Spotlight
Buried Piping Activities
Nuclear power plants have extensive piping systems. Some of these pipes are buried. Cooling water is the most common material transported in buried pipe. Cooling water is generally taken from a lake or river and, except for a slight increase in temperature, is returned unchanged to the same body of water. Generally, this water contains only naturally occurring, background, levels of radioactive materials. Some buried piping also transports smaller amounts of water that may contain slightly elevated levels of radioactive isotopes, most commonly tritium. A few buried pipes may contain materials other than water. Diesel fuel is the most significant of these materials.
The NRC defines buried piping as piping which is in contact with soil. The NRC recognizes that other structures and components exist in nuclear power plants which are beneath the surface of the earth but do not meet the definition of buried piping and are not included in the NRC’s buried piping activities. These other structures and components include piping enclosed in trenches or vaults. The NRC distinguishes between buried piping and other structures and components beneath the surface of the earth because they are exposed to different environments, they corrode by different mechanisms, and they are protected from corrosion differently.
At nuclear power plants, the buried piping systems are comparable to those used in other industries such as public water supply and oil and gas transmission. Preventative measures are taken for piping which may corrode, such as coating piping with corrosion resistant material. While buried piping is normally reliable, damage to the corrosion resistant coatings can lead to small leaks.
As a result of this type of corrosion, several leaks in buried pipes have occurred recently. These leaks have not created safety hazards at the plants because, in spite of the leak, the pipe was still carrying more than enough water to cool the plant. While some of these leaks did introduce slightly elevated levels of radiation into the ground water, they did not result in the exposure of any member of the public or power plant employee to radiation beyond regulatory limits.
While these incidents have not jeopardized public health and safety, the NRC and the nuclear power industry as a whole are reexamining the issue of buried piping to determine whether any changes are required in the current approach to the design, maintenance, and inspection of buried piping. Current NRC activities and some industry activities are described in the linked documents below. The NRC anticipates that, in the short term, the increase in excavation and inspection could increase the frequency of discovery of degraded buried piping.
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- Chairman’s Tasking to Staff Regarding Evaluation of Buried Piping at Nuclear Reactor Facilities
- September 3, 2009, NRC News Release on Chairman’s Tasking
- Summary of October 22, 2009, Meeting Between the NRC and Industry Representatives to Discuss Buried Piping Issues
- 10/22/2009 Meeting Presentation, “Buried Piping” (NRC)
- 10/22/2009 Meeting Presentation "EPRI's Buried Pipe Integrity Group (BPIG)”
- 10/22/2009 Meeting Presentation "INPO Review of Underground Piping”
- 10/22/2009 Meeting Presentation "Industry Buried Piping Activities”
- 10/22/2009 Meeting Presentation "EPRI's Buried Pipe Initiative”
- 10/22/2009 Meeting Presentation "An Overview of the EPRI/BPIG Recommended Program for Buried Piping”
- 10/22/2009 Meeting Attendance Sheet
- Abstracts of EPRI Documents that Address Issues Associated with Buried Piping.
- November 20, 2009, Letter Forwarding Industry Initiative on Buried Piping Integrity
- Proposed Buried Piping Integrity Initiative
- SECY-09-0174 - Staff Progress In Evaluation of Buried Piping At Nuclear Reactor Facilities
- Summary 02/24/2010 Meeting Between The U.S. Nuclear Regulatory Commission And Industry Representatives To Discuss The Industry's Buried Piping Integrity Initiative
- 02/24/2010 Meeting Presentation “Transferring OE to New Plants”
- 02/24/2010 Meeting Presentation “Reporting Strategies”
- 02/24/2010 Meeting Presentation “NEI Slides - Reporting Initiative Implementation”
- 02/24/2010 Meeting Presentation “NEI Slides - History of Buried Piping Integrity Initiative”
- 02/24/2010 Meeting Presentation “NEI Industry Buried Piping Activities”
- 02/24/2010 Meeting Presentation “Buried Piping Integrity NSIAC Initiative Guideline Comparison”
