[Federal Register Volume 64, Number 137 (Monday, July 19, 1999)]
[Rules and Regulations]
[Pages 38551-38557]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-18325]
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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: Final rule.
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SUMMARY: The Nuclear Regulatory Commission (NRC) is amending its power
reactor safety regulations to require that licensees assess the effect
of equipment maintenance on the plant's capability to perform safety
functions before beginning maintenance activities on structures,
systems, and components (SSCs) within the scope of the maintenance
rule. The amendments clarify that these requirements apply under all
conditions of operation, including shutdown, and that the assessments
are to be used so that the increase in risk that may result from the
maintenance activity will be managed to ensure that the plant is not
inadvertently placed in a condition of significant risk or a condition
that would degrade the performance of safety functions to an
unacceptable level. These amendments permit licensees to limit the
scope of the assessments to SSCs that a risk-informed evaluation
process has shown to be significant to public health and safety.
EFFECTIVE DATE: The final rule becomes effective 120 days after
issuance of Revision 3 to Regulatory Guide 1.160, ``Monitoring the
Effectiveness of Nuclear Power Plants.'' The NRC will publish a
document in the Federal Register that announces the issuance of the
revised guidance and that specifies the effective date.
FOR FURTHER INFORMATION CONTACT: Richard P. Correia, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, Washington, DC
20555-0001, 301-415-1009, e-mail rpc@nrc.gov.
SUPPLEMENTARY INFORMATION:
I. 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 (56 FR 31306).
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 of
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 the Nuclear Energy Institute
(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 during
power operations) being performed by licensees and the quality of pre-
maintenance assessments have merited the Commission's concern. To
address this concern, to clarify the plant operating conditions under
which the maintenance rule is applicable, and to make the requirements
fully enforceable, the Commission published proposed revisions to 10
CFR 50.65 in the Federal Register on September 30, 1998 (63 FR 52201-
52206). The 75-day comment period closed December 14, 1998.
II. Comments on the Proposed Rule
Twenty-nine comments were submitted during the comment period, and
five were submitted after the comment period closed. Copies of the
letters are available for public inspection and copying for a fee at
the Commission's Public Document Room, located at 2120 L Street, NW
(Lower Level), Washington, DC. The last public comment was received on
December 29, 1998. All comments were considered in formulating the
final rule. The 34 comments were submitted by 26 utilities with
operating power reactors, one utility with a decommissioning status
facility, three nuclear industry service companies or consultants, one
individual, one State agency, NEI, and one law firm representing
several utilities. Twenty-nine commentors endorsed the NEI comments.
NEI stated in its comment letter that the industry generally supports
the Commission's intent in the proposed rule but has a number of
significant concerns that should be addressed before rulemaking
proceeds. Of the commentors who did not endorse the NEI comments, one
(combined State agencies) supported the concept of the proposed rule
and provided comments to enhance it, and two others (an individual and
a utility) provided recommendations in specific areas to enhance the
proposed rule. Two of the commentors (a consultant and a consulting
firm) stated that the rule was unnecessary and presented supporting
reasons.
The comments have been grouped under the following general topics:
1. Rule issuance
2. New, vague, ambiguous, undefined terminology in the proposed rule
3. Scope issues
4. Suggestions for wording modifications
5. Regulatory controls overlapping technical specifications
6. Performing assessments
7. Assessing and managing risk
8. Emergent maintenance requirements
9. Documentation of the assessment
10. Definition of availability
11. Backfit and regulatory analyses
12. Regulatory analysis cost estimates
13. Application to decommissioning plants
Summaries of the grouped comments and discussions of the NRC
responses follow.
[[Page 38552]]
1. Rule Issuance
Comment. One commentor, a utility, stated that they consider the
proposed rule unnecessary, and NEI and other utilities stated that the
proposed rule, as written, should be withdrawn. However, they also
stated that if the rule is approved, Regulatory Guide 1.160 should be
revised and issued before finalizing the changes to the rule.
