CNS-14-129, Transmittal of Industry High Density Polyethylene (Hdpe) Test Results

Transmittal of Industry High Density Polyethylene (Hdpe) Test Results

ML14345B039
Person / Time
Site:	Catawba
Issue date:	12/08/2014
From:	Henderson K Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNS-14-129
Download: ML14345B039 (117)

Text

Kelvin Henderson S DUKE ev.ee,.

Vice President ENERGY. Catawba Nuclear Station Duke Energy CNO1VP 1 4800 Concord Road York, SC 29745 CNS-14-129 o: 803,701.4251 f: 803.701.3221 December 8, 2014 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

Duke Energy Carolinas, LLC (Duke Energy)

Catawba Nuclear Station, Units 1 and 2 Docket Numbers 50-413 and 50-414 Transmittal of Industry High Density Polyethylene (HDPE) Test Results to NRC

Reference:

Letter from NRC to Duke Energy, "Catawba Nuclear Station, Units 1 and 2, Relief 06-CN-003 for Use of Polyethylene Material in Buried Service Water Piping (TAC Nos. ME0234 and ME0235)", dated May 27, 2009 (ADAMS Accession Number ML091240156)

The reference letter approved the use of a proposed alternative of HDPE material in lieu of steel material in Nuclear Service Water System piping associated with the emergency diesel generator jacket water coolers. The letter documented a regulatory commitment made by Duke Energy as stated below:

"Techniquesto ensure the structuralintegrity of the fusion joints are still evolving.

There is no performance or operating history regardingthe use of HDPEpiping in nuclear safety-relatedapplications. The licensee made the following regulatory commitments to address this issue:

1. Priorto submitting the Catawba 1 and 2 fourth 10-year ISI intervalplan, the licensee will submit information obtained from the above referenced testing program to the NRC staff If the informationsupports operation of the HDPE piping using the PE 4710 material for the remainderof the plant life, then this information will be submitted to the NRC staff for information only.

2. If the results from the testing program do not support the use of HDPEpiping with PE 4710 materialfor the remainderof the plant life, this information will be submitted to the NRC staff as a part of a subsequent request for an alternativeto the fourth 10-year ISI Interval."

Ac-7 www.duke-energy.com

U.S. Nuclear Regulatory Commission Page 2 December 8, 2014 In accordance with this regulatory commitment, please find attached summary results in the form of report abstracts or summaries concerning the industry testing program of HDPE material. It is our understanding that the NRC staff has access to the reports cited in the attachment. Duke Energy has reviewed the information from this program and maintains that, taken collectively, it supports the continued use of PE 4710 material in the approved Catawba application for the remainder of the plant life, including applicable life extension. Therefore, this information is being submitted to the NRC staff for information only prior to submitting the Catawba 1 and 2 fourth 10-year ISI interval plan.

There are no regulatory commitments contained in this letter or its attachment.

If you have any questions concerning this material, please call L.J. Rudy at (803) 701-3084.

Very truly yours, Kelvin Henderson Vice President, Catawba Nuclear Station LJR/s Attachment

U.S. Nuclear Regulatory Commission Page 3 December 8, 2014 xc (with attachment):

V.M. McCree Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 G.A. Hutto, Ill, Senior Resident Inspector U.S. Nuclear Regulatory Commission Catawba Nuclear Station G.E. Miller, Project Manager (addressee only)

U.S. Nuclear Regulatory Commission Mail Stop 8 G9A Washington, D.C. 20555

Attachment Transmittal of Industry High Density Polyethylene (HDPE) Test Results to NRC

I EIRI2l Technical Supporting Paper for Proposed Polyethylene Pipe Code Case 1009663

0.

Technical Supporting Paper for Proposed Polyethylene Pipe Code Case 1009663 Technical Update, December 2004 EPRI Project Manager Jack Spanner EPRI -3412 Hillview Avenue, Palo Alto, California 94304 - PO Box 10412, Palo Alto, California 94303

• USA 800.313.3774 - 650.855.2121 askepn@epd.com www.epd.com

ABSTRACT The purpose of this project is to provide technical support to the ASME Boiler & Pressure Vessel Subcommittee XI to develop a polyethylene replacement pipe Code case to be used as an alternative to repair / replacement for Class 3 piping. This is an interim report that documents some of the technical justifications for proposing the code case. The replacement of carbon steel and stainless steel pipe with polyethylene pipe is an economical solution. The labor costs to install polyethylene pipe are ten times less than that for carbon steel. Historically the ASME Code has not actively supported non-metallic piping in power plants. However, it has been successfully used in non-safety related systems. The technical justification will likely need to address the following potential issues and considerations: seismic, design changes, examination of fusion and coupler joints, personnel qualifications, procedure qualifications, code allowable stress values and development of an acceptance standard for flaw size acceptability. Most, but not all, of these issues are addressed in this document.

.V

If eIRESE II.ECT21C POWER ARCHPINSTITUTE Technical Support for Proposed Polyethylene Pipe Code Case Effective December 6, 2006, this report has been made publicly available In accordance with Section 734.3(b)X3) and published In accordance with Section 734.7 of the U.S. Export Administration Regulations. As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI. This notice supersedes the export control restrictions and any proprietary licensed material notices embedded In the document prior to publication.

5" Technical Support for Proposed Polyethylene Pipe Code Case 1011628 Final Report, December 2005 EPRI Project Manager J. Spanner ELECTRIC POWER RESEARCH INSTITUTE 3420 Hilaiew Avenue, Palo Alto, California 94304-1395 - PO Box 10412, Palo Alto. California 94303-0813 - USA 800.313.3774

• 650.855.2121

• askepr@epd.com - www.epri.com

ABSTRACT The purpose of this project is to provide technical support to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Subcommittee XI in order to develop a Code Case for polyethylene (PE) replacement pipe that can be used as an alternative to repair/replacement for Class 3 piping. This is a final report that documents some of the technical justifications for proposing the Code Case. The replacement of carbon steel (CS) and stainless-steel (SS) pipe with PE pipe is an economical solution. The labor costs to install PE pipe are 10 times less than that for carbon steel. Historically, the ASME Code has not actively supported non-metallic piping in power plants. However, it has been successfully used in non-safety-related systems. Seismic design changes, fusion joint examinations, joining procedure qualifications, Code-allowable stress and fatigue values, and the development of an acceptance standard for flaw size acceptability are potential issues and considerations that this technical justification addresses.

vii

"7 IESEARCH INSTITUTE Design and Qualification of High-Density Polyethylene for ASME Safety Class 3 Piping Systems 1011836

Design and Qualification of High-Density Polyethylene for ASME Safety Class 3 Piping Systems 1011836 Technical Update, December 2005 EPRI Project Managers A. Machiels D. Munson ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1395 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 . 650.855.2121 - askapd@ epd.com

• www.epri.com

REPORT

SUMMARY

This report identifies the activities necessary and recommends a plan to gather needed data to establish design and qualification methods that will serve as the basis for ASME and regulatory approvals for allowing the nuclear power industry to use high-density polyethylene for Safety Class 3 applications.

Background

High-density polyethylene (HDPE) has many advantages as compared to metallic pipe. They include lower cost, lighter weight, higher resistance to seismic loads (particularly with regard to buried piping applications), and no tendency to corrode, form corrosion deposits, or host tubercles. Use of HDPE is permitted by the ASME B3 1.1 code, and has been applied for non-safety applications, but is currently not addressed in the ASME Section III code for safety-related applications.

Objective V To identify the activities necessary to obtain ASME and regulatory approvals for use of HDPE for nuclear (safety) Class 3 applications, and

" To formulate a plan to achieve this goal as related to structural and seismic issues.

Approach A joint ASME Section III/Section XI Plastic Pipe Project Team (which includes members of the research team) has been formed to develop two code cases to allow HDPE to be used in nuclear Class 3 applications. One code case will be for below-ground pipe and one will be for above-ground pipe. The ASME Code requires that appropriate and sufficient rules be developed for General Requirements, Materials, Design, Fabrication, Non-Destructive Examination, Testing, Over-Pressure Protection, and Records so that the material will behave as intended in its environment.

The research team has met and participated with the ASME Project Team and held discussions with numerous individuals and organizations with expertise in HDPE. The research team has also reviewed the meeting minutes of a nuclear plant owner that met with the US Nuclear Regulatory Committee for preliminary discussions on submitting a Request for Regulatory Relief to allow use of HDPE for a specific ASME Class 3 application. Gaps in current knowledge, data and technology as related to structural and seismic requirements have been identified. This activity has included design analyses of two sample piping systems (one below-v

I0 ground and one above-ground). Each analysis identified gaps that have been associated with organizations that are best positioned to resolve them. These organizations include ASME Project Team members' organizations,, other industry organizations, and EPRI.

Results The recommended EPRI activities have been organized into three phases:

- Phase I - Obtaining ASME and regulatory approvals for the first specific application of the lead plant (a specific buried-pipe design).

- Phase II - Obtaining blanket ASME and regulatory approvals for use of a specific HDPE material in both below-ground and above-ground applications.

- Phase III - Extending the knowledge and data base of HDPE to allow:

" Use of a wider range of product types (e.g., more types of piping components and other products such as valves).

" Use of a second HDPE material

" HDPE to be used in environments where fire resistance is required.

" Additional repair options and technology in cases of damage to the product.

EPRI Perspective HDPE appears to be an attractive option for repair or replacement of service water piping that is damaged by corrosion. The work identified in this plan should provide sufficient data to fill the code and regulatory gaps as related to structural and seismic issues.

Keywords Service water systems Polyethylene Below-ground piping Above-ground piping Replacement Safety grade vi

/I IFI.=I21E'CTRC I=rai POWER I RESEARCH INSTITUTE Nondestructive Evaluation:

Seismic Design Criteria for Polyethylene Pipe Replacement Code Case 1013549 Effective December 6, 2006, this report has been made publicly available in accordance with Section 734.3(b)(3) and published in accordance with Section 734.7 of the U.S. Export Administration Regulations. As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI. This notice supersedes the export control restrictions and any proprietary licensed material notices embedded in the document prior to publication.

Nondestructive Evaluation:

Seismic Design Criteria for Polyethylene Pipe Replacement Code Case 1013549 Technical Update, September 2006 EPRI Project Manager J. Spanner ELECTRIC POWER RESEARCH INSTITUTE 3420 Hilivlew Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774

• 650.855.2121, askeprI@eprl.com

• www.epri.com

/3 ABSTRACT EPRI sponsored this report to provide technical support for a Relief Request and an American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Case to allow medium- and high-density polyethylene (PE) pipe to be used as an alternative for repairing or replacing buried Class 3 piping.

The replacement of buried carbon steel pipe with polyethylene pipe is an economical solution.

