Buried Piping Activities

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• Background
• Related Documents
• Public Meetings

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Background

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.

Related Documents

Date	Description
	Groundwater Protection
02/04/2016	Issuance of Final License Renewal Interim Staff Guidance (LR-ISG), LR-ISG-2015-01, "Changes to Buried and Underground Piping and Tank Recommendations"
05/05/2015	Issuance of Draft License Renewal Interim Staff Guidance (LR-ISG), LR-ISG-2015-01, "Changes to Buried and Underground Piping and Tank Recommendations"
April 2013	NEI 09-14 Rev. 3, Guideline for the Management of Underground Piping and Tank Integrity
05/01/2013	Issuance of Rev. 3 to NEI 09-14, Guideline for the Management of Buried Piping Integrity
04/17/2013	NRR Action Plan, Buried Piping, Revision 3
11/2012	NEI 09-14 Rev. 2, Guideline for the Management of Underground Piping and Tank Integrity
11/21/2012	Issuance of Rev. 2 to NEI 09-14, Guideline for the Management of Buried Piping Integrity
06/13/2012	Staff Requirements Memorandum "Proposed Changes to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Associated with Buried Piping", SRM-SECY-12-0060
04/17/2012	Commission Paper "Proposed Changes to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Associated with Buried Piping", SECY-12-0060
05/24/2012	Staff Requirements Memorandum "Options for Revising the Regulatory Approach to Ground Water Protection" SRM-SECY-12-0046
05/14/2012	Buried Pipe Temporary Instruction Phase 2 Requirements
03/29/2012	Commission Paper "Options for Revising the Regulatory Approach to Ground Water Protection", SECY-12-0046
11/30/2011	NRR Action Plan, Buried Piping, Revision 2
08/18/2011	NEI Acknowledgment of Receipt of Information Related to Buried and Underground Piping
06/2011	GAO - Report to Congressional Requesters – "Oversight of Underground Piping Systems Commensurate with Risk, but Proactive Measures Could Help Address Future Leaks"
05/17/2011	Response to Request for Underground Piping Information Attachment 1, Instructions and Observations Data
03/23/2011	Committee Letter Report– Status of Groundwater Protection Task Force Efforts
04/2011	Industry Guidance for the Development of Inspection Plans for Buried Piping
03/07/2011	Underground Piping and Tanks Integrity Initiative
01/2011	Underground Piping and Tanks Initiative Semi-Annual Report
12/2010	NEI 09-14 Rev. 1, Guideline for the Management of Underground Piping and Tank Integrity
11/03/2010	NEI 09-14 (Rev 0),Guideline for the Management of Buried Piping Integrity
09/27/2010	Industry Initiative on Underground Piping and Tanks Integrity
09/14/2010	NRR Action Plan, Buried Piping, Revision 1
08/18/2010	NRC Letter to NEI requesting information concerning the Buried Piping Integrity Initiative
12/02/2009	SECY-09-0174 - Staff Progress In Evaluation of Buried Piping At Nuclear Reactor Facilities
11/18/2009	Proposed Buried Piping Integrity Initiative
10/22/2009	November 20, 2009, Letter Forwarding Industry Initiative on Buried Piping Integrity
09/03/2009	Chairman's Tasking to Staff Regarding Evaluation of Buried Piping at Nuclear Reactor Facilities NRC News Release on Chairman's Tasking
06/2005	Risk-Informed Assessment of Degradation Buried Piping Systems in Nuclear Power Plants (NUREG/CR-6876)