Response. The NRC has determined that the rule is necessary and
believes that the performance of this type of assessment is prudent
because of changes in industry maintenance practices and findings
during NRC inspections of maintenance rule programs. When the
maintenance rule was first promulgated in 1991, the NRC had not
foreseen the significant changes licensees would be making in
maintenance practices. To enhance operational efficiency, made
increasingly necessary 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, subsystems, and components taken off line, but also multiple
systems, subsystems, and components are taken off line simultaneously.
Taking systems and components off line for maintenance could result in
an increase in risk because of the reduced capability to mitigate the
consequences of an accident or a transient, compared to risk that
occurs from expected random equipment failures. In addition, although
the maintenance rule baseline inspections of all operating nuclear
power plant sites found that all licensees have implemented programs to
perform the assessments, about half of the sites had programs with
discernable weaknesses in this area, including instances in which, in
accordance with the licensees' own programs, assessments should have
been made but were not.
The NRC agrees that it is appropriate to revise Regulatory Guide
1.160 to incorporate clarifying guidance before the final rule's
effective date. Accordingly, Revision 3 to Regulatory Guide 1.160 will
be prepared for public comment and will be published in final form 120
days before the effective date of the rule.
2. New, Vague, Ambiguous, Undefined Terminology in the Proposed Rule
Comment. Most commentors identified concerns related to the
proposed rule's introduction of new, vague, ambiguous, or undefined
terminology and recommended that the rule be withdrawn and reissued for
public comment after substantial modification. NEI and utilities
indicated that terms such as ``risk-significant condition'' and
``unacceptable level'' should be explicitly defined.
Response. Paragraph (a)(4) has been reworded. Guidance for the
revised terminology appears below in Item 4 of Section III, ``The Final
Rule.''
3. Scope Issues
Comment. Many commentors stated that assessments required by the
proposed rule should apply only to high safety-significance SSCs. NEI
and utilities expressed concerns that the scope of SSCs subject to
assessments was impractical. Such broad scope would dilute attention
from high safety-significance SSCs by requiring too many detailed
assessments.
Response. Paragraph 50.65(b) defines the scope of SSCs that are
covered by the rule (with the exception of SSCs for decommissioning
plants). Chapter 11.0 of NUMARC 93-01, ``Industry Guidelines for
Monitoring the Effectiveness of Maintenance at Nuclear Power Plants,''
Revision 2, dated April 1996 (which has been endorsed by Regulatory
Guide 1.160, Revision 2, dated March 1997), is entitled ``Evaluation of
Systems to be Removed from Service.'' Chapter 11.0 guidance makes the
evaluation, or assessment, a three-step process: (1) Identify key plant
safety functions to be maintained, (2) identify SSCs that support key
plant safety functions, and (3) consider the overall effect of removing
SSCs from service on key plant safety functions. Requiring, instead of
recommending, those assessments does not change the expectation that
the assessments need only involve SSCs associated with initiating and
mitigating impacts on key plant safety functions. To codify this
expectation, paragraph (a)(4) of the final rule contains a second
sentence as follows: ``The scope of the assessment may be limited to
structures, systems, and components that a risk-informed evaluation
process has shown to be significant to public health and safety.''
4. Suggestions for Wording Modifications
Comment. Five commentors provided suggestions clarifying regulatory
text. Two of these commentors stated that the plant configuration
should be defined as ``SSCs within the scope of the rule,'' and three
commentors suggested limiting the scope of maintenance activities to
those that result in removing equipment from service.
Response. The NRC disagrees with these suggested language changes.
The rule currently applies only to SSCs within the scope of the rule. A
revision to specify that fact is not needed, although this rule is
being revised to permit licensees to limit the scope of their
assessments to SSCs that a risk-informed evaluation process has shown
to be significant to public health and safety. Additionally, certain
maintenance activities are performed that do not remove equipment from
service but have the potential for challenging safety systems. One
example is valve testing on certain balance-of-plant systems during
which open valves are cycled shut and reopened. If such a valve were to
inadvertently stick shut, a transient could ensue. Those scenarios must
be assessed and managed to ensure that the risks associated with these
activities are properly identified and controlled.
