized in the plant's operational and maintenance decision process. 
These concerns were addressed in a letter dated October 6, 1994, from 
the Director of the Office of Nuclear Reactor Regulation to the 
Executive Vice-President of the Nuclear Energy Institute. The growing 
amount of maintenance performed during power operations and the 
underutilization of risk insights in plant operations and maintenance 
activities have raised the Commission's concern.
    In determining the need for the maintenance rule a decade ago, one 
factor the Commission considered was its belief that there existed ``a 
need to broaden its capability to take timely enforcement action where 
maintenance activities fail to provide reasonable assurance that 
safety-significant SSCs [structures, systems, and components] are 
capable of performing their intended function.'' Now, the Commission 
desires to act to help ensure that there is reasonable assurance such 
that maintenance activities will not place a plant in (1) a 
configuration that would degrade unacceptably a SSC's capability to 
perform its intended safety functions or (2) a risk-significant 
configuration, i.e., a configuration for which the incremental 
contribution to the annual risk associated with accidents that result 
in damage to the reactor fuel or the release of fission products to the 
environment is not insignificant.
    The first 50 NRC maintenance rule baseline inspections (MRBIs) for 
which inspection reports had been issued as of April 20, 1998, found 
that all licensees had developed programs to implement the safety 
assessment provision of paragraph (a)(3). However, at 5 sites, 
instances were found in which the licensee did not assess the impact on 
safety of total plant equipment out of service before it entered one or 
more specific plant configurations for maintenance purposes. At 19 
other sites, weaknesses--the term reserved for situations in which the 
overall assessment of a licensee program has found the program, or 
significant aspects of that program, to be particularly ineffective or 
for individual findings that have either high safety significance or 
programmatic implications--were found, among which were paragraph 
(a)(3) safety assessment tools that did not include all high-safety-
significant SSCs.
    Although the safety significance of the unassessed plant 
configurations at the 5 sites was not quantitatively determined during 
the inspection in all cases, it appears that some of the unassessed 
configurations had resulted in plants that were in a state of 
substantially greater risk than was realized by the licensees. Given 
the concerns raised by NRC senior managers during site visits in 1994, 
the increased amount of on-line maintenance, the number of missed 
assessments and their apparent risk significance, in addition to the 
weaknesses found with the paragraph (a)(3) safety assessment programs, 
the Commission considers this to be a safety concern. The Commission, 
therefore, believes it is necessary to explicitly require licensees to 
perform safety assessments prior to removing equipment from service for 
maintenance during all conditions of plant operations including normal 
shutdown.
    With regard to the operating conditions under which the proposed 
rule would apply, extensive interaction among the NRC, the industry, 
and the public has taken place over the need for regulations governing 
activities during shutdown conditions (i.e., shutdown as may be defined 
in each plant's individual technical specifications, but generally 
considered as a time when all control rods are inserted and the average 
reactor coolant temperature is below 200 deg.F). The question of 
whether 10 CFR 50.65 applies during shutdown conditions became an 
issue. The Commission desires to clarify that the rule does apply 
during shutdown conditions.
    Regarding which activities would be preceded by a safety 
assessment, the Commission has recognized that, although definitions 
regarding maintenance activities are fairly consistent from 
organization to organization, there is some variation in the definition 
of corrective maintenance. For example, some definitions bring a time 
dependency while some others consider the urgency of the repair. To 
eliminate inconsistency, and to cause more prudent use of the safety 
assessments, the Commission desires the regulation to cover all planned 
maintenance activities, rather than only the recommended monitoring and 
preventive maintenance in the current rule. Each planned non-emergency 
maintenance activity would now include a safety assessment prior to its 
being authorized to begin. In fact, many licensees have followed the 
guidance contained in Regulatory Guide 1.160 and NUMARC 93-01 and have 
already voluntarily included all planned maintenance activities in the 
scope of their safety assessment programs.
    With regard to the safety assessments themselves, licensee 
implementation has been inconsistent. The Commission desires to specify 
that an appropriate safety assessment would include a review the 
current condition of the plant and the plant condition expected during 
the planned maintenance activity. Assessing the current plant 
configuration as well as expected changes to plant configuration that 
will result from the proposed maintenance activities, as would be 
called for under paragraph (a)(4) of the proposed rule, is intended to 
ensure that the plant is not placed in risk-significant configurations, 
i.e., a configuration for which the incremental contribution to the 
annual risk is not insignificant, or a configuration that would degrade 
safety functions to an unacceptable level. These assessments do not 
necessarily require that a quantitative assessment of probabilistic 
risk be performed. The licensee would have the flexibility to perform a 
probabilistic and/or deterministic assessment, as appropriate. The 
level of sophistication with which such assessments are performed is 
expected to vary, based on the circumstances involved. It should be 
understood, however, that the contribution to risk of a specific plant 
configuration depends on both the degree of degradation of the safety 
functions and the duration for which the plant is in that 
configuration. Further, assessing the degree of safety function 
degradation requires that there be an understanding of the impact of 
removal of the equipment on the capability of the plant to prevent or 
mitigate accidents and transients. The assessments may range from 
deterministic judgements to the use of an on-line, living probabilistic 
risk assessment (PRA).
    Additional guidance will be developed and promulgated in Regulatory 
Guide 1.160, Revision 3 (proposed), to assist licensees in implementing 
this provision of the proposed rule. The guidance will contain 
information regarding risk-significant configurations and unacceptable 
levels of safety function degradation.

