Ali Al Hammadi, Shane R. Schuessler, Mohamed Ali Awadh Jaber
Papers # 2018 Las-Vegas
This paper presents the advancements of HDPE piping materials, design and installation for use in ASME Class 3 piping systems at nuclear power plants. The paper will specifically introduce details of the first ever ASME Class III nuclear new build use of Class 3 HDPE pipe and fittings at the Emirates Nuclear Energy Corporation’s (ENEC) Barakah Nuclear Power Plant near Abu Dhabi, U.A.E.
Global nuclear power plants have relied on buried metallic piping systems since the first commercial plants built in the 1950’s. Corrosion, leaks, and expensive replacement has been the eminent path for many of these metallic piping systems. In the early 2000’s, several nuclear power plant owners decided to alter the buried pipe paradigm by considering plastic pipe as an alternative to metallic piping systems. Their goal was to reduce piping material and installation costs while ensuring safety and performance for the operating life of the plants. Since the HDPE piping systems would be installed in nuclear safety-related systems, the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) formed committees to develop rules for installing high-density polyethylene (HDPE) pipe in ASME BPVC Section III (new build) and Section XI (repair/replacement) Class 3 piping systems.
Three nuclear power plants have used HDPE in ASME Class 3 piping systems where the most recent project took place at the Emirates Nuclear Energy Corporation’s Barakah Nuclear Power Plant located in the United Arab Emirates. This paper will provide an overview of the procurement requirements and installation for this project’s Essential Service Water Discharge system consisting of 21,000 feet (6,480 meters) of 36-inch HDPE pipe. Discussion topics include:
- HDPE source material (pre-compounded PE100/PE4710 resin) requirements including testing for slow crack growth resistance, HDPE's primary failure mechanism
- Design and installation challenges faced due to the extreme desert conditions
- Fusion joint welding highlighting the joint integrity validation methods used specific to the project including ultrasonic non-destructive examination.
This paper will conclude with a brief synopsis of the evolution of HDPE pipe within the ASME Boiler & Pressure Vessel Code, which now provides nuclear power plant owners around the world with a clear path to installing safety-related HDPE piping systems.