POLICY ISSUE 

(Information) 

December 2, 2009 SECY-09-0174

FOR: The Commissioners 

FROM: Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 

SUBJECT: STAFF PROGRESS IN EVALUATION OF BURIED PIPING AT 

NUCLEAR REACTOR FACILITIES 

PURPOSE

This paper responds to the Chairman’s memorandum dated September 3, 2009, (Agencywide 

Documents Access and Management System (ADAMS) Accession No. ML092460648) tasking 

the staff to describe the activities currently underway or planned addressing the issue of leaks 

from buried piping. In his memorandum, Chairman Jaczko requested a staff evaluation of the 

adequacy of (1) Nuclear Regulatory Commission (NRC) requirements for design, inspection and 

maintenance of safety-related buried piping; (2) American Society of Mechanical Engineers 

Code (ASME Code) requirements for design, inspection, and maintenance of safety-related 

piping; and (3) voluntary initiatives for the design, inspection, and maintenance of safety-related 

and nonsafety-related buried piping. The Chairman also requested a discussion of staff plans 

for recommending any revisions to regulations, requirements, practices or oversight related to 

buried piping. 

BACKGROUND

Over the past several years, instances of buried piping leaks have occurred in safety-related 

and nonsafety-related piping at nuclear power plants. Some of these leaks have caused 

inadvertent releases of low-level radioactive material and diesel fuel oil. This has resulted in 

groundwater contamination at several plants. The pipe degradation leading to these leaks has 

not affected the operability of safety systems, and the type and amount of radioactive material 

or chemicals released to the environment have been a small fraction of the regulatory limits. 

Consequently, these pipe leaks have been of low significance with respect to public health and 

safety. 

CONTACT: Robert O. Hardies, NRR/DCI 

 301-415-5802
The Commissioners - 2 - 

The NRC staff has evaluated these recent leakage events, root cause evaluations and licensee 

corrective actions. Based on application of NRC’s performance-based and risk-informed 

Reactor Oversight Process (ROP), these recent events did not constitute performance 

deficiencies of greater than minor safety significance because the radiological consequences 

associated with the leaks were very low and because the capability of the piping to perform its 

safety function was not degraded. Upon application of NRC’s Issue Screening and Significance 

Determination Processes, the staff determined the issues were of minor safety significance.1

 

Accordingly, these buried pipe leakage events have not warranted enforcement actions. 

In May 2006, the U.S. commercial nuclear power plants adopted the Nuclear Energy Institute 

(NEI) Groundwater Protection Initiative (GPI) in response to leaks containing radioactive 

material at several plants. The initiative is described in Attachment 1 to "NEI-07-07 Industry 

Ground Water Protection Initiative - Final Guidance Document," dated August 2007 (ADAMS 

Accession No. ML062260198). The initiative, which all plants committed to follow, identifies 

actions to improve licensee response to inadvertent releases that may result in low but 

detectible levels of plant-related radioactive materials in subsurface soils and water. The GPI 

provides the actions licensees are expected to take including the development of written 

groundwater protection programs, improved stakeholder communications, and program 

oversight. One objective of the GPI is to detect leaks well before they can challenge regulatory 

limits for unintended release of radioactive material. The GPI addresses detection and 

remediation of leaks but is not focused on preventing leaks. 

NUREG/CR-6876, “Risk-Informed Assessment of Degraded Buried Piping Systems in Nuclear 

Power Plants,” evaluated corrosion damage on buried pipe and concluded that structural 

integrity can be maintained even with relatively high levels of general wall thinning. Because 

corrosion of buried piping typically initiates at local areas of coating damage, the resulting 

degradation is localized. From a structural integrity perspective, localized corrosion is much 

less challenging than general wall thinning. Localized degradation of buried piping typically 

causes small leaks that do not challenge structural integrity. Reports of operating experience 

are consistent with this observation; there have been no challenges to functionality or structural 

integrity due to degradation of buried, safety-related piping at nuclear power plants. 

DISCUSSION

Review of Current Regulations 

The NRC staff reviewed applicable regulations governing buried, safety-related piping for 

operating reactors, renewal of licenses, and new reactor licenses. For all nuclear power plants, 

the regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Appendix A, 

“General Design Criteria,” or similar requirements imposed during plant licensing for pre-10 CFR 

Part 50 Appendix A facilities, and 10 CFR 50.55a, “Codes and Standards,” provide design 

requirements for safety-related components, including some buried piping. In addition, 

10 CFR 50.55a provides requirements for examining and testing buried, safety-related piping. 

 

1 Note that leakage at Braidwood Station in 2005, described in NRC Information Notice 2006-13, 

“Ground-water Contamination Due to Undetected Leakage of Radioactive Water” was caused by a 

leaking vacuum breaker and not by degradation of buried piping; therefore, it was not within the scope of 

this review. 
The Commissioners - 3 - 

Licensees are required to verify that radioactive effluents, either from pipe leakage or from 

normal operations, are within NRC regulatory limits and design objectives. The NRC limits for 

radioactive effluents are contained in 10 CFR 20.1301, "Dose Limits for Individual Members of 

the Public," and the design objectives are contained in 10 CFR 50 Appendix I, "Numerical 

Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion ‘As 

Low as is Reasonably Achievable’ for Radioactive Material in Light-Water-Cooled Nuclear 

Power Reactor Effluents." These limits and design objectives are incorporated into licensee’s 

technical specifications and Offsite Dose Calculation Manual. 

For new plants where license applications are submitted after August 20, 1997, 10 CFR 

20.1406 “Minimization of Contamination” requires a description of how the facility's design and 

procedures for operation will minimize (to the extent practicable) contamination of the facility 

and environment, facilitate decommissioning, and minimize the generation of radioactive waste. 

For plants applying to renew their licenses, 10 CFR Part 54, “Requirements for Renewal of 

Operating Licenses for Nuclear Power Plants,” establishes requirements for managing aging 

effects of certain systems and components, including buried piping, that are important to safety 

or whose failure could adversely impact the ability of systems to perform their intended safety 

function. 

With regard to buried piping, the goals of current regulations are to ensure that the piping is able 

to perform its intended safety function by supplying sufficient fluid flow and to maintain 

inadvertent releases below licensee’s technical specifications or other applicable limits. The 

staff has determined that current regulations are adequate for these purposes. 