Public Meetings

Date	Description
09/20/2016	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: NRC Buried and Underground Piping and Tanks NEI Underground Piping and Tanks Integrity Initiative Update
01/21/2015	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: Buried/Underground Piping Update Underground Piping and Tank Integrity Initiative Update TI Conclusions Presentation Buried and Underground Piping and Tanks Buried/Underground Piping
06/11/2014	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: UPT NDE Technology Update Underground Piping and Tank Integrity Initiative Update Buried and Underground Components License Renewal and GALL Update Buried and Underground Piping and Tanks INPO Perspectives - NRC Buried and Underground Piping Meeting Drain Piping Inspection at the Palo Verde Nuclear Generating Station
10/09/2013	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: EPRI Buried Pipe Integrity Task Force, EPRI Buried Pipe Integrity Group Update Buried and Underground Piping and Tanks Underground Piping and Tanks Initiative - Update UPT NDE Technology Update NRC-Industry Buried Pipe Meeting, ASME
04/25/2013	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: Overview of Buried Piping Program Update Presentation for Spring 2013 UPTI Initiative Revision and Revision 3 to NEI 09-14 Buried/Underground Piping, American Society of Mechanical Engineers TI 182 Status Update CSNI Survey on Buried Tanks and Piping NEI Buried Pipe Integrity Task Force EPRI Buried Pipe Integrity Group Update INPO Perspectives NRC Buried and Underground Piping Meeting Underground Piping and Tanks Integrity Initiative Implementation Report to NSIAC Update on NACE Activities "Nuclear Buried Piping" EPRI Underground Pipe and Tank NDE Technology Update
12/05/2012	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: Underground Piping and Tanks Integrity Initiative Implementation Report to NSIAC (NEI) Revision 2 to NEI 09-14 (NEI) Underground Piping and Tanks Integrity Initiative Recent Interpretations (NEI) NDE Technology Update (EPRI) Buried and Underground Piping, NACE Activities (NRC) Underground Piping Update (INPO) Buried/Underground Piping (ASME) Buried and Underground Piping (NRC) Changes to GALL Report Revision 2, AMP XI.M41, Buried and Underground Piping and Tanks (NRC)
04/04/2012	Meeting between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Presentation Materials: Buried and Underground Piping (NRC) Industry Meeting Buried and Underground Piping and Tanks Initiatives (NRC) Buried Pipe NDE Update (EPRI) Underground Piping Update (INPO) Underground Piping and Tanks Integrity Initiative – Inquiries and Interpretations (EPRI) Underground Piping and Tanks Integrity Initiative - Implementation Report to NSIAC (NEI) Buried Piping and Tanks – Interim Staff Guidance (NEI) Buried/Underground Piping (ASME) Update on NACE TG 404 'Nuclear Buried Piping'
10/20/2011	Meeting Between the NRC and Industry Representatives to Discuss the Industry's Buried Piping Integrity Initiative Meeting Summary Presentation Materials: EPRI Buried/Underground Piping Activities Update Industry Comments on Buried Piping TI UPTI – GPI Coordination Underground Piping and Tanks Integrity Initiative Implementation - NSIAC Report Buried Piping and Underground Piping and Tanks Temporary Instruction Buried and Underground Piping – Buried Piping Action Plan Effectiveness of Industry Initiatives: Change in Leak Incidence Rates NRC-Industry Buried Pipe Meeting – ASME Underground Piping Update – INPO
03/30/2011	Meeting Between the NRC and Industry Representatives To Discuss The Industry's Buried Piping Integrity Initiative Meeting Summary Presentation Materials: Buried/Underground Piping (ASME) Buried and Underground Piping (NRC) Update on NACE TG 404 "Nuclear Buried Piping" (NACE) NRC Information Request (NEI) UPTI – GPI Coordination (NEI) Underground Piping and Tanks Integrity Initiative, NEI 09-14, Rev 1 (NEI) Underground Piping Update (INPO) Reasonable Assurance Update (EPRI) EPRI Buried Pipe NDE Technology Update (EPRI) Report to NSIAC (NEI)
09/21/2010	Meeting Between the NRC and Industry Representatives To Discuss The Industry's Buried Piping Integrity Initiative Meeting Summary Presentation Materials: Buried Piping Integrity Initiative Implementation Status Guidelines for the Management of Buried Piping Integrity NEI 09-14, NRC Information Request Risk Ranking for Buried Pipe and EPRI BPWorksTM Software Buried Piping Integrity Initiative Revision Buried Piping
02/24/2010	Meeting Between the NRC and Industry Representatives To Discuss The Industry's Buried Piping Integrity Initiative Meeting Summary Presentation Materials: Transferring OE to New Plants Reporting Strategies NEI Slides - Reporting Initiative Implementation NEI Slides - History of Buried Piping Integrity Initiative NEI Industry Buried Piping Activities Buried Piping Integrity NSIAC Initiative Guideline Comparison Buried Piping Integrity Initiative Inspection Technology Development Buried Piping Integrity Initiative Follow-Up Action
10/22/2009	Meeting Between the NRC and Industry Representatives to Discuss Buried Piping Issues Meeting Summary Meeting Attendance Sheet Presentation Materials: Buried Piping (NRC) EPRI's Buried Pipe Integrity Group (BPIG) INPO Review of Underground Piping Industry Buried Piping Activities EPRI's Buried Pipe Initiative An Overview of the EPRI/BPIG Recommended Program for Buried Piping Abstracts of EPRI Documents that Address Issues Associated with Buried Piping