Proposed Rule

    This proposed rule would make five changes to 10 CFR 50.65:
    1. Add an introductory paragraph to 10 CFR 50.65 clarifying that 
the proposed rule applies under all conditions of operation, including 
normal shutdown.
    Prior to paragraph (a)(1), add the following wording: ``The 
requirements of this section are applicable during all

[[Page 52203]]

conditions of plant operation, including normal shutdown operations.'' 
The intent of this paragraph is to ensure that safety assessments are 
performed before maintenance activities when the plants are shut down 
as well as when the plants are at power. The shutdown condition may be 
defined in a plant's technical specifications, but the intent of this 
paragraph is that shutdown is generally considered as a time when all 
control rods are inserted and the average reactor coolant temperature 
is below 200 deg. F.
    2. Delete the last sentence of paragraph (a)(3) and create a new 
paragraph, (a)(4), that requires the performance of safety assessments.
    The proposed rule would remove the last sentence of paragraph 
(a)(3) and would add a new paragraph, (a)(4), as follows in its 
entirety: ``Before performing maintenance activities on structures, 
systems, or components within the scope of this section (including, but 
not limited to, surveillance testing, post-maintenance testing, 
corrective maintenance, performance/condition monitoring, and 
preventive maintenance), an assessment of the current plant 
configuration as well as expected changes to plant configuration that 
will result from the proposed maintenance activities shall be conducted 
to determine the overall effect on performance of safety functions. The 
results of this assessment shall be used to ensure that the plant is 
not placed in risk-significant configurations or configurations that 
would degrade the performance of safety functions to an unacceptable 
level.'' Deleting the current last sentence in paragraph (a)(3) will 
remove the recommendation for performing safety assessments from the 
paragraph that contains the periodic, programmatic, long-term review 
considerations of the rule. Creating a new paragraph, (a)(4), 
specifically for the safety assessment requirements would cause the 
assessment concept to stand as a separate entity within the maintenance 
rule.
    3. Define in paragraph (a)(4) the scope of the requirement for 
performing those assessments to be all conditions of operation 
including normal shutdown.
    The proposed rule would add the following in paragraph (a)(4) to 
define the scope of pre-maintenance safety assessments: ``Before 
performing maintenance activities on structures, systems, or components 
within the scope of this section (including, but not limited to, 
surveillance testing, post-maintenance testing, corrective maintenance, 
performance/condition monitoring, and preventive maintenance), an 
assessment * * * shall be conducted * * * .'' The NRC's intent is that 
licensees perform safety assessments before all planned maintenance 
activities that require removing from service equipment that is within 
the scope of the maintenance rule, as defined in 10 CFR 50.65(b) and 
(a)(1). The safety assessments required in this paragraph need not be 
sophisticated probabilistic risk assessment analyses in all cases. 
Licensees would have the flexibility to use probabilistic and/or 
deterministic methods, as appropriate, when performing the safety 
assessments required by paragraph (a)(4).
    4. Specify in paragraph (a)(4) that the safety assessments are to 
examine the extant plant condition and the condition expected during 
the planned maintenance activity.
    The proposed rule would include the following wording in paragraph 
(a)(4): ``* * * an assessment of the current plant configuration as 
well as expected changes to the plant configuration that will result 
from the proposed maintenance activities * * * .'' The NRC's intent is 
that a reasonable safety assessment be performed. The assessment may 
range from simple and straightforward to complex. However, 
notwithstanding the degree of sophistication required for the 
assessment, the NRC intends that the assessment will examine the plant 
condition existing prior to the commencement of the maintenance 
activity and examine the changes expected by the proposed maintenance 
activity.
    5. Specify in paragraph (a)(4) that the objective of performing the 
safety assessments is to ensure that the plant is not placed in risk-
significant configurations or configurations that would degrade the 
performance of safety functions to an unacceptable level.
    The proposed rule would add in paragraph (a)(4) the wording to 
specify the NRC's expectations regarding the use of each safety 
assessment, as follows: ``The results of this assessment shall be used 
to ensure that the plant is not placed in risk-significant 
configurations or configurations that would degrade the performance of 
safety functions to an unacceptable level.'' The NRC's intent is to 
require that each licensee perform a safety assessment before 
undertaking each planned maintenance activity and be aware of the risk 
issues associated with that maintenance activity. The guidance to be 
developed for licensees and promulgated in Regulatory Guide 1.160, 
Revision 3 (proposed), is expected to assist the industry in 
implementing this provision of the proposed rule, providing guidance 
regarding risk-significant configurations and unacceptable levels of 
safety function degradation.
    The Commission requests public comment on these proposed rule 
provisions. The Commission also requests public comment on the 
explanatory language in item 3 pertaining to licensee flexibility to 
use probabilistic and/or deterministic methods to perform the safety 
assessments. Specifically, should there be further clarification of 
this point in the final rule?