Review of the ASME Code

The staff reviewed applicable portions of the ASME Code. The ASME Code, Section III, “Rules 

for Construction of Nuclear Facility Components,” provides design rules for materials, design, 

fabrication, installation, examination, testing and overpressure protection to ensure the 

structural integrity of nuclear piping and components. The ASME Code, Section XI, “Rules for 

Inservice Inspection of Nuclear Power Plant Components,” provides requirements for the 

examination and testing of buried, safety-related piping. Section XI also provides acceptance 

criteria, rules for the evaluation of flaws, and repair/replacement rules for piping and 

components. The ASME Code does not currently address nonsafety-related piping nor does it 

address leaks that are not structurally significant. 

The staff has determined that current ASME Code requirements are adequate for ensuring 

structural integrity is maintained for buried, safety-related piping such that the piping will be 

capable of performing its safety function. The staff routinely works with ASME to update the 

Code to address operational experience or improvements in design or inspection technology 

and will continue this participation. 

Inspection 

The staff reviewed NRC inspection guidance on licensee activities related to buried piping 

degradation. Under the ROP, the baseline inspection program allows inspectors to review 

issues associated with buried piping if they are believed to be risk significant. There is no direct 

guidance to select a buried piping issue as an inspection sample; however, inspectors can 
The Commissioners - 4 - 

review flow tests, inservice inspection activities, condition monitoring, post-maintenance testing, 

and corrective actions using select inspection procedures. Historically, most buried pipe ROP 

inspection samples have been selected as a followup to an actual piping failure, known 

degradation, or problem identified during a review of a condition report. In addition, NRC 

reviews licensee implementation of the industry Groundwater Protection Initiative. 

The staff has determined that the current inspection process is adequate to verify appropriate 

licensee implementation of current regulations and the GPI. The staff plans to evaluate and 

revise, as necessary, the ROP to address new industry initiatives for buried pipe. 

Industry Activities

The staff has engaged industry, including at public meetings on August 20, 2009, and 

October 22, 2009, to gather information on the scope and status of their activities related to 

buried piping. Specifically, the staff met with representatives from a specific licensee with 

recent buried piping leakage experience, the Institute of Nuclear Power Operations (INPO), the 

Electric Power Research Institute (EPRI), and NEI. 

INPO conducts performance-based evaluations at each plant about every two years. In 2007 

INPO identified buried piping as a focus area and began to assess buried piping degradation 

management using predictive maintenance criteria. 

In December 2008, EPRI published “Recommendations for an Effective Program to Control the 

Degradation of Buried Pipe,” to provide nuclear power plant licensees with guidance on 

implementing preventive maintenance programs to detect and mitigate degradation in piping 

systems before leakage occurs. The industry has recently begun to implement this guidance. 

By letter dated November 20, 2009 (ADAMS Accession No. ML093350032), NEI indicated that 

the nuclear industry’s chief nuclear officers voted to approve a proposed “Buried Piping Integrity 

Initiative.” The stated goal of the initiative is to “provide reasonable assurance of structural and 

leakage integrity of all buried piping with special emphasis on piping that contains radioactive 

materials.” Objectives include proactive assessment and management of the condition of 

buried piping systems and technology development to improve upon available techniques for 

inspecting and analyzing underground piping. The staff plans to meet with the industry to 

further understand this initiative and assess licensee implementation. 

Conclusions

Based on the staff’s review of operating experience related to buried piping degradation, current 

regulations and ASME Code requirements have been effective in ensuring that the structural 

integrity and functionality of buried, safety-related piping are maintained. Current regulations 

have also been effective in ensuring unintended releases of hazardous material to the 

environment from leaks in buried piping remain below regulatory limits. Therefore, the staff has 

no current plans to recommend regulatory changes to address degradation of buried piping. 

The industry has recently developed the Buried Piping Integrity Initiative. The staff plans to 

meet with the industry to further understand this initiative and monitor industry implementation. 

The staff will also evaluate the need to revise NRC Inspection Procedures to assess licensee 

implementation of this new initiative. 
The Commissioners - 5 - 

The staff will continue to monitor operating experience and assess the need for any further 

regulatory actions or communications. The enclosure to this paper provides additional detail 

related to these conclusions. 

COORDINATION

The Office of the General Counsel has reviewed this paper and has no legal objection. 

 

 /RA/ 

 Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 

Enclosure: 

Additional Information Related to 

 Evaluation of Buried Piping Degradation 

 at Nuclear Reactor Facilities 
The Commissioners - 5 - 

The staff will continue to monitor operating experience and assess the need for any further 

regulatory actions or communications. The enclosure to this paper provides additional detail 

related to these conclusions. 

COORDINATION

The Office of the General Counsel has reviewed this paper and has no legal objection. 

 /RA/ 

 Eric J. Leeds, Director 

 Office of Nuclear Reactor Regulation 

Enclosure: 

Additional Information Related to Evaluation of Buried Piping Degradation at Nuclear Reactor 

Facilities 

WITS Item No.: 200900167/EDATS: OEDO-2009-0535 

ADAMS Accession No.: ML093160004 

OFICE NRR/ADES/DCI TECH ED* NRR/ADES/DCI NRR/ADES/DCI NRR/ADRO/DIRS

NAME RHardies JZabel JLubinski 

(MEvans for) 

MEvans FBrown 

DATE 11/12/09 12/01/09 11/16/09 12/01/09 11/20/09 

OFFICE NRO/DE RES/DE NRR/DLR OGC NRR 

NAME TBergman MCase 

(SRichards for) 

BHolian EWilliamson ELeeds 

DATE 11/19/09 11/20/09 11/20/09 11/23/09 12/02/09 

OFFICIAL RECORD COPY
ADDITIONAL INFORMATION RELATED TO EVALUATION OF BURIED PIPING 

DEGRADATION AT NUCLEAR POWER PLANTS

PURPOSE

This paper provides additional detail related to the Chairman’s memorandum dated 

September 3, 2009, (Agencywide Documents Access and Management System (ADAMS) 

Accession No. ML092460648) tasking the staff to describe the activities currently underway or 

planned addressing the issue of leaks from buried piping. 

INTRODUCTION

In his memorandum, Chairman Jaczko requested a staff evaluation of the adequacy of (1) 

Nuclear Regulatory Commission (NRC) requirements for design, inspection and maintenance of 

safety-related buried piping; (2) American Society of Mechanical Engineers Boiler and Pressure 

Vessel Code (ASME Code) requirements for design, inspection, and maintenance of 

safety-related piping; and (3) voluntary initiatives for the design, inspection, and maintenance of 

safety-related and nonsafety-related buried piping. The Chairman also requested a discussion 

of staff plans for recommending any revisions to regulations, requirements, practices or 

oversight related to buried piping. 