The labor costs to install polyethylene pipe are 10 times less than that for carbon steel. The ASME Code has not historically actively supported nonmetallic piping in power plants.

However, it has been successfully used in non-safety-related systems such as water mains and natural gas pipelines.

This document proposes the analyses and allowable limit of all modes of failure of high-density polyethylene (HDPE) piping made from PE 3408 resin. The methods comply with ASME Power Piping Code B31.1-2004 and Section III of the ASME Boiler and Pressure Vessel Code.

Extensive use was made of industrial research, data, and experience for 40 years of use of HDPE piping. Specifically, information was compiled from the Chevron-Phillips Chemical Company's 2003 Performance Pipe Engineering Manual [1]. ASTM standards and previous manuals on HDPE piping are also referenced. Allowable stresses are based on published data for design and service levels A to D.

Bending fatigue data for this application must be obtained so that the fatigue evaluation from seismic loading can be conducted more accurately. At present, there is no known extensive bending fatigue data on HDPE available in the open literature. A test program has been funded by EPRI. Material and specimens for that program were ordered in March 2006, and data will be obtained this summer. Preliminary testing on HDPE piping indicated that cyclic failure strains are on the order of 20,000 to 25,000 giin/in. Because of these large strains, bending fatigue from seismic excitation on buried pipe should not affect system design. However, these data are needed to understand the dynamic behavior of this material.

If approved as a Code Case, these design recommendations should be incorporated into NCA-2142, NCA-3252, ND-3 100, ND-3600, Non-Mandatory Appendix B, and Non-Mandatory Appendix N of the ASME Boiler and Pressure Vessel Code (BPVC),Section III.

vii

I -

ELECTRIC POWER I RESEARCH INSTITUTE An Integrated Project Plan to Obtain Code and Regulatory Approval to Use High-Density Polyethylene in ASME Class 3 Piping Applications 1013572 Effective December 6, 2006, this report has been made publicly available in accordance with Section 734.3(b)(3) and published in accordance with Section 734.7 of the U.S.

Export Administration Regulations. As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI.

This notice supersedes the export control restrictions and any proprietary licensed material notices embedded in the document prior to publication.

Is' An Integrated Project Plan to Obtain Code and Regulatory Approval to Use High-Density Polyethylene in ASME Class 3 Piping Applications 1013572 Technical Update Report, October 2006 EPRI Project Manager A. Machiels ELECTRIC POWER RESEARCH INSTITUTE 3420 Hilview Avenue, Palo Alto, California 94304-1338 PO Box 10412, Palo Alto, Callfornia 94303-0813 - USA 800.313.3774

• 650.855.2121

• askepri@epri.com . www.epri.com

4r ABSTRACT Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. It is also desirable to improve the safety and reliability of the raw water systems for new nuclear plants. Selection and use of improved materials for these systems would be a significant milestone to meet this goal.

In both the United States and in Europe, high-density polyethylene (PE) has been used in nuclear plant non-safety service water systems and found to perform well. However, high-density polyethylene is not currently included in the ASME Section III Code for use in safety-related systems; and the NRC does not currently permit its use in such systems.

The NRC has indicated that they want industry in general and the ASME Code in particular to take the lead on the issue. ASME is currently in the process of developing and approving Code Case N-755 for buried Class 3 piping systems and will soon undertake a similar effort to develop and approve a Code Case for aboveground Class 3 piping systems.

Three EPRI organizations are currently supporting the development of the two Code Cases.

Nondestructive examination (NDE) has responsibility for installation, inspection, and quality assurance issues. The Repair and Replacement Application Center (RRAC) has responsibility for supporting the development of a fusing standard and qualification of methods to repair damaged PE pipe. Balance of Plant (BOP) Corrosion has responsibility for design and seismic qualification issues. This report is a Project Plan for the BOP Corrosion activities.

v

1"7 Fatigue and Capacity Testing of High-Density Polyethylene Pipe and Pipe Components Fabricated from PE4710 1015062 Final Report, December 2007 EPRI Project Manager S. Findlan ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338

• PO Box 10412, Palo Alto, California 94303-0813 ° USA 800,313.3774 - 650.855.2121

• askepri@epri.com - www.epr.com

(S ABSTRACT For low-temperature piping systems subject to corrosion, such as service water systems in nuclear power plants, replacement of buried carbon steel pipe with high-density polyethylene (HDPE) pipe is a cost-effective solution. Labor costs to install polyethylene pipe are less than that for carbon steel, and HDPE pipe has much greater resistance to corrosion. Until recently, the American Society of Mechanical Engineers (ASME) Code has not accommodated use of non-metallic piping in nuclear safety-class piping systems. However, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and other industries such as water mains and natural gas pipelines. This report presents results of fatigue and capacity testing of PE 4710 (cell classification 445474C) HDPE material and piping products. This information was developed to support and provide a strong technical basis for the stress and fatigue capacities used in the design and analysis of HDPE piping systems in nuclear safety-related applications. The data also may be useful for applications of HDPE pipe in commercial electric power generation plants, chemical plants, process, and wastewater plants.

vii

19

.*RI

, ,POWER C

RtESEARICH I NSTIT"UTE.

Fatigue and Capacity Testing of High Density Polyethylene Pipe Material 1014902 lUNDER THEI 1NUCLEARJ

Fatigue and Capacity Testing of High Density Polyethylene Pipe Material 1014902 Technical Update, April 2007 EPRI Project Manager S. Findlan Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hiltview Avenue, Palo Alto, California 94304-1338

• PO Box 10412, Palo Alto, California 94303-0813

• USA 800.313.3774 -650.855.2121

• askepri@epn.com - www.eprd.corn

ABSTRACT For low temperature piping systems subject to corrosion, like service water systems in nuclear power plants, replacement of buried carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. The labor costs to install polyethylene pipe are less than that for carbon steel and HDPE pipe has a much greater resistance to corrosion. Until recently, the ASME Code has not accommodated the use of non-metallic piping in nuclear safety class piping systems. However, HDPE pipe has been successfully used in non-safety related systems in nuclear power facilities and other industries such as water mains and natural gas pipelines. This report presents the results of fatigue testing of PE 4710 HDPE material, and the load deflection characteristics of a 4710/3408 pipe flange. This information was developed to support and provide a strong technical basis for stress and fatigue capacities to be used in the design and analysis of HDPE piping systems in nuclear safety related applications. The data may also be useful for applications of HDPE pipe in commercial electric power generation plants, chemical plants, process, and waste water plants.

vii

1 EL,2 CTIC POWER RESEARCH INSTITUTE Fatigue Testing of High-Density Polyethylene Pipe and Pipe Components Fabricated from PE 4710- 2008 Update PREPARED UNDER THE NUCLEAR 0

PROGRAM

Fatigue Testing of High-Density Polyethylene Pipe and Pipe Components Fabricated from PE 4710 - 2008 Update 1016719 Final Report, December 2008 EPRI Project Manager S. Findlan Work to develop this product was completed under the EPRI Nuclear Ouality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hiliview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774

• 650.855.2121 - askepri@epr.com

• www.epri.com

ABSTRACT For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. The labor costs to install polyethylene pipe are less than that for carbon steel and HDPE pipe has a much greater resistance to corrosion. In Code Case N-755, the ASME Boiler and Pressure Vessel Code, Section 1I1,Division I currently permits the use of non-metallic piping in buried safety Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and other industries such as water mains and natural gas pipelines. This report presents the results of fatigue testing of PE 4710 (cell classification 445474C and 445574C) HDPE piping components. This infon-nation was developed to support and provide a strong technical basis for the fatigue capacities and stress intensification factors to be used in the design and analysis of HDPE piping systems in nuclear safety-related applications. The data may also be useful for applications of HDPE pipe in commercial electric power generation plants, chemical plants, process, and waste water plants.

vii

ELECTRIC POWER RESEARCH INSTIIUTE Tensile Testing of Cell Classification 445474C High-Density Polyethylene Pipe Material Effective June 10, 2009, this report has been made publicly available in accordance with Section 734.3(b)(3) and published in accordance with Section 734.7 of the U.S.

Export Administration Regulations. As a result of this publication, this report is subject to only copyright protection and does not require any license agreement from EPRI.

This notice supersedes the export control restrictions and any proprietary licensed material notices embedded in the document prior to publication PREPARED UNDERTHE NUCLEAR

Tensile Testing of Cell Classification 445474C High Density Polyethylene Pipe Material 1018351 Final Report, December 2008 EPRI Project Manager S. Findlan Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hiltview Avenue, Palo Alto, California 94304-1338 - PO Box 10412. Palo Alto, Califomia 94303-0813 - USA 800.313.3774

• 650.855.2121

• askeprf@epri.com

• www.epri.com

ABSTRACT For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. The labor costs to install polyethylene pipe are less than that for carbon steel and HDPE pipe has a much greater resistance to corrosion. In Code Case N-755, the ASME Boiler and Pressure Vessel Code,Section III, Division 1 currently permits the use of non-metallic piping in buried safety Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety related systems in nuclear power facilities and other industries such as water mains and natural gas pipelines. This report presents the results of standard tensile testing on cell composition 445474C HDPE material. The objective was to provide sufficient tensile test data of cell classification 445474C HDPE to support and provide a strong technical basis for stress capacities to be used in the design and analysis of HDPE piping systems in nuclear safety related applications. The report provides values for yield stress, yield strain, ultimate strain, and elastic modulus. Material test data were obtained by conducting standard tensile tests on material tensile test specimens. The testing was conducted consistent with the requirements of ASTM D-638-03. Specimens were cut in the axial and hoop direction from cell composition 445474C HDPE piping spools. Both new material and thermally aged specimens were tested at temperatures ranging from 50°F to 180'F. The results of the tensile test data are provided in this report. In addition, the results are compared with the cell classification 345464C HDPE material results presented in EPRI Report 1013479.

vii

ar~rai I ESEARCH INSTITUTE Nondestructive Evaluation: NDE for High Density Polyethylene (HDPE) Pipe for Cold Fusion 2009 Emerging Issue 1019141

Nondestructive Evaluation: NDE for High Density Polyethylene (HDPE) Pipe for Cold Fusion 2009 Emerging Issue 1019141 Technical Update, November 2009 EPRI Project Managers J. Spanner C. Parsnow ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338

• PO Box 10412, Palo Alto. California 94303-0813 - USA 800.313.3774 - 650.855.2121 - askepri@epri.com

• www.epn.com

REPORT

=

Background===

Over the past several years, the Electric Power Research Institute (EPRI) has been investigating nondestructive evaluation (NDE) techniques to volumetrically examine butt fusion joints in high density polyethylene (HDPE) piping. The interest in this comes from AmerenUE's Callaway Plant and Duke Energy's Catawba Plant both submitting relief requests to the U.S. Nuclear Regulatory Commission (NRC) for using HDPE in place of carbon steel piping in Section III, Class 3 systems in accordance with Code Case N-755. Carbon steel piping in service water applications is prone to fouling, corrosion, and microbiological attack. In comparison, HDPE does not rust, rot, corrode, or support biological growth. Although volumetric examination is not currently required for carbon steel Class 3 applications, it is believed that it might become required for other installations of HDPE piping as Callaway was required to do for its relief request. The development of a volumetric examination technique was driven by a concern for cold (that is, partial) fusion or lack of (absence) fusion. Therefore, Structural Integrity Associates has developed a technique for examining butt fusion joints in HDPE using ultrasonic phased array-an alternative technique to the more commonly used time-of-flight diffraction technique.

