AUDIT REPORT

Audit of NRC’s Oversight of Active Component Aging

OIG-14-A-02 –October 28, 2013

All publicly available OIG reports (including this report) are accessible through

NRC’s Web site at: 

http:/www.nrc.gov/reading-rm/doc-collections/insp-gen/
UNITED STATES

NUCLEAR REGULATORY COMMISSION

WASHINGTON, D.C. 20555-0001

OFFICE OF THE

INSPECTOR GENERAL

October 28, 2013

MEMORANDUM TO: Mark A. Satorius

Executive Director for Operations

FROM: Stephen D. Dingbaum /RA/

Assistant Inspector General for Audits

SUBJECT: AUDIT OF NRC’S OVERSIGHT OF ACTIVE COMPONENT 

AGING (OIG-14-A-02)

Attached is the Office of the Inspector General’s (OIG) audit report titled Audit of NRC’s 

Oversight of Active Component Aging.

The report presents the results of the subject audit. The agency provided comments to 

the report on September 27, 2013. The agency’s comments have been incorporated 

into the report at Appendix B.

Please provide information on actions taken or planned on each of the 

recommendations within 30 days of the date of this memorandum. Actions taken or 

planned are subject to OIG followup as stated in Management Directive 6.1.

We appreciate the cooperation extended to us by members of your staff during the 

audit. If you have any questions or comments about our report, please contact me at 

415-5915 or R.K. Wild, Team Leader, Nuclear Reactor Safety Audits Team, 

at 415-5948.

Attachment: As stated 
Audit of NRC’s Oversight of Active Component Aging

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EXECUTIVE SUMMARY

BACKGROUND

The Atomic Energy Act and Nuclear Regulatory Commission (NRC)

regulations limit commercial nuclear power reactor licenses to an initial 40 

years. Due to this selected period, some components may have been 

engineered on the basis of an expected 40-year service life. Components 

degraded due to aging have caused reactor shutdowns, failure of safetyrelated equipment, and reduction in the safety margin of operating nuclear 

power plants. Therefore, effective and proactive management of aging of 

components is a key element for safe and reliable nuclear power plant 

operation. 

NRC has established commercial nuclear power reactor industry 

requirements that exclude some components—referred to as active 

components—from a license renewal aging management review. Active 

components are those that perform their intended functions with moving 

parts or a change in state. Examples of active components include power

supplies, motors, diesel generators, cooling fans, batteries, relays, and 

switches. According to NRC, active components are not subject to review 

as part of NRC’s review of license renewal applications because of the 

existing regulatory process and existing licensee programs and activities. 

The NRC Office of Nuclear Reactor Regulation and the regional offices 

provide regulatory oversight of industry’s active component aging 

activities. NRC addresses aging active component issues through a 

number of different regulations and guidance, to include Title 10 Code of 

Federal Regulations (CFR), Part 50.65, Requirements for monitoring the 

effectiveness of maintenance at nuclear power plants (the Maintenance 

Rule, as amended), 10 CFR Part 50, Appendix B, Quality Assurance 

Criteria for Nuclear Power Plants and Fuel Reprocessing Plants, and 

10 CFR 50.36, Technical specifications.
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OBJECTIVE

The objective of this audit was to determine if NRC is providing effective 

oversight of industry’s aging component programs. 

RESULTS IN BRIEF

Oversight of Active Component Aging Could Be Improved

Oversight of licensees’ activities, including active component aging, 

should be structured and coordinated. However, NRC’s approach for 

oversight of licensees’ management of active component aging is not 

focused or coordinated. This has occurred because NRC has not 

conducted a systematic evaluation of program needs for overseeing 

licensees’ aging management for active components since the 

establishment of the Reactor Oversight Process (ROP) in 2000, and does 

not have mechanisms for systematic and continual monitoring, collecting, 

and trending of age-related data for active components. Consequently, 

NRC cannot be fully assured that it is effectively overseeing licensees’ 

management of aging active components.

RECOMMENDATIONS

This report makes two recommendations to improve the agency’s 

oversight of aging active component activities.

AGENCY COMMENTS

During an August 20, 2013, exit conference and an August 26, 2013, staff 

meeting, agency provided informal comments, which OIG subsequently 

incorporated into the draft report as appropriate. 

On September 27, 2013, NRC provided formal comments to the draft 

report. The agency’s stated that its oversight of active component aging 

issues is being effectively dealt with under existing oversight procedures, 

and that its existing ROP provides the framework for ensuring that aging 

issues with the potential to impact safety are addressed in a timely 

manner. 

OIG’s central message is that because the agency uses regulations and 

inspections procedures for oversight of aging issues that predate the 2000 
Audit of NRC’s Oversight of Active Component Aging

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implementation of ROP and has not since evaluated whether this 

regulations and procedures still function as intended, the agency is not 

able to determine the effectiveness of aging component oversight.

Appendix A contains the audit Objective, Scope, and Methodology; 

Appendix B contains a copy of the agency’s formal comments; and 

Appendix C contains OIG’s analysis of the agency’s formal comments. 
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ABBREVIATIONS AND ACRONYMS

CFR Code of Federal Regulations

IOEB Operating Experience Branch

INL Idaho National Laboratory

NRC Nuclear Regulatory Commission

NRR Office of Nuclear Reactor Regulation

OIG Office of the Inspector General

ROP Reactor Oversight Process
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TABLE OF CONTENTS

EXECUTIVE SUMMARY ........................................................................... i

ABBREVIATIONS AND ACRONYMS .......................................................iv

I. BACKGROUND ............................................................................. 1

II. OBJECTIVE ................................................................................... 4

III. FINDING ........................................................................................ 4

Oversight of Active Component Aging 

Could Be Improved................................................................... 4

Recommendations ................................................................. 15

IV. AGENCY COMMENTS ................................................................. 16

APPENDICES

A. OBJECTIVE, SCOPE, AND METHODOLOGY........................................ 17

B. AGENCY FORMAL COMMENTS ........................................................... 19

C. OIG ANALYSIS OF AGENCY FORMAL COMMENTS ........................... 22
Audit of NRC’s Oversight of Active Component Aging

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I. BACKGROUND 

The Atomic Energy Act and Nuclear Regulatory Commission (NRC) 

regulations limit commercial nuclear power reactor licenses to an initial 40 

years. Due to this selected period, some components may have been 

engineered on the basis of an expected 40-year service life. However, 

components that have aged during the 40-year period can have impacts 

on both the safety and the performance of nuclear power plants. 