5. Regulatory Controls Overlapping Technical Specifications
Comment. Several commentors stated that there is a need to
reconcile the overlapping regulatory regimes of the maintenance rule,
technical specifications (TS), and the configuration risk management
program (CRMP) (described in Regulatory Guide 1.177, ``An Approach for
Plant-Specific, Risk-Informed Decisionmaking: Technical
Specifications''). NEI and the utilities were mainly concerned with the
overlap of regulatory controls in the revised rule and TS.
Response. The NRC agrees that some overlap exists among these
regulatory controls. Under certain conditions, a plant's TS may allow
an SSC to be out of service, while a pre-maintenance assessment
proposing the removal of that same SSC from service may indicate a need
to take other actions to preclude that configuration. It is possible
that allowed outage times of TS may not be in complete agreement with
reasonable out-of-service times resulting from the required
assessments. However, TS limiting conditions for operation were, in
part, developed to address random single failures of plant SSCs; they
were not intended to be used by licensees as rationale for removing
multiple SSCs from service to perform on-line maintenance. In general,
TS may serve as a pre-analyzed assessment, when used with sound
judgement, when a licensee proposes to remove a single SSC from service
for maintenance. Paragraph (a)(4) is intended to cause the licensee to
determine its options and follow a prudent course of action.
Nevertheless, while performing on-line or shutdown
[[Page 38553]]
maintenance, the licensee will remain in conformance with its TS.
In NRC staff requirements memorandum dated June 29, 1998, for SECY-
98-067, the Commission directed the NRC staff to take actions to ensure
that CRMP regulatory guidance conforms to the provisions of the final
maintenance rule. After revisions to the maintenance rule are
completed, the NRC will expeditiously support licensee requests to
remove the CRMP requirements from plant TS.
6. Performing Assessments
Comment. NEI and the utilities expressed the need for clarification
of when an assessment would be required, the level of complexity
necessary in the assessment, and the criteria to be used to evaluate
the adequacy of the assessment process.
Response. Please refer to the discussion in Item 4 of Section III,
``The Final Rule,'' below.
7. Assessing and Managing Risk
Comment. Three commentors expressed similar views related to high-
risk activities. One noted that, under suitable controls, a shorter
time in a more risk-significant configuration may be safer than a
longer time in a less risk-significant configuration. Another noted
that high risk-significant activities should be recognized and avoided,
where practical, and limited in duration when they are necessary. The
third noted that the proposed rule does not address situations in which
failure to perform a maintenance activity may have a greater impact on
risk than performing the high safety-significant activity.
Response. The NRC agrees that the proposed rule precluded entering
risk-significant configurations, no matter the duration, when, in fact,
situations may exist that would yield a net safety benefit by
performing maintenance in a risk-significant configuration for a short
time. The rule has been revised to require licensees to understand
their options with respect to risk and to manage their maintenance
activities according to their best judgment, considering insights from
operating experience and deterministic and probabilistic analyses.
8. Emergent Maintenance Requirements
Comment. Two commentors stated that the proposed rule does not
address expectations for revising assessments upon the discovery of a
previously unknown condition requiring maintenance (emergent
maintenance). They also expressed concerns that if certain emergent
maintenance activities are not completed immediately, the plant could
be at greater risk.
Response. Under the revised rule, an assessment is required to be
initiated following the discovery of emergent failures or changes in
plant conditions to determine the safety impact of the failure or the
change in plant conditions. For additional information on this subject,
please see the discussion in Item 4 of Section III, ``The Final Rule,''
below.
9. Documentation of the Assessment
Comment. Three utility commentors stated that the proposed rule is
not explicit enough regarding assessment documentation expectations.