Twenty-seven 12-in. (305-mm) diameter, 1.25-in. (31.75-mm) thick butt fusion joint samples, some containing cold fusion, were examined using the ultrasonic phased array technique. The 27 samples were fabricated and provided by EPRI. This report documents the findings from the laboratory testing.

Objectives

• To fabricate HDPE butt fusion welds containing cold fusion flaws

" To examine the samples using a 2-D matrix phased array ultrasonic inspection technique Approach Using recent industry experience, butt fusion welds were made outside the acceptable joining parameters set forth by the nuclear and plastic pipe industries. Three variables were altered to provide possibly flawed samples in order to produce cold fusion. Cold fusion is a new issue in the nuclear industry and is still in the early stages of definition. It essentially creates a visually acceptable fusion weld while lacking the integrity to maintain operating pressures for the entirety of its design life because of incomplete cross linking and entanglement of the polyethylene chains across thejoint faces.

The unacceptable fused samples were examined using a newly developed phased array technique that allows for acceptable coverage of the weld and provides the capability of detecting artificial flaws less than 0.1 in. (2.54 mm) in diameter.

The results of the examinations would help the industry to explore possible methods to reliably inspect HDPE volumetrically, and the samples would be destructively tested to confirm, deny, or reveal integrity issues in the weld area that would indicate the presence of a molecularly unreliable joint.

V

31 Results A total of 27 samples made up the scanned sample set, including samples that were fused under acceptable circumstances. The only condition that produced indications in the majority of samples was subjected to the longest amount of cooling time before pressure was applied to create fusion. Two other samples exhibited indications; this might be the result of variations not accounted for during the fabrication of the welds.

The 2-D matrix phased array technology was demonstrated to be a feasible technique before the project was started and has continued to provide reliable and accurate results, which will be confirmed by the final destructive tests of this sample set.

EPRI Perspective The investigation of the use and application of HDPE pipe in the nuclear industry is in its infancy, and every experience provides valuable data for all parties concerned. The development and fabrication of the samples used in this project are indicators that we have yet to accurately define an unacceptable joint using volumetric examination, when unacceptable parameters are used to make joints as indicated by the fusion machine data logger. Each sample in this set was specifically made to look visually acceptable; however, the operation of the fusion process was altered with the intent to challenge the integrity of the fusion weld. Research to demonstrate an inspection technique that can detect welds with flaws indicative of an improper weld will continue as the implementation of this material grows throughout the nuclear industry.

Keywords Cold fusion High density polyethylene (HDPE)

Phased array Ultrasound vi

I__1.21-*.1 ELECTRIC POWE RESEARCH INSTITUTE Repair of High Density Polyethylene Pipe 1019172 NOTICE: This report contains proprietary information that is the intellectual property of EPRI. Accordingly, it is available only under license from EPRI and may not be reproduced or disclosed, wholly or in part, by any licensee to any other person or organization.

33 Repair of High Density Polyethylene Pipe 1019172 Technical Update, November 2009 EPRI Project Manager A. Peterson Cosponsors RRAC Steering Committee ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 PO Box 10412, Palo Alto, California 94303-0813 USA 800.313.3774 650.855.2121 askepd@epd.com www.epd.com

31t.

PRODUCT DESCRIPTION Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of their existing carbon steel piping components.

High-density polyethylene (HDPE) pipe has been used in non-safety service water systems for more than 10 years and has performed well. Recent applications of HDPE pipe at Duke Energy's Catawba Station and Ameren's Calloway Plant have encouraged the nuclear industry to consider using this type of pipe as an alternative to steel in low-energy applications. This action has been facilitated by the issuance of American Society of Mechanical Engineers (ASME) Code Case N-755, Use of Polyethylene (PE) Plastic Pipe,Section III, Division I and XI. The results described in this report are intended to support the nuclear industry by providing additional repair techniques for use on HDPE pipe. When these results are used in conjunction with a Request for Regulatory Relief, a nuclear plant operator will have a viable option for replacing a conventional steel Class 3 system with HDPE pipe; alternative repair techniques for that system will also be available should they be needed.

Results and Findings The repair methods described in conjunction with those already available-including saddle fusion repair, electro-fusion patch repair, electro-fusion spool repair, mechanical fitting repair, repairs with solid sleeve, and flange adapter spool repair-should provide sufficient options for most scenarios. Also of note is that the new techniques-tapered hole and plug repair and cavity repair-require practice. For example, the amount of time to heat the sidewalls of the hole or the amount of pressure applied to the plug will likely vary with the size of the component.

A review of the testing yields several conclusions:

• Sufficient heat must be applied using both techniques in order for the process to work.

• When using the tapered plug method it is critical that the angles machined for the plug and hole allow for full contact.

" Grinding or sanding a flaw out of the pipe wall for purposes of filling the cavity with HDPE "filler" material should be done such that the heating tool has easy access to all walls and corners.

• Mechanical testing confirms that the tapered plug method of repair is a viable option that maintains structural integrity.

Challenges and Objective(s)

The objective of this research was to apply two new techniques-tapered hole and plug as well as cavity repair-to the repair of HDPE piping. The challenge in repairing plastics is that melted polyethylene does not "flow" or behave the same way as molten steels, and new training with plastics is often required.

Applications, Values, and Use HDPE materials will offer significant economic benefits to utilities. The primary savings comes from the short installation time of HDPE piping compared to the weld times currently required V

for steel piping. While current rules only allow for HDPE piping in buried piping systems, the beginning stages for aboveground use are already being drafted.

EPRI Perspective Three separate EPRI groups have provided technical support for implementation of Code Case N-755-Balance of Plant (BOP), Non-Destructive Examination (NDE), and Welding and Repair Technology Center (WRTC). BOP staff has focused primarily on design and seismic qualification requirements. NDE staff has primary responsibility for examination issues. The WRTC has investigated potential repair techniques that could be employed in the field. All of these areas will need to be considered for future ASME Code Case development.

Additional information about HDPE piping is available in the following EPRI reports: An IntegratedProjectPlan to Obtain Code and RegulatoiyApproval to Use High-Density Polyethylene in ASME Class 3 PipingApplications (1013572, October 2006); Design and QualIfication of High-Density Polyethylenefor ASME Safety Class 3 PipingSystems (1011836, December 2005); Tensile Testing of Cell Classification345464C High Density Polyethylene Pipe Material (1013479, December 2006); and Fatigueand Capacity Testing of High Density Polyethylene Pipe Material(1014902, April 2007).

Approach After repairing several coupons using tapered hole and plug and cavity repair methods, investigators sectioned the samples to examine the integrity of the repair. They validated successful fusion by destructively examining repaired samples via sectioning, visual observation, and tensile testing.

Keywords High Density Polyethylene (HDPE) Pipe Plastic pipe Fused joint Pipe repair ASME Code Case N-755 vi

I (.

ELECTRIC POWER r IRESEARCH INSTITUTE 2012 TECHNICAL REPORT I _

Program on Technology Innovation:

Crystallinity Characterization in High-Density Polyethylene Pipe and Welds Using Portable Nuclear Magnetic Resonance I

37 Program on Technology Innovation: Crystallinity Characterization in High-Density Polyethylene Pipe and Welds Using Portable Nuclear Magnetic Resonance This document does NOT meet the requirements of IOCFR50 Appendix B, IOCFR Part 2 1, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

EPRI Project Manager

j. Wall RESEARCHINSTITUTE 3420 Hillview Avenue Palo Alto, CA 94304-1338 USA PO Box 10412 Palo Alto, CA 943030813 USA 800.313.3774 650.855.2121 asýepri@epri .cor 1025581 w,,w.epfi.or Final Report, May 2012

Abstract Portable nuclear magnetic resonance was used to determine the crystallinity of welds and sections of high-density polyethylene pipe.

Researchers determined that the pipe sections tested exhibited heterogeneous crystallinity due to original processing. The pipe fusion welds showed a relative increase in crystallinity as compared to the unwelded pipe material, as expected. It is unlikely that portable nuclear magnetic resonance can be used to resolve defects in high-density polyethylene pipe fusion welds. The crystallinity heterogeneity of the samples is an interesting finding because such a phenomenon might contribute to fusion weld defects. More research is required to determine whether there is a correlation between crystallinity heterogeneity in high-density polyethylene pipes and fusion weld defects.

Keywords Crystallinity Fusion weld defects High-density polyethylene pipe Nuclear magnetic resonance

39) armaiI ELECTRIC POWER RESEARCH INSTITUTE Capacity Testing of High-Density Polyethylene Bolted Flanged Joints

Lfo Capacity Testing of High-Density Polyethylene Bolted Flanged Joints 1020438 Final Report, March 2010 EPRI Project Manager B. Clark Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program in compliance with 10 CFR 50, Appendix B and 10 CFR 21.

1 NO ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338

• PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121 - askepri@epri.com - www.epri.com

IfI ABSTRACT For corroded piping in low-temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high-density polyethylene (HDPE) pipe is a cost-effective solution. The labor costs to install polyethylene pipe are less than that for carbon steel, and HDPE pipe has a much greater resistance to corrosion. In Code Case N-755, the ASME Boiler and Pressure Vessel Code,Section III, Division 1 permits the use of HDPE piping in buried safety-related Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and other industries such as water mains and natural gas pipelines.