Components degraded due to aging have caused reactor shutdowns, 

failure of safety-related equipment, and reduction in the safety margin of 

operating nuclear power plants. Therefore, effective and proactive 

management of aging of components is a key element for safe and 

reliable nuclear power plant operation. 

Aging is defined as a general process in which characteristics of 

components1 gradually change with time or use. Some examples of aging 

mechanisms include wear, fatigue, erosion, microbiological fouling, 

embrittlement, and chemical or biological reactions, or combinations of 

these processes. Proactive aging management means management of 

the aging of components that is implemented with foresight and 

anticipation throughout the component’s lifetime.

2

NRC has established commercial nuclear power reactor industry

requirements that exclude some components—referred to as active 

components—from a license renewal aging management review.

3 Active 

components are those that perform their intended functions with moving 

parts or a change in state. Examples of active components include power

supplies, motors, diesel generators, cooling fans, batteries, relays, and 

switches. According to NRC, active components are not subject to review 

as part of NRC’s review of license renewal applications because of the 

existing regulatory process and existing licensee programs and activities.

 1 For the purposes of this report, the Office of the Inspector General (OIG) uses the term components in place of 

safety-related structures, systems, and components. 2 Proactive Management of Ageing for Nuclear Power Plants, International Atomic Energy Agency, Vienna, 2009. 3 Commercial power reactor licenses can and have been renewed beyond 40 years. As part of license renewal, 

plants undergo an aging management review by the NRC that includes passive components. Passive components 

are components that perform an intended function (as described in Title 10 Code of Federal Regulations (CFR) Part 

54.4) without moving parts or without a change in configuration or properties and include the reactor vessel, steam 

generators, and ventilation ducts.
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Oversight Responsibility for Active Component Aging Activities

The NRC Office of Nuclear Reactor Regulation (NRR) and the regional 

offices provide regulatory oversight of industry’s active component aging 

activities. Agency officials stated that NRC oversight of reactor licensees 

is conducted within the Reactor Oversight Process (ROP) framework. The 

ROP is the agency’s program to inspect, measure, and assess the safety 

performance of commercial nuclear power plants and to respond to any 

decline in performance. OIG auditors did not review the entire ROP

framework. OIG focused on NRC’s active component aging-related 

oversight activities both within and outside the ROP framework.

Primarily, two branches in the NRR Division of Inspections and Regional 

Support—as well as the Divisions of Reactor Projects in NRC regional 

offices—have responsibility for regulatory oversight of licensee programs, 

which would include licensee management of active component aging. 

Within NRR, Reactor Inspection Branch responsibilities include providing 

programmatic leadership and support for activities associated with 

inspecting and assessing licensee performance at commercial nuclear 

power plants. This includes providing the necessary infrastructure for the 

inspection program in coordination with the regional offices, and 

supporting enhanced inspection teams and the ROP. The Operating 

Experience Branch (IOEB) collects, evaluates, and communicates 

information that may have caused domestic and international reactor 

events and provides lessons learned from those events to headquarters, 

the regions, and licensees. While not responsible for oversight, the Office 

of Nuclear Regulatory Research provides support that includes technical 

advice, technical tools, and information for identifying and resolving safety 

issues, including for aging phenomena.

Regulations Applicable to Active Component Aging Oversight 

No Federal law or regulation that pertains to NRC specifically provides for 

the oversight of aging active components. However, NRC inspectors have 

used the following regulations to support a basis for age-related inspection

findings and violations:

• 10 CFR Part 50.65, Requirements for monitoring the 

effectiveness of maintenance at nuclear power plants (the 

Maintenance Rule, as amended) was issued on July 10, 1991. 
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The Maintenance Rule requires, in part, that licensees: 

...shall monitor the performance or condition 

of structures, systems, or components, 

against licensee-established goals, in a 

manner sufficient to provide reasonable 

assurance that these structures, systems, 

and components [...] are capable of fulfilling 

their intended functions. These goals shall 

be established commensurate with safety 

and, where practical, take into account 

industry-wide operating experience. [...]

Monitoring [...] is not required where it has 

been demonstrated that the performance or 

condition of a structure, system, or 

component is being effectively controlled 

through the performance of appropriate 

preventive maintenance... .

• 10 CFR Part 50, Appendix B, Quality Assurance Criteria for 

Nuclear Power Plants and Fuel Reprocessing Plants (10 CFR 

Part 50, Appendix B), requires licensees to maintain a quality 

assurance program for the design, fabrication, construction, and 

testing of the structures, systems, and components of the 

facility.

• 10 CFR Part 50.36, Technical specifications, requires licensees 

to maintain administrative controls, including procedures for 

maintenance, to assure operation of the facility in a safe 

manner. Inspectors sometimes cite licensees for inadequate 

procedures that led to age-related degradation under this 

regulation.

Additionally, there are ROP and other inspection procedures, as well as 

industry operating experience that offer NRC inspectors and staff flexibility 

when used for active component aging oversight. Some, but not all, 

relevant inspection procedures, reports, and studies are listed in Appendix

A of this report.
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II. OBJECTIVE 

The objective of this audit was to determine if NRC is providing effective 

oversight of industry’s aging component programs. 

Appendix A of this report contains information on the audit scope and 

methodology.

III. FINDING

OVERSIGHT OF ACTIVE COMPONENT AGING COULD BE IMPROVED

Oversight of licensees’ activities, including active component aging,

should be structured and coordinated. However, NRC’s approach for 

oversight of licensees’ management of active component aging is not 

focused or coordinated. This has occurred because NRC has not 

conducted a systematic evaluation of program needs for overseeing 

licensees’ aging management for active components since the 

establishment of ROP in 2000, and does not have mechanisms for 

systematic and continual monitoring, collecting, and trending of agerelated data for active components. Consequently, NRC cannot be fully 

assured that it is effectively overseeing licensees’ management of aging 

active components.