Response. The rule has no explicit documentation requirements.
Instead, the rule emphasizes performance. A licensee's assessment
process is expected to identify the impact on safety that is caused by
the performance of maintenance. Licensees should use documentation to
the extent necessary to assure themselves that the requirement for an
assessment has been acknowledged and performed adequately. NRC
expectations are that a licensee will have a requirement for the
assessments and an explanation of the process to be followed in its
maintenance rule program, along with a description of assessment
tool(s) to be used and their limitations, implementing procedures, and
explicit direction covering instances when the plant configuration is
or is proposed to be outside the span of the assessment tool. Further,
the assessment process is expected to be incorporated into the
maintenance planning and scheduling process and into work package
requirements. Moreover, control room operators, who are expected to
understand, use, and know the limitations of the assessment tools,
generally use and maintain a variety of documents, such as logs and
checklists, that contain information relating to out-of-service SSCs.
10. Definition of Availability
Comment. Three commentors stated that the definition of
availability will be key to this rulemaking. They also stated that the
availability definition should take into account the time required to
restore the functionality of an SSC and should also be risk informed.
Response. A definition of availability for licensee maintenance
rule programs is set forth in NUMARC 93-01, Revision 2, which was
endorsed by the NRC in Regulatory Guide 1.160, Revision 2, of March
1997. According to that document, availability is ``(t)he time that
a(n) SSC is capable of performing its intended function (expressed) as
a fraction (usually as percent) of the total time that the function may
be demanded.'' Also according to that document, under the definition of
``unavailability,'' is the following statement: ``An SSC that is
required to be available for automatic operation must be available and
respond without human action.'' Additionally, in the instance where an
SSC is taken out of service for testing but could be manually
activated, the NRC has accepted that, as long as the dedicated
operator's written procedure specifies a single action that would
permit an automatic initiation of the out-of-service SSC in the event
of an accident or transient during the test, the SSC could be
considered available. (Meeting Summary--November 19, 1991, NRC/NUMARC
Public Meeting on the Development of Guidance Documents for the
Implementation of the Maintenance Rule (10 CFR 50.65), R.P. Correia,
Office of Nuclear Reactor Regulation, memorandum to E.W. Brach, Office
of Nuclear Reactor Regulation, dated November 23, 1991.) The NRC's
expectation is that, by procedure, the dedicated operator is stationed
at the equipment and is ready and qualified to perform that single
action in a moment. An acceptable single action could be the rapid
repositioning of a switch or a lever; an unacceptable action would be
racking in a breaker or, in some instances, opening a manual gate
valve.
With respect to risk-informing the maintenance rule definition of
availability, the reliance of initial availability performance measures
on probabilistic risk assessment (PRA) data provided such a basis.
However, in quality maintenance programs, availability is monitored to
identify and trend the performance of equipment, thereby permitting
certain conclusions to be drawn about the effectiveness of the
equipment's maintenance program. Paragraph (a)(3) of the rule requires
that the prevention of SSC failures (reliability) through maintenance
is appropriately balanced against the objective of minimizing
unavailability. Omitting unavailability time from the maintenance
effectiveness determination analysis is flawed logic. Omitting
unavailability time because, in an accident scenario, the equipment may
not be needed for the time it may take to restore its safety function
recognizes the role of the equipment but masks the actual requirement
for maintenance. The maintenance rule requires licensees to monitor the
effectiveness of their maintenance
[[Page 38554]]
programs. Omitting significant details, such as how much maintenance
time an SSC requires in order to attain the objective of preventing
failures, is contrary to the purpose of the rule.
Note also that maintenance rule ``availability'' is not technical
specification ``operability.''
11. Backfit and Regulatory Analyses
Comment. One commentor stated that the regulatory analysis does not
justify the expansion of the maintenance rule to ``normal shutdown
operations'' and that a revision of the analysis to better consider
such expansion would show through backfit considerations that the
expansion is not justified. Another commentor also presented a concern
that the overall implications of the rule were not supported by the
backfit analysis.