 

The staff responded to the Chairman tasking memorandum with SECY-09-0174, Staff Progress 

in Evaluation of Buried Piping at Nuclear Reactor Facilities (ADAMS Accession 

No. ML093160004). This paper provides additional detail related to conclusions made in 

SECY-09-0174. 

BACKGROUND

Over the past decade, instances of buried piping leaks have occurred in safety-related and 

nonsafety-related piping at nuclear power plants. Some of these leaks have caused inadvertent 

releases of low-level radioactive material. This has resulted in groundwater contamination at 

several plants. The staff evaluated these events individually and contemporaneously. The pipe 

degradation leading to these leaks did not affect the operability of safety systems, and the type 

and amount of radioactive material or chemicals released to the environment was a small 

fraction of the regulatory limits. Consequently, these pipe leaks have been of low significance 

with respect to public health and safety and the environment. 

In June 2005, as part of a program to assess a variety of forms of age-related degradation in 

passive components, the staff published NUREG/CR-6876, “Risk-Informed Assessment of 

Degraded Buried Piping Systems in Nuclear Power Plants.” This report evaluated corrosion 

damage on buried pipe and concluded that structural integrity can be maintained even with 

relatively high levels of general wall thinning. 

ENCLOSURE 
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In May 2006, the U.S. commercial nuclear power plants adopted the Nuclear Energy Institute 

(NEI) Groundwater Protection Initiative (GPI) in response to abnormal releases of radioactive 

material at several plants (which were not necessarily related to buried piping degradation). 

The initiative is described in Attachment 1 to "NEI-07-07 Industry Ground Water Protection 

Initiative - Final Guidance Document," dated August 2007 (ADAMS Accession No. 

ML062260198). The initiative, which all plants committed to follow, identifies actions to improve 

licensee response to inadvertent releases that may result in low but detectable levels of plantrelated radioactive materials in subsurface soils and water. These actions include the 

development of written groundwater protection programs, improved stakeholder 

communications, and program oversight. One objective of the GPI is to detect leaks well before 

they can challenge regulatory limits for unintended release of radioactive material to the public 

and the environment. The GPI addresses detection and remediation of leaks but is not focused 

on preventing leaks. 

Degradation of buried piping is caused by corrosion. Structural integrity of buried piping can be 

readily maintained because corrosion normally occurs at localized points associated with 

coating damage. This corrosion has little effect on the structural integrity of the pipe because 

little or no corrosion occurs in areas where coating damage does not occur. Instead, localized 

degradation of buried piping typically causes small leaks that do not challenge structural 

integrity. Reports of operating experience are consistent with this observation; there have been 

no challenges to functionality or structural integrity due to degradation of buried, safety-related 

piping at nuclear power plants. Safety-related piping that has been excavated for the purposes 

of repairing leaks has been inspected to determine whether degradation has affected the 

structural integrity of the piping. In no cases has structural integrity been compromised. 

EVALUATION

In preparing its response to the Chairman’s tasking memorandum, the staff evaluated 

operational experience, regulations, codes and standards, NRC inspection activities, industry 

activities and international activities. The following sections discuss the staff’s evaluation, 

conclusions and follow-up actions for each of these areas. 

Operational Experience

The staff operating experience clearinghouse performed a screening of several events involving 

leakage from buried piping and on July 16, 2009 identified and assigned buried piping as an 

Issue for Resolution (IFR). As part of the IFR generic evaluation process, the staff collected and 

evaluated recent operational events that were reported to the NRC. The NRC staff has 

evaluated these recent leakage events, root cause evaluations and licensee corrective actions. 

Based on application of NRC’s performance-based and risk-informed Reactor Oversight 

Process (ROP), these recent events did not constitute performance deficiencies of greater than 

low safety significance because the radiological consequences associated with the leaks were 

very minor and because the piping remained capable of performing its safety function. Upon 
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application of NRC’s Issue Screening and Significance Determination Processes, the staff 

determined the issues were of low safety significance.2

 

The staff performed a review of a database of operational events that is maintained by the 

Institute of Nuclear Power Operations (INPO) and includes descriptions of events that are not 

required to be reported to the NRC. The review did not reveal any additional instances (not 

already reported to the NRC) of degradation of safety-related buried piping or inadvertent 

release of radioactive material. The staff also reviewed NRC inspection findings related to 

buried piping. None of the findings involved events where piping functionality or structural 

integrity was compromised. 

Conclusions

Based on a review of operational events, the staff concluded that the pipe leaks from these 

events have been of low significance with respect to public health and safety and the 

environment. 

Actions

The staff is scheduled to issue the IFR report during the second quarter of FY2010 and will take 

any additional action, if necessary, based on the results of this generic evaluation. 

The staff will continue to review operating experience of buried pipe as part of its normal 

operating experience review process. 

Review of Current Regulations 

The NRC staff reviewed applicable regulations governing buried piping. These regulations 

establish criteria or limits that, if met, ensure the health and safety of the public are maintained. 

The criteria and limits for safety-related piping require the piping to be able to perform its safety 

function and require that any radioactive material that may be released not pose any credible 

threat of harm to public health and safety. The staff evaluated whether current regulations 

establish appropriate criteria with respect to degradation of and release from buried piping. 

The review encompassed regulations related to safety function and to release of radioactive 

material. Within these categories of safety function and release of radioactive materials the staff 

evaluated regulations related to operating plants, license renewal and new plants. Safetyrelated is defined by Title 10 of the Code of Federal Regulations (10 CFR) 50.2 and means 

those items relied upon to remain functional during and following design basis events to 

 

2 Note that leakage at Braidwood Station in 2005, described in NRC Information Notice 2006-13, 

“Ground-water Contamination Due to Undetected Leakage of Radioactive Water” was caused by a 

leaking vacuum breaker and not by degradation of buried piping; therefore, it was not within the scope of 

this review.
- 4 -

assure: (1) the integrity of the reactor coolant pressure boundary, (2) the capability to shut down 

the reactor and maintain it in a safe shutdown condition; or (3) the capability to prevent or 

mitigate the consequences of accidents which could result in potential offsite exposures 

comparable to the applicable guideline exposures set forth in 10 CFR 50.34(a)(1) or 

10 CFR 100.11, as applicable. Safety related piping systems generally fall into one of the 

ASME Code classifications (i.e. Class 1, 2 or 3). Piping Code classification is determined by 

using Regulatory Guide 1.26, “Quality Group Classifications and Standards for Water-, Steam-, 

and Radioactive-Waste-Containing Components of Nuclear Power Plants“ and 10 CFR 50.55a. 

Safety-related buried piping falls under ASME Code Class 3, which means it generally contains 

relatively low pressure and low temperature water. 