Structured Oversight 

Oversight of licensee’s activities should be structured, coordinated, and 

based on the best available knowledge from research and operational 

experience. Commonly accepted, formal approaches to planning of 

Government programs include establishing an overall strategy and goals, 

establishing methodologies for setting priorities, identifying programspecific performance metrics, and managing resources. Additionally, NRC

Principles of Good Regulation require that NRC manages and administers 

its regulatory activities cooperatively and efficiently, that regulatory 

decisions should be made without undue delay, and that regulations 

should be based on the best available knowledge from research and 

operational experience. 
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Furthermore, current and former NRC Commissioners, senior 

management officials, and managers have expectations that the agency is 

providing effective oversight of industry’s active component aging 

programs and have repeatedly emphasized the importance of aging 

oversight. During the 2013 NRC Regulatory Information Conference, the

current NRC Chairman noted that despite an established rigorous 

program for aging management, NRC and industry must be prepared to 

contend with unknowns. Former NRC Commissioners, senior 

management officials, and managers have also expressed the importance 

of strong aging management programs, including those for active

components, and one senior manager stated that NRC currently has

programs in place to monitor aging of active components. Agency 

managers have also emphasized the importance of oversight for active 

component aging activities. However, current and former managers 

having expectations for effective oversight of industry’s aging plants 

generally did not make a distinction between active components and those 

passive components covered by license renewal aging management 

reviews. 

Oversight Structure for Aging Active Component Activities Is Not 

Focused or Coordinated

NRC’s approach for oversight of licensees’ management of active 

component aging is not focused or coordinated. This approach includes 

staff-initiated projects and inspection activities using regulations to cite

licensees for age-related degradation of active components that are not

specific to aging. This challenge is compounded by agency senior 

managers who are not aware of these uncoordinated activities. 

Staff-Initiated Projects

NRC program offices in headquarters and the regions have undertaken 

staff-initiated projects to evaluate age-related active component failures. 

Specifically, the staff-initiated projects have been for data collection,

analysis, and inspection.

Independent of any specific management direction, NRC staff have 

initiated efforts to obtain data for addressing the subject of aging active 
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components because operating experience data is not routinely evaluated 

for information pertaining to the aging of active components. In 2012, 

NRR’s Operating Experience Branch (IOEB) published the IOEB 

Component Aging Study 2007-2011 — Insights from Inspection Findings 

and Reportable Events, July 24, 2012 (IOEB Study).4

 The IOEB Study

focused on safety-related and important-to-safety active component 

failures attributed to age-related degradation. In part, the IOEB Study

noted that the number of occurrences involving age-related active 

component failures has increased since 2009. The IOEB Study concluded 

that some licensees do not have effective life-cycle preventive 

maintenance programs for some components where industry and vendor 

experience has suggested this is necessary. Furthermore, the IOEB 

Study concluded that NRC oversight programs may not be focused on 

aging management of active components and these programs could be 

better prepared to deal effectively with an industry that potentially is 

experiencing notable occurrences of age-related component failures. 

The results of the IOEB Study prompted other NRC offices to generate

active component age-related projects, again, without top agency 

management oversight and without any coordination. The Office of 

Nuclear Regulatory Research reviewed available active component agerelated data5 contained in the Idaho National Laboratory (INL) report, 

Component Age Traits from EPIX, July 3, 2012. The INL report also 

evaluated the extent to which age-related active component failures were 

increasing, but Office of Nuclear Regulatory Research staff could not 

determine from the INL report if that was the case, due to limitations with 

the available data.

In another active component age-related project, regional office 

inspection staff familiar with active component aging problems and the 

IOEB Study conducted what staff described as an inspection to determine

if active component aging could be addressed through existing inspection 

procedures. Accordingly, a Problem Identification and Resolution

inspection was scheduled and conducted in November 2012 with the 

objective of gathering information to determine if a licensee had a periodic,

time-based replacement program for aging active components.

 4 This study is publically available; see ADAMS accession number ML13044A469.

5 These data were originally sourced from the Institute for Nuclear Power Operations Equipment Performance and 

Information Exchange database.
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Regulations Used for Citing Licensees for Age-Related Degradation

Inspectors can use various NRC regulations to cite licensees for agerelated degradation of active components that are not specific to aging.

These regulations do not establish limits on the age of active components 

in commercial nuclear power plants, or prohibit degradation of active 

components by aging. Instead, NRC has regulations that establish 

equipment performance requirements that may not be met by components 

that have degraded due to aging. Inspectors said that they use the 

following regulations for inspections to meet the challenge of identifying 

aging active components and citing licensees for age-related violations:

• 10 CFR 50.65, Requirements for monitoring the effectiveness of 

maintenance at nuclear power plants (the Maintenance Rule).

• 10 CFR Part 50, Appendix B, Quality Assurance Criteria for 

Nuclear Power Plants and Fuel Reprocessing Plants.

• 10 CFR 50.36, Technical specifications.

The Maintenance Rule

NRC inspectors’ experience with citing licensees for violations of the 

Maintenance Rule for age-related active component failures varies

because—as NRR and regional inspection staff explained—the 

Maintenance Rule is not well understood by less experienced NRC staff.

Furthermore, NRR and regional staff said that there are not enough NRC 

staff with Maintenance Rule experience who can use it to cite licensees for 

age-related failures within the performance-based ROP framework. NRC 

management and staff also conveyed that an experienced inspector may 

cite a licensee for age-related inspection findings and violations under the

Maintenance Rule Section (a)(3) when the licensee has not taken into 

consideration applicable operating experience, whereas less experienced 

inspectors are less likely to do so. Other NRC staff voiced a similar 

concern regarding a lack of inspectors with experience using the 

Maintenance Rule. OIG noted that inspectors have rarely used the 

Maintenance Rule to cite licensees for failure of safety-related 

components due to aging. Of the 105 age-related active component

failures and reportable events from 2007 to 2011 identified in the IOEB 

Study, only 3 were cited for violations of the Maintenance Rule. Although 

Maintenance Rule violations do include some findings attributed to aging, 
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most Maintenance Rule violations do not include end of life aging as 

defined by the IOEB Study.