Finding of No Significant Environmental Impact: Environmental 
Assessment

    The Commission has determined under the National Environmental 
Policy Act of 1969, as amended, and the Commission's regulations in 
Subpart A of 10 CFR Part 51 that this rule, if adopted, would not be a 
major Federal action significantly affecting the quality of the human 
environment and, therefore, an environmental impact statement is not 
required. The draft environmental assessment that forms the basis for 
this determination reads as follows.

Identification of the Proposed Action

    The Commission is proposing to amend its regulations to require 
commercial nuclear power plant licensees to perform assessments of the 
plant's status before performing maintenance activities on structures, 
systems, and components (SSCs) within the scope of 10 CFR 50.65, the 
maintenance rule. The rule would be modified by adding an introductory 
sentence to clarify that the proposed rule would apply under all 
conditions of operation, including normal shutdown; deleting the last 
sentence of paragraph (a)(3); and creating a new paragraph, (a)(4). The 
new paragraph (a)(4) would change ``should'' to ``shall'' regarding the 
performance of safety assessments; define the scope of the requirement 
for performing those assessments to include all planned maintenance 
activities; specify that the safety assessments are to examine the 
extant plant condition and the condition expected during the 
maintenance activity; and specify that the safety assessments are to be 
used to ensure that, by the conduct of maintenance, the plant is not 
placed in risk-significant conditions or safety system performance is 
not degraded to an unacceptable level.

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The Need for the Proposed Action

