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CSNI Survey on 

Buried Tanks and Piping

* The views expressed herein are those of the author and do not represent official positions of the U.S. NRC.

Robert L. Tregoning *

Sr. Technical Advisor for Materials 

Engineering

Nuclear Regulatory Commission

Office of Nuclear Regulatory Research

Buried Tanks and Piping Public Meeting

April 25, 2013

Rockville, MD
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Introduction

• A buried tanks and piping (BTP) survey was conducted through the 

Nuclear Energy Agency (NEA) Committee on the Safety of Nuclear 

Installations (CSNI)

• CSNI is a body of primarily international regulatory bodies and their 

technical support organizations (TSOs)

• Survey consisted of 20 questions in the following categories

• Technical and regulatory concerns

• Operating experience

• Relevant codes and standards 

• Regulatory framework and actions

• Industry responsibilities and initiatives

• Five countries and the Joint Research Center (JRC) responded to the 

survey:

• Canada, Czech Republic, Slovakia, Switzerland, USA
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Summary of Responses to 

Selected Questions

• No other country, other than US, reported any tritium leaks within the 

last 5 years in BTP

• No country has a simple regulatory mechanism to track leakage 

events in BTP

• All reporting countries only have regulatory authority for safetyrelated BTP

• Only a limited number of safety-related BTP internationally

• For non-safety related BTP, 

 Most countries have no additional regulations

 A few countries require aging management programs (AMPs) 

related to long-term operation (LTO)
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Research related to managing or 

detecting leakage in BTP

• Canada

 None currently

• Czech Republic

 Conducted several studies over last 10 years on degradation in BTP

 None currently

• Slovakia

 Evaluating condition of essential service water (ESW) piping 

 Planning study on replacement and condition monitoring (including detection of 

potential leakage) of buried ESW and SW piping

• Switzerland

 None currently

• US

 Research on detection and consequences of BTP degradation 

(NUREG/CR-6876)

 Summary of activities used to manage contamination issues 

(NUREG/CR-7029)
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Industry initiatives and related 

research

• Canada

 CANDU Owners Group (COG) issued COG-09-4055 “NDE Methods for Buried 

Pipe: Review and Best-Practice Recommendations”. 

 Methods reviewed by EPRI are largely applicable to CANDU buried pipe

• Czech Republic

 Industry is summarizing available codes and standards, including US ones, to 

create a proposal for a BP program 

• Slovakia

 Evaluating condition of all the relevant piping (started in 2011) 

 Summarizing operational events, failures, repair and replacement, evaluation of 

condition of piping and components with the determination of their reliability

• US

 EPRI established Buried Piping Integrity Group for overseeing initiatives

 Ongoing research includes 

 Development of risk-ranking software

 Development and evaluation of remote inspection techniques 

 Design, maintenance, and evaluation of CP

 Development of NDE
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Technical issues and activities 

related to BTP

• Canada

 Issue: develop a more structured monitoring and oversight process

 Activity: developing standard for inspecting BOP pressure boundary components

• Czech Republic

 Issue: leakage is not a generic problem and is limited to some systems only

 Activity: addressing specific leakage issues at the Temelin and Dukovany plants 

• Slovakia

 Issue: current methods for condition monitoring are not sufficient

 Activities

 Evaluating condition of relevant BTP

 Preparing to test new methods of BTP condition monitoring

• Switzerland

 Issue: MIC and pitting in some buried auxiliary cooling water systems

 Activity: Initiated special maintenance measures for non-safety relevant BTP 

• US

 Issue: No issues with respect to safe operation

 Activities

 Reducing cost and improving inspection reliability

 EPRI has produced several reports related to BTP and NDE of BTP