The following table provides additional details relating to the three

Maintenance Rule violations noted above. In each case, the licensee left 

active components in service until they failed through shortcomings in 

preventive maintenance activities. 

Figure 1: Three NRC Maintenance Rule Citations, 2007-2011

Date Plant Type of Age-Related Failure Cause

2011 Waterford Electronic control components for 

cooling towers failed after operating 

for 25 years. 

Aging. The 

maintenance to 

replace the 

components was 

deleted from 

preventive 

maintenance 

activities.

2009 Catawba Auxiliary feed water sump valves 

important to plant safety failed.

Aging. No 

maintenance was 

performed on the 

valves since plant 

startup in 1985.

2007 Brunswick A relay for controlling an emergency 

diesel generator failed. 

Aging. The relay’s 

coil failed due to the 

deferral of 

maintenance.

Source: IOEB Study

According to agency staff, the ROP’s emphasis on performance-based 

and risk-informed oversight limits their ability to evaluate licensee 

preventive maintenance programs. This limitation exists because NRC 

does not perform programmatic inspections of licensees’ preventive 

maintenance programs. For example, a regional senior management 
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official described how there were aging problems found at Fort Calhoun by 

the inspectors during additional inspections after a flood, but routine ROP 

inspections are not structured to focus inspection resources on active 

component age-related issues. Another regional senior management 

official confirmed that the ROP does not have provisions to look at a 

licensee’s preventive maintenance programs, but focuses on performance 

and evaluates licensee response to failures after the fact—that is, after a 

component failure—and how the licensee addresses the cause of the 

failure as part of its Corrective Action Program.

Several NRC staff with inspection experience stated that the Maintenance 

Rule as currently in use is not structured to address aging active 

components.

Other Regulations Used for Citing Licensees for Age-Related Failures

Inspectors are likely to use other regulatory provisions—specifically, 

10 CFR Part 50, Appendix B, and plant technical specifications—for citing 

licensees for age-related failures because findings can be supported and 

justified more readily than by using the Maintenance Rule. According to 

NRC staff, using 10 CFR Part 50, Appendix B, provisions to cite licensees 

for quality assurance shortcomings related to component design, 

fabrication, construction, operation, and testing is easier than using the 

Maintenance Rule. Similarly, NRC inspectors have cited licensees for 

violating plant technical specifications, specifically for lacking adequate 

justification for running active components beyond vendor recommended 

life and not having appropriate maintenance procedures in place. 

However, 10 CFR Part 50, Appendix B, and 10 CFR 50.36, Technical 

specifications, do not contain age-related criteria for supporting agerelated findings.

Management Not Always Cognizant of Active Aging Component Activities

Agency managers are not always cognizant of the staff’s activities related 

to active component aging. NRR senior managers were not aware of the 

status of staff implementation of the IOEB Study conclusions and 

recommendations. Although senior managers indicated that NRC has 

robust programs in place that address active component aging and that 

staff were following up on the IOEB Study conclusions and 

recommendations, neither was the case during the course of the audit. 
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Staff indicated that the agency is taking action to follow up on the results 

of the aging component study, but the agency’s plan for considering and 

implementing the IOEB Study conclusions and recommendations is 

unclear.

Although the IOEB Study was peer-reviewed and issued internally via 

OpE COMM6 in June 2012 and presented to an ROP enhancement group 

in March 2013, a number of senior managers and program office and 

regional staff having active component aging responsibilities were 

unfamiliar with the status of staff implementation of the IOEB Study

conclusions and recommendations. One NRR senior manager indicated

that the IOEB Study was an important effort and thought that agency staff 

were following up on the study’s conclusions and recommendations. 

However, the NRR senior manager’s direct report and regional senior 

managers that the NRR senior manager identified as familiar with the 

IOEB Study were not aware of the details of the study or proposed 

followup actions. 

NRR senior management also indicated that regional office management 

officials would provide insight on aging active component efforts and 

follow up on the IOEB Study conclusions and recommendations.

However, of the two regional management officials to whom NRC staff 

had provided copies of the report, one noted that the IOEB Study was for 

informational purposes only and did not require action. Furthermore,

neither was aware of the details of the IOEB Study and therefore was not 

able to offer insight on aging active component efforts and staff followup 

on the IOEB Study conclusions and recommendations. 

Furthermore, agency managers and staff have conflicting understandings

of and did not coordinate how a biennial ROP enhancement effort7 may 

incorporate changes to active component aging oversight. Specifically, 

senior managers indicated that IOEB Study conclusions and 

 6

 OpE COMMs (Operating Experience Communications) contain preliminary information in the interest of timely 

internal communication of operating experience. OpE COMMs may be predecisional and may contain sensitive 

information. They are not intended for distribution outside the agency. 7 The biennial ROP review allows NRC to evaluate licensee performance on a regular, recurring basis. In 2013, NRC 

undertook to enhance the review by taking additional measures as part of the review. During the review, named ROP 

Enhancement—Baseline Inspection Program, champions and key staff will make changes to the inspection 

procedures based on analysis completed by the inspection procedure owners, information and knowledge from 

inspectors, special groups and reports, lessons learned, and recent events and inspections. 
Audit of NRC’s Oversight of Active Component Aging

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recommendations will likely be included in the 2013 ROP enhancement 

effort. However, a key NRR staff member involved with the review said

that ROP enhancement will not include active component aging because

the Maintenance Rule, in the staff’s opinion, already addresses active 

component aging. Yet staff in the IOEB stated that, as far as they were 

aware, there had been no official coordination between the operating

experience and the inspection branches for including active component 

aging oversight. Nonetheless, NRC staff were unable to provide any 

specific documentation of the agency’s plan for including the IOEB Study

conclusions and recommendations in the ROP enhancement effort. 

Consequently, OIG could not independently confirm the extent to which 

the subject of active component aging is being considered for inclusion in 

the review.

NRC Has Not Evaluated or Analyzed the Need for a Formal Program

and Has Not Systematically and Continually Collected or Evaluated 

Active Component Age-Related Data

The unfocused and uncoordinated approach NRC uses in its oversight of 

licensees’ active aging component activities is occurring because NRC:

• Has not conducted a systematic evaluation of program needs for 

overseeing licensees’ aging management for active components.