    Paragraph (a)(3) of the maintenance rule, in part, currently 
recommends that, ``(I)n performing monitoring and preventive 
maintenance activities, an assessment of the total plant equipment that 
is out of service should be taken into account to determine the overall 
effect on performance of safety functions.'' The Commission believes 
the performance of this type of assessment is prudent. The maintenance 
rule baseline inspections, being performed at each commercial nuclear 
power plant site, have found that all inspected licensees have 
implemented programs to perform the assessments, but about half of the 
sites inspected had programs with discernable weaknesses in this area, 
including instances in which, in accordance with the licensee's own 
programs, safety assessments should have been made but were not. 
Because of the hortatory nature of the safety assessment provision in 
Sec. 50.65(a)(3), the Commission cannot ensure that licensees perform 
the assessments. Moreover, licensees are free to remove the performance 
of the assessments from their programs as they so desire. This proposed 
change to the Commission's regulations will permit the Commission to 
ensure that licensees perform the assessments, as appropriate.
    The other changes are clarifications regarding applicability of the 
rule. During preliminary discussions prior to potential development of 
a rule on shutdown plant operations, a major question arose regarding 
whether 10 CFR 50.65 requirements apply during the time a plant is shut 
down. The Commission concluded that inclusion of a statement to the 
affirmative would eliminate the doubt.
    Removing the provision regarding safety assessments from paragraph 
(a)(3) and creating for it a new, separate paragraph, (a)(4), would 
disassociate that new requirement from the more time-dependent 
requirement for evaluating of the program and the program's 
effectiveness at maintaining an appropriate balance between reliability 
and availability for each SSC. In the new paragraph, the requirement 
for safety assessment performance is stipulated to ensure licensees 
will perform those assessments. Because there were questions regarding 
when the assessments were to be performed, what plant conditions are to 
be evaluated and how they were to be used, the proposed new paragraph 
(a)(4) describes that the assessments are to be performed before all 
planned maintenance activities, are to examine pre-maintenance plant 
conditions and expected changes due to the proposed maintenance 
activity, and are to be used to ensure that the plant is not placed in 
risk-significant configurations or configurations that would degrade 
the performance of safety functions to an unacceptable level.

Environmental Impacts of the Proposed Action

    The proposed rule would require that commercial nuclear power plant 
licensees perform certain assessments of plant equipment status prior 
to performing all planned maintenance activities. The purpose of the 
proposed rule is to increase the effectiveness of the maintenance rule 
by requiring licensees to perform an assessment of plant conditions 
prior to planned maintenance and changes expected to result from the 
planned maintenance activity, to ensure that licensees understand the 
assessments are to be performed when the plant is shut down as well as 
at power, and to improve licensees' understanding of what conditions to 
assess and to what use to put the completed assessment. Accordingly, 
implementation of this proposed rule would not have any significant 
adverse impact on the quality of the human environment. The Commission 
believes that proper implementation of the proposed rule will reduce 
the likelihood of an accidental release of radioactive material caused 
by imprudently prioritized, planned, or scheduled maintenance.
    The determination of this environmental assessment is that there 
will be no significant offsite impact to the public from this action. 
The NRC has also committed to complying with Executive Order (EO) 
12898, ``Federal Actions to Address Environmental Justice in Minority 
Populations and Low-Income Populations,'' dated February 11, 1994, in 
all its actions. The NRC has determined that there are no 
disproportionate, high, or adverse impacts on minority or low-income 
populations. In the letter and spirit of EO 12898, the NRC is 
requesting public comment on any environmental justice considerations 
or questions that the public thinks may be related to this proposed 
rule but somehow were not addressed. Comments on any aspect of the 
Environmental Assessment, including environmental justice, may be 
submitted to the NRC as indicated under the ADDRESSES heading.

States Consulted and Sources Used

    The NRC has sent a copy of this proposed rule to every State 
Liaison Officer and requested his or her comments on the Environmental 
Assessment.

Paperwork Reduction Act Statement

    This proposed rule does not contain a new or an amended information 
collection requirement subject to the requirements of the Paperwork 
Reduction Act of 1995 (44 U.S.C. 3501 et seq.). Existing requirements 
were approved by the Office of Management and Budget, approval number 
3150-0011.

Public Protection Notification

    If an information collection requirement does not display a 
currently valid OMB control number, the NRC may not conduct or sponsor, 
and a person is not required to respond to, the information collection.

