A review of nondestructive examination technology for polyethylene pipe in nuclear power plant

Abstract

Polyethylene (PE) pipe, particularly highdensity polyethylene (HDPE) pipe, has been successfully utilized to transport cooling water for both non-safety-and safety-related applications in nuclear power plant (NPP). Though ASME Code Case N755, which is the first code case related to NPP HDPE pipe, requires a thorough nondestructive examination (NDE) of HDPE joints. However, no executable regulations presently exist because of the lack of a feasible NDE technique for HDPE pipe in NPP. This work presents a review of current developments in NDE technology for both HDPE pipe in NPP with a diameter of less than 400 mm and that of a larger size. For the former category, phased array ultrasonic technique is proven effective for inspecting typical defects in HDPE pipe, and is thus used in Chinese national standards GB/T 29460 and GB/T 29461. A defectrecognition technique is developed based on pattern recognition, and a safety assessment principle is summarized from the database of destructive testing. On the other hand, recent research and practical studies reveal that in current ultrasonic-inspection technology, the absence of effective ultrasonic inspection for large size was lack of consideration of the viscoelasticity effect of PE on acoustic wave propagation in current ultrasonic inspection technology. Furthermore, main technical problems were analyzed in the paper to achieve an effective ultrasonic test method in accordance to the safety and efficiency requirements of related regulations and standards. Finally, the development trend and challenges of NDE test technology for HDPE in NPP are discussed.

High-Density Polyethylene Pipe Butt-Fusion Joint Detection via Total Focusing Method and Spatiotemporal Singular Value Decomposition

“…It may even lead to gas leakage, resulting in safety accidents and economic losses. In order to safeguard the weld quality of HDPE pipe butt-fusion joints from structural failure, non-destructive evaluation (NDE) using a number of intelligent inspection tools is essential [11,12]. Ultrasonic phased array inspection technology is a widely used method in NDE, known for its effectiveness in identifying defects and quantitatively characterizing HDPE materials [7,[13][14][15][16][17].…”

Fluorinated bis(arylimino)‐6,7‐dihydro‐5H‐quinoline‐cobalt polymerization catalysts: Electronic versus steric modulation in the formation of vinyl‐terminated linear PE waxes

“…Highly linear polyethylenes in the form of high‐density polyethylene (HDPE) constitute a significant portion of the polyolefins market as they are widely used in applications such as in pipes, armors, helmets, and cables. [ 1–5 ] While Ziegler‐Natta and Phillips heterogeneous catalysts have led the way in their manufacture, both academic and industrial researchers have shown an ongoing interest in using late transition metal catalysts. [ 6–15 ] In comparison with their heterogeneous counterparts, molecular catalysts based on late transition metals offer some distinct advantages including their ease of tuning via straightforward ligand modification, which can make the resulting polymer properties more controllable.…”

Semantic instance segmentation using convolutional networks for reconstruction of spatial distribution of material properties

“…The metal grains size estimation plays a crucial role in manufacturing and inspection in fields such as nuclear reactors, energy and oil industry [1 ]. The grain size in metals can vary in the range from tens of micrometres up to several millimetres and depends on manufacturing or welding technology [2 ].…”