This report provides the initial bolt torque requirements for HDPE-to-steel and HDPE-to-HDPE flanged connections to ensure that the flange capacity (and the subsequent flange qualification) is controlled by the capacity of the pipe-to-flange-adapter butt fusion joint. For the HDPE-to-steel flanges, test data from previously conducted flange capacity testing were used to develop and benchmark finite element models. These models were used to establish the interfacial pressure that was achieved during the testing. Using this base model, test data from previously conducted leak capacity testing of flanged HDPE-to-steel joints were used. The bolt torques required to achieve this interfacial stress were calculated for various HDPE pipe sizes and standard diameter ratios (SDR). The results were then compared to the torques specified in Plastics Pipe Institute (PPI) Technical Note 38 (PPI-TN-38). For the HDPE-to-HDPE flanged connections, leakage capacity testing was conducted for 4-inch SDR 7 and SDR 11 pipe. Finally, suggested changes to implement the results of this investigation in Code Case N-755 are provided.

vii

ELECTRIC POWER RESEARCH INSTITUTE Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 1: Testing Results PREPARED UNDERTHE NUCLEAR

q3 Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 1: Testing Results 1020439, V1 Final Report, October 2010 EPRI Project Manager B. Clark Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hiliview Avenue, Palo Alto, California 94304-1338

• PO Box 10412, Palo Alto, California 94303-0813 USA 800.313.3774 . 650.855.2121

• askeprt@epri.com

• www.epri.com

ABSTRACT For corroded piping in low-temperature systems, such as service water systems in nuclear power plants, the replacement of carbon steel pipe with high-density polyethylene (HDPE) pipe is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs than carbon steel pipe, and HDPE pipe has a much greater resistance to corrosion. The ASME Boiler and Pressure Vessel Code,Section III, Division 1 currently permits the use of nonmetallic piping in buried safety Class 3 piping systems. In addition, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and is commonly used in other industries such as water mains and natural gas pipelines.

This report presents the results of fatigue testing of PE 4710 (cell classification 445474C and 445574C) HDPE piping components. The information was developed to support and provide a strong technical basis for the fatigue capacities of HDPE pipe fittings. Stress intensification factors and flexibility factors for use in the design and analysis of HDPE piping systems in nuclear safety-related applications were also developed. The data might also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process, and wastewater plants through their possible use in the B31 series piping codes.

vii

4%r ELECTRIC POWER RESEARCH INSTITUTE Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 2: Test Procedures PREPARED UNDERTHE NUCLEAR

Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 2: Test Procedure 1020439, V2 Final Report, October 2010 EPRI Project Manager B. Clark Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813

• USA 800.313.3774

• 650.855.2121 . askepfl@epd.com . www.epri.com

14.7 REPORT

SUMMARY

The results presented in this report are intended to support the development of American Society of Mechanical Engineers (ASME) Code Case N-755 for the use of high-density polyethylene (HDPE) in buried and aboveground ASME Boiler and Pressure Vessel Code, Section I1I, Division 1 safety-related piping applications by determining the fatigue capacities and ASME stress intensification factors (SIFs) needed for piping design. These include fatigue data, stress intensification factors, and flexibility factors for selected components. This report presents the detailed results of the fatigue testing of molded tees, electrofusion branch saddles, sidewall fusion branch connections, 450 wyes, and HDPE-to-HDPE flanged connections. Stress intensification factors are developed for those fittings. Empirical equations for stress intensification factors and flexibility factors are also developed for elbows, bends, tees, and branched connections in support of Code Case N-755. Detailed fatigue testing results for these components were previously reported in Electric Power Research Institute (EPRI) reports 1015062 and 1016479. Data and information from the previous reports are repeated as required for clarification and for the development of the empirical equations.

Background

The degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require the repair or replacement of existing carbon steel piping components. HDPE has been used in non-safety service water systems for more than eight years and found to perform well.

Objective

• To develop SLFs and flexibility factors for common types of HDPE pipe fittings to support the use of HDPE Pipe in ASME Boiler and Pressure Vessel Code,Section III, Division 1, Subsection ND (safety Class 3) applications Approach Stress versus cycles (S-N) failure curves were developed for the HDPE pipe fittings. They were generated using displacement-controlled cyclic testing based on the requirements of the ASME Boiler and Pressure Vessel Code,Section III, Division 1, Mandatory Appendix II. The S-N curves for the fittings were then compared with the S-N curves previously developed for butt-fusion joints. The SIFs were developed based on the comparison of the S-N curves, and flexibility factors were developed on the basis of static tests and comparison to finite element (stick) models.

PE 47 10 HDPE material with a cell classification of 445474C was used for the run pipe segments, and molded pipe fittings were manufactured from PE 4710 with a cell classification of 445574C-the material presently used by most molded fitting manufacturers.

v

. l.. , I ELECTRIC POWER RESEARCH INSTITUTE Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 3: Supporting Data PREPARED UNDER THE NUCLEAR 140'

Stress Intensification and Flexibility Factors of High Density Polyethylene Pipe Fittings Volume 3: Supporting Data 1020439, V3 Final Report, October 2010 EPRI Project Manager B. Clark Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 . PO Box 10412, Palo Alto, California 94303-0813

• USA 800.313.3774 .650.855.2121

• askepd@epd.com

• www.eprl.com

ABSTRACT For corroded piping in low-temperature systems, such as service water systems in nuclear power plants, the replacement of carbon steel pipe with high-density polyethylene (HDPE) pipe is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs than carbon steel pipe, and HDPE pipe has a much greater resistance to corrosion. The ASME Boiler and Pressure Vessel Code,Section III, Division 1 currently permits the use of nonmetallic piping in buried safety Class 3 piping systems. In addition, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and is commonly used in other industries such as water mains and natural gas pipelines.

This report presents the results of fatigue testing of PE 4710 (cell classification 445474C and 445574C) HDPE piping components. The information was developed to support and provide a strong technical basis for the fatigue capacities of HDPE pipe fittings. Stress intensification factors and flexibility factors for use in the design and analysis of HDPE piping systems in nuclear safety-related applications were also developed. The data might also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process, and wastewater plants through their possible use in the B31 series piping codes.

vii

i; I ELECTRIC POWER aaf~ e l IRESEARCH INSTITUTE Evaluation of Design Methods for Above Ground High Density Polyethylene Pipe I

Evaluation of Design Methods for Above Ground High Density Polyethylene Pipe 1021094 Final Report, December 2010 EPRI Project Manager J. Hamel This document does NOT meet the requirements of 10CFR50 Appendix B, 10CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338

• PO Box 10412. Palo Alto, California 94303-0813

• USA 800.313.3774

• 650.855.2121 - askepri@epd.com

• www.epri.corn

573 ABSTRACT The purpose of this report is to present and illustrate the method for the design analysis and qualification of safety class 2 and 3 above ground high density polyethylene (HDPE) piping systems.

There are potential economic and safety benefits for pursuing the use of HDPE pipe above-ground due to its resistance to microbial attack and corrosion. Buried HDPE pipe has been used successfully used in many industries, including the nuclear power industry. HDPE has also been used extensively above-ground, typically near the ground on closely spaced, ground-mounted supports. In this report we examine its use in suspended systems, a viable option, as evidenced by applications in non-nuclear industries, and in a non-safety application in the turbine building at the Catawba Nuclear Station.

ASME Code Case N-755 has established a method'for the design analysis and qualification of buried class 2 and 3 HDPE piping systems. Enclosed in this report are proposed design rules for above ground piping which relies primarily on the technical basis of Code Case N-755, but also addresses issues specific to above-ground piping. Design issues addressed by the proposed above-ground code case include sustained loads, seismic loads, thermal expansion loads, joint flexibility, piping supports and the concept of long-term and short-term HDPE properties.

Included is an example problem for which all of the criteria in the proposed code rules are analyzed. This example problem incorporates both hand solutions to some of the code-case equations and numerical solution utilizing Caesar II v5.20 software. Attached in Appendix B is an independent check of the CAESAR II software with the Finite Element Analysis (FEA) software package, Abaqus 6.10-1.

vii

irt-EI=P1I* ELECTRIC POWER RESEARCH INSTn7UTE Seismic Properties for High-Density Polyethylene Pipe for Use in Aboveground Applications Volume 1 PREPARED UNDER THE NUCLEAR PROGRAM

Seismic Properties for High-Density Polyethylene for Use in Aboveground Applications Volume 1 Work to develop Ihis product was completed under the EPRI Nuclear Quality Assurance Program.

EPRI Project Manager D. Munson IEIIAICH I NmU 3420 Hillview Avenue Palo Alo, CA 94304.1338 USA PO Box 10412 Polo Alto, CA 94303.0813 USA 800.313.3774 650.855.2121 SL 1021095

, Final Report, September 2011

Abstract The data developed in the three testing tasks described in this report are intended to be used for the seismic design of aboveground high-density polyethylene (HDPE) piping systems. Under the first task, the material damping values for HDPE pipe material were developed through experimental methods using the log decrement approach. Cantilevered beam samples were deflected and released, and the resulting free vibration response was recorded. The possible relationship of the damping value to the natural frequency and stress level of the test samples was studied.

Under the second task, the relationship between tensile elastic modulus and strain rates commensurate with seismic loading was determined. This was accomplished by first establishing a seismic strain rate for HDPE and then conducting tensile tests using standard ASTM D-638 Type III tensile specimens. The tensile testing was conducted at three pull speeds to establish a basic relationship between tensile elastic modulus and strain rates. This relationship was then used to calculate the modulus at the strain rates expected under seismic loading. The third task consisted of the dynamic testing of selected vent-and-drain valve configurations to provide proof of the conceptual designs. The configurations were subjected to Seismic Qualification Report and Testing Standardization (SQURTS) spectral acceleration followed by checks for leakage and operability of the valves.

<vii >

SELECTRI POWER RESEARCH INSTITUTE Nondestructive Evaluation: High Density Polyethylene Inspection Technology and Techniques 1021165

Nondestructive Evaluation: High Density Polyethylene Inspection Technology and Techniques 1021165 Technical Update, December 2010 EPRI Project Manager C. Parsnow This document does NOT meet the requirements of 10CFR50 Appendix B, 10CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 -PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121 , askepd@epri.com - www.epr.com

109 REPORT

SUMMARY

Over the past several years, the Electric Power Research Institute (EPRI) has been investigating nondestructive examination (NDE) techniques to volumetrically examine butt-fusion joints in high-density polyethylene (HDPE) piping. The development of a volumetric examination technique was driven by concern about decreased bonding strength in the weld interface without visual indications on the outside surface of the weld bead. EPRI created HDPE samples of various diameters and wall thicknesses that exhibit decreased bond strength, simulated contamination from the field environment, and ultrasonic reflectors. This report documents findings from HDPE sample fabrication and laboratory testing.

Background

The interest in developing volumetric examination techniques for HDPE in nuclear power plants comes from Ameren UE's Callaway Plant and Duke Energy's Catawba Plant submitting relief requests to the U.S. Nuclear Regulatory Commission (USNRC) to use HDPE in place of carbon steel piping in Section III, Class 3 systems in accordance with Code Case N-755 [2]. Carbon steel piping in service water applications is prone to fouling, corrosion, and microbiological attack. In comparison, HDPE does not rust, rot, corrode, or support biological growth. While volumetric examination is not currently required for carbon steel Class 3 applications, it is believed that it may become required for other HDPE piping installations because Callaway was required to perform it for its relief request.