Regulatory Analysis

    The Commission has prepared a draft regulatory analysis on this 
proposed regulation. The analysis examined the costs and benefits of 
the alternatives considered by the Commission for revising 10 CFR 
50.65, the maintenance rule. Those alternatives were to (1) make no 
change to the rule, (2) require the safety assessments currently 
recommended in paragraph (a)(3) of the rule, and (3) make comprehensive 
revisions to paragraph (a)(3) of the rule. The analysis selected 
Alternative 2 as the preferred course of action. Details of the 
alternative selection are contained in the draft analysis, which is 
available for inspection in the NRC Public Document Room, 2120 L Street 
NW (Lower Level), Washington, D.C. Single copies of the analysis may be 
obtained from Richard P. Correia, Office of Nuclear Reactor Regulation, 
U.S. Nuclear Regulatory Commission, Washington, DC 20555, 301-415-1009, 
e-mail [email protected].
    The Commission requests public comments on the draft regulatory 
analysis. Comments on the draft analysis may be submitted to the NRC as 
indicated under the ADDRESSES heading.

Regulatory Flexibility Certification

    In accordance with the Regulatory Flexibility Act of 1980 (5 U.S.C. 
605(b)), the Commission certifies that this proposed rule will not, if 
adopted, have a significant economic impact on a substantial number of 
small entities. This proposed rule affects only the operation of 
nuclear power plants. The companies that own these plants do not fall 
within the scope of the definition of small entities set forth in the 
Regulatory Flexibility Act or the size standards adopted by the NRC (10 
CFR 2.810).

[[Page 52205]]

Backfit Analysis

    As required by 10 CFR 50.109, the Commission has completed a 
backfit analysis for this proposed rule. The Commission has determined, 
on the basis of this analysis, that backfitting to comply with the 
requirements of this proposed rule provides a substantial increase in 
protection to the public health and safety or the common defense and 
security at a cost that is justified by the increased protection.
    When the maintenance rule was first promulgated in 1991, the NRC 
staff did not foresee the significant changes licensees would be making 
in maintenance practices. To enhance operational efficiency brought 
about by the rate deregulation of the electric utility industry, 
licensees are shortening their refueling outages by performing more 
maintenance while the plant is at power. At-power maintenance practices 
have evolved to the point that not only are major systems and 
components taken off line, but also multiple systems and components are 
taken off line simultaneously. Taking systems and components off line 
for maintenance could result in an increased likelihood of an accident 
or transient, compared to risk that occurs from expected random 
equipment failures.
    The objective of this proposed rule is to make mandatory that 
licensees assess the cumulative impact of out-of-service equipment on 
the capability of the plant to perform safety functions and that 
licensees consider the results of the assessment before undertaking 
maintenance activities at operating nuclear power plants in order to 
ensure that the plants are not placed in risk-significant 
configurations or configurations that would degrade the performance of 
safety functions to an unacceptable level. Thus, the proposed rule 
would state that licensees must perform safety assessments before 
removing SSCs from service for planned maintenance.
    In addition, this proposed rule would (1) add an introductory 
sentence to 10 CFR 50.65 clarifying that the rule applies under all 
conditions of operation, including normal shutdown; (2) delete the last 
sentence of paragraph (a)(3) of the rule and create a new paragraph, 
(a)(4), that requires the performance of safety assessments; (3) 
specify that the scope of the requirement for performing those 
assessments covers all planned maintenance activities; (4) specify that 
the safety assessments are to examine the extant plant condition and 
the condition expected during the maintenance activity; and (5) specify 
that the results of the safety assessments are to be used to help the 
licensee ensure that the plant is not placed in risk-significant 
configurations or configurations that would degrade safety functions to 
an unacceptable level.
    The pre-maintenance assessments, along with the clarifications 
regarding their scope and their use, which the Commission proposes to 
require are intended to cause licensees to manage this risk and ensure 
their plants are not placed in risk-significant conditions or 
conditions in which the performance of safety functions is not degraded 
to unacceptable levels.
    The details of this backfit analysis have been incorporated in the 
regulatory analysis.
    For the reasons elaborated in the regulatory analysis, which also 
contains cost information, the Commission concludes that the proposed 
modification to the maintenance rule will result in a level of safety 
beyond that currently provided by the Commission's regulations, a 
substantial increase in the overall protection of public health and 
safety, and that the net costs of the rule are justified in view of 
this increased level of safety.

List of Subjects in 10 CFR Part 50

    Antitrust, Classified information, Criminal penalties, Fire 
protection, Intergovernmental relations, Nuclear power plant and 
reactors, Radiation protection, Reactor siting criteria, Reporting and 
recordkeeping requirements.