For all nuclear power plants, the regulations in Title 10 of the Code of Federal Regulations

(10 CFR) Part 50, Appendix A, “General Design Criteria,” or similar requirements imposed 

during plant licensing for pre-10 CFR Part 50, Appendix A facilities, provide requirements for 

systems, structures, and components important to safety. These regulations specify piping, 

including buried piping, be designed in a robust manner that ensures piping structural integrity, 

capability to withstand the effects of natural phenomenon such as earthquakes, configuration to 

permit inspection to assure integrity and capability of the system, and capability to permit 

appropriate periodic pressure and functional testing. The criteria presented in 10 CFR 50, 

Appendix A, are design and operational objectives that provide a foundation for safety at 

nuclear power plants. The process of degradation of buried piping does not create any 

challenge to safety that is not already addressed by the existing GDC. Adoption of changes to 

the GDC to address buried piping degradation would be redundant to existing GDC. For 

example, a proposed enhancement to the GDC to require buried safety-related piping to be 

designed to be capable of withstanding natural events would be redundant to the existing 

requirements that all safety-related piping, including buried piping, be designed to withstand 

natural events. Accordingly, the staff concludes that the existing GDC are adequate, so do not 

need to be enhanced to address buried piping degradation. 

In addition, the regulations in 10 CFR 50.55a, “Codes and Standards,” require the application of 

various codes and standards such as the ASME Code. Section III of the Code applies to the 

design of safety-related pressure-boundary components (including buried piping) in nuclear 

power plants. Section XI of the Code provides requirements for the examination and testing of 

safety-related buried piping. Among the requirements established by Section XI is a 

requirement to perform periodic flow tests of safety-related piping, including buried piping. The 

flow tests ensure piping segments are capable of performing their safety function of delivering 

fluid in the appropriate quantity upon demand. In practice plants test safety-related piping every 

ninety days. The trend from the results of this testing indicate buried safety-related piping 

continues to be able to perform its safety function even in instances where leaks have occurred. 

The safety function has not been compromised due to degradation. The staff concludes that the 

requirements in 10 CFR 50.55a to perform testing are adequate and that the results of the 

testing indicate that buried piping degradation is not currently impacting the ability of safetyrelated buried piping to perform its safety function. 

10 CFR 50.55a requires that once leakage through the wall of Class 3 piping is discovered, it 

must be repaired. However, the regulation permits the licensee to postpone the repairs for up to 

24 months, depending on operational circumstances. These requirements apply equally to 
- 5 -

buried piping and to piping that may be more accessible, such as inside buildings. Licensees 

are required to evaluate the leakage to ensure the piping remains capable of performing its 

safety function until such time as repairs can be accomplished. These requirements provide 

flexibility to perform repairs on a schedule that permits adequate planning while still ensuring the 

piping always remains capable of performing its safety function. 

Licensees are required to maintain radioactive effluents, either from pipe leakage or from 

normal operations, within NRC regulatory limits and design objectives. The NRC limits for 

radioactive effluents are contained in 10 CFR 20.1301, "Dose Limits for Individual Members of 

the Public," and the design objectives are contained in 10 CFR 50, Appendix I, "Numerical 

Guides for Design Objectives and Limiting Conditions for Operation to Meet the Criterion ‘As 

Low as is Reasonably Achievable’ for Radioactive Material in Light-Water-Cooled Nuclear 

Power Reactor Effluents." These limits and design objectives are incorporated into the licensing 

basis for each site (e.g., licensee’s technical specifications and Offsite Dose Calculation Manual 

(ODCM)). The effluent concentration limits of 10 CFR 20, Appendix B, Table 2 

(10 CFR 20.1302(b)) would be applicable to members of the public. These regulations limit the 

potential dose to members of the public that could result from an inadvertent release of 

radioactive material. 

The staff evaluated whether the occurrences of release of radioactive material into the ground 

as a result of degradation of buried piping indicated a need to establish limits at a location other 

than the site boundary (within the site boundary). As part of the operational experience review, 

the staff determined that none of the events associated with degradation of buried piping 

resulted in releases that exceeded a small fraction of existing limits for members of the public at 

the site boundary. A tabulation that describes the radiological consequences of the leakage 

during the events that occurred in 2009 is provided in Table 1. As part of the industry’s GPI, 

licensees monitor groundwater using wells, to understand whether leakage of radioactive 

materials is occurring. Once radionuclides are detected in groundwater onsite, licensees are 

required (by their licensing basis such as Technical Specifications and ODCM) to monitor 

ground water and drinking water if local supplies are likely to be affected. The intent of this 

routine monitoring is to assure that leaks will be detected in a timely manner, before established 

limits could be challenged. Since the staff’s review of the known pipe leaks indicated the dose 

impact was a small fraction of existing limits at the site boundary, the staff concluded that it is 

not currently necessary to establish any new requirements that would be applicable inside the 

site boundary to address buried piping degradation. 

Leakage from degraded buried piping can create contaminated soil. Worker dose accumulated 

during any necessary maintenance or remediation activities is controlled by site radiation 

protection programs and these activities have not exceeded small fractions of regulatory dose 

limits. Accordingly, the staff concludes that no changes to worker dose limits are warranted as 

a result of leakage from buried piping. 

Tritium is a naturally occurring element. Its presence in public drinking water supplies is limited 

by Environmental Protection Agency regulations to be at concentrations no greater than 20,000 

picocuries per liter (pCi/l). Most of the leaks from buried piping have been of water containing 
- 6 -

less than 20,000 pCi/l tritium, including the recent leak at Indian Point Unit 2, where the leaking 

water contained 2000 pCi/l, approximately one tenth the limit for drinking water. Some of the 

leakage events (Dresden in June, 2009, for example) involved water contaminated with tritium 

at concentrations that exceed EPA limits for safe drinking water. However, the water that has 

leaked from degraded buried piping is not intended for consumption. Additionally, water that 

leaks from buried piping becomes diluted as it moves away from the location of the leak. The 

effects of dilution are such that none of the leaks of tritiated water that have occurred have 

resulted in leakage offsite that exceeds a fraction of EPA limits for drinking water. This 

discussion is provided to illustrate the relatively low magnitude of tritium leakage from buried 

piping. 

In addition to the above requirements which address operating power plants, 10 CFR Part 54 

establishes additional requirements for power plants seeking to renew their operating licenses. 

These regulations require that the effects of aging be managed for structures, systems, and 

components which are passive and long lived and which are safety related; are not safety 

related, but whose failure could adversely affect safety related functions; or are relied upon to 

demonstrate compliance with certain regulations. License renewal regulations apply to some, 

but not all buried piping. 