• Does not have mechanisms for systematic and continual monitoring, 

collecting, and trending of age-related data for active components. 

NRC Has Not Conducted a Systematic Program Needs Evaluation and 

Analysis

Since the ROP was initiated in 2000, NRC has not conducted an

evaluation and analysis that would systematically determine whether the 

need exists for a formal active aging component oversight program. NRC 

has not systematically evaluated the need for specific program policies, 

goals, and objectives, and the need for program feedback and corrective 

actions for continual improvement, all within the context of the current 

ROP environment.8

 The most recent evaluation of the agency’s regulatory 

 8

This is not to suggest that NRC inspection procedures have remained static over the years. For example, according 

to agency staff, Inspection Procedure 71111.21, Component Design Bases Inspection, was updated in August 2012 
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oversight of active component aging was in 19969—which pre-dates the 

ROP—and stressed the importance of aging studies as an important part 

of efforts to identify and solve potential aging problems.

In addition, nuclear plants have aged almost 20 years since the most 

recent evaluation of the agency’s regulatory oversight of active component 

aging in 1996. The report that resulted from this evaluation asserted that,

...active components generally do not 

present a significant aging problem in 

nuclear power plants. Design criteria and 

effective preventative maintenance 

programs, including timely replacement of 

components, are effective in mitigating 

potential aging problems... .

However, NRC does not inspect preventive maintenance programs 

directly and comprehensively to ensure they are effective. Aging can 

cause active component degradation and failure resulting in unexpected 

reactor power changes, failures of components to perform their safety 

function, and adverse effects to the safety margin. For example:

• OIG identified an unexpected reactor power change and automatic 

reactor shutdown that occurred at a commercial power reactor in 

2012. The shutdown was due to a failed switch which had been in 

service over 40 years with no preventive maintenance performed.

• The IOEB Study reported an incident from 2010 whereby a relay 

failed after not being replaced or monitored at the required 

periodicity, resulting in the failure of an emergency diesel generator 

to provide power to safety systems when it was called upon to do 

so during a partial loss of electrical power at the plant.

 

to include the statement “...inspectors should try to determine through review of these corrective work 

maintenance activities whether licensee’s preventive maintenance or other programs such as aging management 

are being reasonably effective in preventing component failures.” OIG’s wider point is that activities—such as 

inspection procedure changes—have been undertaken without the benefit of a systematic program needs 

evaluation and analysis.

9 NUREG/CR-6442, Evidence of Aging Effects on Certain Safety-Related Components, NRC and Idaho National 

Laboratories, 1996.
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• The IOEB Study also reported that in 2010, an age-related failure of 

a pressure switch caused an unexpected reactor power change 

and automatic reactor shutdown. This pressure switch had been 

installed for 39 years. 

Other active component aging studies conducted both in the United States 

and internationally offer examples of qualitative and quantitative data 

related to active component failures. In general, these studies all 

emphasize the importance of having a continual awareness of potential 

aging problems. 

NRC Has Not Systematically and Continually Collected or Evaluated 

Active Component Age-Related Data

NRC has not developed and incorporated within policy and guidance the 

existing mechanisms used for systematic and continual monitoring, 

collecting, and trending of age-related data for active components. 

Age-related studies have emphasized the importance of continual 

monitoring, collecting, and trending of age-related data for active 

components in an ever changing environment. Yet, NRC has not 

systematically and continually collected or evaluated age-related data to 

determine if a specific oversight program is needed or what type of 

program would be necessary. Currently, NRC may identify data on active 

component aging intermittently during ROP inspections, but not through 

any methods of systematic data collection, analysis, and trending. 

Although the IOEB Study and the INL report identified age-related data 

from existing reports and evaluated it based on types of failure and 

age-related causes, discussions with NRC staff revealed that at present, 

age-related failures are not consistently identified in existing reporting 

mechanisms, when they are identified at all. An experienced NRR staff 

member told OIG that there could be a rise in the number of identified 

age-related events if the proper regulatory tools were in place to identify 

them.

NRC Cannot Be Fully Assured of Effective Oversight 

Despite management’s belief that active component aging issues are 

being satisfactorily addressed, NRC is not in a position to draw any 

conclusions one way or the other. If NRC’s unfocused and uncoordinated 

approach for oversight of licensees’ active component aging activities 
Audit of NRC’s Oversight of Active Component Aging

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continues, NRC will not be fully assured that it is effectively overseeing 

licensees’ aging active component programs. Specifically, the agency will 

not be a position to:

• Identify and evaluate trends that have safety implications. 

• Proactively identify active components subject to age-related 

failure before they are run to failure. 

• Provide complete inspector training and guidance.

• Close the performance gap between experienced inspectors 

who know how to identify active components that are run 

beyond their reasonably expected service lives and less

experienced inspectors who must evaluate active component 

failures where age degradation may have been a significant 

factor. 

Conclusions

NRC’s unfocused and uncoordinated approach for oversight of active 

aging component activities is characterized by staff-initiated projects and 

inspection activities, and incognizant managers. Without direction from 

senior management, staff are conducting work to heighten awareness of 

active component aging and senior management is not aware of various 

active component aging oversight activities that are underway. 

Despite concerns of component aging in nuclear power plants that are 

growing older, the agency does not routinely collect and monitor instances 

of active component failures due to aging. Indeed, the very act of 

inspecting for these aging effects before failures occur appears to be 

difficult for the agency to undertake under ROP. This failure to routinely 

collect and monitor such data runs counter to the need to do so for the 

agency to maintain and adjust its approach to active component aging 

oversight.
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Recommendations

OIG recommends that the Executive Director for Operations:

1. Perform and document a thorough and systematic evaluation of the 

need for an NRC program to oversee the management of active 

component aging activities, all within the context of the current ROP 

environment. Evaluation elements are to include, but should not be 

limited to, the need for:

(a) Program policies, goals, and objectives.

(b) Program feedback and corrective actions for continual 

improvement.

2. Develop and incorporate the mechanisms for monitoring, collecting, 

and trending age-related data for active components within NRC 

policy and procedures.
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IV. AGENCY COMMENTS

On July 22, 2013, OIG issued the discussion draft of this report to the Executive 

Director for Operations. OIG met with NRC management and staff on August 20, 

2013, at an exit conference and on August 26, 2013 at a staff meeting to discuss 

the draft report content. At these meetings, the agency provided informal 

comments, which OIG subsequently incorporated into the draft report as 

appropriate. 