Response. The new preamble to the rule is an introductory sentence
clarifying that the rule applies under all operating conditions,
including normal shutdown. The Commission intended the rule to apply to
all operating conditions, and it has been implemented by the NRC staff
consistent with such an interpretation. Moreover, Section 11.2.3 of
NUMARC 93-01 specifically states that ``assessment applies during all
modes of plant operation.'' The overall implications of the rule were
assessed in the backfit analysis for the original maintenance rule,
which was issued July 10, 1991.
12. Regulatory Analysis Cost Estimates
Comment. One commentor raised the concern that if facilities are
required to develop numerical models for every combination of low
safety-significance SSCs, the cost of implementing the program would be
significantly higher than estimated in the regulatory analysis.
Response. The NRC does not expect licensees to develop numerical
models for assessing all possible combinations of low risk-significant
SSCs. The regulatory analysis states that the complexity of assessments
to be performed can vary, depending upon the configuration of SSCs to
be maintained on line or out of service. It was presumed that
assessments involving SSCs having little bearing on safety could be
performed in an uncomplicated, deterministic manner and that the cost
of the overall program would be dominated by the need for assessment of
combinations of SSCs, which, when taken out of service simultaneously,
could have an adverse effect on the safe operation of the facility.
Additionally, the licensee controls the degree of complexity of the
proposed configuration and thereby controls the level of sophistication
required for the assessment. Consequently, the licensee should not
propose to enter a plant configuration the complexity of which exceeds
the licensee's ability to assess.
13. Application to Decommissioning Plants
Comment. One commentor presented concerns regarding the application
of the rule to plants in a decommissioning status. The commentor
requested that, as part of this rulemaking, the NRC remove the
applicability of the rule to decommissioning status plants following
some modest level of fission product decay.
Response. This rulemaking is focused on requiring pre-maintenance
assessments of plant risk. However, the NRC is considering the issue in
a separate rulemaking activity.
III. The Final Rule
The final rule amends 10 CFR 50.65 as follows:
1. An introductory paragraph has been added to 10 CFR 50.65
clarifying that the rule applies under all conditions of operation,
including shutdown. This introductory language reads as follows: ``The
requirements of this section are applicable during all conditions of
plant operation, including normal shutdown operations.'' The intent of
this paragraph is to ensure that assessments are performed before
maintenance activities when the plants are shut down as well as when
the plants are at power. (Note that the word ``section,'' as used in
this rulemaking, means all of Sec. 50.65.)
2. The second sentence in paragraph (a)(3) has been revised as
follows: ``The evaluations shall take into account, where practical,
industry-wide operating experience.'' The change was made only to
simplify the language and is purely editorial.
3. The last sentence of paragraph (a)(3), containing the current,
non-mandatory provision for performing safety assessments, is deleted.
The revised paragraph (a)(3) now contains only the requirement for
periodic, programmatic, long-term review.
4. A new paragraph, (a)(4), has been added requiring the
performance of assessments. The first sentence of the new (a)(4)
paragraph states: ``Before performing maintenance activities (including
but not limited to surveillance, post-maintenance testing, and
corrective and preventive maintenance), the licensee shall assess and
manage the increase in risk that may result from the proposed
maintenance activities.'' Separating the assessment requirement from
the long-term review requirement in paragraph (a)(3) will more clearly
distinguish between the two types of activity.
The intent of this requirement is to have licensees appropriately
assess the risks related to proposed maintenance activities that will
directly, or may inadvertently, result in equipment being taken out of
service and then, using insights from the assessment, suitably minimize
the time needed for the proposed maintenance activities while also
controlling the configuration of the total plant to maintain and
support the key plant safety functions.
Risk is the result of the likelihood of an event with due
consideration of the consequences of that same event. The term ``risk''
is used to address what can go wrong, its likelihood, and its
consequences. The risk perspective can be assessed deterministically or
probabilistically.