The license renewal rule requires applicants for license renewal to demonstrate that for each 

applicable structure, system, or component, the effects of aging will be adequately managed so 

that the intended functions will be maintained consistent with the current licensing basis for the 

period of extended operation. This is normally accomplished through the development of Aging 

Management Programs (AMPs). To assist in this process the staff has provided examples of 

AMPs in the Generic Aging Lessons Learned (GALL) report (NUREG-1801). Applicant 

programs which are consistent with the GALL AMPs are generally considered to be acceptable 

methods for managing aging. The GALL report contains several AMPs related to aging of the 

interior and exterior surfaces of buried piping. 

Applicant’s AMPs are generally considered adequate to manage aging when they are consistent 

with the GALL AMPs and when the plant operating experience is no more adverse than the 

conditions for which the GALL AMP was designed. Several recent license renewal applications 

have included additional excavations and visual inspections, nondestructive examinations 

(various forms of ultrasonic testing), and selective replacement of some piping in response to 

adverse operating experience or recognized increased susceptibility of piping to aging. 

The GALL report is currently undergoing a scheduled revision. During this revision all the aging 

management programs, including those associated with internal and external corrosion of 

buried piping are being examined and revised as necessary to address emerging issues. 

Current plans for the revision of these AMPs are to adjust or clarify inspection procedures, 

frequencies and locations to conform to current industry practices but to retain the goal of 

preventing loss of function, rather than establishing a goal of leak tightness, for these pipes. 

The revised GALL report, including revisions to the AMPs related to buried piping, is scheduled 

to be published in December 2010. 
- 7 -

The GALL report is one acceptable way to meet the regulations. However, the staff concludes 

that no enhancements to regulations are required to address degradation of buried piping for 

plants applying for renewed licenses. 

New reactors will be required to meet the requirements discussed above. In addition, they will 

need to comply with 10 CFR 20.1406 (Minimization of contamination), which requires license 

applications submitted after August 1997 to demonstrate how the facility's design and 

procedures for operation will reduce contamination of the facility and environment and the 

generation of radioactive waste. Proper implementation of this regulation for new facilities 

should substantially reduce or eliminate the occurrence of residual contamination for the next 

generation of nuclear facilities, and could include adoption of predictive maintenance practices 

to ensure leakage and contamination is maintained as low as reasonably achievable. It should 

be noted that this rule permits a licensee to address residual radioactivity by either reducing it or 

by provisioning additional decommissioning funding to address remediation of the residual 

radioactivity. 

The staff has prepared a draft final rule (SECY 09-0042 - March 13, 2009) for consideration by 

the Commission related to minimization of contamination such as from leaks from buried piping 

at current operating facilities. Implementation of such a rule change would provide an incentive 

to operating facilities to institute predictive maintenance programs that minimize leaks from 

buried piping. 

In practice, the combined operating license applications currently under review do not have 

safety-related buried piping. All of the safety related piping is proposed to be either above 

ground or installed in vaults or chases that provide accessibility and the ability to capture any 

leakage. If an applicant submitted a new design certification for consideration that featured 

buried safety-related piping, NRC staff reviewers would request information from the applicant 

describing how they intended to satisfy the requirements of 10 CFR 20.1406. 

Conclusions

With regard to buried piping, the goals of current regulations are to ensure that the piping is able 

to perform its intended safety function by supplying sufficient fluid flow and to maintain 

inadvertent releases below licensee’s technical specifications or other applicable limits which 

apply at the site boundary. The staff has determined that current regulations are adequate for 

these purposes. 

Actions

The revised GALL report, including revisions to the AMPs related to buried piping, is scheduled 

to be published in December 2010. 

Code and Standards

For all nuclear power plants 10 CFR 50.55a endorses the ASME Code. The ASME Code, 

Section III, “Rules for Construction of Nuclear Facility Components,” provides design rules for 

materials, design, margins, fabrication, installation, examination, testing and overpressure 
- 8 -

protection to ensure the structural integrity of safety-related nuclear piping and components. 

These rules ensure that installed piping, including buried piping, is robust and capable of 

performing its safety function. Degradation of buried piping is manifested primarily as localized 

corrosion that is caused, in part, by choice of maintenance practices that do not emphasize 

prevention of corrosion. Section III rules are applied to buried piping before it is placed into the 

ground, so do not specify or address maintenance or long term corrosion protection activities. 

The staff considered recent examples of buried piping degradation and determined that most of 

the events occurred on nonsafety-related piping, that structural integrity was not challenged in 

any of the events, and that the degradation generally occurred because of a choice that the 

licensee made regarding maintenance practices. In order to change Section III so that it 

addressed the situations observed in the operating events, its scope would need to be 

expanded to 1) piping systems that it currently does not address (nonsafety related piping is not 

within the scope of Section III), 2) a purpose that is not currently within its objectives (Section III 

requires structural integrity rather than leak tightness), and 3) address processes that it does not 

currently address (Section III addresses design and installation, not maintenance). 

Therefore, the staff concludes that current Section III rules are adequate for their intended 

purpose of specifying a robust piping system and no changes are warranted. 

The ASME Code, Section XI, “Rules for Inservice Inspection of Nuclear Power Plant 

Components,” provides requirements for the examination and testing of buried, safety-related 

piping. Section XI also provides acceptance criteria, rules for the evaluation of flaws, and 

repair/replacement rules for piping and components. Periodic flow testing required by 

Section XI ensures that buried piping remains capable of performing its safety function to deliver 

a specified quantity of liquid on demand. The staff considered whether such testing, which 

offers retrospective proof that safety-related buried piping is capable of performing its safety 

function, provide sufficient information about the future. Section XI only requires the testing be 

performed every approximately three years, but in practice all 104 nuclear power plants perform 

flow testing every ninety days. The results of quarterly tests from the start of plant operation 

indicate that degradation of buried piping has not compromised its ability to perform its safety 

function. Accordingly, the staff concludes that current ASME Code Section XI requirements are 

adequate for ensuring structural integrity is maintained for buried, safety-related piping such that 

the piping will be capable of performing its safety function. 

The staff routinely works with ASME to update the Code to address operational experience or 

improvements in design or inspection technology and will continue this active participation. 

