HDPE piping in nuclear power plant systems
Use of HDPE in Nuclear Power Plant Piping Systems
Piping systems in U.S. nuclear power plants that are relied on for safe shutdown of the plant (i.e. “safety-related”) are typically constructed to Section III of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code[1]. The materials allowed by the ASME B&PV Code have been limited to metallic materials only[2][3]. Due to the historical success of high density polyethylene (HDPE), power plants in the U.S. have expressed interest in using HDPE piping in ASME B&PV Code Class 3 safety-related applications. In 2008, the first U.S. NPP was approved by the United States Nuclear Regulatory Commission (U.S. NRC) to install HDPE in a safety-related system[4]. Since then, the rules for using HDPE have been integrated into the 2015 Edition of the ASME B&PV Code (Ref 2015 edition). The NRC approval of the 2015 Edition is still pending[1].
History
- 1963 – Section III (Nuclear Power) of the ASME Boiler and Pressure Vessel Code – only allows for metallic materials[5].
- 2007 – Code Case N-755 issued for on behalf of Duke Energy for the use of Polyethylene Plastic Pipe for Class 3 applications. HDPE fusing limited to butt-fusing (hot plate) (NEED SPECIFIC CODE REFERENCE).
- 2008 – US. NRC grants Callaway Nuclear Power Plant permission to use HDPE in the Essential Service Water System based on Code Case N-755 and additional plant specific information[4].
- 2009 - US. NRC grants Catawba Nuclear Power Plant permission to use HDPE in the Nuclear Service Water System based on Code Case N-755 and additional plant specific information[6].
- 2010 – First Revision to Code Case N-755 issued (NEED SPECIFIC CODE REFERENCE).
- 2013 – Second Revision to Code Case N-755 issued (NEED SPECIFIC CODE REFERENCE).
- 2014 - U.S. NRC rejects Code Case N-755-0 for generic use due to unresolved issues concerning the joining procedure, degradation processes, and examination of joints[7].
- 2015 - US. NRC grants Hatch Nuclear Power Plant permission to use HDPE in the Plant Service Water System[8].
- 2015 – Code Case N-755 incorporated into Mandatory Appendix XXVI of ASME Section III[9].
- 2017 – U.S. NRC rejects Code Case N-755-1 for generic use due to unresolved issues concerning the joining procedure, degradation processes, and examination of joints[10] (Ref 1.193 R5).
ASME B&PV Code Sections
ASME BPVC Section III – Rules for Construction of Nuclear Facility Components[9]
- Division 1 – Appendix XXVI – Rules for Construction of Class 3 Buried Polyethylene Pressure Piping
- Article XXVI-1000: General Requirements
- Article XXVI-2000: Materials
- Article XXVI-3000: Design
- Article XXVI-4000: Fabrication and Installation
- Article XXVI-5000: Examination
- Article XXVI-6000: Testing
- Article XXVI-7000: Overpressure Protection
- Article XXVI-8000: Nameplates, Stamping, and Reports
- Article XXVI-9000: Glossary
- Mandatory Supplements I – III
- Non-mandatory Supplements A - D
ASME BPVC Section IX – Welding, Brazing, and Fusing Qualifications
- Part QF – Plastic Fusing
- Article XXI - Plastic Fusing General Requirements
- Article XXII - Fusing Procedure Qualifications
Application
The use of HDPE in U.S. nuclear power plants is limited to PE4710 since this was the material first identified in Code Case N-755 and reviewed by the U.S. NRC. Code Case N-755 was initially limited to butt-fusing (hot plate) but electrofusion was included when incorporated into the ASME B&PV Code, Section III, Appendix XXVI. Both N-755 and Appendix XXVI limit the use of HDPE to Class 3 piping systems. (NEED SPECIFIC CODE REFERENCE -755 and Section III)
Benefits
The carbon steel used in Service Water systems are often subjected to various forms of degradation including general corrosion, microbiological induced corrosion, tuberculation, and galvanic corrosion. HDPE is typically impervious to these forms of degradation. Additionally, nuclear power plants typically have robust seismic requirements and HDPE is very flexible which increases its ability to survive an earthquake. (NEED SPECIFIC CODE REFERENCE -NRC presentation and tuberculation)
Challenges
The use of HDPE in nuclear power plants requires extensive qualification and testing efforts to demonstrate that the material is safe under all design basis conditions. The U.S. NRC has raised concerns with the use of HDPE related to butt fusion joint integrity, the ability to detect flaws in joints, and the potential for slow crack growth[10][6]. Power plants can still request approval from the U.S. NRC on a case-by-case basis (i.e., relief request).