In previous reports, EPRI has referred to HDPE joints that are considered visually acceptable yet exhibit a poor fusion condition without experiencing "cold fusion." However, as the term "cold fusion" is also used to describe a condition found in traditional metallic welds and lacks a proper definition to use interchangeably in the HDPE industry, the term "reduced bond strength" is used to provide clarification. This term is more accurate and less susceptible to scrutiny as it can encompass all unacceptable joints that display visually acceptable outer surface weld bead conditions and unacceptable fusion interface strength parameters when referenced to bulk pipe strength. These joints may lack the integrity to maintain operating pressures for their design life due to incomplete cross-linking and entanglement of the polyethylene chains across the joint faces.

Objectives

" To fabricate HDPE butt-fusion welds exhibiting reduced bond strength or contamination.

" To examine these samples using various volumetric inspection techniques, including two-dimensional and tandem phased array, time-of-flight diffraction and other ultrasonic and microwave techniques Approach Utilizing recent industry experience, the butt-fusion welds were made outside the acceptable joining parameters set forth by the nuclear and plastic pipe industry. Three variables were altered to provide flawed samples with reduced bond strength, which is used in place of the term "cold fusion." The unacceptable fused samples were examined using a newly developed tandem technique and a two-dimensional phased array technique that allows acceptable coverage of the weld and is capable of detecting artificial flaws less than 0.1 (2.54mm) inch in diameter. The v

&0 project team chose these techniques as the initial inspection tool because they were used in the 2009 Emerging Issues project (described in EPRI report 1019141) and have proved successful in demonstrations to detect contaminants in HDPE weld interfaces.

Results The project team scanned 40 samples, including some that were fused under unacceptable circumstances. The results cannot yet be confirmed as only samples with contamination and decreased bond strength fusion conditions were inspected and the control samples have not yet defined the good condition.

The two-dimensional phased array technology was demonstrated to be a feasible technique before the project was initiated and has continued to provide reliable and accurate results, which will be confirmed by the final destructive tests of this sample set.

The results of the examinations will help the industry explore additional inspection methods to reliably inspect HDPE volumetrically. The project team will destructively test all of the samples at the end of all of the volumetric testing to confirm, deny, or reveal integrity issues in the weld area that indicate the presence of an unreliable joint.

EPRI Perspective Investigating the use and application of HDPE pipe in the nuclear industry is in its infancy, and every experience provides valuable data and information. The industry is currently defining what constitutes an unacceptable joint. However, it is still necessary to begin development and fabrication of samples that represent potential damage mechanisms. The project team used unacceptable joining parameters to make joints representative of decreased bond strength as indicated by the fusion machine data logger. Each of the samples in this set was made by altering the fusion process from the qualified parameters with the intent to challenge the integrity of the fusion weld. Research to demonstrate an inspection technique that can detect welds with flaws indicative of an improper weld will continue as implementation of this material grows throughout the nuclear industry.

Keywords Ultrasound Phased array High density polyethylene (HDPE)

Cold fusion Reduced bond strength vi

(01 er-=kri I RESEARCH POWER ELECTRIC INSTITUTE Slow Crack Growth Testing of High-Density Polyethylene Pipe: 2011 Update PREPARED UNDER THE NUCLEAR B

PROGRAM

Slow Crack Growth Testing of High-Density Polyethylene Pipe:

2011 Update 1022565 Interim Report, August 2011 EPRI Project Manager D. Munson Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program in compliance with 10 CFR 50, Appendix B and 10 CFR 21, 1 NO ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121 - askepi@epri.com -www.epri.com

ABSTRACT The ASME Boiler and Pressure Vessel Code, Section 111, Division I currently permits the use of nonmetallic piping in buried Safety Class 3 piping systems. There have been concerns with the slow crack growth (SCG) resistance from scratches that might occur during fabrication and installation or the use of high-density polyethylene (HDPE) piping. This report presents the results of an investigation into the SCG resistance of notched PE 4710 HDPE pipe and pipe material. Both bimodal and unimodal Plastics Pipe Institute rated PE 4710 materials were included in the testing. Tensile bar coupons were subjected to a constant tensile stress at an elevated temperature, and capped pipe specimens were maintained at constant internal pressure and submerged in water kept at an elevated temperature. Two different types of scratches as well as blended-out scratches were applied to the specimens. For both the tensile coupon specimens and the pressurized pipe specimens, a summary of the failure data is provided. To estimate pipe life at 140°F (60 0C)-the maximum temperature permitted in Code Case N-755-I--Popelar data shifts from the test temperatures to this temperature were performed for the pressurized pipe specimens. In addition, the pipe life at various other temperature and stress combinations was projected. The results also demonstrated a definite correlation between manufacturers' stated PENT values and pipe life.

vii

ELECTRC POWER RESEARCH INSTITUTE Nondestructive Evaluation: Ultrasonic Examination Techniques for High Density Polyethylene Pipes 1022941

Nondestructive Evaluation: Ultrasonic Examination Techniques for High Density Polyethylene Pipes 1022941 Technical Update, November 2011 EPRI Project Manager J. Spanner This document does NOT meet the requirements of 10CFR50 Appendix B, 10CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Aito, California 94303-0813

• USA 800.313.3774 - 650.855.2121 - askepl@epri.rom - www.epfl.com

&"7 ABSTRACT High density polyethylene (HDPE) pipe has been used as a replacement material for buried carbon steel pipe in non-safety-related systems. Using the current butt fusion procedure that uses heat and pressure to melt and join two sections of plastic pipe, concerns have been raised that would indicate that the presence of decreased bond strength when the welding parameters for fusion set forth by the plastic pipe industry were not followed. Currently two utilities, Ameren UE at Callaway and Duke-Energy at Catawba, have installed HDPE pipe following the approval of individual relief requests to use Code Case N-755. Because HDPE pipe is a new material in the nuclear industry, there are no standardized volumetric examination methods available and new inspection methods are being investigated to find a reliable nondestructive evaluation (NDE) technique. This report describes the examination results using ultrasonic linear and tandem phased array techniques and conventional time-of-flight diffraction (TOFD) method for the selected HDPE samples that were fabricated in 2010.

In 2010, the Electric Power Research Institute (EPRI) fabricated 80 joints of HDPE samples, 20 joints for each diameter used. These joints were made using 4710 HDPE pipe in four outer diameter sizes: 6, 12, 14, and 18 in. (15.24, 30.48, 35.56, and 45.72 cm).

The ultrasonic phased array scanning was performed by Structural Integrity, and TOFD examinations were performed by EPRI NDE Program staff. Because there are currently no industry-established criteria, all detection and sizing (length and through-wall) examinations were performed using best practices.

Keywords Cold fusion High density polyethylene (HDPE)

Phased array Ultrasound V

'-7 SF=Ia I ELECTRICPOWER RESEARCH INSTITUTE Fire Testing of High-Density Polyethylene Pipe

Fire Testing of High-Density Polyethylene Pipe 1023004 Final Report, August 2011 EPRI Project Manager D. Munson This document does NOT meet the requirements of 10CFR50 Appendix B, 10CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alo, California 94304-1338 -PO Box 10412, Palo Alto, California 94303-0813

• USA 800.313.3774 -650,855.2121

• askepd@epd.com - www.epd.com

'7 ABSTRACT This report presents and demonstrates a method that can be used to provide a fire-resistant barrier for aboveground high-density polyethylene (HDPE) piping systems that might be required to withstand a postulated fire event.

There are potential economic and safety benefits for pursuing the use of HDPE pipe in piping systems containing raw or minimally treated water because of its resistance to microbial attack and corrosion. Buried HDPE pipe has been successfully used in many industries, including the nuclear power industry. HDPE has also been used extensively aboveground but in areas in which fire resistance is not an issue. The work summarized in this report is intended to provide a basis for the use of HDPE in areas in which fire resistance is required. The work performed in this study was intended to be proof-of-concept only and should not be considered as a qualification or certification test.

vii

-70

• iFI~~1 ELECTRIC POWER V RESEARCH INSTITUTE 2012 TECHNICAL REPORT Long Term Performance of PE4710 Materials in Disinfectant Treated Nuclear Raw Water Systems

71 Long Term Performance of PE471 0 Materials in Disinfectant Treated Nuclear Raw Water Systems This document does NOT meet the requirements of 10CFR50 Appendix B, IOCFR Part 2 1, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994).

EPRI Project Managers A. Summe D. Munson aUIfa 1RRSEARC' H E INSTITUT 3420 Hillview Avenue Palo Alto, CA 94304-1338 USA PO Box 10412 Palo Alto, CA 94303-0813 USA 800.313.3774 650.855.2121 askepri@epri.com 1025296 wwwepd .corn Final Report, November 2012

Report Summary Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components. High-density polyethylene (HDPE) has been used in non-safety service water systems for over ten years and found to perform well. Although HDPE has been approved in Code Case N-755-1 of the ASME Boiler and Pressure Vessel Code,Section III, Division 1 for use in buried safety-related Class 3 systems, the Code Case has not yet been accepted by the Nuclear Regulatory Commission. One issue concerning the long-term performance of HDPE piping is its aging in disinfectant treated nuclear power plant raw water systems.

Background

HDPE is considered to have three stages in its aging process. The mechanism of Stage I is the ductile-mechanical viscoelastic creep common to all plastics. The mechanism of Stage II is a brittle-mechanical regime that results in stress-driven slow crack growth.

The mechanism of Stage III is a mechanical-chemical process that involves oxidation of the polymer and stress-driven propagation of a crack through the degraded material. It is not only dependent on the temperature, stress, and pipe material, but also on the oxidative aggressiveness of the transport fluid.

Objectives

" To conduct an engineering assessment of the expected performance of polyethylene PE 4710 materials in nuclear power plant disinfectant treated nuclear raw water systems due to Stage III aging.

" To identify areas where a more detailed assessment may be needed.

Approach This project was separated into 2 phases. In Phase 1, 216 end use cases were modeled for systems with chlorine and chlorine-bromine treatments. These cases were intended to demonstrate the general life expectancy trends for the range of operating parameters for nuclear raw water systems. In Phase 2, the operating parameters were refmed using the results of Phase 1 and a survey of raw water systems in 19 nudear plants, culminating in 48 additional cases. Each case was constructed to represent what is believed to be a conservative approach to projecting performance. The material characteristics used in the evaluation were from one of the potential conforming suppliers to the nuclear industry. Phase 2 included an additional 144

73 cases using the three generic compound categorizations defined by Plastics Pipe Institute (PPI) standard TN-43.