Examples of current Code activities that demonstrate evolution of the Code in response to 

operational experience include a committee that has been empanelled to provide a liaison 

function between Section XI and Section III so that experience from operating plants can be 

transmitted to and addressed by Section III, with the intent that new plants are able to avoid 

some challenges that were faced by older plants. Additionally, a Section III committee is 

developing updated design rules specifically for buried piping. The proposed changes involve 

incorporating newer soil loading calculative procedures. Once Section III publishes the newer 

design rules, Section XI intends to implement flaw evaluation procedures specific to buried 

piping. A final example of current Code activities related to buried piping involves the 

application of high density polyethylene (HDPE) as a material for buried piping. Buried HDPE 

piping has been extensively used in the water and gas industries, where its advantages of low 

cost, ease of fabrication and immunity to corrosion make it an attractive alternative to coated 
- 9 -

steel. The ASME is developing material property information related to long-term mechanical 

performance of this material in order to justify its addition as an acceptable material for 

application in buried, Class 3 applications. The staff is actively participating in all of these 

activities. 

Recognizing that leaks in buried piping, if undetected for extended periods, could represent 

precursors to loss of structural integrity, the staff discussed the issue of buried piping 

degradation informally with Code members during committee meetings in November 2009. 

ASME Code committee members pointed out that, in general, the industry examples of 

degradation of buried piping had been discovered in nonsafety-related, nonclass piping, which 

were not subject to the jurisdiction of the ASME Code. Participants indicated that extension of 

ASME Code jurisdiction to nonsafety-related piping would be a large undertaking without an 

obvious benefit in terms of safety. With respect to the infrequent occurrences of degradation of 

safety-related piping, ASME Code committee personnel noted that the observed degradation 

did not affect structural integrity. They observed that changes to the Code to require leak 

tightness would be a significant effort that would not necessarily have any beneficial effect on 

structural integrity. They concluded that such changes to the Code were probably not 

warranted. 

Codes and Standards in other Industries

Recognizing that many facilities and installations other than nuclear power plants employ buried 

piping, the staff evaluated regulations and codes and standards applicable to other industries. 

Buried piping and buried tanks used to contain or transport potentially hazardous or 

environmentally sensitive material are regulated under Department of Transportation (40 CFR) 

and Environmental Protection Agency (49 CFR) regulations. Generally, these regulations 

implement installation, corrosion protection, maintenance and condition monitoring standards 

developed by NACE International (formerly National Association of Corrosion Engineers). The 

implementation of these standards has been highly effective in preventing leaks in buried piping 

and buried tanks. The staff reviewed these standards and concluded that implementation of 

these standards at nuclear power facilities could be an effective means of reducing the potential 

for degradation and consequential leakage from buried piping. These corrosion protection 

standards are required to be applied to many thousands of miles of buried petroleum product 

transportation piping and many hundreds of thousands of buried tanks in the United States, but 

are not required to be implemented at nuclear power plants. Current NACE Standards have not 

been optimized for use by nuclear power plant operators. NACE has recognized the significant 

interest by nuclear power plant operators in the issue of buried piping and has formed a 

"Nuclear Buried Piping" task group. The purpose of this task group is to evaluate the need for 

specific corrosion protection standards that could be implemented at nuclear power facilities. 

The staff is participating in this committee, which will hold its first meeting during Spring 2010. 

Conclusions

While the ASME Code Sections III and XI are adequate to ensure the capability of safety-related 

buried piping to perform its safety function, implementation of NACE Standards could be an 

effective means of reducing the potential for degradation and consequential leakage from buried 

piping. 
- 10 -

Actions

The staff will continue to participate in ASME and NACE committees to develop enhancements 

related to advancements in technology or application of buried piping. 

Inspection of Licensee Activities under the Reactor Oversight Program

The staff reviewed NRC inspection guidance on licensee activities related to buried piping 

degradation. Under the Reactor Oversight Program (ROP), the baseline inspection program 

does not require specific inspections of licensees’ oversight of buried piping. The ROP allows 

inspectors to review issues associated with buried piping if they are believed to be risk 

significant. There is no direct guidance to select a buried piping issue as an inspection sample; 

however, inspectors can review flow tests, inservice inspection activities, condition monitoring, 

post-maintenance testing, and corrective actions using select inspection procedures. 

Historically, most buried pipe ROP inspection samples have been selected as a follow-up to an 

actual piping failure, known degradation, or a problem identified during a review of a condition 

report. 

Examples of buried piping activities inspectors may review are as follows. 

1. Inspectors may observe a licensee’s periodic flow or pressure test of underground pipes, the 

video or results of a video or camera inspection of underground piping, results of a sound 

detection system used to detect leaks in underground piping, or the periodic maintenance 

conducted on a cathodic protection system (or similar system) used to protect underground 

piping and detect any potential leaks. These reviews can be captured under IP 71111.19, 

“Post Maintenance Testing” or IP 71111.22, “Surveillance Testing.” Inspectors would review 

the licensee activities against any facility specific standards or procedures. 

2. Inspectors may review a licensee’s activities associated with buried piping during an 

inservice inspection (ISI) as one of the sample requirements in IP 71111.08, “Inservice 

Inspection Activities,” which requires a review of two or three types of Non-Destructive 

Examination (NDE) activities. The licensee actions would be reviewed against the ASME 

Code requirements for the ISI activity. Most often for buried pipe this entails a flow test or 

pressure test. 

3. If a buried pipe is within the licensee’s maintenance rule scope, inspectors can evaluate the 

handling of the pipe performance or condition monitoring using IP 71111.12, “Maintenance 

Effectiveness.” 

4. If a licensee excavates underground piping for the purpose of repair and replacement, 

inspectors can use this opportunity for direct visual inspection of the piping. These activities 

can be reviewed under IP 71111.17, “Evaluations of Changes, Test, or Experiments and 

Permanent Plant Modifications” or IP 71111.19, “Post Maintenance Testing.” 
- 11 -

5. When a licensee implements corrective actions due to suspected underground piping leaks 

(as potentially identified by tritium issues, tank inventory loss, chemical loss, excessive 

running of pumps on fire protection piping or other “keep pressure” systems, as sink hole, 

etc.), an inspector can review the licensee’s actions under IP 71152, “Identification and 

Resolution of Problems” or IP 71111.15, “Operability Evaluations.” 

An article was generated for the July edition of the quarterly Inspector Newsletter. This article 

provided the background associated with buried piping and detailed how these baseline NRC 

inspection program tools can be used to evaluate buried piping issues. 

License renewal inspections are conducted to support the NRC’s review of the license renewal 

application and to review the licensees programs for managing aging effects on systems, 

structures and components (SSCs) that fall under the scope of the license renewal. IP 71002, 

“License Renewal Inspection” is conducted to verify that passive, long lived SSCs within the 

scope of license renewal are subject to an aging management review and have existing or 

planned aging management programs (AMPs) that conform to descriptions contained in the 

license renewal application. The inspection also verifies that AMPs can reasonably manage the 

effects of aging for these SSCs. IP 71003, “Post-Approval Site Inspection for License Renewal” 

verifies that a licensee has completed the necessary actions to comply with the license and has 

implemented the AMPs included in the staff’s license renewal safety evaluation report. 