On September 27, 2013, NRC provided formal comments to the draft report that 

indicated their disagreement with the audit report content. The agency’s formal 

comments state, in part, that NRC disagrees that it needs to perform a thorough 

and systematic evaluation to determine the need for a specific NRC program to 

oversee the management of active component aging activities, because the ROP 

performs this task by providing a framework for ensuring that both active and 

passive aging issues are addressed. OIG auditors concluded that the agency is 

not in a position to determine the effectiveness of active component aging 

oversight. This is because the agency uses regulations and inspection 

procedures for oversight of active component aging that were established prior to 

the implementation of ROP in 2000 and has not, since ROP implementation, 

evaluated whether those regulations and inspection procedures work the same 

way as intended in the pre-ROP regulatory environment.

Appendix A contains the audit Objective, Scope and Methodology; Appendix B 

contains a copy of the agency’s formal comments; and Appendix C contains 

OIG’s analysis of the agency’s formal comments.
Audit of NRC’s Oversight of Active Component Aging

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APPENDIX A

OBJECTIVE, SCOPE, AND METHODOLOGY

OBJECTIVE

The audit objective was to determine if NRC is providing effective 

oversight of industry’s aging component programs. 

SCOPE

We conducted this performance audit at NRC headquarters in Rockville, 

MD, and collected information from the regional offices via telephone and 

in conjunction with the Audit of NRC’s Support for Resident Inspectors, 

from October 2012 through May 2013. The audit scope was limited to 

NRC’s regulatory responsibilities as they pertain to aging active 

component programs at commercial nuclear power plants. Internal 

controls related to the audit objectives were reviewed and analyzed. 

METHODOLOGY

To address the audit objective, OIG interviewed agency senior 

management officials, and headquarters and regional staff. OIG also 

reviewed NRC regulations and guidance, as well as domestic and 

international operational experience reports pertaining to active aging 

components. OIG subsequently compared the information provided 

during the interviews with staff actions. Throughout the audit, auditors 

were aware of the possibility or existence of fraud, waste, or misuse in the 

program. Some of the key documents referred to in this report include the 

following: 

Regulations:

• 10 CFR Part 50.65, Requirements for monitoring the effectiveness 

of maintenance at nuclear power plants.

• 10 CFR Part 50, Appendix B, Quality Assurance Criteria for Nuclear 

Power Plants and Fuel Reprocessing Plants.

• 10 CFR Part 50.36, Technical specifications.
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Inspection Procedures:

• Inspection Procedure 71111.21, Component Design Bases 

Inspection.

• Inspection Procedure 71152, Problem Identification and Resolution.

Operating Experience Reports: 

• IOEB Component Aging Study (2007-2011) – Insights from 

Inspection Findings and Reportable Events, July 24, 2012.

• IOEB Analysis Team Study on Recent Operating Experience 

Ineffective Use of Vendor Technical Recommendations, June 6, 

2011.

• Idaho National Laboratories, Component Age Traits from EPIX, 

July 3, 2012.

• International Atomic Energy Agency Safety Report Series, No. 62, 

Proactive Management of Ageing for Nuclear Power Plants, 2009. 

• European Commission Joint Research Center, Ageing Related 

Events Topical Study, 2011.

• NRC and Idaho National Laboratories, Evidence of Aging Effects 

on Certain Safety-Related Components, NUREG/CR-6442, 1996.

We conducted this performance audit in accordance with generally 

accepted government auditing standards. Those standards require that 

we plan and perform the audit to obtain sufficient, appropriate evidence to 

provide a reasonable basis for our findings and conclusions based on our 

audit objectives. We believe that the evidence obtained provides a 

reasonable basis for our findings and conclusions based on our audit 

objectives. 

Contributors to this report were R.K. Wild, Team Leader; Kevin Nietmann, 

Senior Technical Advisor; Vicki Foster, Audit Manager; Timothy Wilson, 

Senior Management Analyst; Larry Weglicki, Senior Auditor; Jenny 

Cheung, Auditor; and Tariq Noaman, Management Analyst.
Audit of NRC’s Oversight of Active Component Aging

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APPENDIX B

AGENCY FORMAL COMMENTS
Audit of NRC’s Oversight of Active Component Aging

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Audit of NRC’s Oversight of Active Component Aging

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APPENDIX C

OIG ANALYSIS OF AGENCY FORMAL COMMENTS

On July 22, 2013, OIG issued the discussion draft of this report to the Executive 

Director for Operations. OIG met with NRC management and staff on August 20, 

2013, at an exit conference and on August 26, 2013, at a staff meeting to discuss 

the draft report content. At these meetings, the agency provided informal 

comments, which OIG subsequently incorporated into the draft report as 

appropriate. On September 27, 2013, NRC provided formal comments to the 

draft report that indicated their disagreement with the audit report contents. 

OIG’s analysis of those comments is as follows:

OIG maintains that NRC needs to improve the unfocused and uncoordinated 

approach management officials use for oversight of licensees’ management of 

active component aging. The comments that the agency provided reflect an 

overall misunderstanding and misinterpretation of the report content. 

OIG has assigned a reference number to each of the agency’s comments to aid 

the following point-by-point analysis:

Agency Comment 1:

“NRC disagrees with the major premise of this audit, which is that the NRC 

oversight of active component aging is not being effectively dealt with under 

existing oversight programs.”

OIG Response to Agency Comment 1:

The agency misunderstands and has misinterpreted the audit’s major premise. 

The major premise of this report is not that oversight of active component aging 

is not being effectively dealt with under existing oversight programs. The 

message is that OIG could not determine the extent to which NRC provides 

effective oversight due to a lack of agency analysis that tests its assumptions 

regarding active component aging. OIG concluded that this has occurred 

because NRC has not conducted a systematic evaluation of program needs for 

overseeing licensees’ aging management for active components since the 

establishment of ROP in 2000, and does not have mechanisms for continual 

monitoring and trending of age-related data for active components. 