Instructor Comments
The first topic is very good, so I went ahead and assigned it yo you. You might think of a better title. Also, you may find it to be very broad, and if that is the case, you could concentrate on HDPE Piping for Nuclear Plants including Butt Fusion and Electrofusion joining of these pipes.
Possible Topics:
- Use of HDPE at Nuclear Power Plants (new article, would include regulatory history, ASME Code implications, and all uses to date based on publicly available submittals to the NRC)
- HDPE Pipe
- Horizontal Directional Drilling
- Sliplining
- ^ a b "NRC: 10 CFR 50.55a Codes and standards". www.nrc.gov. Retrieved 2019-02-16.
- ^ An International Code - ASME Boiler & Pressure Vessel Code Section III Rules for Construction of Nuclear Facility Components - Division 1. ASME. 2010 Edition.
{{cite book}}: Check date values in:|year=(help)CS1 maint: year (link) - ^ An International Code - ASME Boiler & Pressure Vessel Code Section II Materials, Part D. ASME. 2010 Edition.
{{cite book}}: Check date values in:|year=(help)CS1 maint: year (link) - ^ a b Markley, Michael (U.S. NRC). "CALLAWAY PLANT, UNIT 1 -RELIEF REQUEST 13R-10 APPROVED ON OCTOBER 31,2008 FOR THIRD 10-YEAR INSERVICE INSPECTION INTERVAL -USE OF POLYETHYLENE PIPE IN LIEU OF CARBON STEEL PIPE IN BURIED ESSENTIAL SERVICE WATER PIPING SYSTEM (TAC NO. MD6792)" (PDF). www.nrc.gov.
{{cite web}}: Check date values in:|date=(help); Cite has empty unknown parameter:|dead-url=(help); line feed character in|title=at position 157 (help) - ^ An International Code - ASME Boiler & Pressure Vessel Code Section III Rules for Construction of Nuclear Vessels. ASME. 1963 Edition.
{{cite book}}: Check date values in:|year=(help)CS1 maint: year (link) - ^ a b Wong, Melanie (U.S. NRC). "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)" (PDF). www.nrc.gov.
{{cite web}}: Check date values in:|date=(help); Cite has empty unknown parameter:|dead-url=(help) - ^ "Regulatory Guide 1.193 ASME Code Cases Not Approved for Use" (PDF). www.nrc.gov. Revision 4, August 2014.
{{cite web}}: Check date values in:|date=(help); Cite has empty unknown parameter:|dead-url=(help) - ^ Markley, Michael (U.S. NRC). "EDWIN I. HATCH NUCLEAR PLANT, UNIT 2, ALTERNATIVE HNP-ISl-ALTHDPE-01 FOR USE OF HIGH DENSITY POLYETHYLENE IN PLANT SERVICE WATER PIPING (TAC MF6712)" (PDF). www.nrc.gov.
{{cite web}}: Check date values in:|date=(help); Cite has empty unknown parameter:|dead-url=(help) - ^ a b An International Code - ASME Boiler & Pressure Vessel Code Section III Rules for Construction of Nuclear Facility Components - Division 1. ASME. 2015 Edition.
{{cite book}}: Check date values in:|year=(help)CS1 maint: year (link) - ^ a b "Regulatory Guide 1.193 ASME Code Cases Not Approved for Use" (PDF). www.nrc.gov. Revision 5, August 2017.
{{cite web}}: Check date values in:|date=(help); Cite has empty unknown parameter:|dead-url=(help)