Groundwater Protection Initiative (GPI) inspections are performed using Temporary 

Instruction (TI) 2515/173, “Review of the Implementation of the Industry Ground Water 

Protection Voluntary Initiative.” The objective of this one-time inspection is to assess ground 

water protection programs to determine whether licensees have implemented the voluntary 

industry GPI. 

As discussed below, the industry has recently instituted a Buried Piping Integrity Initiative. 

While evaluating the establishment and implementation of this initiative, the staff may perform 

some audits of selected licensees and may develop a TI to assess the effectiveness of this 

initiative. 

Conclusions

Based on its evaluation of operating experience discussed above, the staff has determined that 

the priority placed on buried piping degradation within the current inspection process is 

adequate to verify appropriate licensee implementation of current regulations and the GPI. 

Actions

The staff may perform audits and/or develop a TI to evaluate licensee implementation of the 

Buried Piping Integrity industry initiative. In addition, the staff will continue to use existing 

inspection tools to evaluate buried piping integrity issues on an as available basis. 
- 12 -

Industry Activities 

The staff held several public meetings with industry to gather information on the scope and 

status of their activities related to buried piping. For example, the staff met with INPO at a 

public meeting on October 22, 2009, to discuss buried piping issues. INPO conducts 

performance-based evaluations at each plant approximately every two years. These 

evaluations address the performance of passive components, such as piping and heat 

exchangers. In 2007, INPO identified underground piping as a focus area and began to assess 

buried piping degradation management using predictive maintenance criteria described in 

NACE standards. INPO has completed at least one evaluation of every plant and has elected to 

continue evaluating buried piping during the current two-year inspection cycle. During the 

October 22, 2009, meeting industry executives indicated that, in part due to the INPO inspection 

results, the industry decided to initiate some activities with the Electric Power Research Institute 

(EPRI) to develop specific guidance for buried piping maintenance. 

In December 2008, EPRI published “Recommendations for an Effective Program to Control the 

Degradation of Buried Pipe’” to provide nuclear power plants with guidance on implementing 

preventive maintenance programs to detect and mitigate degradation in buried piping systems 

before leakage occurs. The staff has met with EPRI representatives and attended training on 

the guidance, which is modeled on the NACE standards. The industry has recently begun to 

implement this guidance. 

In the past, the industry has reacted to operational events by establishing initiatives, such as the 

Groundwater Initiative (NEI 07-07) and the "Industry Initiative on Management of Materials 

Issues" (NEI 03-08). These initiatives established frameworks that describe the required 

activities, standardized approaches, action plans, and assessment criteria used to manage 

degradation. These initiatives include processes to ensure consistent implementation across 

the industry. The NRC can perform inspections of activities associated with initiatives to assess 

the effectiveness of plant performance with respect to the specified guidance. Where the staff 

has determined that the initiative guidance, scope, goals and schedule for implementation are 

appropriate, that the implementation of the guidance is effective and consistent, and that new 

regulatory requirements are not needed, additional staff regulatory actions have not been 

necessary. 

By letter dated November 20, 2009 (ADAMS Accession No. ML093350032), NEI indicated that 

the nuclear industry’s chief nuclear officers voted to approve a proposed “Buried Piping Integrity 

Initiative.” The stated goal of the initiative is to “provide reasonable assurance of structural and 

leakage integrity of all buried piping with special emphasis on piping that contains radioactive 

materials.” Objectives include proactive assessment and management of the condition of 

buried piping systems and technology development to improve upon available techniques for 

inspecting and analyzing underground piping. The initiative implements the EPRI program that 

is modeled after the NACE Standards. Industry representatives have met among themselves to 

begin to develop implementation guidelines and other program documents. They have 

scheduled meetings in January and early February. They will meet with NRC staff at a public 

meeting in late February to provide more information related to the initiative. 
- 13 -

Conclusions

The industry has developed a Buried Piping Integrity initiative that is intended to implement a 

program that is consistent with guidance provided in NACE Standards. This initiative has the 

potential to reduce the incidence of leakage from buried piping. 

Actions

The staff will work with industry to understand the initiative, including the schedule for action. 

Also, as discussed previously, the staff will determine whether to perform audits and/or develop 

a TI to assess licensee implementation of the industry Buried Piping Integrity Initiative. 

International Activities

The staff plans to assess international operating experience, standards, and maintenance 

practices related to buried piping. Staff has proposed to lead this activity through the Nuclear 

Energy Association’s Committee on the Safety of Nuclear Installations (CSNI). This activity falls 

under a broader international effort to assess issues related to the long-term operation 

(i.e., more than 60 years) of nuclear plants. The proposed activity on buried piping was 

approved by CSNI during its semiannual meeting in December 2009. Results from this activity 

will also be used to assess the need for, and subsequently inform, future regulatory actions. 

SUMMARY

Based on the staff’s review of operating experience related to buried piping degradation, current 

regulations and ASME Code requirements have been effective in ensuring that the structural 

integrity and functionality of buried, safety-related piping are maintained. Current regulations 

have also been effective in ensuring unintended releases of hazardous material to the 

environment from leaks in both safety-related and nonsafety-related buried piping remain below 

regulatory limits. Therefore, the staff has no current plans to recommend regulatory changes to 

address degradation of buried piping. 

The staff will continue to actively participate in ASME Code and NACE standards activities. The 

revised GALL report, including revisions to the AMPs related to buried piping, is scheduled to be 

published in December 2010. 

The industry has recently developed the Buried Piping Integrity Initiative. The staff plans to 

meet with the industry to further understand this initiative and monitor industry implementation. 

The staff will also evaluate the need to revise NRC inspection procedures to assess licensee 

implementation of this new initiative. 

The staff will continue to monitor operating experience and assess the need for any further 

regulatory actions or communications. 
Table 1: Radiological Consequences of Several Recent Buried Piping Degradation Events 

Date Site Brief Description

August 25, 

2009 

Oyster 

Creek, 

Unit 1 

On August 25, 2009 water containing tritium leaked from an 

underground condensate transfer pipe at Oyster Creek, Unit 1. The 

aluminum pipe is 6" in diameter (with 0.288" wall thickness) and is not 

safety related. It had been replaced in 1994 and was examined most 

recently in April 2009. At the point of the leak, the tritium 

concentration was approximately 11E6 pCi/l, and the flow rate was 

approximately 5 gpm. Since the leak was on Oyster Creek property, 

no member of the public has received any exposure from this leak. 