- 02/24/2010 Meeting Presentation “Buried Piping Integrity Initiative Inspection Technology Development”
- 02/24/2010 Meeting Presentation “Buried Piping Integrity Initiative Follow-Up Action”
- NRC Letter to NEI dated 08/18/2010 requesting information concerning the Buried Piping Integrity Initiative
- NRR Action Plan, Buried Piping, Revision 1, 9/14/2010
- Summary 09/21/2010 Meeting Between The U.S. Nuclear Regulatory Commission And Industry Representatives To Discuss The Industry's Buried Piping Integrity Initiative
- 09/21/2010 Meeting Presentation, “Buried Piping Integrity Initiative Implementation Status”
- 09/21/2010 Meeting Presentation, “Guidelines for the Management of Buried Piping Integrity”
- 09/21/2010 Meeting Presentation, “NEI 09-14, NRC Information Request”
- 09/21/2010 Meeting Presentation, “Risk Ranking for Buried Pipe and EPRI BPWorksTM Software”
- 09/21/2010 Meeting Presentation, “Buried Piping Integrity Initiative Revision”
- 09/21/2010 Meeting Presentation, “Buried Piping”
- Industry Initiative on Underground Piping and Tanks Integrity
- NEI 09-14 (Rev 0),Guideline for the Management of Buried Piping Integrity
- Underground Piping and Tanks Integrity Initiative
- NEI 09-14 Rev. 1, Guideline for the Management of Underground Piping and Tank Integrity
- Underground Piping and Tanks Initiative Semi-Annual Report
- Summary 03/30/2011 Meeting Between The U.S. Nuclear Regulatory Commission And Industry Representatives To Discuss The Industry’s Buried Piping Integrity Initiative
- 03/30/2011 Meeting Presentation, “Buried/Underground Piping”, (ASME)
- 03/30/2011 Meeting Presentation, “Buried and Underground Piping”, (NRC)
- 03/30/2011 Meeting Presentation, “Update on NACE TG 404 ‘Nuclear Buried Piping’”, (NACE)
- 03/30/2011 Meeting Presentation, “NRC Information Request”, (NEI)
- 03/30/2011 Meeting Presentation, “UPTI – GPI Coordination”, (NEI)
- 03/30/2011 Meeting Presentation, “Underground Piping and Tanks Integrity Initiative, NEI 09-14, Rev 1”, (NEI)
- 03/30/2011 Meeting Presentation, “Underground Piping Update”, (INPO)
- 03/30/2011 Meeting Presentation, “Reasonable Assurance Update”, (EPRI)
- 03/30/2011 Meeting Presentation, “EPRI Buried Pipe NDE Technology Update”, (EPRI)
- 03/30/2011 Meeting Presentation, “Report to NSIAC”, (NEI)
- Response to Request for Underground Piping Information
- Summary of 10/20/2011 Meeting Between the U. S. Nuclear Regulatory Commission and Industry Representatives to Discuss the Industry’s Buried Piping Integrity Initiative
- 10/20/2011 Meeting Presentation, “EPRI Buried/Underground Piping Activities Update”
- 10/20/2011 Meeting Presentation, “Industry Comments on Buried Piping TI”
- 10/20/2011 Meeting Presentation, “UPTI – GPI Coordination”
- 10/20/2011 Meeting Presentation, “Underground Piping and Tanks Integrity Initiative Implementation - NSIAC Report”
- 10/20/2011 Meeting Presentation, “Buried Piping and Underground Piping and Tanks Temporary Instruction”
- 10/20/2011 Meeting Presentation, “Buried and Underground Piping – Buried Piping Action Plan”
- 10/20/2011 Meeting Presentation, “Effectiveness of Industry Initiatives: Change in Leak Incidence Rates”
- 10/20/2011 Meeting Presentation, “NRC-Industry Buried Pipe Meeting – ASME”
- 10/20/2011 Meeting Presentation, “Underground Piping Update – INPO”
- NRR Action Plan, Buried Piping, Revision 2, 11/30/2011
- Risk-Informed Assessment of Degradation Buried Piping Systems in Nuclear Power Plants (NUREG/CR-6876)
- Summary of April 4, 2012 Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues
- 04/04/2012 Meeting Presentation "Buried and Underground Piping" (NRC)
- 04/04/2012 Meeting Presentation "Industry Meeting Buried and Underground Piping and Tanks Initiatives" (NRC)
- 04/04/2012 Meeting Presentation "Buried Pipe NDE Update" (EPRI)
- 04/04/2012 Meeting Presentation "Underground Piping Update" (INPO)
- 04/04/2012 Meeting Presentation "Underground Piping and Tanks Integrity Initiative – Inquiries and Interpretations" (EPRI)
- 04/04/2012 Meeting Presentation "Underground Piping and Tanks Integrity Initiative - Implementation Report to NSIAC" (NEI)
- 04/04/2012 Meeting Presentation "Buried Piping and Tanks – Interim Staff Guidance" (NEI)
- 04/04/2012 Meeting Presentation "Buried/Underground Piping" (ASME)
- 04/04/2012 Meeting Presentation "Update on NACE TG 404 'Nuclear Buried Piping'"
- Buried Pipe Temporary Instruction Phase 2 Requirements
- Groundwater Protection