Each of the 408 cases (216 cases from Phase 1 and an additional 192 cases from Phase 2) was evaluated using a Stage III aging model based on accelerated testing of specific resins, with the data shifted to operating conditions of the specific case. Case results were placed in one of three categories: green (high probability for > 40 year life),

yellow (likely to perform satisfactorily for 40 years), and red (more detailed evaluation required).

Results The specific piping material examined in this report was a Category 2 resin as defined by PPI TN-43. In general, it is projected to provide good performance for the end-use scenarios considered. Of the 216 cases evaluated in Phase 1, 179 were designated with a green categorization, 34 were designated as yellow, and 3 as red. All of the yellow and red categorizations were for the higher temperature heat exchanger discharge piping, where it is believed that the operating parameters were quite conservative. In Phase 2, 48 new scenarios were modeled for four conservative cases based on refined operating parameters. Of the 48 scenarios, 40 were designated with green performance categorizations and 8 as yellow.

Also modeled in Phase 2 were the 3 categories of HDPE piping as defined by PPI TN-43. The Category 1 resin (the highest performance category) showed excellent performance with only four yellow performance categorizations for all 48 conservative cases considered.

Applications, Value, and Use Clearly understanding the mechanisms of aging for any material, and hence the key factors impacting performance in end-use, is critical to understanding both how the material is best applied and the development of methodologies for projecting long-term performance in service. To that end, research has been conducted on the long-term aging mechanisms of plastic piping materials in general and PE pipe materials specifically. In general, the specific PE4710 piping material examined in this report is projected to provide good performance for the end-use scenarios considered. Also, as discussed in the report, the modeling approach is newly evolved and there are a number of potential further evolutions that could provide more refined projections.

Keywords High-density polyethylene, Raw water piping, Aging, Disinfectants

< vi >

. l.-l JELECTRIC POWER RESEARCH INSTITUTE Plant Engineering: Compilation of Lessons Learned on Buried and Underground Piping in Nuclear Power Plants 1025272

75-Plant Engineering: Compilation of Lessons Learned on Buried and Underground Piping in Nuclear Power Plants 1025272 Technical Update, November 2012 EPRI Project Manager T. Eckert This document does NOT meet the requirements of 10 CFR50 Appendix B, 10 CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 HIllview Avenue, Palo Alto, California 94304-1338 - PO Box 10412. Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121

• askeprl@epd.com - www.epri.com

ABSTRACT This is a Technical Update report for the Electric Power Research Institute (EPRI) project Collation of Buried Pipe Lessons Learned, which is planned to continue through 2013. The project is part of EPRI's overall strategy to provide buried pipe program owners with the guidance documents and reference materials to help ensure that buried pipe management guidance is appropriately deployed in the field, as described in the EPRI Nuclear Sector's "Underground Piping and Tank Integrity Strategic Roadmap." The roadmap contains several other buried piping technologies for inspection, analysis, repair, and mitigation of ongoing corrosion in buried infrastructure. These include the following:

• Development and delivery of appropriate reference documents and training to support broad knowledge awareness for buried and underground piping

" Development and transfer of new buried pipe inspection technologies, such as remote field nondestructive evaluation (NDE) inspection robotics

• Identification and evaluation of existing technologies that may be directly applied or easily adapted for nuclear plant buried piping inspection

" Improved understanding regarding the usefulness of guided wave acoustic NDE technologies for buried piping inspections

• Availability of repair and replacement alternatives for buried pipe applications, including high-density polyethylene

• Enhanced buried pipe risk-ranking technologies through updates to existing software Keywords Buried pipe Cathodic protection (CP)

Excavation High-density polyethylene (HDPE)

In-line inspection (ILl)

Prestressed concrete cylinder pipe (PCCP) v

ELECTRIC POWER af Il I j RESEARCH INSTITUTE Advanced Nuclear Technology: The Long-Term Oxidative Resistance of Butt Fusion Joints in High-Density Polyethylene Piping

Advanced Nuclear Technology: The Long-Term Oxidative Resistance of Butt Fusion Joints in High-Density Polyethylene Piping All or a portion of the requirements of the EPRI Nuclear Quality Assurance Program apply to this product.

YES e EPRI Project Manager A. Summe REERHINSTITUTE 3420 Hillview Avenue Palo Alto, CA 94304-1338 USA PO Box 10412 Palo Alto, CA 94303-0813 USA 800.313.3774 650.855.2121 ask.epri@epri.com 3002003120 www.veprl.corn Final Report, July 2014

77 Product A previous EPRI report (Long Term PerformanceofPE4710Materials Description in Disinfectant Treated Nuclear Raw Water Systems, 1025296) projected the performance of PE4710 materials at various end-use conditions at a nuclear plant. This work predicted strong pipe performance; however, a knowledge gap was identified on the lack of data on the long-term oxidative resistance of butt fusion joints in high-density polyethylene (HDPE). As butt fusions are a common method of joining PE pipe, the current project was undertaken to assess their impact on the long-term performance of a piping system.

Background

The long-term oxidative resistance of butt fusions to disinfected water is generally uncharacterized. The long-term aging mechanism of PE pipe involves stabilizer depletion, crack initiation, and crack propagation with the time for each of these events defining the overall failure time of a pipe. The impact of fusion joints on these events is uncertain.

Objectives The objective of this project was to determine whether a butt fusion detrimentally impacts the projected long-term oxidative resistance of an HDPE piping system by accelerating the long-term aging mechanism of PE pipe.

Approach Testing butt fusions through exposure to chlorinated water at a single elevated temperature and stress condition was conducted to accelerate the long-term aging mechanism. The results of the exposure can be used to project the performance of PE pipe at various end-use conditions.

Results The conclusions, based on the testing results and subsequent preliminary failure analysis, include the following:

The butt fusion joints had no apparent impact on the long-term oxidative resistance of the tested HDPE pipe. All specimens tested in this project failed in the parent material and not at the fused joint; the fused joints lasted longer than the parent material and did not show preferential oxidation.

" The parent material did not meet the expected resistance to chlorine exposure (CC2 as defined in Plastics Pipe Institute TN-43). The premature pipe failure results are not considered a valid indicator of production pipe performance due to several irregularities discovered during a preliminary root cause analysis.

" The samples were produced on a pipe extrusion line in a resin supplier laboratory and not on commercial equipment. The resulting pipe quality was not typical of commercially produced pipe.

" The presence of atypical degradation indicates extrusion defects that apparently created areas of lower oxidative chlorine resistance.

" The presence of windows (unpigmented areas) through the pipe wall thickness is indicative of an issue with carbon black distribution and, consequently, non-production quality pipe.

Applications, Value and Use The data collected on the long-term oxidative resistance of butt fusions suggest that no decrease in performance relative to the parent material should be expected. Therefore, any predictive models would likely not require updating to capture the performance of piping systems containing butt fusions.

The preliminary assessment of the lower-than-expected performance of the laboratory-produced HDPE pipe samples led to the following recommendations, which should improve the quality of HDPE material in future research and development projects:

" Enhanced quality checks and documentation for test sample procurement from a pilot-scale facility should be standard.

" Thorough visual examination of procured test samples, including examining a cross-section of the pipe wall for windows, should be performed.

" Nondestructive evaluation, such as microwave analysis, should be considered as a counterpart to the visual analysis.

Keywords Butt fusion High-density polyethylene HDPE)

Oxidative resistance Plastics Pipe Institute (PPI) TN-43

<vi >

I IELECTRIC POWER RESEARCH INSTITUTE Nondestructive Evaluation: High-Density Polyethylene NDE Technology

Nondestructive Evaluation:

High-Density Polyethylene NDE Technology All or a portion of the requirements of the EPRI Nuclear Quality Assurance Program apply to this product.

YES EPRI Project Manager R. Bouck

' a =-ar i I E2iSEC -EIR HPO 3420 Hillview Avenue Palo Alto, CA 94304-1338 USA PO Box 10412 Polo Alto, CA 943030813 USA 800.313.3774 650.855.2121 askepri@eori.com 3002000439 www.eo~ri.com Final Report, November 2013

Abstract High-density polyethylene (HDPE) is considered a cost-effective material suited for Class HII nuclear applications. In order to efficiently use HDPE in nuclear applications, reliable nondestruction evaluation (NDE) methods validated through performance demonstration are needed. The project that is the subject of this report focused on producing simulated cold fusion in a controlled fashion for the purpose of NDE technique assessments and performance demonstration. Having a consistently repeatable process of implanting simulated flaws of known dimensions is required in both evaluating NDE techniques and administering performance demonstration on NDE procedures, equipment, and NDE personnel.

A vii

ELECTRIC POWER aar~ a i IRESEARCH INSTITUTE An Assessment of Industry Data Related to Essential Variables for Fusing High Density Polyethylene Pipe

An Assessment of Industry Data Related to Essential Variables for Fusing High Density Polyethylene Pipe All or a portion of the requirements of the EPRI Nuclear Quality Assurance Program apply to this product.

YES e EPRI Project Manager D. Munson

~I2I RESEARCHINSTITUTE 3420 Hillview Avenue Palo Alio, CA 94304-1338 USA PO Box 10412 Palo Alto, CA 94303-0813 USA 800.313.3774 650.855.2121 o5kenrI@epri com 3002000598 wwwepfi.com Final Report, July 2013

.9',

Abstract As ASME Code Cases N-755 and N-755-1, "Use of Polyethylene (PE) Plastic Pipe," have been developed, the U.S. Nuclear Regulatory Commission (NRC) has expressed concerns. Several questions relate to the essential variables and others to validation of the butt fusion process. The Plastic Pipe Institute (PPI) periodically updates TR-33, Generic Butt FusionJoining Procedurefor FieldJoining of Polyethylene Pipe. Upon completion of PPI TR-33 (2012), copies of that report along with two validation reports were presented to the NRC to determine if information in the reports could answer questions related to essential variables and validation of a butt fusion procedure. This report evaluates the data in PPI TR-33 (2012) and shows that issues associated with essential variables can easily be addressed, but additional comprehensive testing of many sizes and wall thicknesses is needed to validate a safety-related butt fusion procedure.