In general, a risk assessment is necessary before all planned
maintenance activities. Assessments should also be performed when an
unexpected SSC failure initiates required maintenance activities or
when changes to plant conditions affect a previously performed
assessment. However, the reevaluation of a previous assessment should
not interfere with, or delay, the plant staff's taking timely actions
to restore the appropriate SSC to service or taking compensatory
actions necessary to ensure that plant safety is maintained. If the SSC
is restored to service before performing the assessment, the assessment
need not be conducted.
Assessments may vary from simple and straightforward to highly
complex. However, the degree of sophistication required for the
assessment notwithstanding, the NRC intends that the assessment process
will examine the plant condition existing before the commencement of
the maintenance activity, examine the changes expected by the proposed
maintenance activity, and identify the increase in risk that may result
from the maintenance activity. The assessments are expected to provide
insights for identifying and limiting risk-significant maintenance
activities and their durations.
The level of complexity necessary in the assessment would be
expected to differ from configuration to configuration. When a licensee
proposes to perform maintenance on a single SSC from service for
maintenance while no other SSC is out of service, a simple
deterministic assessment may suffice. If the SSC is covered by TS, a
qualitative
[[Page 38555]]
assessment based on TS allowed outage time pertinent to the SSC and the
informed judgement of a trained, licensed operator is sufficient. When
one SSC is out of service and the licensee proposes to remove a second
SSC from service for maintenance, the assessment could be simplified
through the use of a table of results for pre-analyzed combinations,
typically high safety-significance SSCs paired against each other.
However, more detailed assessments are required if a licensee proposes
to remove multiple SSCs from service during power operations or to
remove from service systems necessary to maintain safe shutdown during
shutdown or startup operations. These more detailed assessments are
expected to involve probabilistic analyses where possible, and to also
include considerations of key plant safety functions to be maintained
and defense in depth.
The NRC believes that an appropriate assessment and management
process should include the following considerations:
a. The likelihood that the maintenance activity will increase the
frequency of an initiating event;
b. The probability that the activity will affect the ability to
mitigate the initiating event;
c. The probability that the activity will affect the ability to
maintain containment integrity;
d. Whether multiple trains are affected;
e. How probabilistic insights are used;
f. How non-probabilistic insights are used;
g. Component and system dependencies;
h. Measures to prevent concurrent unavailabilities of equipment
necessary for accident mitigation;
i. Methods to determine the duration of the activity and account for
the projected duration;
j. The analytical basis for allowed configurations (quantitative or
qualitative consideration);
k. Provisions for accommodating configurations not encompassed by
preanalyzed, acceptable configurations; and
l. Scope and quality of analysis for quantified assessments.
In general, it is the NRC's expectation that the processes for
managing the risk are scrutable and control the risk increase of the
proposed maintenance activities. This process should include an
understanding of the nature (i.e., affecting the core damage, or large
early release frequency) and significance of the risk implications of a
maintenance configuration on the overall plant baseline risk level. For
example, risk-significant plant configurations should generally be
avoided, as should conditions where a key plant safety function would
be significantly degraded while conducting maintenance activities. The
effective control of potentially significant risk increase due to an
unexpected failure of another risk-important SSC can be reasonably
assured by planning for contingencies, or coordinating, scheduling,
monitoring, and modifying the duration of planned maintenance
activities.
5. The second sentence in the new (a)(4) paragraph states: ``The
scope of the assessments may be limited to structures, systems, and
components that a risk-informed evaluation process has shown to be
significant to public health and safety.'' In response to public
comments on the proposed rule, this second sentence has been added so
that licensees may reduce the scope of SSCs subject to the pre-
maintenance assessment to those SSCs which, singularly or in
combination, can be shown to have a significant effect on the
performance of key plant safety functions. The focus of the assessments
should be on the SSCs modeled in the licensee's PRA, in addition to all
SSCs evaluated as risk significant (high safety-significance) by the
licensee's maintenance rule expert panel. Typically, these SSCs have
been analyzed as causing potential initiating events, if failed, and as
accident mitigators, or as high safety-significance SSCs with their
support systems. Such SSCs may be identified by operating experience or
by deterministic or probabilistic analyses.