Consequently, NRC cannot be fully assured that it is effectively overseeing 

licensees’ management of aging active components.
Audit of NRC’s Oversight of Active Component Aging

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Agency Comment 2:

“Nearly all of the active component aging data contained within the Office of 

Nuclear Reactor Regulation (NRR) Operating Experience Branch (IOEB) Aging 

Study was derived from inspection findings in which NRC inspectors effectively 

documented active component aging issues and cited associated violations of 

the regulations.”

OIG Response to Agency Comment 2:

NRC’s statement that nearly all of the active component aging data contained 

within the Office of Nuclear Reactor Regulation IOEB Component Aging Study 

2007-2011 — Insights from Inspection Findings and Reportable Events, July 24, 

2012 (IOEB Study) was derived from inspection findings in which NRC inspectors 

effectively documented active component aging issues and cited associated 

violations of the regulations is not correct.

OIG analysis of the inspection and event reports from which the IOEB Study data 

was derived indicates that about one quarter of the failures identified in the report 

were not derived from inspection reports. Rather, these failures were provided 

by licensees to NRC in licensee event reports. Moreover, almost all of the 

regulatory non-compliances are non-cited violations. The agency’s claim that 

almost all of the 105 events were cited violations derived from inspection activity

is inaccurate. In fact, more than half of the events in the report did not result in

violations of any kind.

Prior OIG analysis10 indicates that for every safety-related component failure that 

occurs and is reported, there are several that occur but do not meet the level of 

reportability using 10 CFR Part 50.72, Immediate Notification Requirements for 

Operating Nuclear Power Plants and 10 CFR 50.73, Licensee Event Report 

System reporting criteria, indicating that there may be many more safety-related 

components that have degraded or failed due to aging that have not been 

reported to NRC.

 10 Audit of NRC's Implementation of 10 CFR Part 21, Reporting of Defects and Noncompliance, OIG-11-A-08, March 

23, 2011.
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Agency Comment 3:

“The staff also does not agree that its activities for managing active component 

aging are not focused or coordinated. While we agree that there is no one 

section of the regulations or oversight programs that specifically deals with active 

component aging, and while there is always room for improvement, active 

component aging issues are effectively addressed through various aspects of the 

regulations and oversight programs. For example, the staff relies on Title 10 of 

the Code of Federal Regulations (10 CFR) Part 50, “Domestic Licensing of 

Production and Utilization Facilities,” Appendix B, “Quality Assurance Criteria for 

Nuclear Power Plants and Fuel Reprocessing Plants,” (Criteria III, V, XI, and 

XVI), technical specifications, and the Maintenance Rule, all of which deal with 

component degradation and age related performance issues.” 

OIG Response to Agency Comment 3:

OIG did not conclude that regulations were unfocused and uncoordinated or that 

active component aging issues are not effectively addressed through various 

aspects of the regulations and oversight programs. Rather, OIG concluded that 

NRC’s approach for oversight of licensees’ management of active component 

aging is not focused or coordinated because NRC’s approach includes staffinitiated projects, using inspections that are not aging-related, and agency senior 

managers who are not aware of these uncoordinated activities. 

Furthermore, NRC asserted that active component aging issues are effectively 

addressed through various aspects of the regulations and oversight programs. 

For the sake of clarity, OIG did not indicate anywhere in the report that the use of 

the regulations was ineffective. OIG even stated in the report that inspectors 

have used those regulations to support a basis for age-related inspection 

findings. However, with regard to effectiveness, OIG stated in the report that it 

could not determine the extent to which NRC provides effective oversight due to 

a lack of agency analysis that tests its assumptions regarding active component 

aging.

Agency Comment 4:

“Licensee performance is assessed against these regulations under the Reactor 

Oversight Process (ROP), which allows inspectors and NRC managers to ensure 

regulatory compliance. The NRC deals with issues identified under the ROP in a 

performance based and risk informed manner. Furthermore, the NRC has ample 

regulations that require licensees to report performance issues that may be 

caused by active component aging. These include the reporting requirements of 

10 CFR 50.72, “Immediate Notification Requirements for Operating Nuclear 

Power Plants,” and 10 CFR 50.73, “Licensee Event Report System.” 
Audit of NRC’s Oversight of Active Component Aging

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OIG Response to Agency Comment 4:

The agency states that NRC has ample regulations that require licensees to 

report performance issues that may be caused by active component aging. 

However, OIG did not conclude that regulations or reporting methods were 

inadequate. OIG did note that NRC was not in a position to determine whether 

or not oversight of active aging components was effective because NRC had not

collected and evaluated the requisite data to determine the need for further 

action regarding active component aging. In such a scenario, it would be 

inappropriate for OIG, NRC, or anybody else to conclude one way or the other 

whether the regulations or reporting methods were adequate.

Agency Comment 5:

“When this information is combined with ROP inspection results and industry 

component failure databases—all of which are routinely assessed by the staff—

they provide ample visibility for the staff to collect and evaluate age related data 

for active components. The staff does not believe that additional programs that 

involve monitoring, collecting, and trending of active component aging are 

necessary to identify adverse trends or to take appropriate regulatory action.”

OIG Response to Agency Comment 5:

NRC states that the staff does not believe that additional programs that involve 

monitoring, collecting, and trending of active component aging are necessary to 

identify adverse trends or to take appropriate regulatory action. OIG recognizes 

that NRC collects a great deal of industry operating experience. However, the 

agency does not collect or evaluate it for aging active component degradation or 

failures. Given the evidence reviewed in this audit, OIG concluded that NRC

should establish a factual basis for its belief that no additional programs for the 

monitoring, collecting, and trending of active component aging data are

necessary. 

Agency Comment 6:

“The staff also disagrees that it needs to perform a thorough and systematic 

evaluation to determine the need for a specific NRC program to oversee the 

management of active component aging activities. The ROP performs this task 

by providing a framework for ensuring that both active and passive aging issues 

with the potential to impact safety are addressed in a timely manner. The NRC 

has processes in place to systematically evaluate the results of the ROP, along 

with other data sources, and these processes provide adequate assurance that 

the NRC will identify safety-significant, age-related failures of active 

components.”
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OIG Response to Agency Comment 6:

As noted in the report, the agency is not in a position to determine the 

effectiveness of active aging oversight because they have not done the 

necessary evaluation to conclude whether or not an active component aging 

oversight program is needed. OIG asked for, and the agency did not provide,

evidence that it already performs a systematic evaluation that proves specifically 

how ROP and the other processes adequately address active component aging. 