< vii >

r ELECTRIC POWER I IRESEARCH INSTITUTE Applicability of High-Density Polyethylene in Nuclear Piping Systems with Internal Radionuclides

Applicability of High-Density Polyethylene in Nuclear Piping Systems with Internal Radionuclides 3002000524 Final Report, May 2013 EPRI Project Manager A. Summe This document does NOT meet the requirements of 1 CFR50 Appendix B, 10CFR Part 21, ANSI N45.2-1977 and/or the intent of ISO-9001 (1994)

ELECTRIC POWER RESEARCH INSTITUTE 3420 HIlIvIew Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Afto, California 94303-0813

• USA 800.313.3774

• 650.855.2121

• askepri@eprl.com - www.epri.com

PRODUCT DESCRIPTION This report serves as a preliminary evaluation on the long-term impact of radiation on high-density polyethylene (HDPE) piping for nuclear power plant applications. A short literature review is provided on the impact of radiation on HDPE material, followed by a Monte Carlo N-Particle (MCNP) model of internal radiation exposure from radionuclides commonly encountered at nuclear power facilities. Ultimately, this work seeks to provide guidance on the applicability of HDPE piping in radioactive environments and an expectation of service life in these conditions.

To meet these goals, an industry-wide survey was conducted to obtain radionuclide concentration data in relevant liquid effluent systems. These data were analyzed using the results of an MCNP model, and it was concluded that the internal radiation exposure to HDPE will be orders of magnitude below the dose thresholds of observable changes in material properties for all systems considered under normal operating conditions for a service life of 80 years. However, accident scenarios could be postulated to occur in which HDPE piping could be exposed for a limited amount of time to doses of considerable significance. To bound the impact on HDPE piping systems during accident scenarios, this report evaluates the dose and dose rates resulting from an extremely conservative accident scenario.

Background

HDPE piping offers several benefits over traditional piping materials; the two primary benefits are corrosion resistance and significantly lower costs than corrosion-resistant alloys. The nuclear industry has been using HDPE pipe in raw water applications for several years and is seeking to expand its use to other areas of the plant. The Advanced Nuclear Technology (ANT) program within the Electric Power Research Institute (EPRI) has been tasked with evaluating potential knowledge gaps with respect to the expanding application of HDPE.

Objectives The primary objective of this task is to provide a feasibility assessment of HDPE piping for nuclear power plant applications exposed to internal and/or external radiation. This objective was addressed through a literature review and further characterization of internal dose for specific nuclear systems. A set of recommendations and follow-up steps are provided in the conclusion of the report.

Approach A literature review was conducted to accurately characterize the effects associated with radiation damage in HDPE and summarize the relevant degradation mechanisms along with an evaluation of the general material property trends observed. This review also served to identify which nuclear systems were of particular interest to the nuclear industry for using HDPE pipe. The identified systems were then evaluated for their potential internal and external radiation exposure. This led to the modeling of internal radiation exposure levels in systems with v

CIO potentially significant quantities of radionuclides. To quantify the doses and dose rates, multiple nuclear power plants were surveyed for system-specific radionuclide activity concentration data in their liquid effluent systems. The data collected were used to run a multitude of MCNP cases to model the anticipated exposure through the pipe wall. Also modeled was a particularly conservative accident scenario to bound the results and provide further insight.

Results The literature review revealed various dose thresholds for HDPE that, when exceeded, would initiate measurable changes in material properties. It was also revealed that a dose-rate threshold existed, where higher dose rates would lead to neutral or improved material performance when compared to degraded material performance for lower dose rates at an equivalent integrated dose. Although site and system specific, a large majority of the nuclear systems identified for potential application are expected to remain below the dose threshold limits. Of the systems identified for further analysis, it was found that all systems predicted an integrated dose that is an order of magnitude or more below the dose thresholds for normal operation over 80 years.

Therefore, with respect to internal radioactivity during normal operation, each system was found acceptable for HDPE application. For external exposure and accident scenarios, it is recommended that a site- and system-specific analysis be performed to verify exposure levels below the identified thresholds. During accident scenarios with significant levels of exposure, it was determined that there was a lack of data to fully evaluate the competing effects of the opposing degradation mechanisms.

Applications, Value, and Use This report provides guidance on the impact of radiation exposure on HDPE piping over its service life at an operating nuclear facility and provides a means to trend accrued radiation dose against threshold dose values, which relate to potential service life limitations.

Keywords HDPE High-density polyethylene MCNP Nuclear piping Radiation damage vi

qI RE2AELECTRIC POWER ra-(=ralIRESEARCH INSTITUTE Feasibility Evaluation of Glass Reinforced Spiral Wound High Density Polyethylene for Circulating Water System Piping

Feasibility Evaluation of Glass Reinforced Spiral Wound High Density Polyethylene for Circulating Water System Piping This document does NOT meet the requirements of IOCFR50 Appendix B, 10CFR Part 2 1, ANSI N45.2-1977 and/or the intent of ISO-9001 (19941.

EPRI Project Managers A. Summe D. Munson IIIRESEARCH IN$SI'TUE 3420 Hillview Avenue Palo Alto, CA Q4304-1338 USA PO Box 10412 Palo Alto, CA 94303-0813 USA 800.313.3774 650.855.2121 oskepri@epri.com 1025297 www.epr .com Final Report, December 2012

q3 I -I Abstract The Electric Power Research Institute (EPRI) sponsored this report to investigate the feasibility of glass reinforced spiral wound high-density polyethylene (PE-GF) piping for application in Circulating Water Systems at nuclear power plants. Conventional high-density polyethylene (HDPE) pipe has already proven beneficial to the nuclear power industry for its exceptional performance in raw water systems due to its resistance to corrosion and microbiological growth.

Additionally, combined material and labor costs for PE-GF may be lower than pre-stressed concrete cylinder pipe (PCCP) or lined carbon steel. By incorporating a reinforcing layer of glass fibers, PE-GF can significantly reduce the required wall thicknesses over that of HDPE to make it a viable option for large diameter piping. Other industries have already utilized this material with success in low pressure waterworks or drainage systems, and have begun expanding its use to include moderate pressure applications.

This document presents available product application and test data for PE-GF, and discusses the viability of its use for large bore direct-buried piping for nuclear power plant Circulating Water Systems.

Current manufacturing capabilities and limitations are presented, along with system design and constructability issues. Presently, the availability of large bore fittings utilizing PE-GF is a significant challenge that must be addressed through further testing and product development. Industry support of these efforts will be critical.

To realize the potential economic and technical benefits of this material, it will be necessary to obtain a Code listing in American Society of Mechanical Engineers (ASME) B31.1, Power Piping Code. A roadmap is included within this report that details the product testing and development necessary to achieve this status.

< vii >

41(f i 121 ,ELECTRICPOWER RESEARCH INSTITUTE Repair of High Density Polyethylene Pipe 1019172 IE 0 4

A%

NOTICE: This report contains proprietary information that is the intellectual property of EPRI. Accordingly, it is available only under license from EPRI and may not be reproduced or disclosed, wholly or in part, by any licensee to any other person or organization.

Repair of High Density Polyethylene Pipe 1019172 Technical Update, November 2009 EPRI Project Manager A. Peterson Cosponsors RRAC Steering Committee ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 PO Box 10412, Palo Alto, California 94303-0813 USA 800.313.3774 650.855.2121 askepr@epn.com www.epd.com

PRODUCT DESCRIPTION Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of their existing carbon steel piping components.

High-density polyethylene (HDPE) pipe has been used in non-safety service water systems for more than 10 years and has performed well. Recent applications of HDPE pipe at Duke Energy's Catawba Station and Ameren's Calloway Plant have encouraged the nuclear industry to consider using this type of pipe as an alternative to steel in low-energy applications. This action has been facilitated by the issuance of American Society of Mechanical Engineers (ASME) Code Case N-755, Use of Polyethylene (PE) Plastic Pipe, Section 111, Division I and XI. The results described in this report are intended to support the nuclear industry by providing additional repair techniques for use on HDPE pipe. When these results are used in conjunction with a Request for Regulatory Relief, a nuclear plant operator will have a viable option for replacing a conventional steel Class 3 system with HDPE pipe; alternative repair techniques for that system will also be available should they be needed.

Results and Findings The repair methods described in conjunction with those already available-including saddle fusion repair, electro-fusion patch repair, electro-fusion spool repair, mechanical fitting repair, repairs with solid sleeve, and flange adapter spool repair-should provide sufficient options for most scenarios. Also of note is that the new techniques-tapered hole and plug repair and cavity repair-require practice. For example, the amount of time to heat the sidewalls of the hole or the amount of pressure applied to the plug will likely vary with the size of the component.

A review of the testing yields several conclusions:

" Sufficient heat must be applied using both techniques in order for the process to work.

" When using the tapered plug method it is critical that the angles machined for the plug and hole allow for full contact.

• Grinding or sanding a flaw out of the pipe wall for purposes of filling the cavity with HDPE "filler" material should be done such that the heating tool has easy access to all walls and corners.

" Mechanical testing confirms that the tapered plug method of repair is a viable option that maintains structural integrity.

Challenges and Objective(s)

The objective of this research was to apply two new techniques-tapered hole and plug as well as cavity repair-to the repair of HDPE piping. The challenge in repairing plastics is that melted polyethylene does not "flow" or behave the same way as molten steels, and new training with plastics is often required.

Applications, Values, and Use HDPE materials will offer significant economic benefits to utilities. The primary savings comes from the short installation time of HDPE piping compared to the weld times currently required v

for steel piping. While current rules only allow for HDPE piping in buried piping systems, the beginning stages for aboveground use are already being drafted.

EPRI Perspective Three separate EPRI groups have provided technical support for implementation of Code Case N-755-Balance of Plant (BOP), Non-Destructive Examination (NDE), and Welding and Repair Technology Center (WRTC). BOP staff has focused primarily on design and seismic qualification requirements. NDE staff has primary responsibility for examination issues. The WRTC has investigated potential repair techniques that could be employed in the field. All of these areas will need to be considered for future ASME Code Case development.

Additional information about HDPE piping is available in the following EPRI reports: An IntegratedProjectPlan to Obtain Code and Regulatory Approval to Use High-Density Polyethylene in ASME Class 3 PipingApplications (1013572, October 2006); Design and Qualificationof High-Density Polyethylenefor ASME Safety Class 3 PipingSystems (1011836, December 2005); Tensile Testing of Cell Classification345464C High Density Polyethylene Pipe Material (1013479, December 2006); and Fatigueand Capacity Testing of High Density Polyethylene Pipe Material(1014902, April 2007).

Approach After repairing several coupons using tapered hole and plug and cavity repair methods, investigators sectioned the samples to examine the integrity of the repair. They validated successful fusion by destructively examining repaired samples via sectioning, visual observation, and tensile testing.

Keywords High Density Polyethylene (HDPE) Pipe Plastic pipe Fused joint Pipe repair ASME Code Case N-755 vi

ELECTRIC POWER RESEARCH INSTITUTE Development of Crack Growth Curves and Correlation to Sustained Pressure Test Results for Cell Classification 445574C High-Density Polyethylene Pipe Material PKPA E LUNWRtE I NCLEAR

Development of Crack Growth Curves and Correlation to Sustained Pressure Test Results for Cell Classification 445574C High-Density Polyethylene Pipe Material 1025253 Final Report, September 2012 EPRI Project Manager D. Munson Work to develop this product was completed under the EPRI Nuclear Quality Assurance Program.

ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillew Avenue, Palo Alto. California 94304-1338

• PO Box 10412, Palo Alto, California 94303-0813

• USA 800.313.3774 - 650.855.2121 askepd@epd.com -www.epri.com

(oD ABSTRACT Code Case N-755-1 of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section III, Division I Code currently permits the use of high-density polyethylene (HDPE) in buried safety-related Class 3 piping systems. There have been concerns with the slow crack growth (SCG) of HDPE emanating from scratches that can occur during fabrication or installation. The possible use of tensile coupon tests for determining the life span of the pipe with surface scratches could provide a more cost-effective testing method than the use of sustained pressurized crack pipe tests does. This report presents the results of further investigation into the SCG rates of notched PE 4710 HDPE pipe made from a cell classification 445 574C bimodal resin. The da/dt versus KI curves were developed from notched coupon testing. Standard fracture methods were then used to predict the failure time of the notched pressurized pipe specimens subjected to long-term hydraulic stress. The results for the SCG depth of the externally notched sustained pressurized pipe tests are provided along with the notched coupon test results. The actual failure times of the notched pressurized pipe tests are compared to the predicted failure times for the same specimens.

vii

I1 POWER RESELECTRIC

• =Er-maI RESEARCH INSTITUTE Tensile Stress-Strain Properties and Elastic Modulus of PE 4710 Cell Classification 445574C High Density Polyethylene Pipe Material PREPARED UNDER THE e

NUCLEAR PROGRAM I

Tensile Stress-Strain Properties and Elastic Modulus of PE 4710 Cell Classification 445574C High Density Polyethylene Pipe Material Work to develop this product wos completed under I the EPRI Nuclear Quality Assurance Progmra EPRI Project Manager D. Munson IISEAICHINSTItUE 3420 Hillview Avenue Palo Alto, CA 94304 1338 USA PO Box 10412 Polo Alto, CA 94303-081 3 USA 800,313.3774 650.855.2121

.as.,,6ae.l cm.

rr 1025254 Final Report, December 2012

(03 Abstract For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs than carbon steel pipe and HDPE pipe has a much greater resistance to corrosion. The ASME Boiler and Pressure Vessel Code,Section III, Division 1 currently permits the use of non-metallic piping in buried safety Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and is commonly used in other industries such as water mains and natural gas pipelines. This report presents the results of tensile testing of PE 4710 cell dassification 445574C pipe. This information was developed to support and provide a strong technical basis for tensile properties of HDPE pipe. The data may also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process and waste water plants via its possible use in the B31 series piping codes. The report provides values for yield stress, yield strain, ultimate strain, and Elastic Modulus. The standard tensile tests were conducted consistent with the requirements of ASTM D638-10. Specimens were cut in the axial direction from cell composition 445574C HDPE piping spools. In addition, the results are compared with the PE 3608 cell dassification 345464C and PE 4710 cell classification 445474C HDPE material results presented in EPRI reports 1013479 and 1018351, respectively.

< vii>

I Ol-3rf! i ELECTRIC POWER RESEARCH INSTITUTE Creep and Fatigue Properties of PE 4710 Cell Classification 445574C High Density Polyethylene Pipe Material UNDER I THE NUCLEAR

Creep and Fatigue Properties of PE 4710 Cell Classification 445574C High Density Polyethylene Pipe Material 3002000592 Final Report, November 2013 EPRI Project Manager D. Munson All or a portion of the requirements of the EPRI Nuclear Quality Assurance Program apply to this product.

e NO ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121

• askepri@epri.com - www.epri.com

jO06 ABSTRACT For corroded piping in low temperature systems, such as service water systems in nuclear power plants, replacement of carbon steel pipe with high density polyethylene (HDPE) pipe is a cost-effective solution. Polyethylene pipe can be installed at much lower labor costs than carbon steel pipe and HDPE pipe has a much greater resistance to corrosion. The ASME Boiler and Pressure Vessel Code,Section III, Division 1 currently permits the use of non-metallic piping in buried safety Class 3 piping systems. Additionally, HDPE pipe has been successfully used in non-safety-related systems in nuclear power facilities and is commonly used in other industries such as water mains and natural gas pipelines. This report presents the results of creep and fatigue testing of PE 4710 cell classification 445574C pipe. This information was developed to support and provide a strong technical basis for material properties of HDPE pipe for use in ASME Boiler and Pressure Vessel Code,Section III, Division 1, Class 3 applications and in ASME Boiler and Pressure Vessel Code,Section XI repair or replacement activites. The data may also be useful for applications of HDPE pipe in commercial electric power generation facilities and chemical, process and waste water plants via its possible use in the B31 series piping codes. The report provides long term creep and modulus data, as well as an analysis of the stress dependency of both. The report also provides fatigue data in the form of Code S-N curves for fusion butt joints in PE 4710 HDPE.

vii

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Advanced Nuclear Technology:

Material Properties Affecting the Butt Fusion of HDPE Pipe 3002003133 Final Report, September 2014 EPRI Project Managers A. Summe D. Munson All or a portion of the requirements of the EPRI Nuclear Quality Assurance Program apply to this product.

YES ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 - PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774 - 650.855.2121 - askepri@epri.com - www.epd.com

1o'1 ABSTRACT In an effort to control the quality of butt fusion, variables which can affect the quality of the fusion joint have been identified and are called essential variables. It is acknowledged that there are several essential variables for butt fusion which must be controlled within acceptable ranges to have reasonable assurance of strong and durable joints. This report provides a detailed consideration of material properties of HDPE in order to create a deeper understanding of the scientific principles that inform butt fusion to benefit all nuclear safety-related application stakeholders.

vii

I10

~lELECTIC P¶OWER IRESEARCH INSTITUTE Slow Crack Growth Testing Of High Density Polyethylene Pipe - Interim Results 1019180

I(I Slow Crack Growth Testing Of High Density Polyethylene Pipe - Interim Results 1019180 Technical Update, December 2009 EPRI Project Manager T. Eckert ELECTRIC POWER RESEARCH INSTITUTE 3420 Hillview Avenue, Palo Alto, California 94304-1338 , PO Box 10412, Palo Alto, California 94303-0813 - USA 800.313.3774

• 650.855.2121 - askepri@epd.com - www.epri.com

REPORT

SUMMARY

The results reported in this document are intended to support continued development of American Society of Mechanical Engineers (ASME) Code Case N-755 for use of high-density polyethylene (HDPE) in buried and above ground ASME Boiler and Pressure Vessel Code,Section III, Division I safety-related piping applications. Project results support this development by determining material and engineering properties needed for pipe design. These include full-range stress-strain data, fatigue data, stress intensification factors and flexibility factors for selected components, and data to establish an acceptable flaw or scratch depth size.

To establish acceptable flaw or scratch depth size, data that provides slow crack growth (SCG) rate as a function of stress intensity (da/dt versus K, curves) are required. These data will then be supported by confirmation pressure tests of actual flawed pipe specimens. This report presents interim results for two separate tasks under the HDPE pipe test program. Under the first task, da/dt versus K, curves are being determined for one of the PE 47 10 materials. Test samples were cut from HDPE pipe with two different types of initial cracks that are 10% deep and subjected to a constant tensile load at a constant elevated temperature. Under the second task, 4"-diameter HDPE pipe specimens with three different types of initial flaws that are 10% deep are being subjected to internal pressure stresses at elevated temperatures.

Background

Degradation of service water systems is a major issue facing nuclear power plant owners, and many plants will require repair or replacement of existing carbon steel piping components.

HDPE has been used in non-safety service water systems for over 10 years and has performed well. Although HDPE has been approved in Code Case N-755 of the ASME Boiler and Pressure Vessel Code,Section III, Division I for use in buried safety-related Class 3 systems, the Code Case has not yet been accepted by the Nuclear Regulatory Commission.

Objectives To provide SCG data that can be used as input for future fracture mechanics analysis of damaged pipe and to provide a strong technical basis for the establishment of allowable initial scratch or flaw sizes for HDPE pipe used for replacement of buried ASME Class 3 carbon steel service water piping (the allowable scratch depth will be based on assuring that a through-wall SCG failure will not occur during the projected lifetime).

Approach Crack growth rate test data are being obtained from long-term testing under constant tensile load and will be correlated to sustained pressure tests of actual flawed pipe specimens at constant elevated temperatures.

Results The report provides a summary of the testing completed to date. For development of the da/dt versus K, curves, initial displacement data are presented. In addition, measured crack growth data also are provided. Testing was conducted at 50% yield stress and 95°C (203 0 F). For pressurized pipe specimens, a summary of the failure data to date is provided. Tests are being conducted at pressures that result in 30%, 40%, and 50% yield stress in the piping. Test temperatures are 85°C V

(185°F) and 95°C (203'F). Pipe materials considered were PE 4710 cell classifications 445474C and 445574C.

EPRI Perspective The data are being developed for use by industry in the design and analysis of safety and non-safety-related HDPE piping systems in commercial nuclear power plants. The data also may apply to HDPE pipe in commercial electric power generation plants, chemical plants, process, and wastewater plants.

Additional information about the project is available in the following reports:

• Design and Qualification of High Density Polyethylene for ASME Safety Class 3 Piping Systems, EPRI, Palo Alto, CA: 2005. 1011836.

" Nondestructive Evaluation: Seismic Criteriafor Polyethylene Pipe Replacement Code Case, EPRI, Palo Alto, CA: 2006. 1013549.

" An Integrated ProjectPlan to Obtain Code and Regulatory Approval to Use High-Density Polyethylene in ASME Class 3 PipingApplications, EPRI, Palo Alto, CA: 2006. 1013572.

" Tensile Testing of Cell Classification345464C High Density Polyethylene Pipe Material, EPRI, Palo Alto, CA: 2006. 1013479.

" Fatigueand Capacity Testing of High Density Polyethylene Pipe Material, EPRI, Palo Alto, CA: 2007. 1014902.

" Fatigueand Capacity Testing of High Density Polyethylene Pipe and Pipe Components Fabricatedfrom PE 4710, EPRI, Palo Alto, CA: 2007. 1015062.

" Tensile Testing of Cell Classification445474C High Density Polyethylene Pipe Material, EPRI, Palo Alto, CA: 2005. 1018351.

• Fatigue and Capacity Testing of High Density Polyethylene Pipe and Pipe Components Fabricatedfrom PE 4710 - 2008 Update, EPRI, Palo Alto, CA: 2008. 1011836.

Keywords High-density polyethylene Slow crack growth Buried piping vi