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 final rule is not a major Federal
action significantly affecting the quality of the human environment
and, therefore, an environmental impact statement is not required. The
environmental assessment that forms the basis for this determination
reads as follows:
Identification of the Proposed Action
The Commission is amending its regulations to require commercial
nuclear power plant licensees to perform assessments of changes to the
plant's status that would result from maintenance activities before
performing the maintenance activities on structures, systems, and
components (SSCs) within the scope of 10 CFR 50.65, the maintenance
rule. Thus, the maintenance rule has been modified by adding an
introductory sentence to clarify that the rule applies under all
conditions of operation, including normal shutdown; by making editorial
revision to the second sentence of paragraph (a)(3); by deleting the
last sentence of paragraph (a)(3); and by creating a new paragraph,
(a)(4), that requires licensees to assess and manage the risk that may
result from proposed maintenance activities and gives licensees an
option to limit the scope of SSCs subject to the assessments.
The Need for the Proposed Action
Formerly, paragraph (a)(3) of the maintenance rule was in the form
of a recommendation because it read as follows: ``(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 that the performance of this type
of assessment is prudent. The maintenance rule baseline inspections,
performed at each operating nuclear power plant site, found that all
licensees have implemented programs to perform the assessments.
However, about half of the sites had programs with discernable
weaknesses in this area, including instances in which, in accordance
with the licensee's own programs, assessments should have been made but
were not. Because of the hortatory nature of the 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 final rule permits the Commission to ensure that licensees perform
the assessments, as appropriate.
Removing the provision regarding safety assessments from paragraph
(a)(3) and creating for it a new, separate paragraph, (a)(4),
disassociates the new requirement from the more time-dependent
requirement for evaluating 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
assessment performance is stipulated to ensure that licensees will
perform those assessments. There were questions regarding when the
assessments are to be performed, which plant conditions are to be
evaluated, how the assessments are to be used, and which SSCs are
subject to the assessments. The new paragraph (a)(4) was revised to
describe that the assessments are to be performed before proposed
maintenance activities and are to examine pre-maintenance plant
conditions and
[[Page 38556]]
expected changes as a result of the proposed maintenance activities.
The assessments may be limited to SSCs that a risk-informed evaluation
process has shown to be significant to public health and safety. The
assessments are to be used to manage the increase in risk that may
result from the maintenance activity.
Environmental Impacts of the Proposed Action
This final rule requires that commercial nuclear power plant
licensees perform certain assessments of the status of plant equipment
before performing proposed maintenance activities. The purpose of this
change is to increase the effectiveness of the maintenance rule by
requiring licensees to--
(1) Perform an assessment of the plant conditions before the
proposed maintenance and the changes expected to result from the
proposed maintenance activity;
(2) Ensure that the assessments are performed when the plant is
shut down as well as at power; and
(3) Manage the increase in risk that may result from the proposed
maintenance activity.
The Commission believes that proper implementation of the rule will
reduce the likelihood and consequences 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 requested
public comment on any environmental justice considerations or questions
that the public thinks may be related to this rule but somehow were not
addressed. No public comments on this issue were received.
States Consulted and Sources Used
The NRC sent a copy of the proposed rule to every State Liaison
Officer and requested his or her comments on the environmental
assessment. No comments were received on this issue.
Paperwork Reduction Act Statement
This final 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 (OMB), approval
number 3150-0011.
Public Protection Notification
If a means used to impose an information collection 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 final regulatory analysis for this
rule. 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 supported the selection of Alternative
2 as the preferred course of action. Details of the alternative
selection are contained in the regulatory analysis, which is available
for inspection in the NRC Public Document Room, 2120 L Street NW (Lower
Level), Washington, DC. Single copies of the analysis may be obtained
from Richard P. Correia, Office of Nuclear Reactor Regulation, U.S.