    For the reasons set out in the preamble and under the authority of 
the Atomic Energy Act of 1954, as amended; the Energy Reorganization 
Act of 1974, as amended; and 5 U.S.C. 553, the NRC is proposing to 
adopt the following amendments to 10 CFR Part 50:

PART 50--DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION 
FACILITIES

    1. The authority citation for part 50 continues to read as follows:

    Authority: Secs. 102, 103, 104, 105, 161, 182, 183, 186, 189, 68 
Stat. 936, 937, 938, 948, 953, 954, 955, 956, as amended, sec. 234, 
83 Stat. 444, as amended (42 U.S.C. 2132, 2133, 2134, 2135, 2201, 
2232, 2233, 2236, 2239, 2282); secs. 201, as amended, 202, 206, 88 
Stat. 1242, as amended, 1244, 1246, (42 U.S.C. 5841, 5842, 5846).
    Section 50.7 also issued under Pub. L. 95-601, sec. 10, 92 Stat. 
2951 (42 U.S.C. 5851). Section 50.10 also issued under secs. 101, 
185, 68 Stat. 936, 955, as amended (42 U.S.C. 2131, 2235); sec. 102, 
Pub. L. 91-190, 83 Stat. 853 (42 U.S.C. 4332). Sections 50.13, 
50.54(dd), and 50.103 also issued under sec. 108, 68 Stat. 939, as 
amended (42 U.S.C. 2138). Sections 50.23, 50.35, 50.55, and 50.56 
also issued under sec. 185, 68 Stat. 955 (42 U.S.C. 2235). Sections 
50.33a, 50.55a, and Appendix Q also issued under sec. 102, Pub. L. 
91-190, 83 Stat. 853 (42 U.S.C. 4332). Sections 50.34 and 50.54 also 
issued under sec. 204, 88 Stat. 1245 (42 U.S.C. 5844). Sections 
50.58, 50.91, and 50.92 also issued under Pub. L. 97-415, 96 Stat. 
2073 (42 U.S.C. 2239). Section 50.78 also issued under sec. 122, 68 
Stat. 939 (42 U.S.C. 2152). Sections 50.80-50.81 also issued under 
sec. 184, 68 Stat. 954, as amended (42 U.S.C. 2234). Appendix F also 
issued under sec. 187, 66 Stat. 955 (42 U.S.C. 2237).

    2. In Sec. 50.65, an introductory paragraph is added, paragraph 
(a)(3) is revised, and a new paragraph (a)(4) is added, to read as 
follows:


Sec. 50.65  Requirements for monitoring the effectiveness of 
maintenance at nuclear power plants.

    The requirements of this section are applicable during all 
conditions of plant operation, including normal shutdown operations.
    (a) * * *
    (3) Performance and condition monitoring activities and associated 
goals and preventive maintenance activities shall be evaluated at least 
every refueling cycle provided the interval between evaluations does 
not exceed 24 months. The evaluations shall be conducted taking into 
account, where practical, industry-wide operating experience. 
Adjustments shall be made where necessary to ensure that the objective 
of preventing failures of structures, systems, and components through 
maintenance is appropriately balanced against the objective of 
minimizing unavailability of structures, systems, and components due to 
monitoring or preventive maintenance.
    (4) Before performing maintenance activities on structures, 
systems, or components within the scope of this section (including, but 
not limited to, surveillance testing, post-maintenance testing, 
corrective maintenance, performance/condition monitoring, and 
preventive maintenance), an assessment of the current plant 
configuration as well as expected changes to plant configuration that 
will result from the proposed maintenance activities shall be conducted 
to determine the overall effect on performance of safety functions. The 
results of this assessment shall be used to ensure that the plant is 
not placed in risk-significant configurations or configurations that 
would degrade the performance of safety functions to an unacceptable 
level.
* * * * *
    Dated at Rockville, Maryland, this 24th day of September, 1998.


[[Page 52206]]


    For the Nuclear Regulatory Commission.
John C. Hoyle,
Secretary of the Commission.
[FR Doc. 98-26204 Filed 9-29-98; 8:45 am]
BILLING CODE 7590-01-P