No radioactivity from this leak has been detected in any publically 

accessible area. The water in the ground on-site is not publicly 

accessible and is not drinking water, so the Environmental Protection 

Agency (EPA) drinking water standards would not apply. However, 

EPA would classify drinking water containing 11E6 pCi/l of tritium as 

exceeding the safe drinking water standards for radionuclides of 

20,000 picocuries per liter (pCi/L). 

Tritium from the leak is being diluted by the ground water and as a 

result, the remaining tritium concentration is constantly being reduced 

as it travels underground toward the site boundary. Once the tritium 

leaves Oyster Creek’s property, the projected public doses will be 

below the Oyster Creek’s licensing limits (described in the licensee’s 

Technical Specification and ODCM). As a result, when the tritium 

leaves Oyster Creek’s property, the effluents will conform to NRC’s 

design objectives described in 10 CFR 50, Appendix I. This satisfies 

the NRC requirement that effluents are ALARA. The NRC is 

concerned because this release was an abnormal release from an 

unapproved release point. The licensee is required to include 

information about this leak in either the licensee’s Annual Effluent 

Report or the Annual Environmental Report. 

This level of tritium does not exceed any NRC limit (that would be 

applicable on-site), and after additional dilution and decay it will not 

exceed any NRC limit at the site boundary or offsite. Although this 

leak does not exceed any NRC limit, either on-site or offsite, this level 

of tritium would trigger the licensee to initiate voluntary 

communications with local and state officials as outlined in the 

industry Groundwater Initiative, NEI 07-07. 

During an October 22, 2009, public meeting the licensee indicated 

future plans to reposition existing risk significant piping to above 

ground or more accessible locations to enable enhanced monitoring 

of pipe conditions. 
Date Site Brief Description

July 9, 

2009 

Peach 

Bottom 

The results of 6 tritium test wells in the vicinity of the Unit 3 turbine 

building show the tritium level in 3 wells were > 20,000 pCi/L. The 

maximum level was 122,748 pCi/L from geo-probe well #4 for a 

sample drawn on July 8, 2009. The licensee followed the NEI 

Voluntary Tritium Reporting Initiative in communicating with external 

stakeholders. There is no information that the tritium is migrating 

offsite or affecting drinking water sources for site personnel. 

This level of tritium does not exceed any NRC limit (that would be 

applicable on-site), and after additional dilution and decay it will not 

exceed any NRC limit offsite. Although this leak does not exceed any 

NRC limit, either on-site or offsite, this level of tritium would trigger the 

licensee to initiate voluntary communications with local and state 

officials as outlined in NEI 07-07. 

June 5, 

2009 

Dresden On June 5, 2009 water containing tritium leaked from two 

underground condensate transfer pipes at Dresden. At (or near) the 

point of the leaks, the tritium concentration was as high as 

approximately 3.2E6 pCi/l. Since these leaks were on Dresden 

property, no member of the public has received any exposure from 

these leaks. No radioactivity from this leak has been detected in any 

publically accessible area. The water in the ground on-site is not 

publicly accessible and is not drinking water, so the EPA drinking 

water standards would not apply. However, EPA would classify 

drinking water containing 3.2E6 pCi/l of tritium as exceeding the safe 

drinking water standards for radionuclides. 

Tritium from the leak is being diluted by the ground water and as a 

result, the remaining tritium concentration is constantly being reduced 

as it travels underground toward the site boundary. Once the tritium 

leaves Dresden’s property, the projected public doses will be below 

Dresden’s licensing limits (described in the licensee’s Technical 

Specification and ODCM). As a result, when the tritium leaves 

Dresden’s property, the effluents will conform to NRC’s design 

objectives described in 10 CFR 50, Appendix I. This satisfies the 

NRC requirement that effluents are ALARA. The NRC is concerned 

because this release was an abnormal release from an unapproved 

release point. The licensee is required to include information about 

this leak in either the licensee’s Annual Effluent Report or the Annual 

Environmental Report. 

This level of tritium does not exceed any NRC limit (that would be 

applicable on-site), and after additional dilution and decay it will not 

exceed any NRC limit offsite. Although this leak does not exceed any 

NRC limit, either on-site or offsite, this level of tritium would trigger the 

licensee to initiate voluntary communications with local and state 

officials as outlined in NEI 07-07. State of Illinois regulations require 
Date Site Brief Description

notification if off-site releases are greater than 200 pCi/l or if 

concentrations on-site exceed 0.002 curies. The licensee estimated 

the total amount of tritium on site exceeded 0.002 curies and the state 

of Illinois was contacted. 

Dresden experienced similar leaks In 2004 and 2006 and had 

replaced some underground pipe at that time. 

April 15, 

2009 

Oyster 

Creek 

On April 15, 2009, water containing tritium leaked from two 

underground condensate transfer pipes at Oyster Creek, Unit 1. Both 

pipes were carbon steel pipe; one 8" in diameter and the other 10” in 

diameter. Neither is safety related. Near the point of the leaks, the 

tritium concentration was approximately 4.5E6 pCi/l. Since the leak 

was on Oyster Creek property, no member of the public has received 

any exposure from this leak. No radioactivity from this leak has been 

detected in any publically accessible area. The water in the ground at 

the source of the leak on-site is not publicly accessible and is not 

drinking water, so the EPA drinking water standards would not apply 

on-site at that location. However, EPA would classify drinking water 

containing 4.5E6 pCi/l of tritium as exceeding the safe drinking water 

standards for radionuclides. 

Tritium from the leak is being diluted by the ground water and as a 

result, the remaining tritium concentration is constantly being reduced 

as it travels underground toward the site boundary. Once the tritium 

leaves Oyster Creek’s property, the projected public doses will be 

below the Oyster Creek’s licensing limits (described in the licensee’s 

Technical Specification and ODCM). As a result, when the tritium 

leaves Oyster Creek’s property, the effluents will conform to NRCs 

design objectives (described in 10 CFR 50, Appendix I). This 

satisfies the NRC requirement that effluents are ALARA. The NRC is 

concerned because this release was an abnormal release from an 

unapproved release point, and as a result, the licensee is required to 

include information about this leak in either the licensee’s Annual 

Effluent Report or the Annual Environmental Report. 

This level of tritium does not exceed any NRC limit (that would be 

applicable on-site), and after additional dilution and decay it will not 

exceed any NRC limit offsite. Although this leak does not exceed any 

NRC limit, either on-site or offsite, this level of tritium would trigger the 

licensee to initiate voluntary communications with local and state 

officials as outlined in NEI 07-07.