Nuclear Regulatory Commission, Washington, DC 20555-0001, 301-415-1009,
e-mail rpc@nrc.gov.
Regulatory Flexibility Certification
In accordance with the Regulatory Flexibility Act of 1980 (5 U.S.C.
605(b)), the Commission certifies that this final rule will not have a
significant economic impact on a substantial number of small entities.
This 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).
Backfit Analysis
As required by 10 CFR 50.109, the Commission has completed a
backfit analysis for this final rule. The Commission has determined, on
the basis of this analysis, that backfitting to comply with the
requirements of this 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 issued, the NRC had not foreseen the
rate deregulation of the electric utility industry and the changes to
maintenance practices that licensees would make to enhance operational
efficiency. Specifically of concern is the significant increase in
maintenance while the plant is at power, permitting shortened refueling
outages. At-power maintenance practices have evolved to the point that
multiple systems, trains, and components are simultaneously out of
service. Compared to the risk that occurs from expected random
equipment failures, the risk of an accident or transient caused by
taking systems, trains, and components off line for maintenance or from
performing maintenance on systems, trains, or components while they
remain on line could be increased.
The objective of this rule is to require that--
(1) Licensees assess the impact of equipment maintenance on the
capability of the plant to perform key plant safety functions; and
(2) Licensees use the results of the assessment before undertaking
maintenance activities at operating nuclear power plants to manage the
increase in risk caused by those activities.
Thus, the rule adds a new paragraph, (a)(4), that requires the
performance of assessments, specifies that the scope of the requirement
for performing those assessments covers proposed maintenance
activities, specifies that the scope of SSCs to be assessed may be
limited to those that a risk-informed evaluation process has shown to
be significant to public health and safety, and specifies that the
increase in risk that may occur from the maintenance activity must be
managed.
This final rule also adds an introductory sentence to 10 CFR 50.65
clarifying that the rule applies under all conditions of operation,
including normal shutdown; revises the second sentence of paragraph
(a)(3) to simplify the language; and deletes the last sentence of
paragraph (a)(3) of the rule.
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 this modification to the maintenance rule will result in
a substantial increase in the overall protection to the public health
and safety, and that the net costs
[[Page 38557]]
of the rule are justified in view of this increased level of safety.
Small Business Regulatory Enforcement Fairness Act
In accordance with the Small Business Regulatory Enforcement
Fairness Act of 1996, the NRC has determined that this action is not a
major rule and has verified this determination with the Office of
Information and Regulatory Affairs of OMB.
National Technology Transfer and Advancement Act
The National Technology Transfer and Advancement Act of 1995, Pub.
L. 104-113, requires that Federal agencies use technical standards
developed or adopted by voluntary consensus standards bodies unless the
use of such a standard is inconsistent with applicable law or is
otherwise impractical. There are no industry consensus standards that
apply to the area of maintenance. Thus, the provisions of the Act do
not apply to this rulemaking.
List of Subjects in 10 CFR Part 50
Antitrust, Classified information, Criminal penalties, Fire
protection, Intergovernmental relations, Nuclear power plants 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. 552 and 553, the NRC is adopting
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. 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, 68 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 take 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 (including but not
limited to surveillance, post-maintenance testing, and corrective and
preventive maintenance), the licensee shall assess and manage the
increase in risk that may result from the proposed maintenance
activities. The scope of the assessment may be limited to structures,
systems, and components that a risk-informed evaluation process has
shown to be significant to public health and safety.
* * * * *
Dated at Rockville, Maryland, this 13th day of July, 1999.
For the Nuclear Regulatory Commission.
Annette Vietti-Cook,
Secretary of the Commission.
[FR Doc. 99-18325 Filed 7-16-99; 8:45 am]
BILLING CODE 7590-01-P