Furthermore, for ROP and the other processes that NRC asserts adequately 

address active component aging, the agency does not evaluate program results 

to determine if active component aging degradation and failures are acceptable 

or not. A recent example—whereby inspectors found numerous active 

component age-related issues during additional inspections in response to 

failures at the Fort Calhoun Nuclear Power Plant after notable performance 

deficiencies occurred—suggests the need to evaluate all of those regulations and 

processes that NRC claims have been effective in the oversight of active 

component aging.

Agency Comment 7:

“Furthermore, the staff believes that no additional mechanisms are needed to 

monitor, collect, and trend age-related data on active component aging. The 

staff already collects or has access to operating experience data gathered from 

reportable events, international events, industry failure data, and inspection 

findings that are routinely screened for significance and trending and analysis. 

The creation of additional mechanisms to perform these tasks is not necessary.”

OIG Response to Agency Comment 7:

The staff believes that no additional mechanisms are needed to monitor, collect, 

and trend age-related data on active component aging because the staff already 

collects or has access to operating experience data. In fact, OIG found that the 

staff does collect data, but the data is not analyzed to identify or trend active 

component degradation/failures. Furthermore, OIG notes that existing operating 

experience data gathered from reportable events, international events, industry 

failure data, and inspection findings are routinely screened for significance and 

trending and analysis but not for active component degradation and failure due to 

aging. NRC does not collect active aging data using “active component aging”

as a specific, discrete subcategory, although the infrastructure is in place to do 

so. According to an industry organization representative’s presentation during 

the 2013 NRC Regulatory Information Conference, the system NRC uses to 

obtain age-related data could be programmed to include aging as a cause code 

field that can be selected for age-related data collection purposes. Furthermore, 
Audit of NRC’s Oversight of Active Component Aging

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an NRR senior manager said that he would communicate with an industry 

contact to obtain NRC access to additional operating experience data.

OIG determined that NRC has not developed or incorporated within policy and 

guidance the mechanisms for continually monitoring, collecting, and trending 

age-related data for active components. These mechanisms could be the 

existing infrastructure for collecting and evaluating operating experience data or 

new mechanisms at NRC’s discretion. 

OIG made changes to this report to clarify that NRC has not systematically and 

continually collected or evaluated active component age-related data using 

existing mechanisms.

Agency Comment 8: 

“There are valid reasons why inspectors cite different requirements to document 

findings involving age-related issues. These may include variability in the 

identified performance deficiencies, event causes, and plant licensing bases. 

Reasons for the variability in citing different requirements were not explored in 

the report.”

OIG Response to Agency Comment 8:

OIG described how inspectors cite licensees against regulations to address 

aging active component failures and did not challenge the use of multiple 

regulations to cite licensees. OIG did not state that the reasons why inspectors 

cite different requirements to document findings involving age–related issues was 

invalid or question the variability in citing different requirements. OIG does call 

into question, however, the variability in use of any of the regulatory or inspection 

tools that is due to unfamiliarity or lack of inspector experience as described in 

this report with regard to a lack of understanding of the Maintenance Rule for 

purposes of inspecting for active component aging phenomena. That such 

variability exists for these reasons and that NRC managers are unaware of this 

variability is a central message of the OIG report.

Agency Comment 9:

“The staff is actively considering recommendations identified in the IOEB Study

for improving inspector awareness of aging issues and clarifying inspection 

procedure guidance as part of the ongoing ROP Enhancement Project.”

OIG Response to Agency Comment 9:

The IOEB Study was completed in July 2012 and was presented to NRR 

management in November 2012. In March 2013, NRC staff provided OIG with 
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conflicting information regarding inclusion of the aging study as part of the ROP 

Enhancement Project, which was documented in the audit report. OIG continues 

to note that NRC is actively considering the IOEB Study recommendations;

however, the agency has not been clear as to what, exactly, comprises that

consideration.

Agency Comment 10:

“The IOEB study represented a new approach for performing analysis of ROP 

data. While the program has experience with the communication and 

implementation of recommendations for specific technical issues, the structure 

for implementing the kind of broad recommendations that were presented in this 

study, and which require coordination across multiple offices, is being refined as 

the recommendations are being implemented, presenting learning opportunities 

and challenges for their completion.”

OIG Response to Agency Comment 10:

The agency states that it is in the process of implementing the IOEB Study 

recommendations. However, OIG notes that this comment is inconsistent with 

Agency Comment 9 above that states the IOEB Study is being considered as 

part of the ROP Enhancement Project. Based on these formal comments, it is 

not clear whether the agency is considering or implementing the 

recommendations. The agency has been rather opaque in its responses to OIG 

auditor inquiries as to what recommendations, specifically, are under 

consideration or being implemented.

Agency Comment 11:

“The NRC staff points to the overall capability of the ROP (including the structure 

of the Significance Determination Process) and current reporting requirements as 

substantive evidence that there is adequate assurance that it is addressing active 

component aging issues impacting safety.”

OIG Response to Agency Comment 11: 

The agency did not provide substantive evidence of adequate assurance that it is 

addressing active component aging issues impacting safety. In fact, the agency 

provided no evidence and believes that active component issues are addressed 

through ROP. OIG could not therefore determine the extent to which NRC 

provides effective oversight due to a lack of agency analysis that tests its 

assumptions regarding active component aging. 

Furthermore, OIG did not state that there was inadequate assurance that ROP

and current reporting requirements were addressing active component aging 
Audit of NRC’s Oversight of Active Component Aging

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issues impacting safety. OIG noted that a systematic evaluation of program 

needs for overseeing licensees’ aging management for active components has 

not been conducted since the establishment of ROP in 2000. Additionally, NRC 

does not trend active component aging degradation and failures that could 

provide evidence of adequate assurance that it is addressing active component 

aging issues impacting safety. Consequently, NRC cannot be fully assured that 

it is effectively overseeing licensees’ management of aging active components.